Initial import

29 files changed, 3418 insertions, 0 deletions

diff --git a/arch/tile/lib/Makefile b/arch/tile/lib/Makefile
new file mode 100644
index 000000000..c4211cbb2
--- /dev/null
+++ b/arch/tile/lib/Makefile
@@ -0,0 +1,18 @@
+#
+# Makefile for TILE-specific library files..
+#
+
+lib-y = cacheflush.o checksum.o cpumask.o delay.o uaccess.o \
+	memmove.o memcpy_$(BITS).o memchr_$(BITS).o memset_$(BITS).o \
+	strchr_$(BITS).o strlen_$(BITS).o strnlen_$(BITS).o
+
+lib-$(CONFIG_TILEGX) += memcpy_user_64.o
+lib-$(CONFIG_TILEPRO) += atomic_32.o atomic_asm_32.o
+lib-$(CONFIG_SMP) += spinlock_$(BITS).o usercopy_$(BITS).o
+
+obj-$(CONFIG_MODULES) += exports.o
+
+# The finv_buffer_remote() and copy_{to,from}_user() routines can't
+# have -pg added, since they both rely on being leaf functions.
+CFLAGS_REMOVE_cacheflush.o = -pg
+CFLAGS_REMOVE_memcpy_user_64.o = -pg
diff --git a/arch/tile/lib/atomic_32.c b/arch/tile/lib/atomic_32.c
new file mode 100644
index 000000000..c89b211fd
--- /dev/null
+++ b/arch/tile/lib/atomic_32.c
@@ -0,0 +1,183 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/cache.h>
+#include <linux/delay.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/atomic.h>
+#include <arch/chip.h>
+
+/* This page is remapped on startup to be hash-for-home. */
+int atomic_locks[PAGE_SIZE / sizeof(int)] __page_aligned_bss;
+
+int *__atomic_hashed_lock(volatile void *v)
+{
+	/* NOTE: this code must match "sys_cmpxchg" in kernel/intvec_32.S */
+	/*
+	 * Use bits [3, 3 + ATOMIC_HASH_SHIFT) as the lock index.
+	 * Using mm works here because atomic_locks is page aligned.
+	 */
+	unsigned long ptr = __insn_mm((unsigned long)v >> 1,
+				      (unsigned long)atomic_locks,
+				      2, (ATOMIC_HASH_SHIFT + 2) - 1);
+	return (int *)ptr;
+}
+
+#ifdef CONFIG_SMP
+/* Return whether the passed pointer is a valid atomic lock pointer. */
+static int is_atomic_lock(int *p)
+{
+	return p >= &atomic_locks[0] && p < &atomic_locks[ATOMIC_HASH_SIZE];
+}
+
+void __atomic_fault_unlock(int *irqlock_word)
+{
+	BUG_ON(!is_atomic_lock(irqlock_word));
+	BUG_ON(*irqlock_word != 1);
+	*irqlock_word = 0;
+}
+
+#endif /* CONFIG_SMP */
+
+static inline int *__atomic_setup(volatile void *v)
+{
+	/* Issue a load to the target to bring it into cache. */
+	*(volatile int *)v;
+	return __atomic_hashed_lock(v);
+}
+
+int _atomic_xchg(int *v, int n)
+{
+	return __atomic_xchg(v, __atomic_setup(v), n).val;
+}
+EXPORT_SYMBOL(_atomic_xchg);
+
+int _atomic_xchg_add(int *v, int i)
+{
+	return __atomic_xchg_add(v, __atomic_setup(v), i).val;
+}
+EXPORT_SYMBOL(_atomic_xchg_add);
+
+int _atomic_xchg_add_unless(int *v, int a, int u)
+{
+	/*
+	 * Note: argument order is switched here since it is easier
+	 * to use the first argument consistently as the "old value"
+	 * in the assembly, as is done for _atomic_cmpxchg().
+	 */
+	return __atomic_xchg_add_unless(v, __atomic_setup(v), u, a).val;
+}
+EXPORT_SYMBOL(_atomic_xchg_add_unless);
+
+int _atomic_cmpxchg(int *v, int o, int n)
+{
+	return __atomic_cmpxchg(v, __atomic_setup(v), o, n).val;
+}
+EXPORT_SYMBOL(_atomic_cmpxchg);
+
+unsigned long _atomic_or(volatile unsigned long *p, unsigned long mask)
+{
+	return __atomic_or((int *)p, __atomic_setup(p), mask).val;
+}
+EXPORT_SYMBOL(_atomic_or);
+
+unsigned long _atomic_andn(volatile unsigned long *p, unsigned long mask)
+{
+	return __atomic_andn((int *)p, __atomic_setup(p), mask).val;
+}
+EXPORT_SYMBOL(_atomic_andn);
+
+unsigned long _atomic_xor(volatile unsigned long *p, unsigned long mask)
+{
+	return __atomic_xor((int *)p, __atomic_setup(p), mask).val;
+}
+EXPORT_SYMBOL(_atomic_xor);
+
+
+long long _atomic64_xchg(long long *v, long long n)
+{
+	return __atomic64_xchg(v, __atomic_setup(v), n);
+}
+EXPORT_SYMBOL(_atomic64_xchg);
+
+long long _atomic64_xchg_add(long long *v, long long i)
+{
+	return __atomic64_xchg_add(v, __atomic_setup(v), i);
+}
+EXPORT_SYMBOL(_atomic64_xchg_add);
+
+long long _atomic64_xchg_add_unless(long long *v, long long a, long long u)
+{
+	/*
+	 * Note: argument order is switched here since it is easier
+	 * to use the first argument consistently as the "old value"
+	 * in the assembly, as is done for _atomic_cmpxchg().
+	 */
+	return __atomic64_xchg_add_unless(v, __atomic_setup(v), u, a);
+}
+EXPORT_SYMBOL(_atomic64_xchg_add_unless);
+
+long long _atomic64_cmpxchg(long long *v, long long o, long long n)
+{
+	return __atomic64_cmpxchg(v, __atomic_setup(v), o, n);
+}
+EXPORT_SYMBOL(_atomic64_cmpxchg);
+
+
+/*
+ * If any of the atomic or futex routines hit a bad address (not in
+ * the page tables at kernel PL) this routine is called.  The futex
+ * routines are never used on kernel space, and the normal atomics and
+ * bitops are never used on user space.  So a fault on kernel space
+ * must be fatal, but a fault on userspace is a futex fault and we
+ * need to return -EFAULT.  Note that the context this routine is
+ * invoked in is the context of the "_atomic_xxx()" routines called
+ * by the functions in this file.
+ */
+struct __get_user __atomic_bad_address(int __user *addr)
+{
+	if (unlikely(!access_ok(VERIFY_WRITE, addr, sizeof(int))))
+		panic("Bad address used for kernel atomic op: %p\n", addr);
+	return (struct __get_user) { .err = -EFAULT };
+}
+
+
+void __init __init_atomic_per_cpu(void)
+{
+	/* Validate power-of-two and "bigger than cpus" assumption */
+	BUILD_BUG_ON(ATOMIC_HASH_SIZE & (ATOMIC_HASH_SIZE-1));
+	BUG_ON(ATOMIC_HASH_SIZE < nr_cpu_ids);
+
+	/*
+	 * On TILEPro we prefer to use a single hash-for-home
+	 * page, since this means atomic operations are less
+	 * likely to encounter a TLB fault and thus should
+	 * in general perform faster.  You may wish to disable
+	 * this in situations where few hash-for-home tiles
+	 * are configured.
+	 */
+	BUG_ON((unsigned long)atomic_locks % PAGE_SIZE != 0);
+
+	/* The locks must all fit on one page. */
+	BUILD_BUG_ON(ATOMIC_HASH_SIZE * sizeof(int) > PAGE_SIZE);
+
+	/*
+	 * We use the page offset of the atomic value's address as
+	 * an index into atomic_locks, excluding the low 3 bits.
+	 * That should not produce more indices than ATOMIC_HASH_SIZE.
+	 */
+	BUILD_BUG_ON((PAGE_SIZE >> 3) > ATOMIC_HASH_SIZE);
+}
diff --git a/arch/tile/lib/atomic_asm_32.S b/arch/tile/lib/atomic_asm_32.S
new file mode 100644
index 000000000..6bda3132c
--- /dev/null
+++ b/arch/tile/lib/atomic_asm_32.S
@@ -0,0 +1,197 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ *
+ * Support routines for atomic operations.  Each function takes:
+ *
+ * r0: address to manipulate
+ * r1: pointer to atomic lock guarding this operation (for ATOMIC_LOCK_REG)
+ * r2: new value to write, or for cmpxchg/add_unless, value to compare against
+ * r3: (cmpxchg/xchg_add_unless) new value to write or add;
+ *     (atomic64 ops) high word of value to write
+ * r4/r5: (cmpxchg64/add_unless64) new value to write or add
+ *
+ * The 32-bit routines return a "struct __get_user" so that the futex code
+ * has an opportunity to return -EFAULT to the user if needed.
+ * The 64-bit routines just return a "long long" with the value,
+ * since they are only used from kernel space and don't expect to fault.
+ * Support for 16-bit ops is included in the framework but we don't provide
+ * any (x86_64 has an atomic_inc_short(), so we might want to some day).
+ *
+ * Note that the caller is advised to issue a suitable L1 or L2
+ * prefetch on the address being manipulated to avoid extra stalls.
+ * In addition, the hot path is on two icache lines, and we start with
+ * a jump to the second line to make sure they are both in cache so
+ * that we never stall waiting on icache fill while holding the lock.
+ * (This doesn't work out with most 64-bit ops, since they consume
+ * too many bundles, so may take an extra i-cache stall.)
+ *
+ * These routines set the INTERRUPT_CRITICAL_SECTION bit, just
+ * like sys_cmpxchg(), so that NMIs like PERF_COUNT will not interrupt
+ * the code, just page faults.
+ *
+ * If the load or store faults in a way that can be directly fixed in
+ * the do_page_fault_ics() handler (e.g. a vmalloc reference) we fix it
+ * directly, return to the instruction that faulted, and retry it.
+ *
+ * If the load or store faults in a way that potentially requires us
+ * to release the atomic lock, then retry (e.g. a migrating PTE), we
+ * reset the PC in do_page_fault_ics() to the "tns" instruction so
+ * that on return we will reacquire the lock and restart the op.  We
+ * are somewhat overloading the exception_table_entry notion by doing
+ * this, since those entries are not normally used for migrating PTEs.
+ *
+ * If the main page fault handler discovers a bad address, it will see
+ * the PC pointing to the "tns" instruction (due to the earlier
+ * exception_table_entry processing in do_page_fault_ics), and
+ * re-reset the PC to the fault handler, atomic_bad_address(), which
+ * effectively takes over from the atomic op and can either return a
+ * bad "struct __get_user" (for user addresses) or can just panic (for
+ * bad kernel addresses).
+ *
+ * Note that if the value we would store is the same as what we
+ * loaded, we bypass the store.  Other platforms with true atomics can
+ * make the guarantee that a non-atomic __clear_bit(), for example,
+ * can safely race with an atomic test_and_set_bit(); this example is
+ * from bit_spinlock.h in slub_lock() / slub_unlock().  We can't do
+ * that on Tile since the "atomic" op is really just a
+ * read/modify/write, and can race with the non-atomic
+ * read/modify/write.  However, if we can short-circuit the write when
+ * it is not needed, in the atomic case, we avoid the race.
+ */
+
+#include <linux/linkage.h>
+#include <asm/atomic_32.h>
+#include <asm/page.h>
+#include <asm/processor.h>
+
+	.section .text.atomic,"ax"
+ENTRY(__start_atomic_asm_code)
+
+	.macro  atomic_op, name, bitwidth, body
+	.align  64
+STD_ENTRY_SECTION(__atomic\name, .text.atomic)
+	{
+	 movei  r24, 1
+	 j      4f		/* branch to second cache line */
+	}
+1:	{
+	 .ifc \bitwidth,16
+	 lh     r22, r0
+	 .else
+	 lw     r22, r0
+	 addi   r28, r0, 4
+	 .endif
+	}
+	.ifc \bitwidth,64
+	lw      r23, r28
+	.endif
+	\body /* set r24, and r25 if 64-bit */
+	{
+	 seq    r26, r22, r24
+	 seq    r27, r23, r25
+	}
+	.ifc \bitwidth,64
+	bbnst   r27, 2f
+	.endif
+	bbs     r26, 3f		/* skip write-back if it's the same value */
+2:	{
+	 .ifc \bitwidth,16
+	 sh     r0, r24
+	 .else
+	 sw     r0, r24
+	 .endif
+	}
+	.ifc \bitwidth,64
+	sw      r28, r25
+	.endif
+	mf
+3:	{
+	 move   r0, r22
+	 .ifc \bitwidth,64
+	 move   r1, r23
+	 .else
+	 move   r1, zero
+	 .endif
+	 sw     ATOMIC_LOCK_REG_NAME, zero
+	}
+	mtspr   INTERRUPT_CRITICAL_SECTION, zero
+	jrp     lr
+4:	{
+	 move   ATOMIC_LOCK_REG_NAME, r1
+	 mtspr  INTERRUPT_CRITICAL_SECTION, r24
+	}
+#ifndef CONFIG_SMP
+	j       1b		/* no atomic locks */
+#else
+	{
+	 tns    r21, ATOMIC_LOCK_REG_NAME
+	 moveli r23, 2048       /* maximum backoff time in cycles */
+	}
+	{
+	 bzt    r21, 1b		/* branch if lock acquired */
+	 moveli r25, 32         /* starting backoff time in cycles */
+	}
+5:	mtspr   INTERRUPT_CRITICAL_SECTION, zero
+	mfspr   r26, CYCLE_LOW  /* get start point for this backoff */
+6:	mfspr   r22, CYCLE_LOW  /* test to see if we've backed off enough */
+	sub     r22, r22, r26
+	slt     r22, r22, r25
+	bbst    r22, 6b
+	{
+	 mtspr  INTERRUPT_CRITICAL_SECTION, r24
+	 shli   r25, r25, 1     /* double the backoff; retry the tns */
+	}
+	{
+	 tns    r21, ATOMIC_LOCK_REG_NAME
+	 slt    r26, r23, r25   /* is the proposed backoff too big? */
+	}
+	{
+	 bzt    r21, 1b		/* branch if lock acquired */
+	 mvnz   r25, r26, r23
+	}
+	j       5b
+#endif
+	STD_ENDPROC(__atomic\name)
+	.ifc \bitwidth,32
+	.pushsection __ex_table,"a"
+	.align  4
+	.word   1b, __atomic\name
+	.word   2b, __atomic\name
+	.word   __atomic\name, __atomic_bad_address
+	.popsection
+	.endif
+	.endm
+
+atomic_op _cmpxchg, 32, "seq r26, r22, r2; { bbns r26, 3f; move r24, r3 }"
+atomic_op _xchg, 32, "move r24, r2"
+atomic_op _xchg_add, 32, "add r24, r22, r2"
+atomic_op _xchg_add_unless, 32, \
+	"sne r26, r22, r2; { bbns r26, 3f; add r24, r22, r3 }"
+atomic_op _or, 32, "or r24, r22, r2"
+atomic_op _andn, 32, "nor r2, r2, zero; and r24, r22, r2"
+atomic_op _xor, 32, "xor r24, r22, r2"
+
+atomic_op 64_cmpxchg, 64, "{ seq r26, r22, r2; seq r27, r23, r3 }; \
+	{ bbns r26, 3f; move r24, r4 }; { bbns r27, 3f; move r25, r5 }"
+atomic_op 64_xchg, 64, "{ move r24, r2; move r25, r3 }"
+atomic_op 64_xchg_add, 64, "{ add r24, r22, r2; add r25, r23, r3 }; \
+	slt_u r26, r24, r22; add r25, r25, r26"
+atomic_op 64_xchg_add_unless, 64, \
+	"{ sne r26, r22, r2; sne r27, r23, r3 }; \
+	{ bbns r26, 3f; add r24, r22, r4 }; \
+	{ bbns r27, 3f; add r25, r23, r5 }; \
+	slt_u r26, r24, r22; add r25, r25, r26"
+
+	jrp     lr              /* happy backtracer */
+
+ENTRY(__end_atomic_asm_code)
diff --git a/arch/tile/lib/cacheflush.c b/arch/tile/lib/cacheflush.c
new file mode 100644
index 000000000..9c0ec2200
--- /dev/null
+++ b/arch/tile/lib/cacheflush.c
@@ -0,0 +1,173 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/export.h>
+#include <asm/page.h>
+#include <asm/cacheflush.h>
+#include <arch/icache.h>
+#include <arch/spr_def.h>
+
+
+void __flush_icache_range(unsigned long start, unsigned long end)
+{
+	invalidate_icache((const void *)start, end - start, PAGE_SIZE);
+}
+
+
+/* Force a load instruction to issue. */
+static inline void force_load(char *p)
+{
+	*(volatile char *)p;
+}
+
+/*
+ * Flush and invalidate a VA range that is homed remotely on a single
+ * core (if "!hfh") or homed via hash-for-home (if "hfh"), waiting
+ * until the memory controller holds the flushed values.
+ */
+void __attribute__((optimize("omit-frame-pointer")))
+finv_buffer_remote(void *buffer, size_t size, int hfh)
+{
+	char *p, *base;
+	size_t step_size, load_count;
+
+	/*
+	 * On TILEPro the striping granularity is a fixed 8KB; on
+	 * TILE-Gx it is configurable, and we rely on the fact that
+	 * the hypervisor always configures maximum striping, so that
+	 * bits 9 and 10 of the PA are part of the stripe function, so
+	 * every 512 bytes we hit a striping boundary.
+	 *
+	 */
+#ifdef __tilegx__
+	const unsigned long STRIPE_WIDTH = 512;
+#else
+	const unsigned long STRIPE_WIDTH = 8192;
+#endif
+
+#ifdef __tilegx__
+	/*
+	 * On TILE-Gx, we must disable the dstream prefetcher before doing
+	 * a cache flush; otherwise, we could end up with data in the cache
+	 * that we don't want there.  Note that normally we'd do an mf
+	 * after the SPR write to disabling the prefetcher, but we do one
+	 * below, before any further loads, so there's no need to do it
+	 * here.
+	 */
+	uint_reg_t old_dstream_pf = __insn_mfspr(SPR_DSTREAM_PF);
+	__insn_mtspr(SPR_DSTREAM_PF, 0);
+#endif
+
+	/*
+	 * Flush and invalidate the buffer out of the local L1/L2
+	 * and request the home cache to flush and invalidate as well.
+	 */
+	__finv_buffer(buffer, size);
+
+	/*
+	 * Wait for the home cache to acknowledge that it has processed
+	 * all the flush-and-invalidate requests.  This does not mean
+	 * that the flushed data has reached the memory controller yet,
+	 * but it does mean the home cache is processing the flushes.
+	 */
+	__insn_mf();
+
+	/*
+	 * Issue a load to the last cache line, which can't complete
+	 * until all the previously-issued flushes to the same memory
+	 * controller have also completed.  If we weren't striping
+	 * memory, that one load would be sufficient, but since we may
+	 * be, we also need to back up to the last load issued to
+	 * another memory controller, which would be the point where
+	 * we crossed a "striping" boundary (the granularity of striping
+	 * across memory controllers).  Keep backing up and doing this
+	 * until we are before the beginning of the buffer, or have
+	 * hit all the controllers.
+	 *
+	 * If we are flushing a hash-for-home buffer, it's even worse.
+	 * Each line may be homed on a different tile, and each tile
+	 * may have up to four lines that are on different
+	 * controllers.  So as we walk backwards, we have to touch
+	 * enough cache lines to satisfy these constraints.  In
+	 * practice this ends up being close enough to "load from
+	 * every cache line on a full memory stripe on each
+	 * controller" that we simply do that, to simplify the logic.
+	 *
+	 * On TILE-Gx the hash-for-home function is much more complex,
+	 * with the upshot being we can't readily guarantee we have
+	 * hit both entries in the 128-entry AMT that were hit by any
+	 * load in the entire range, so we just re-load them all.
+	 * With larger buffers, we may want to consider using a hypervisor
+	 * trap to issue loads directly to each hash-for-home tile for
+	 * each controller (doing it from Linux would trash the TLB).
+	 */
+	if (hfh) {
+		step_size = L2_CACHE_BYTES;
+#ifdef __tilegx__
+		load_count = (size + L2_CACHE_BYTES - 1) / L2_CACHE_BYTES;
+#else
+		load_count = (STRIPE_WIDTH / L2_CACHE_BYTES) *
+			      (1 << CHIP_LOG_NUM_MSHIMS());
+#endif
+	} else {
+		step_size = STRIPE_WIDTH;
+		load_count = (1 << CHIP_LOG_NUM_MSHIMS());
+	}
+
+	/* Load the last byte of the buffer. */
+	p = (char *)buffer + size - 1;
+	force_load(p);
+
+	/* Bump down to the end of the previous stripe or cache line. */
+	p -= step_size;
+	p = (char *)((unsigned long)p | (step_size - 1));
+
+	/* Figure out how far back we need to go. */
+	base = p - (step_size * (load_count - 2));
+	if ((unsigned long)base < (unsigned long)buffer)
+		base = buffer;
+
+	/*
+	 * Fire all the loads we need.  The MAF only has eight entries
+	 * so we can have at most eight outstanding loads, so we
+	 * unroll by that amount.
+	 */
+#pragma unroll 8
+	for (; p >= base; p -= step_size)
+		force_load(p);
+
+	/*
+	 * Repeat, but with finv's instead of loads, to get rid of the
+	 * data we just loaded into our own cache and the old home L3.
+	 * No need to unroll since finv's don't target a register.
+	 * The finv's are guaranteed not to actually flush the data in
+	 * the buffer back to their home, since we just read it, so the
+	 * lines are clean in cache; we will only invalidate those lines.
+	 */
+	p = (char *)buffer + size - 1;
+	__insn_finv(p);
+	p -= step_size;
+	p = (char *)((unsigned long)p | (step_size - 1));
+	for (; p >= base; p -= step_size)
+		__insn_finv(p);
+
+	/* Wait for these finv's (and thus the first finvs) to be done. */
+	__insn_mf();
+
+#ifdef __tilegx__
+	/* Reenable the prefetcher. */
+	__insn_mtspr(SPR_DSTREAM_PF, old_dstream_pf);
+#endif
+}
+EXPORT_SYMBOL_GPL(finv_buffer_remote);
diff --git a/arch/tile/lib/checksum.c b/arch/tile/lib/checksum.c
new file mode 100644
index 000000000..c3ca3e64d
--- /dev/null
+++ b/arch/tile/lib/checksum.c
@@ -0,0 +1,89 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ * Support code for the main lib/checksum.c.
+ */
+
+#include <net/checksum.h>
+#include <linux/module.h>
+
+__wsum do_csum(const unsigned char *buff, int len)
+{
+	int odd, count;
+	unsigned long result = 0;
+
+	if (len <= 0)
+		goto out;
+	odd = 1 & (unsigned long) buff;
+	if (odd) {
+		result = (*buff << 8);
+		len--;
+		buff++;
+	}
+	count = len >> 1;		/* nr of 16-bit words.. */
+	if (count) {
+		if (2 & (unsigned long) buff) {
+			result += *(const unsigned short *)buff;
+			count--;
+			len -= 2;
+			buff += 2;
+		}
+		count >>= 1;		/* nr of 32-bit words.. */
+		if (count) {
+#ifdef __tilegx__
+			if (4 & (unsigned long) buff) {
+				unsigned int w = *(const unsigned int *)buff;
+				result = __insn_v2sadau(result, w, 0);
+				count--;
+				len -= 4;
+				buff += 4;
+			}
+			count >>= 1;		/* nr of 64-bit words.. */
+#endif
+
+			/*
+			 * This algorithm could wrap around for very
+			 * large buffers, but those should be impossible.
+			 */
+			BUG_ON(count >= 65530);
+
+			while (count) {
+				unsigned long w = *(const unsigned long *)buff;
+				count--;
+				buff += sizeof(w);
+#ifdef __tilegx__
+				result = __insn_v2sadau(result, w, 0);
+#else
+				result = __insn_sadah_u(result, w, 0);
+#endif
+			}
+#ifdef __tilegx__
+			if (len & 4) {
+				unsigned int w = *(const unsigned int *)buff;
+				result = __insn_v2sadau(result, w, 0);
+				buff += 4;
+			}
+#endif
+		}
+		if (len & 2) {
+			result += *(const unsigned short *) buff;
+			buff += 2;
+		}
+	}
+	if (len & 1)
+		result += *buff;
+	result = csum_long(result);
+	if (odd)
+		result = swab16(result);
+out:
+	return result;
+}
diff --git a/arch/tile/lib/cpumask.c b/arch/tile/lib/cpumask.c
new file mode 100644
index 000000000..75947edcc
--- /dev/null
+++ b/arch/tile/lib/cpumask.c
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/cpumask.h>
+#include <linux/ctype.h>
+#include <linux/errno.h>
+#include <linux/smp.h>
+#include <linux/export.h>
+
+/*
+ * Allow cropping out bits beyond the end of the array.
+ * Move to "lib" directory if more clients want to use this routine.
+ */
+int bitmap_parselist_crop(const char *bp, unsigned long *maskp, int nmaskbits)
+{
+	unsigned a, b;
+
+	bitmap_zero(maskp, nmaskbits);
+	do {
+		if (!isdigit(*bp))
+			return -EINVAL;
+		a = simple_strtoul(bp, (char **)&bp, 10);
+		b = a;
+		if (*bp == '-') {
+			bp++;
+			if (!isdigit(*bp))
+				return -EINVAL;
+			b = simple_strtoul(bp, (char **)&bp, 10);
+		}
+		if (!(a <= b))
+			return -EINVAL;
+		if (b >= nmaskbits)
+			b = nmaskbits-1;
+		while (a <= b) {
+			set_bit(a, maskp);
+			a++;
+		}
+		if (*bp == ',')
+			bp++;
+	} while (*bp != '\0' && *bp != '\n');
+	return 0;
+}
+EXPORT_SYMBOL(bitmap_parselist_crop);
diff --git a/arch/tile/lib/delay.c b/arch/tile/lib/delay.c
new file mode 100644
index 000000000..cdacdd11d
--- /dev/null
+++ b/arch/tile/lib/delay.c
@@ -0,0 +1,45 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/thread_info.h>
+#include <asm/timex.h>
+
+void __udelay(unsigned long usecs)
+{
+	if (usecs > ULONG_MAX / 1000) {
+		WARN_ON_ONCE(usecs > ULONG_MAX / 1000);
+		usecs = ULONG_MAX / 1000;
+	}
+	__ndelay(usecs * 1000);
+}
+EXPORT_SYMBOL(__udelay);
+
+void __ndelay(unsigned long nsecs)
+{
+	cycles_t target = get_cycles();
+	target += ns2cycles(nsecs);
+	while (get_cycles() < target)
+		cpu_relax();
+}
+EXPORT_SYMBOL(__ndelay);
+
+void __delay(unsigned long cycles)
+{
+	cycles_t target = get_cycles() + cycles;
+	while (get_cycles() < target)
+		cpu_relax();
+}
+EXPORT_SYMBOL(__delay);
diff --git a/arch/tile/lib/exports.c b/arch/tile/lib/exports.c
new file mode 100644
index 000000000..82733c87d
--- /dev/null
+++ b/arch/tile/lib/exports.c
@@ -0,0 +1,94 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ *
+ * Exports from assembler code and from libtile-cc.
+ */
+
+#include <linux/module.h>
+
+/* arch/tile/lib/usercopy.S */
+#include <linux/uaccess.h>
+EXPORT_SYMBOL(strnlen_user_asm);
+EXPORT_SYMBOL(strncpy_from_user_asm);
+EXPORT_SYMBOL(clear_user_asm);
+EXPORT_SYMBOL(flush_user_asm);
+EXPORT_SYMBOL(finv_user_asm);
+
+/* arch/tile/kernel/entry.S */
+#include <linux/kernel.h>
+#include <asm/processor.h>
+EXPORT_SYMBOL(current_text_addr);
+EXPORT_SYMBOL(dump_stack);
+
+/* arch/tile/kernel/head.S */
+EXPORT_SYMBOL(empty_zero_page);
+
+#ifdef CONFIG_FUNCTION_TRACER
+/* arch/tile/kernel/mcount_64.S */
+#include <asm/ftrace.h>
+EXPORT_SYMBOL(__mcount);
+#endif /* CONFIG_FUNCTION_TRACER */
+
+/* arch/tile/lib/, various memcpy files */
+EXPORT_SYMBOL(memcpy);
+EXPORT_SYMBOL(__copy_to_user_inatomic);
+EXPORT_SYMBOL(__copy_from_user_inatomic);
+EXPORT_SYMBOL(__copy_from_user_zeroing);
+#ifdef __tilegx__
+EXPORT_SYMBOL(__copy_in_user_inatomic);
+#endif
+
+/* hypervisor glue */
+#include <hv/hypervisor.h>
+EXPORT_SYMBOL(hv_dev_open);
+EXPORT_SYMBOL(hv_dev_pread);
+EXPORT_SYMBOL(hv_dev_pwrite);
+EXPORT_SYMBOL(hv_dev_preada);
+EXPORT_SYMBOL(hv_dev_pwritea);
+EXPORT_SYMBOL(hv_dev_poll);
+EXPORT_SYMBOL(hv_dev_poll_cancel);
+EXPORT_SYMBOL(hv_dev_close);
+EXPORT_SYMBOL(hv_sysconf);
+EXPORT_SYMBOL(hv_confstr);
+EXPORT_SYMBOL(hv_get_rtc);
+EXPORT_SYMBOL(hv_set_rtc);
+
+/* libgcc.a */
+uint32_t __udivsi3(uint32_t dividend, uint32_t divisor);
+EXPORT_SYMBOL(__udivsi3);
+int32_t __divsi3(int32_t dividend, int32_t divisor);
+EXPORT_SYMBOL(__divsi3);
+uint64_t __udivdi3(uint64_t dividend, uint64_t divisor);
+EXPORT_SYMBOL(__udivdi3);
+int64_t __divdi3(int64_t dividend, int64_t divisor);
+EXPORT_SYMBOL(__divdi3);
+uint32_t __umodsi3(uint32_t dividend, uint32_t divisor);
+EXPORT_SYMBOL(__umodsi3);
+int32_t __modsi3(int32_t dividend, int32_t divisor);
+EXPORT_SYMBOL(__modsi3);
+uint64_t __umoddi3(uint64_t dividend, uint64_t divisor);
+EXPORT_SYMBOL(__umoddi3);
+int64_t __moddi3(int64_t dividend, int64_t divisor);
+EXPORT_SYMBOL(__moddi3);
+#ifndef __tilegx__
+int64_t __muldi3(int64_t, int64_t);
+EXPORT_SYMBOL(__muldi3);
+uint64_t __lshrdi3(uint64_t, unsigned int);
+EXPORT_SYMBOL(__lshrdi3);
+uint64_t __ashrdi3(uint64_t, unsigned int);
+EXPORT_SYMBOL(__ashrdi3);
+uint64_t __ashldi3(uint64_t, unsigned int);
+EXPORT_SYMBOL(__ashldi3);
+int __ffsdi2(uint64_t);
+EXPORT_SYMBOL(__ffsdi2);
+#endif
diff --git a/arch/tile/lib/memchr_32.c b/arch/tile/lib/memchr_32.c
new file mode 100644
index 000000000..cc3d9badf
--- /dev/null
+++ b/arch/tile/lib/memchr_32.c
@@ -0,0 +1,71 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/module.h>
+
+void *memchr(const void *s, int c, size_t n)
+{
+	const uint32_t *last_word_ptr;
+	const uint32_t *p;
+	const char *last_byte_ptr;
+	uintptr_t s_int;
+	uint32_t goal, before_mask, v, bits;
+	char *ret;
+
+	if (__builtin_expect(n == 0, 0)) {
+		/* Don't dereference any memory if the array is empty. */
+		return NULL;
+	}
+
+	/* Get an aligned pointer. */
+	s_int = (uintptr_t) s;
+	p = (const uint32_t *)(s_int & -4);
+
+	/* Create four copies of the byte for which we are looking. */
+	goal = 0x01010101 * (uint8_t) c;
+
+	/* Read the first word, but munge it so that bytes before the array
+	 * will not match goal.
+	 *
+	 * Note that this shift count expression works because we know
+	 * shift counts are taken mod 32.
+	 */
+	before_mask = (1 << (s_int << 3)) - 1;
+	v = (*p | before_mask) ^ (goal & before_mask);
+
+	/* Compute the address of the last byte. */
+	last_byte_ptr = (const char *)s + n - 1;
+
+	/* Compute the address of the word containing the last byte. */
+	last_word_ptr = (const uint32_t *)((uintptr_t) last_byte_ptr & -4);
+
+	while ((bits = __insn_seqb(v, goal)) == 0) {
+		if (__builtin_expect(p == last_word_ptr, 0)) {
+			/* We already read the last word in the array,
+			 * so give up.
+			 */
+			return NULL;
+		}
+		v = *++p;
+	}
+
+	/* We found a match, but it might be in a byte past the end
+	 * of the array.
+	 */
+	ret = ((char *)p) + (__insn_ctz(bits) >> 3);
+	return (ret <= last_byte_ptr) ? ret : NULL;
+}
+EXPORT_SYMBOL(memchr);
diff --git a/arch/tile/lib/memchr_64.c b/arch/tile/lib/memchr_64.c
new file mode 100644
index 000000000..f8196b3a9
--- /dev/null
+++ b/arch/tile/lib/memchr_64.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright 2011 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/module.h>
+#include "string-endian.h"
+
+void *memchr(const void *s, int c, size_t n)
+{
+	const uint64_t *last_word_ptr;
+	const uint64_t *p;
+	const char *last_byte_ptr;
+	uintptr_t s_int;
+	uint64_t goal, before_mask, v, bits;
+	char *ret;
+
+	if (__builtin_expect(n == 0, 0)) {
+		/* Don't dereference any memory if the array is empty. */
+		return NULL;
+	}
+
+	/* Get an aligned pointer. */
+	s_int = (uintptr_t) s;
+	p = (const uint64_t *)(s_int & -8);
+
+	/* Create eight copies of the byte for which we are looking. */
+	goal = copy_byte(c);
+
+	/* Read the first word, but munge it so that bytes before the array
+	 * will not match goal.
+	 */
+	before_mask = MASK(s_int);
+	v = (*p | before_mask) ^ (goal & before_mask);
+
+	/* Compute the address of the last byte. */
+	last_byte_ptr = (const char *)s + n - 1;
+
+	/* Compute the address of the word containing the last byte. */
+	last_word_ptr = (const uint64_t *)((uintptr_t) last_byte_ptr & -8);
+
+	while ((bits = __insn_v1cmpeq(v, goal)) == 0) {
+		if (__builtin_expect(p == last_word_ptr, 0)) {
+			/* We already read the last word in the array,
+			 * so give up.
+			 */
+			return NULL;
+		}
+		v = *++p;
+	}
+
+	/* We found a match, but it might be in a byte past the end
+	 * of the array.
+	 */
+	ret = ((char *)p) + (CFZ(bits) >> 3);
+	return (ret <= last_byte_ptr) ? ret : NULL;
+}
+EXPORT_SYMBOL(memchr);
diff --git a/arch/tile/lib/memcpy_32.S b/arch/tile/lib/memcpy_32.S
new file mode 100644
index 000000000..a2771ae5d
--- /dev/null
+++ b/arch/tile/lib/memcpy_32.S
@@ -0,0 +1,559 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <arch/chip.h>
+
+
+/*
+ * This file shares the implementation of the userspace memcpy and
+ * the kernel's memcpy, copy_to_user and copy_from_user.
+ */
+
+#include <linux/linkage.h>
+
+#define IS_MEMCPY	  0
+#define IS_COPY_FROM_USER  1
+#define IS_COPY_FROM_USER_ZEROING  2
+#define IS_COPY_TO_USER   -1
+
+	.section .text.memcpy_common, "ax"
+	.align 64
+
+/* Use this to preface each bundle that can cause an exception so
+ * the kernel can clean up properly. The special cleanup code should
+ * not use these, since it knows what it is doing.
+ */
+#define EX \
+	.pushsection __ex_table, "a"; \
+	.align 4; \
+	.word 9f, memcpy_common_fixup; \
+	.popsection; \
+	9
+
+
+/* __copy_from_user_inatomic takes the kernel target address in r0,
+ * the user source in r1, and the bytes to copy in r2.
+ * It returns the number of uncopiable bytes (hopefully zero) in r0.
+ */
+ENTRY(__copy_from_user_inatomic)
+.type __copy_from_user_inatomic, @function
+	FEEDBACK_ENTER_EXPLICIT(__copy_from_user_inatomic, \
+	  .text.memcpy_common, \
+	  .Lend_memcpy_common - __copy_from_user_inatomic)
+	{ movei r29, IS_COPY_FROM_USER; j memcpy_common }
+	.size __copy_from_user_inatomic, . - __copy_from_user_inatomic
+
+/* __copy_from_user_zeroing is like __copy_from_user_inatomic, but
+ * any uncopiable bytes are zeroed in the target.
+ */
+ENTRY(__copy_from_user_zeroing)
+.type __copy_from_user_zeroing, @function
+	FEEDBACK_REENTER(__copy_from_user_inatomic)
+	{ movei r29, IS_COPY_FROM_USER_ZEROING; j memcpy_common }
+	.size __copy_from_user_zeroing, . - __copy_from_user_zeroing
+
+/* __copy_to_user_inatomic takes the user target address in r0,
+ * the kernel source in r1, and the bytes to copy in r2.
+ * It returns the number of uncopiable bytes (hopefully zero) in r0.
+ */
+ENTRY(__copy_to_user_inatomic)
+.type __copy_to_user_inatomic, @function
+	FEEDBACK_REENTER(__copy_from_user_inatomic)
+	{ movei r29, IS_COPY_TO_USER; j memcpy_common }
+	.size __copy_to_user_inatomic, . - __copy_to_user_inatomic
+
+ENTRY(memcpy)
+.type memcpy, @function
+	FEEDBACK_REENTER(__copy_from_user_inatomic)
+	{ movei r29, IS_MEMCPY }
+	.size memcpy, . - memcpy
+	/* Fall through */
+
+	.type memcpy_common, @function
+memcpy_common:
+	/* On entry, r29 holds one of the IS_* macro values from above. */
+
+
+	/* r0 is the dest, r1 is the source, r2 is the size. */
+
+	/* Save aside original dest so we can return it at the end. */
+	{ sw sp, lr; move r23, r0; or r4, r0, r1 }
+
+	/* Check for an empty size. */
+	{ bz r2, .Ldone; andi r4, r4, 3 }
+
+	/* Save aside original values in case of a fault. */
+	{ move r24, r1; move r25, r2 }
+	move r27, lr
+
+	/* Check for an unaligned source or dest. */
+	{ bnz r4, .Lcopy_unaligned_maybe_many; addli r4, r2, -256 }
+
+.Lcheck_aligned_copy_size:
+	/* If we are copying < 256 bytes, branch to simple case. */
+	{ blzt r4, .Lcopy_8_check; slti_u r8, r2, 8 }
+
+	/* Copying >= 256 bytes, so jump to complex prefetching loop. */
+	{ andi r6, r1, 63; j .Lcopy_many }
+
+/*
+ *
+ * Aligned 4 byte at a time copy loop
+ *
+ */
+
+.Lcopy_8_loop:
+	/* Copy two words at a time to hide load latency. */
+EX:	{ lw r3, r1; addi r1, r1, 4; slti_u r8, r2, 16 }
+EX:	{ lw r4, r1; addi r1, r1, 4 }
+EX:	{ sw r0, r3; addi r0, r0, 4; addi r2, r2, -4 }
+EX:	{ sw r0, r4; addi r0, r0, 4; addi r2, r2, -4 }
+.Lcopy_8_check:
+	{ bzt r8, .Lcopy_8_loop; slti_u r4, r2, 4 }
+
+	/* Copy odd leftover word, if any. */
+	{ bnzt r4, .Lcheck_odd_stragglers }
+EX:	{ lw r3, r1; addi r1, r1, 4 }
+EX:	{ sw r0, r3; addi r0, r0, 4; addi r2, r2, -4 }
+
+.Lcheck_odd_stragglers:
+	{ bnz r2, .Lcopy_unaligned_few }
+
+.Ldone:
+	/* For memcpy return original dest address, else zero. */
+	{ mz r0, r29, r23; jrp lr }
+
+
+/*
+ *
+ * Prefetching multiple cache line copy handler (for large transfers).
+ *
+ */
+
+	/* Copy words until r1 is cache-line-aligned. */
+.Lalign_loop:
+EX:	{ lw r3, r1; addi r1, r1, 4 }
+	{ andi r6, r1, 63 }
+EX:	{ sw r0, r3; addi r0, r0, 4; addi r2, r2, -4 }
+.Lcopy_many:
+	{ bnzt r6, .Lalign_loop; addi r9, r0, 63 }
+
+	{ addi r3, r1, 60; andi r9, r9, -64 }
+
+	/* No need to prefetch dst, we'll just do the wh64
+	 * right before we copy a line.
+	 */
+EX:	{ lw r5, r3; addi r3, r3, 64; movei r4, 1 }
+	/* Intentionally stall for a few cycles to leave L2 cache alone. */
+	{ bnzt zero, .; move r27, lr }
+EX:	{ lw r6, r3; addi r3, r3, 64 }
+	/* Intentionally stall for a few cycles to leave L2 cache alone. */
+	{ bnzt zero, . }
+EX:	{ lw r7, r3; addi r3, r3, 64 }
+	/* Intentionally stall for a few cycles to leave L2 cache alone. */
+	{ bz zero, .Lbig_loop2 }
+
+	/* On entry to this loop:
+	 * - r0 points to the start of dst line 0
+	 * - r1 points to start of src line 0
+	 * - r2 >= (256 - 60), only the first time the loop trips.
+	 * - r3 contains r1 + 128 + 60    [pointer to end of source line 2]
+	 *   This is our prefetch address. When we get near the end
+	 *   rather than prefetching off the end this is changed to point
+	 *   to some "safe" recently loaded address.
+	 * - r5 contains *(r1 + 60)       [i.e. last word of source line 0]
+	 * - r6 contains *(r1 + 64 + 60)  [i.e. last word of source line 1]
+	 * - r9 contains ((r0 + 63) & -64)
+	 *     [start of next dst cache line.]
+	 */
+
+.Lbig_loop:
+	{ jal .Lcopy_line2; add r15, r1, r2 }
+
+.Lbig_loop2:
+	/* Copy line 0, first stalling until r5 is ready. */
+EX:	{ move r12, r5; lw r16, r1 }
+	{ bz r4, .Lcopy_8_check; slti_u r8, r2, 8 }
+	/* Prefetch several lines ahead. */
+EX:	{ lw r5, r3; addi r3, r3, 64 }
+	{ jal .Lcopy_line }
+
+	/* Copy line 1, first stalling until r6 is ready. */
+EX:	{ move r12, r6; lw r16, r1 }
+	{ bz r4, .Lcopy_8_check; slti_u r8, r2, 8 }
+	/* Prefetch several lines ahead. */
+EX:	{ lw r6, r3; addi r3, r3, 64 }
+	{ jal .Lcopy_line }
+
+	/* Copy line 2, first stalling until r7 is ready. */
+EX:	{ move r12, r7; lw r16, r1 }
+	{ bz r4, .Lcopy_8_check; slti_u r8, r2, 8 }
+	/* Prefetch several lines ahead. */
+EX:	{ lw r7, r3; addi r3, r3, 64 }
+	/* Use up a caches-busy cycle by jumping back to the top of the
+	 * loop. Might as well get it out of the way now.
+	 */
+	{ j .Lbig_loop }
+
+
+	/* On entry:
+	 * - r0 points to the destination line.
+	 * - r1 points to the source line.
+	 * - r3 is the next prefetch address.
+	 * - r9 holds the last address used for wh64.
+	 * - r12 = WORD_15
+	 * - r16 = WORD_0.
+	 * - r17 == r1 + 16.
+	 * - r27 holds saved lr to restore.
+	 *
+	 * On exit:
+	 * - r0 is incremented by 64.
+	 * - r1 is incremented by 64, unless that would point to a word
+	 *   beyond the end of the source array, in which case it is redirected
+	 *   to point to an arbitrary word already in the cache.
+	 * - r2 is decremented by 64.
+	 * - r3 is unchanged, unless it points to a word beyond the
+	 *   end of the source array, in which case it is redirected
+	 *   to point to an arbitrary word already in the cache.
+	 *   Redirecting is OK since if we are that close to the end
+	 *   of the array we will not come back to this subroutine
+	 *   and use the contents of the prefetched address.
+	 * - r4 is nonzero iff r2 >= 64.
+	 * - r9 is incremented by 64, unless it points beyond the
+	 *   end of the last full destination cache line, in which
+	 *   case it is redirected to a "safe address" that can be
+	 *   clobbered (sp - 64)
+	 * - lr contains the value in r27.
+	 */
+
+/* r26 unused */
+
+.Lcopy_line:
+	/* TODO: when r3 goes past the end, we would like to redirect it
+	 * to prefetch the last partial cache line (if any) just once, for the
+	 * benefit of the final cleanup loop. But we don't want to
+	 * prefetch that line more than once, or subsequent prefetches
+	 * will go into the RTF. But then .Lbig_loop should unconditionally
+	 * branch to top of loop to execute final prefetch, and its
+	 * nop should become a conditional branch.
+	 */
+
+	/* We need two non-memory cycles here to cover the resources
+	 * used by the loads initiated by the caller.
+	 */
+	{ add r15, r1, r2 }
+.Lcopy_line2:
+	{ slt_u r13, r3, r15; addi r17, r1, 16 }
+
+	/* NOTE: this will stall for one cycle as L1 is busy. */
+
+	/* Fill second L1D line. */
+EX:	{ lw r17, r17; addi r1, r1, 48; mvz r3, r13, r1 } /* r17 = WORD_4 */
+
+	/* Prepare destination line for writing. */
+EX:	{ wh64 r9; addi r9, r9, 64 }
+	/* Load seven words that are L1D hits to cover wh64 L2 usage. */
+
+	/* Load the three remaining words from the last L1D line, which
+	 * we know has already filled the L1D.
+	 */
+EX:	{ lw r4, r1;  addi r1, r1, 4;   addi r20, r1, 16 }   /* r4 = WORD_12 */
+EX:	{ lw r8, r1;  addi r1, r1, 4;   slt_u r13, r20, r15 }/* r8 = WORD_13 */
+EX:	{ lw r11, r1; addi r1, r1, -52; mvz r20, r13, r1 }  /* r11 = WORD_14 */
+
+	/* Load the three remaining words from the first L1D line, first
+	 * stalling until it has filled by "looking at" r16.
+	 */
+EX:	{ lw r13, r1; addi r1, r1, 4; move zero, r16 }   /* r13 = WORD_1 */
+EX:	{ lw r14, r1; addi r1, r1, 4 }                   /* r14 = WORD_2 */
+EX:	{ lw r15, r1; addi r1, r1, 8; addi r10, r0, 60 } /* r15 = WORD_3 */
+
+	/* Load second word from the second L1D line, first
+	 * stalling until it has filled by "looking at" r17.
+	 */
+EX:	{ lw r19, r1; addi r1, r1, 4; move zero, r17 }  /* r19 = WORD_5 */
+
+	/* Store last word to the destination line, potentially dirtying it
+	 * for the first time, which keeps the L2 busy for two cycles.
+	 */
+EX:	{ sw r10, r12 }                                 /* store(WORD_15) */
+
+	/* Use two L1D hits to cover the sw L2 access above. */
+EX:	{ lw r10, r1; addi r1, r1, 4 }                  /* r10 = WORD_6 */
+EX:	{ lw r12, r1; addi r1, r1, 4 }                  /* r12 = WORD_7 */
+
+	/* Fill third L1D line. */
+EX:	{ lw r18, r1; addi r1, r1, 4 }                  /* r18 = WORD_8 */
+
+	/* Store first L1D line. */
+EX:	{ sw r0, r16; addi r0, r0, 4; add r16, r0, r2 } /* store(WORD_0) */
+EX:	{ sw r0, r13; addi r0, r0, 4; andi r16, r16, -64 } /* store(WORD_1) */
+EX:	{ sw r0, r14; addi r0, r0, 4; slt_u r16, r9, r16 } /* store(WORD_2) */
+EX:	{ sw r0, r15; addi r0, r0, 4; addi r13, sp, -64 } /* store(WORD_3) */
+	/* Store second L1D line. */
+EX:	{ sw r0, r17; addi r0, r0, 4; mvz r9, r16, r13 }/* store(WORD_4) */
+EX:	{ sw r0, r19; addi r0, r0, 4 }                  /* store(WORD_5) */
+EX:	{ sw r0, r10; addi r0, r0, 4 }                  /* store(WORD_6) */
+EX:	{ sw r0, r12; addi r0, r0, 4 }                  /* store(WORD_7) */
+
+EX:	{ lw r13, r1; addi r1, r1, 4; move zero, r18 }  /* r13 = WORD_9 */
+EX:	{ lw r14, r1; addi r1, r1, 4 }                  /* r14 = WORD_10 */
+EX:	{ lw r15, r1; move r1, r20   }                  /* r15 = WORD_11 */
+
+	/* Store third L1D line. */
+EX:	{ sw r0, r18; addi r0, r0, 4 }                  /* store(WORD_8) */
+EX:	{ sw r0, r13; addi r0, r0, 4 }                  /* store(WORD_9) */
+EX:	{ sw r0, r14; addi r0, r0, 4 }                  /* store(WORD_10) */
+EX:	{ sw r0, r15; addi r0, r0, 4 }                  /* store(WORD_11) */
+
+	/* Store rest of fourth L1D line. */
+EX:	{ sw r0, r4;  addi r0, r0, 4 }                  /* store(WORD_12) */
+	{
+EX:	sw r0, r8                                       /* store(WORD_13) */
+	addi r0, r0, 4
+	/* Will r2 be > 64 after we subtract 64 below? */
+	shri r4, r2, 7
+	}
+	{
+EX:	sw r0, r11                                      /* store(WORD_14) */
+	addi r0, r0, 8
+	/* Record 64 bytes successfully copied. */
+	addi r2, r2, -64
+	}
+
+	{ jrp lr; move lr, r27 }
+
+	/* Convey to the backtrace library that the stack frame is size
+	 * zero, and the real return address is on the stack rather than
+	 * in 'lr'.
+	 */
+	{ info 8 }
+
+	.align 64
+.Lcopy_unaligned_maybe_many:
+	/* Skip the setup overhead if we aren't copying many bytes. */
+	{ slti_u r8, r2, 20; sub r4, zero, r0 }
+	{ bnzt r8, .Lcopy_unaligned_few; andi r4, r4, 3 }
+	{ bz r4, .Ldest_is_word_aligned; add r18, r1, r2 }
+
+/*
+ *
+ * unaligned 4 byte at a time copy handler.
+ *
+ */
+
+	/* Copy single bytes until r0 == 0 mod 4, so we can store words. */
+.Lalign_dest_loop:
+EX:	{ lb_u r3, r1; addi r1, r1, 1; addi r4, r4, -1 }
+EX:	{ sb r0, r3;   addi r0, r0, 1; addi r2, r2, -1 }
+	{ bnzt r4, .Lalign_dest_loop; andi r3, r1, 3 }
+
+	/* If source and dest are now *both* aligned, do an aligned copy. */
+	{ bz r3, .Lcheck_aligned_copy_size; addli r4, r2, -256 }
+
+.Ldest_is_word_aligned:
+
+EX:	{ andi r8, r0, 63; lwadd_na r6, r1, 4}
+	{ slti_u r9, r2, 64; bz r8, .Ldest_is_L2_line_aligned }
+
+	/* This copies unaligned words until either there are fewer
+	 * than 4 bytes left to copy, or until the destination pointer
+	 * is cache-aligned, whichever comes first.
+	 *
+	 * On entry:
+	 * - r0 is the next store address.
+	 * - r1 points 4 bytes past the load address corresponding to r0.
+	 * - r2 >= 4
+	 * - r6 is the next aligned word loaded.
+	 */
+.Lcopy_unaligned_src_words:
+EX:	{ lwadd_na r7, r1, 4; slti_u r8, r2, 4 + 4 }
+	/* stall */
+	{ dword_align r6, r7, r1; slti_u r9, r2, 64 + 4 }
+EX:	{ swadd r0, r6, 4; addi r2, r2, -4 }
+	{ bnz r8, .Lcleanup_unaligned_words; andi r8, r0, 63 }
+	{ bnzt r8, .Lcopy_unaligned_src_words; move r6, r7 }
+
+	/* On entry:
+	 * - r0 is the next store address.
+	 * - r1 points 4 bytes past the load address corresponding to r0.
+	 * - r2 >= 4 (# of bytes left to store).
+	 * - r6 is the next aligned src word value.
+	 * - r9 = (r2 < 64U).
+	 * - r18 points one byte past the end of source memory.
+	 */
+.Ldest_is_L2_line_aligned:
+
+	{
+	/* Not a full cache line remains. */
+	bnz r9, .Lcleanup_unaligned_words
+	move r7, r6
+	}
+
+	/* r2 >= 64 */
+
+	/* Kick off two prefetches, but don't go past the end. */
+	{ addi r3, r1, 63 - 4; addi r8, r1, 64 + 63 - 4 }
+	{ prefetch r3; move r3, r8; slt_u r8, r8, r18 }
+	{ mvz r3, r8, r1; addi r8, r3, 64 }
+	{ prefetch r3; move r3, r8; slt_u r8, r8, r18 }
+	{ mvz r3, r8, r1; movei r17, 0 }
+
+.Lcopy_unaligned_line:
+	/* Prefetch another line. */
+	{ prefetch r3; addi r15, r1, 60; addi r3, r3, 64 }
+	/* Fire off a load of the last word we are about to copy. */
+EX:	{ lw_na r15, r15; slt_u r8, r3, r18 }
+
+EX:	{ mvz r3, r8, r1; wh64 r0 }
+
+	/* This loop runs twice.
+	 *
+	 * On entry:
+	 * - r17 is even before the first iteration, and odd before
+	 *   the second.  It is incremented inside the loop.  Encountering
+	 *   an even value at the end of the loop makes it stop.
+	 */
+.Lcopy_half_an_unaligned_line:
+EX:	{
+	/* Stall until the last byte is ready. In the steady state this
+	 * guarantees all words to load below will be in the L2 cache, which
+	 * avoids shunting the loads to the RTF.
+	 */
+	move zero, r15
+	lwadd_na r7, r1, 16
+	}
+EX:	{ lwadd_na r11, r1, 12 }
+EX:	{ lwadd_na r14, r1, -24 }
+EX:	{ lwadd_na r8, r1, 4 }
+EX:	{ lwadd_na r9, r1, 4 }
+EX:	{
+	lwadd_na r10, r1, 8
+	/* r16 = (r2 < 64), after we subtract 32 from r2 below. */
+	slti_u r16, r2, 64 + 32
+	}
+EX:	{ lwadd_na r12, r1, 4; addi r17, r17, 1 }
+EX:	{ lwadd_na r13, r1, 8; dword_align r6, r7, r1 }
+EX:	{ swadd r0, r6,  4; dword_align r7,  r8,  r1 }
+EX:	{ swadd r0, r7,  4; dword_align r8,  r9,  r1 }
+EX:	{ swadd r0, r8,  4; dword_align r9,  r10, r1 }
+EX:	{ swadd r0, r9,  4; dword_align r10, r11, r1 }
+EX:	{ swadd r0, r10, 4; dword_align r11, r12, r1 }
+EX:	{ swadd r0, r11, 4; dword_align r12, r13, r1 }
+EX:	{ swadd r0, r12, 4; dword_align r13, r14, r1 }
+EX:	{ swadd r0, r13, 4; addi r2, r2, -32 }
+	{ move r6, r14; bbst r17, .Lcopy_half_an_unaligned_line }
+
+	{ bzt r16, .Lcopy_unaligned_line; move r7, r6 }
+
+	/* On entry:
+	 * - r0 is the next store address.
+	 * - r1 points 4 bytes past the load address corresponding to r0.
+	 * - r2 >= 0 (# of bytes left to store).
+	 * - r7 is the next aligned src word value.
+	 */
+.Lcleanup_unaligned_words:
+	/* Handle any trailing bytes. */
+	{ bz r2, .Lcopy_unaligned_done; slti_u r8, r2, 4 }
+	{ bzt r8, .Lcopy_unaligned_src_words; move r6, r7 }
+
+	/* Move r1 back to the point where it corresponds to r0. */
+	{ addi r1, r1, -4 }
+
+	/* Fall through */
+
+/*
+ *
+ * 1 byte at a time copy handler.
+ *
+ */
+
+.Lcopy_unaligned_few:
+EX:	{ lb_u r3, r1; addi r1, r1, 1 }
+EX:	{ sb r0, r3;   addi r0, r0, 1; addi r2, r2, -1 }
+	{ bnzt r2, .Lcopy_unaligned_few }
+
+.Lcopy_unaligned_done:
+
+	/* For memcpy return original dest address, else zero. */
+	{ mz r0, r29, r23; jrp lr }
+
+.Lend_memcpy_common:
+	.size memcpy_common, .Lend_memcpy_common - memcpy_common
+
+	.section .fixup,"ax"
+memcpy_common_fixup:
+	.type memcpy_common_fixup, @function
+
+	/* Skip any bytes we already successfully copied.
+	 * r2 (num remaining) is correct, but r0 (dst) and r1 (src)
+	 * may not be quite right because of unrolling and prefetching.
+	 * So we need to recompute their values as the address just
+	 * after the last byte we are sure was successfully loaded and
+	 * then stored.
+	 */
+
+	/* Determine how many bytes we successfully copied. */
+	{ sub r3, r25, r2 }
+
+	/* Add this to the original r0 and r1 to get their new values. */
+	{ add r0, r23, r3; add r1, r24, r3 }
+
+	{ bzt r29, memcpy_fixup_loop }
+	{ blzt r29, copy_to_user_fixup_loop }
+
+copy_from_user_fixup_loop:
+	/* Try copying the rest one byte at a time, expecting a load fault. */
+.Lcfu:	{ lb_u r3, r1; addi r1, r1, 1 }
+	{ sb r0, r3; addi r0, r0, 1; addi r2, r2, -1 }
+	{ bnzt r2, copy_from_user_fixup_loop }
+
+.Lcopy_from_user_fixup_zero_remainder:
+	{ bbs r29, 2f }  /* low bit set means IS_COPY_FROM_USER */
+	/* byte-at-a-time loop faulted, so zero the rest. */
+	{ move r3, r2; bz r2, 2f /* should be impossible, but handle it. */ }
+1:      { sb r0, zero; addi r0, r0, 1; addi r3, r3, -1 }
+	{ bnzt r3, 1b }
+2:	move lr, r27
+	{ move r0, r2; jrp lr }
+
+copy_to_user_fixup_loop:
+	/* Try copying the rest one byte at a time, expecting a store fault. */
+	{ lb_u r3, r1; addi r1, r1, 1 }
+.Lctu:	{ sb r0, r3; addi r0, r0, 1; addi r2, r2, -1 }
+	{ bnzt r2, copy_to_user_fixup_loop }
+.Lcopy_to_user_fixup_done:
+	move lr, r27
+	{ move r0, r2; jrp lr }
+
+memcpy_fixup_loop:
+	/* Try copying the rest one byte at a time. We expect a disastrous
+	 * fault to happen since we are in fixup code, but let it happen.
+	 */
+	{ lb_u r3, r1; addi r1, r1, 1 }
+	{ sb r0, r3; addi r0, r0, 1; addi r2, r2, -1 }
+	{ bnzt r2, memcpy_fixup_loop }
+	/* This should be unreachable, we should have faulted again.
+	 * But be paranoid and handle it in case some interrupt changed
+	 * the TLB or something.
+	 */
+	move lr, r27
+	{ move r0, r23; jrp lr }
+
+	.size memcpy_common_fixup, . - memcpy_common_fixup
+
+	.section __ex_table,"a"
+	.align 4
+	.word .Lcfu, .Lcopy_from_user_fixup_zero_remainder
+	.word .Lctu, .Lcopy_to_user_fixup_done
diff --git a/arch/tile/lib/memcpy_64.c b/arch/tile/lib/memcpy_64.c
new file mode 100644
index 000000000..4815354b8
--- /dev/null
+++ b/arch/tile/lib/memcpy_64.c
@@ -0,0 +1,367 @@
+/*
+ * Copyright 2011 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/module.h>
+/* EXPORT_SYMBOL() is in arch/tile/lib/exports.c since this should be asm. */
+
+/* Must be 8 bytes in size. */
+#define op_t uint64_t
+
+/* Threshold value for when to enter the unrolled loops. */
+#define	OP_T_THRES	16
+
+#if CHIP_L2_LINE_SIZE() != 64
+#error "Assumes 64 byte line size"
+#endif
+
+/* How many cache lines ahead should we prefetch? */
+#define PREFETCH_LINES_AHEAD 4
+
+/*
+ * Provide "base versions" of load and store for the normal code path.
+ * The kernel provides other versions for userspace copies.
+ */
+#define ST(p, v) (*(p) = (v))
+#define LD(p) (*(p))
+
+#ifndef USERCOPY_FUNC
+#define ST1 ST
+#define ST2 ST
+#define ST4 ST
+#define ST8 ST
+#define LD1 LD
+#define LD2 LD
+#define LD4 LD
+#define LD8 LD
+#define RETVAL dstv
+void *memcpy(void *__restrict dstv, const void *__restrict srcv, size_t n)
+#else
+/*
+ * Special kernel version will provide implementation of the LDn/STn
+ * macros to return a count of uncopied bytes due to mm fault.
+ */
+#define RETVAL 0
+int __attribute__((optimize("omit-frame-pointer")))
+USERCOPY_FUNC(void *__restrict dstv, const void *__restrict srcv, size_t n)
+#endif
+{
+	char *__restrict dst1 = (char *)dstv;
+	const char *__restrict src1 = (const char *)srcv;
+	const char *__restrict src1_end;
+	const char *__restrict prefetch;
+	op_t *__restrict dst8;    /* 8-byte pointer to destination memory. */
+	op_t final; /* Final bytes to write to trailing word, if any */
+	long i;
+
+	if (n < 16) {
+		for (; n; n--)
+			ST1(dst1++, LD1(src1++));
+		return RETVAL;
+	}
+
+	/*
+	 * Locate the end of source memory we will copy.  Don't
+	 * prefetch past this.
+	 */
+	src1_end = src1 + n - 1;
+
+	/* Prefetch ahead a few cache lines, but not past the end. */
+	prefetch = src1;
+	for (i = 0; i < PREFETCH_LINES_AHEAD; i++) {
+		__insn_prefetch(prefetch);
+		prefetch += CHIP_L2_LINE_SIZE();
+		prefetch = (prefetch < src1_end) ? prefetch : src1;
+	}
+
+	/* Copy bytes until dst is word-aligned. */
+	for (; (uintptr_t)dst1 & (sizeof(op_t) - 1); n--)
+		ST1(dst1++, LD1(src1++));
+
+	/* 8-byte pointer to destination memory. */
+	dst8 = (op_t *)dst1;
+
+	if (__builtin_expect((uintptr_t)src1 & (sizeof(op_t) - 1), 0)) {
+		/* Unaligned copy. */
+
+		op_t  tmp0 = 0, tmp1 = 0, tmp2, tmp3;
+		const op_t *src8 = (const op_t *) ((uintptr_t)src1 &
+						   -sizeof(op_t));
+		const void *srci = (void *)src1;
+		int m;
+
+		m = (CHIP_L2_LINE_SIZE() << 2) -
+			(((uintptr_t)dst8) & ((CHIP_L2_LINE_SIZE() << 2) - 1));
+		m = (n < m) ? n : m;
+		m /= sizeof(op_t);
+
+		/* Copy until 'dst' is cache-line-aligned. */
+		n -= (sizeof(op_t) * m);
+
+		switch (m % 4) {
+		case 0:
+			if (__builtin_expect(!m, 0))
+				goto _M0;
+			tmp1 = LD8(src8++);
+			tmp2 = LD8(src8++);
+			goto _8B3;
+		case 2:
+			m += 2;
+			tmp3 = LD8(src8++);
+			tmp0 = LD8(src8++);
+			goto _8B1;
+		case 3:
+			m += 1;
+			tmp2 = LD8(src8++);
+			tmp3 = LD8(src8++);
+			goto _8B2;
+		case 1:
+			m--;
+			tmp0 = LD8(src8++);
+			tmp1 = LD8(src8++);
+			if (__builtin_expect(!m, 0))
+				goto _8B0;
+		}
+
+		do {
+			tmp2 = LD8(src8++);
+			tmp0 =  __insn_dblalign(tmp0, tmp1, srci);
+			ST8(dst8++, tmp0);
+_8B3:
+			tmp3 = LD8(src8++);
+			tmp1 = __insn_dblalign(tmp1, tmp2, srci);
+			ST8(dst8++, tmp1);
+_8B2:
+			tmp0 = LD8(src8++);
+			tmp2 = __insn_dblalign(tmp2, tmp3, srci);
+			ST8(dst8++, tmp2);
+_8B1:
+			tmp1 = LD8(src8++);
+			tmp3 = __insn_dblalign(tmp3, tmp0, srci);
+			ST8(dst8++, tmp3);
+			m -= 4;
+		} while (m);
+
+_8B0:
+		tmp0 = __insn_dblalign(tmp0, tmp1, srci);
+		ST8(dst8++, tmp0);
+		src8--;
+
+_M0:
+		if (__builtin_expect(n >= CHIP_L2_LINE_SIZE(), 0)) {
+			op_t tmp4, tmp5, tmp6, tmp7, tmp8;
+
+			prefetch = ((const char *)src8) +
+				CHIP_L2_LINE_SIZE() * PREFETCH_LINES_AHEAD;
+
+			for (tmp0 = LD8(src8++); n >= CHIP_L2_LINE_SIZE();
+			     n -= CHIP_L2_LINE_SIZE()) {
+				/* Prefetch and advance to next line to
+				   prefetch, but don't go past the end.  */
+				__insn_prefetch(prefetch);
+
+				/* Make sure prefetch got scheduled
+				   earlier.  */
+				__asm__ ("" : : : "memory");
+
+				prefetch += CHIP_L2_LINE_SIZE();
+				prefetch = (prefetch < src1_end) ? prefetch :
+					(const char *) src8;
+
+				tmp1 = LD8(src8++);
+				tmp2 = LD8(src8++);
+				tmp3 = LD8(src8++);
+				tmp4 = LD8(src8++);
+				tmp5 = LD8(src8++);
+				tmp6 = LD8(src8++);
+				tmp7 = LD8(src8++);
+				tmp8 = LD8(src8++);
+
+				tmp0 = __insn_dblalign(tmp0, tmp1, srci);
+				tmp1 = __insn_dblalign(tmp1, tmp2, srci);
+				tmp2 = __insn_dblalign(tmp2, tmp3, srci);
+				tmp3 = __insn_dblalign(tmp3, tmp4, srci);
+				tmp4 = __insn_dblalign(tmp4, tmp5, srci);
+				tmp5 = __insn_dblalign(tmp5, tmp6, srci);
+				tmp6 = __insn_dblalign(tmp6, tmp7, srci);
+				tmp7 = __insn_dblalign(tmp7, tmp8, srci);
+
+				__insn_wh64(dst8);
+
+				ST8(dst8++, tmp0);
+				ST8(dst8++, tmp1);
+				ST8(dst8++, tmp2);
+				ST8(dst8++, tmp3);
+				ST8(dst8++, tmp4);
+				ST8(dst8++, tmp5);
+				ST8(dst8++, tmp6);
+				ST8(dst8++, tmp7);
+
+				tmp0 = tmp8;
+			}
+			src8--;
+		}
+
+		/* Copy the rest 8-byte chunks. */
+		if (n >= sizeof(op_t)) {
+			tmp0 = LD8(src8++);
+			for (; n >= sizeof(op_t); n -= sizeof(op_t)) {
+				tmp1 = LD8(src8++);
+				tmp0 = __insn_dblalign(tmp0, tmp1, srci);
+				ST8(dst8++, tmp0);
+				tmp0 = tmp1;
+			}
+			src8--;
+		}
+
+		if (n == 0)
+			return RETVAL;
+
+		tmp0 = LD8(src8++);
+		tmp1 = ((const char *)src8 <= src1_end)
+			? LD8((op_t *)src8) : 0;
+		final = __insn_dblalign(tmp0, tmp1, srci);
+
+	} else {
+		/* Aligned copy. */
+
+		const op_t *__restrict src8 = (const op_t *)src1;
+
+		/* src8 and dst8 are both word-aligned. */
+		if (n >= CHIP_L2_LINE_SIZE()) {
+			/* Copy until 'dst' is cache-line-aligned. */
+			for (; (uintptr_t)dst8 & (CHIP_L2_LINE_SIZE() - 1);
+			     n -= sizeof(op_t))
+				ST8(dst8++, LD8(src8++));
+
+			for (; n >= CHIP_L2_LINE_SIZE(); ) {
+				op_t tmp0, tmp1, tmp2, tmp3;
+				op_t tmp4, tmp5, tmp6, tmp7;
+
+				/*
+				 * Prefetch and advance to next line
+				 * to prefetch, but don't go past the
+				 * end.
+				 */
+				__insn_prefetch(prefetch);
+
+				/* Make sure prefetch got scheduled
+				   earlier.  */
+				__asm__ ("" : : : "memory");
+
+				prefetch += CHIP_L2_LINE_SIZE();
+				prefetch = (prefetch < src1_end) ? prefetch :
+					(const char *)src8;
+
+				/*
+				 * Do all the loads before wh64.  This
+				 * is necessary if [src8, src8+7] and
+				 * [dst8, dst8+7] share the same cache
+				 * line and dst8 <= src8, as can be
+				 * the case when called from memmove,
+				 * or with code tested on x86 whose
+				 * memcpy always works with forward
+				 * copies.
+				 */
+				tmp0 = LD8(src8++);
+				tmp1 = LD8(src8++);
+				tmp2 = LD8(src8++);
+				tmp3 = LD8(src8++);
+				tmp4 = LD8(src8++);
+				tmp5 = LD8(src8++);
+				tmp6 = LD8(src8++);
+				tmp7 = LD8(src8++);
+
+				/* wh64 and wait for tmp7 load completion. */
+				__asm__ ("move %0, %0; wh64 %1\n"
+					 : : "r"(tmp7), "r"(dst8));
+
+				ST8(dst8++, tmp0);
+				ST8(dst8++, tmp1);
+				ST8(dst8++, tmp2);
+				ST8(dst8++, tmp3);
+				ST8(dst8++, tmp4);
+				ST8(dst8++, tmp5);
+				ST8(dst8++, tmp6);
+				ST8(dst8++, tmp7);
+
+				n -= CHIP_L2_LINE_SIZE();
+			}
+#if CHIP_L2_LINE_SIZE() != 64
+# error "Fix code that assumes particular L2 cache line size."
+#endif
+		}
+
+		for (; n >= sizeof(op_t); n -= sizeof(op_t))
+			ST8(dst8++, LD8(src8++));
+
+		if (__builtin_expect(n == 0, 1))
+			return RETVAL;
+
+		final = LD8(src8);
+	}
+
+	/* n != 0 if we get here.  Write out any trailing bytes. */
+	dst1 = (char *)dst8;
+#ifndef __BIG_ENDIAN__
+	if (n & 4) {
+		ST4((uint32_t *)dst1, final);
+		dst1 += 4;
+		final >>= 32;
+		n &= 3;
+	}
+	if (n & 2) {
+		ST2((uint16_t *)dst1, final);
+		dst1 += 2;
+		final >>= 16;
+		n &= 1;
+	}
+	if (n)
+		ST1((uint8_t *)dst1, final);
+#else
+	if (n & 4) {
+		ST4((uint32_t *)dst1, final >> 32);
+		dst1 += 4;
+        }
+        else
+        {
+		final >>= 32;
+        }
+	if (n & 2) {
+		ST2((uint16_t *)dst1, final >> 16);
+		dst1 += 2;
+        }
+        else
+        {
+		final >>= 16;
+        }
+	if (n & 1)
+		ST1((uint8_t *)dst1, final >> 8);
+#endif
+
+	return RETVAL;
+}
+
+#ifdef USERCOPY_FUNC
+#undef ST1
+#undef ST2
+#undef ST4
+#undef ST8
+#undef LD1
+#undef LD2
+#undef LD4
+#undef LD8
+#undef USERCOPY_FUNC
+#endif
diff --git a/arch/tile/lib/memcpy_user_64.c b/arch/tile/lib/memcpy_user_64.c
new file mode 100644
index 000000000..88c701649
--- /dev/null
+++ b/arch/tile/lib/memcpy_user_64.c
@@ -0,0 +1,94 @@
+/*
+ * Copyright 2011 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ *
+ * Do memcpy(), but trap and return "n" when a load or store faults.
+ *
+ * Note: this idiom only works when memcpy() compiles to a leaf function.
+ * Here leaf function not only means it does not have calls, but also
+ * requires no stack operations (sp, stack frame pointer) and no
+ * use of callee-saved registers, else "jrp lr" will be incorrect since
+ * unwinding stack frame is bypassed. Since memcpy() is not complex so
+ * these conditions are satisfied here, but we need to be careful when
+ * modifying this file. This is not a clean solution but is the best
+ * one so far.
+ *
+ * Also note that we are capturing "n" from the containing scope here.
+ */
+
+#define _ST(p, inst, v)						\
+	({							\
+		asm("1: " #inst " %0, %1;"			\
+		    ".pushsection .coldtext.memcpy,\"ax\";"	\
+		    "2: { move r0, %2; jrp lr };"		\
+		    ".section __ex_table,\"a\";"		\
+		    ".align 8;"					\
+		    ".quad 1b, 2b;"				\
+		    ".popsection"				\
+		    : "=m" (*(p)) : "r" (v), "r" (n));		\
+	})
+
+#define _LD(p, inst)						\
+	({							\
+		unsigned long __v;				\
+		asm("1: " #inst " %0, %1;"			\
+		    ".pushsection .coldtext.memcpy,\"ax\";"	\
+		    "2: { move r0, %2; jrp lr };"		\
+		    ".section __ex_table,\"a\";"		\
+		    ".align 8;"					\
+		    ".quad 1b, 2b;"				\
+		    ".popsection"				\
+		    : "=r" (__v) : "m" (*(p)), "r" (n));	\
+		__v;						\
+	})
+
+#define USERCOPY_FUNC __copy_to_user_inatomic
+#define ST1(p, v) _ST((p), st1, (v))
+#define ST2(p, v) _ST((p), st2, (v))
+#define ST4(p, v) _ST((p), st4, (v))
+#define ST8(p, v) _ST((p), st, (v))
+#define LD1 LD
+#define LD2 LD
+#define LD4 LD
+#define LD8 LD
+#include "memcpy_64.c"
+
+#define USERCOPY_FUNC __copy_from_user_inatomic
+#define ST1 ST
+#define ST2 ST
+#define ST4 ST
+#define ST8 ST
+#define LD1(p) _LD((p), ld1u)
+#define LD2(p) _LD((p), ld2u)
+#define LD4(p) _LD((p), ld4u)
+#define LD8(p) _LD((p), ld)
+#include "memcpy_64.c"
+
+#define USERCOPY_FUNC __copy_in_user_inatomic
+#define ST1(p, v) _ST((p), st1, (v))
+#define ST2(p, v) _ST((p), st2, (v))
+#define ST4(p, v) _ST((p), st4, (v))
+#define ST8(p, v) _ST((p), st, (v))
+#define LD1(p) _LD((p), ld1u)
+#define LD2(p) _LD((p), ld2u)
+#define LD4(p) _LD((p), ld4u)
+#define LD8(p) _LD((p), ld)
+#include "memcpy_64.c"
+
+unsigned long __copy_from_user_zeroing(void *to, const void __user *from,
+				       unsigned long n)
+{
+	unsigned long rc = __copy_from_user_inatomic(to, from, n);
+	if (unlikely(rc))
+		memset(to + n - rc, 0, rc);
+	return rc;
+}
diff --git a/arch/tile/lib/memmove.c b/arch/tile/lib/memmove.c
new file mode 100644
index 000000000..fd615ae6a
--- /dev/null
+++ b/arch/tile/lib/memmove.c
@@ -0,0 +1,63 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/module.h>
+
+void *memmove(void *dest, const void *src, size_t n)
+{
+	if ((const char *)src >= (char *)dest + n
+	    || (char *)dest >= (const char *)src + n) {
+		/* We found no overlap, so let memcpy do all the heavy
+		 * lifting (prefetching, etc.)
+		 */
+		return memcpy(dest, src, n);
+	}
+
+	if (n != 0) {
+		const uint8_t *in;
+		uint8_t x;
+		uint8_t *out;
+		int stride;
+
+		if (src < dest) {
+			/* copy backwards */
+			in = (const uint8_t *)src + n - 1;
+			out = (uint8_t *)dest + n - 1;
+			stride = -1;
+		} else {
+			/* copy forwards */
+			in = (const uint8_t *)src;
+			out = (uint8_t *)dest;
+			stride = 1;
+		}
+
+		/* Manually software-pipeline this loop. */
+		x = *in;
+		in += stride;
+
+		while (--n != 0) {
+			*out = x;
+			out += stride;
+			x = *in;
+			in += stride;
+		}
+
+		*out = x;
+	}
+
+	return dest;
+}
+EXPORT_SYMBOL(memmove);
diff --git a/arch/tile/lib/memset_32.c b/arch/tile/lib/memset_32.c
new file mode 100644
index 000000000..2042bfe65
--- /dev/null
+++ b/arch/tile/lib/memset_32.c
@@ -0,0 +1,143 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/module.h>
+#include <arch/chip.h>
+
+void *memset(void *s, int c, size_t n)
+{
+	uint32_t *out32;
+	int n32;
+	uint32_t v16, v32;
+	uint8_t *out8 = s;
+	int to_align32;
+
+	/* Experimentation shows that a trivial tight loop is a win up until
+	 * around a size of 20, where writing a word at a time starts to win.
+	 */
+#define BYTE_CUTOFF 20
+
+#if BYTE_CUTOFF < 3
+	/* This must be at least at least this big, or some code later
+	 * on doesn't work.
+	 */
+#error "BYTE_CUTOFF is too small"
+#endif
+
+	if (n < BYTE_CUTOFF) {
+		/* Strangely, this turns out to be the tightest way to
+		 * write this loop.
+		 */
+		if (n != 0) {
+			do {
+				/* Strangely, combining these into one line
+				 * performs worse.
+				 */
+				*out8 = c;
+				out8++;
+			} while (--n != 0);
+		}
+
+		return s;
+	}
+
+	/* Align 'out8'. We know n >= 3 so this won't write past the end. */
+	while (((uintptr_t) out8 & 3) != 0) {
+		*out8++ = c;
+		--n;
+	}
+
+	/* Align 'n'. */
+	while (n & 3)
+		out8[--n] = c;
+
+	out32 = (uint32_t *) out8;
+	n32 = n >> 2;
+
+	/* Tile input byte out to 32 bits. */
+	v16 = __insn_intlb(c, c);
+	v32 = __insn_intlh(v16, v16);
+
+	/* This must be at least 8 or the following loop doesn't work. */
+#define CACHE_LINE_SIZE_IN_WORDS (CHIP_L2_LINE_SIZE() / 4)
+
+	/* Determine how many words we need to emit before the 'out32'
+	 * pointer becomes aligned modulo the cache line size.
+	 */
+	to_align32 =
+		(-((uintptr_t)out32 >> 2)) & (CACHE_LINE_SIZE_IN_WORDS - 1);
+
+	/* Only bother aligning and using wh64 if there is at least
+	 * one full cache line to process.  This check also prevents
+	 * overrunning the end of the buffer with alignment words.
+	 */
+	if (to_align32 <= n32 - CACHE_LINE_SIZE_IN_WORDS) {
+		int lines_left;
+
+		/* Align out32 mod the cache line size so we can use wh64. */
+		n32 -= to_align32;
+		for (; to_align32 != 0; to_align32--) {
+			*out32 = v32;
+			out32++;
+		}
+
+		/* Use unsigned divide to turn this into a right shift. */
+		lines_left = (unsigned)n32 / CACHE_LINE_SIZE_IN_WORDS;
+
+		do {
+			/* Only wh64 a few lines at a time, so we don't
+			 * exceed the maximum number of victim lines.
+			 */
+			int x = ((lines_left < CHIP_MAX_OUTSTANDING_VICTIMS())
+				  ? lines_left
+				  : CHIP_MAX_OUTSTANDING_VICTIMS());
+			uint32_t *wh = out32;
+			int i = x;
+			int j;
+
+			lines_left -= x;
+
+			do {
+				__insn_wh64(wh);
+				wh += CACHE_LINE_SIZE_IN_WORDS;
+			} while (--i);
+
+			for (j = x * (CACHE_LINE_SIZE_IN_WORDS / 4);
+			     j != 0; j--) {
+				*out32++ = v32;
+				*out32++ = v32;
+				*out32++ = v32;
+				*out32++ = v32;
+			}
+		} while (lines_left != 0);
+
+		/* We processed all full lines above, so only this many
+		 * words remain to be processed.
+		 */
+		n32 &= CACHE_LINE_SIZE_IN_WORDS - 1;
+	}
+
+	/* Now handle any leftover values. */
+	if (n32 != 0) {
+		do {
+			*out32 = v32;
+			out32++;
+		} while (--n32 != 0);
+	}
+
+	return s;
+}
+EXPORT_SYMBOL(memset);
diff --git a/arch/tile/lib/memset_64.c b/arch/tile/lib/memset_64.c
new file mode 100644
index 000000000..03ef69cd7
--- /dev/null
+++ b/arch/tile/lib/memset_64.c
@@ -0,0 +1,142 @@
+/*
+ * Copyright 2011 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/module.h>
+#include <arch/chip.h>
+#include "string-endian.h"
+
+void *memset(void *s, int c, size_t n)
+{
+	uint64_t *out64;
+	int n64, to_align64;
+	uint64_t v64;
+	uint8_t *out8 = s;
+
+	/* Experimentation shows that a trivial tight loop is a win up until
+	 * around a size of 20, where writing a word at a time starts to win.
+	 */
+#define BYTE_CUTOFF 20
+
+#if BYTE_CUTOFF < 7
+	/* This must be at least at least this big, or some code later
+	 * on doesn't work.
+	 */
+#error "BYTE_CUTOFF is too small"
+#endif
+
+	if (n < BYTE_CUTOFF) {
+		/* Strangely, this turns out to be the tightest way to
+		 * write this loop.
+		 */
+		if (n != 0) {
+			do {
+				/* Strangely, combining these into one line
+				 * performs worse.
+				 */
+				*out8 = c;
+				out8++;
+			} while (--n != 0);
+		}
+
+		return s;
+	}
+
+	/* Align 'out8'. We know n >= 7 so this won't write past the end. */
+	while (((uintptr_t) out8 & 7) != 0) {
+		*out8++ = c;
+		--n;
+	}
+
+	/* Align 'n'. */
+	while (n & 7)
+		out8[--n] = c;
+
+	out64 = (uint64_t *) out8;
+	n64 = n >> 3;
+
+	/* Tile input byte out to 64 bits. */
+	v64 = copy_byte(c);
+
+	/* This must be at least 8 or the following loop doesn't work. */
+#define CACHE_LINE_SIZE_IN_DOUBLEWORDS (CHIP_L2_LINE_SIZE() / 8)
+
+	/* Determine how many words we need to emit before the 'out32'
+	 * pointer becomes aligned modulo the cache line size.
+	 */
+	to_align64 = (-((uintptr_t)out64 >> 3)) &
+		(CACHE_LINE_SIZE_IN_DOUBLEWORDS - 1);
+
+	/* Only bother aligning and using wh64 if there is at least
+	 * one full cache line to process.  This check also prevents
+	 * overrunning the end of the buffer with alignment words.
+	 */
+	if (to_align64 <= n64 - CACHE_LINE_SIZE_IN_DOUBLEWORDS) {
+		int lines_left;
+
+		/* Align out64 mod the cache line size so we can use wh64. */
+		n64 -= to_align64;
+		for (; to_align64 != 0; to_align64--) {
+			*out64 = v64;
+			out64++;
+		}
+
+		/* Use unsigned divide to turn this into a right shift. */
+		lines_left = (unsigned)n64 / CACHE_LINE_SIZE_IN_DOUBLEWORDS;
+
+		do {
+			/* Only wh64 a few lines at a time, so we don't
+			 * exceed the maximum number of victim lines.
+			 */
+			int x = ((lines_left < CHIP_MAX_OUTSTANDING_VICTIMS())
+				  ? lines_left
+				  : CHIP_MAX_OUTSTANDING_VICTIMS());
+			uint64_t *wh = out64;
+			int i = x;
+			int j;
+
+			lines_left -= x;
+
+			do {
+				__insn_wh64(wh);
+				wh += CACHE_LINE_SIZE_IN_DOUBLEWORDS;
+			} while (--i);
+
+			for (j = x * (CACHE_LINE_SIZE_IN_DOUBLEWORDS / 4);
+			     j != 0; j--) {
+				*out64++ = v64;
+				*out64++ = v64;
+				*out64++ = v64;
+				*out64++ = v64;
+			}
+		} while (lines_left != 0);
+
+		/* We processed all full lines above, so only this many
+		 * words remain to be processed.
+		 */
+		n64 &= CACHE_LINE_SIZE_IN_DOUBLEWORDS - 1;
+	}
+
+	/* Now handle any leftover values. */
+	if (n64 != 0) {
+		do {
+			*out64 = v64;
+			out64++;
+		} while (--n64 != 0);
+	}
+
+	return s;
+}
+EXPORT_SYMBOL(memset);
diff --git a/arch/tile/lib/spinlock_32.c b/arch/tile/lib/spinlock_32.c
new file mode 100644
index 000000000..b34f79aad
--- /dev/null
+++ b/arch/tile/lib/spinlock_32.c
@@ -0,0 +1,259 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <asm/processor.h>
+#include <arch/spr_def.h>
+
+#include "spinlock_common.h"
+
+void arch_spin_lock(arch_spinlock_t *lock)
+{
+	int my_ticket;
+	int iterations = 0;
+	int delta;
+
+	while ((my_ticket = __insn_tns((void *)&lock->next_ticket)) & 1)
+		delay_backoff(iterations++);
+
+	/* Increment the next ticket number, implicitly releasing tns lock. */
+	lock->next_ticket = my_ticket + TICKET_QUANTUM;
+
+	/* Wait until it's our turn. */
+	while ((delta = my_ticket - lock->current_ticket) != 0)
+		relax((128 / CYCLES_PER_RELAX_LOOP) * delta);
+}
+EXPORT_SYMBOL(arch_spin_lock);
+
+int arch_spin_trylock(arch_spinlock_t *lock)
+{
+	/*
+	 * Grab a ticket; no need to retry if it's busy, we'll just
+	 * treat that the same as "locked", since someone else
+	 * will lock it momentarily anyway.
+	 */
+	int my_ticket = __insn_tns((void *)&lock->next_ticket);
+
+	if (my_ticket == lock->current_ticket) {
+		/* Not currently locked, so lock it by keeping this ticket. */
+		lock->next_ticket = my_ticket + TICKET_QUANTUM;
+		/* Success! */
+		return 1;
+	}
+
+	if (!(my_ticket & 1)) {
+		/* Release next_ticket. */
+		lock->next_ticket = my_ticket;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(arch_spin_trylock);
+
+void arch_spin_unlock_wait(arch_spinlock_t *lock)
+{
+	u32 iterations = 0;
+	while (arch_spin_is_locked(lock))
+		delay_backoff(iterations++);
+}
+EXPORT_SYMBOL(arch_spin_unlock_wait);
+
+/*
+ * The low byte is always reserved to be the marker for a "tns" operation
+ * since the low bit is set to "1" by a tns.  The next seven bits are
+ * zeroes.  The next byte holds the "next" writer value, i.e. the ticket
+ * available for the next task that wants to write.  The third byte holds
+ * the current writer value, i.e. the writer who holds the current ticket.
+ * If current == next == 0, there are no interested writers.
+ */
+#define WR_NEXT_SHIFT   _WR_NEXT_SHIFT
+#define WR_CURR_SHIFT   _WR_CURR_SHIFT
+#define WR_WIDTH        _WR_WIDTH
+#define WR_MASK         ((1 << WR_WIDTH) - 1)
+
+/*
+ * The last eight bits hold the active reader count.  This has to be
+ * zero before a writer can start to write.
+ */
+#define RD_COUNT_SHIFT  _RD_COUNT_SHIFT
+#define RD_COUNT_WIDTH  _RD_COUNT_WIDTH
+#define RD_COUNT_MASK   ((1 << RD_COUNT_WIDTH) - 1)
+
+
+/*
+ * We can get the read lock if everything but the reader bits (which
+ * are in the high part of the word) is zero, i.e. no active or
+ * waiting writers, no tns.
+ *
+ * We guard the tns/store-back with an interrupt critical section to
+ * preserve the semantic that the same read lock can be acquired in an
+ * interrupt context.
+ */
+int arch_read_trylock(arch_rwlock_t *rwlock)
+{
+	u32 val;
+	__insn_mtspr(SPR_INTERRUPT_CRITICAL_SECTION, 1);
+	val = __insn_tns((int *)&rwlock->lock);
+	if (likely((val << _RD_COUNT_WIDTH) == 0)) {
+		val += 1 << RD_COUNT_SHIFT;
+		rwlock->lock = val;
+		__insn_mtspr(SPR_INTERRUPT_CRITICAL_SECTION, 0);
+		BUG_ON(val == 0);  /* we don't expect wraparound */
+		return 1;
+	}
+	if ((val & 1) == 0)
+		rwlock->lock = val;
+	__insn_mtspr(SPR_INTERRUPT_CRITICAL_SECTION, 0);
+	return 0;
+}
+EXPORT_SYMBOL(arch_read_trylock);
+
+/*
+ * Spin doing arch_read_trylock() until we acquire the lock.
+ * ISSUE: This approach can permanently starve readers.  A reader who sees
+ * a writer could instead take a ticket lock (just like a writer would),
+ * and atomically enter read mode (with 1 reader) when it gets the ticket.
+ * This way both readers and writers would always make forward progress
+ * in a finite time.
+ */
+void arch_read_lock(arch_rwlock_t *rwlock)
+{
+	u32 iterations = 0;
+	while (unlikely(!arch_read_trylock(rwlock)))
+		delay_backoff(iterations++);
+}
+EXPORT_SYMBOL(arch_read_lock);
+
+void arch_read_unlock(arch_rwlock_t *rwlock)
+{
+	u32 val, iterations = 0;
+
+	mb();  /* guarantee anything modified under the lock is visible */
+	for (;;) {
+		__insn_mtspr(SPR_INTERRUPT_CRITICAL_SECTION, 1);
+		val = __insn_tns((int *)&rwlock->lock);
+		if (likely((val & 1) == 0)) {
+			rwlock->lock = val - (1 << _RD_COUNT_SHIFT);
+			__insn_mtspr(SPR_INTERRUPT_CRITICAL_SECTION, 0);
+			break;
+		}
+		__insn_mtspr(SPR_INTERRUPT_CRITICAL_SECTION, 0);
+		delay_backoff(iterations++);
+	}
+}
+EXPORT_SYMBOL(arch_read_unlock);
+
+/*
+ * We don't need an interrupt critical section here (unlike for
+ * arch_read_lock) since we should never use a bare write lock where
+ * it could be interrupted by code that could try to re-acquire it.
+ */
+void arch_write_lock(arch_rwlock_t *rwlock)
+{
+	/*
+	 * The trailing underscore on this variable (and curr_ below)
+	 * reminds us that the high bits are garbage; we mask them out
+	 * when we compare them.
+	 */
+	u32 my_ticket_;
+	u32 iterations = 0;
+	u32 val = __insn_tns((int *)&rwlock->lock);
+
+	if (likely(val == 0)) {
+		rwlock->lock = 1 << _WR_NEXT_SHIFT;
+		return;
+	}
+
+	/*
+	 * Wait until there are no readers, then bump up the next
+	 * field and capture the ticket value.
+	 */
+	for (;;) {
+		if (!(val & 1)) {
+			if ((val >> RD_COUNT_SHIFT) == 0)
+				break;
+			rwlock->lock = val;
+		}
+		delay_backoff(iterations++);
+		val = __insn_tns((int *)&rwlock->lock);
+	}
+
+	/* Take out the next ticket and extract my ticket value. */
+	rwlock->lock = __insn_addb(val, 1 << WR_NEXT_SHIFT);
+	my_ticket_ = val >> WR_NEXT_SHIFT;
+
+	/* Wait until the "current" field matches our ticket. */
+	for (;;) {
+		u32 curr_ = val >> WR_CURR_SHIFT;
+		u32 delta = ((my_ticket_ - curr_) & WR_MASK);
+		if (likely(delta == 0))
+			break;
+
+		/* Delay based on how many lock-holders are still out there. */
+		relax((256 / CYCLES_PER_RELAX_LOOP) * delta);
+
+		/*
+		 * Get a non-tns value to check; we don't need to tns
+		 * it ourselves.  Since we're not tns'ing, we retry
+		 * more rapidly to get a valid value.
+		 */
+		while ((val = rwlock->lock) & 1)
+			relax(4);
+	}
+}
+EXPORT_SYMBOL(arch_write_lock);
+
+int arch_write_trylock(arch_rwlock_t *rwlock)
+{
+	u32 val = __insn_tns((int *)&rwlock->lock);
+
+	/*
+	 * If a tns is in progress, or there's a waiting or active locker,
+	 * or active readers, we can't take the lock, so give up.
+	 */
+	if (unlikely(val != 0)) {
+		if (!(val & 1))
+			rwlock->lock = val;
+		return 0;
+	}
+
+	/* Set the "next" field to mark it locked. */
+	rwlock->lock = 1 << _WR_NEXT_SHIFT;
+	return 1;
+}
+EXPORT_SYMBOL(arch_write_trylock);
+
+void arch_write_unlock(arch_rwlock_t *rwlock)
+{
+	u32 val, eq, mask;
+
+	mb();  /* guarantee anything modified under the lock is visible */
+	val = __insn_tns((int *)&rwlock->lock);
+	if (likely(val == (1 << _WR_NEXT_SHIFT))) {
+		rwlock->lock = 0;
+		return;
+	}
+	while (unlikely(val & 1)) {
+		/* Limited backoff since we are the highest-priority task. */
+		relax(4);
+		val = __insn_tns((int *)&rwlock->lock);
+	}
+	mask = 1 << WR_CURR_SHIFT;
+	val = __insn_addb(val, mask);
+	eq = __insn_seqb(val, val << (WR_CURR_SHIFT - WR_NEXT_SHIFT));
+	val = __insn_mz(eq & mask, val);
+	rwlock->lock = val;
+}
+EXPORT_SYMBOL(arch_write_unlock);
diff --git a/arch/tile/lib/spinlock_64.c b/arch/tile/lib/spinlock_64.c
new file mode 100644
index 000000000..d6fb9581e
--- /dev/null
+++ b/arch/tile/lib/spinlock_64.c
@@ -0,0 +1,104 @@
+/*
+ * Copyright 2011 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <asm/processor.h>
+
+#include "spinlock_common.h"
+
+/*
+ * Read the spinlock value without allocating in our cache and without
+ * causing an invalidation to another cpu with a copy of the cacheline.
+ * This is important when we are spinning waiting for the lock.
+ */
+static inline u32 arch_spin_read_noalloc(void *lock)
+{
+	return atomic_cmpxchg((atomic_t *)lock, -1, -1);
+}
+
+/*
+ * Wait until the high bits (current) match my ticket.
+ * If we notice the overflow bit set on entry, we clear it.
+ */
+void arch_spin_lock_slow(arch_spinlock_t *lock, u32 my_ticket)
+{
+	if (unlikely(my_ticket & __ARCH_SPIN_NEXT_OVERFLOW)) {
+		__insn_fetchand4(&lock->lock, ~__ARCH_SPIN_NEXT_OVERFLOW);
+		my_ticket &= ~__ARCH_SPIN_NEXT_OVERFLOW;
+	}
+
+	for (;;) {
+		u32 val = arch_spin_read_noalloc(lock);
+		u32 delta = my_ticket - arch_spin_current(val);
+		if (delta == 0)
+			return;
+		relax((128 / CYCLES_PER_RELAX_LOOP) * delta);
+	}
+}
+EXPORT_SYMBOL(arch_spin_lock_slow);
+
+/*
+ * Check the lock to see if it is plausible, and try to get it with cmpxchg().
+ */
+int arch_spin_trylock(arch_spinlock_t *lock)
+{
+	u32 val = arch_spin_read_noalloc(lock);
+	if (unlikely(arch_spin_current(val) != arch_spin_next(val)))
+		return 0;
+	return cmpxchg(&lock->lock, val, (val + 1) & ~__ARCH_SPIN_NEXT_OVERFLOW)
+		== val;
+}
+EXPORT_SYMBOL(arch_spin_trylock);
+
+void arch_spin_unlock_wait(arch_spinlock_t *lock)
+{
+	u32 iterations = 0;
+	while (arch_spin_is_locked(lock))
+		delay_backoff(iterations++);
+}
+EXPORT_SYMBOL(arch_spin_unlock_wait);
+
+/*
+ * If the read lock fails due to a writer, we retry periodically
+ * until the value is positive and we write our incremented reader count.
+ */
+void __read_lock_failed(arch_rwlock_t *rw)
+{
+	u32 val;
+	int iterations = 0;
+	do {
+		delay_backoff(iterations++);
+		val = __insn_fetchaddgez4(&rw->lock, 1);
+	} while (unlikely(arch_write_val_locked(val)));
+}
+EXPORT_SYMBOL(__read_lock_failed);
+
+/*
+ * If we failed because there were readers, clear the "writer" bit
+ * so we don't block additional readers.  Otherwise, there was another
+ * writer anyway, so our "fetchor" made no difference.  Then wait,
+ * issuing periodic fetchor instructions, till we get the lock.
+ */
+void __write_lock_failed(arch_rwlock_t *rw, u32 val)
+{
+	int iterations = 0;
+	do {
+		if (!arch_write_val_locked(val))
+			val = __insn_fetchand4(&rw->lock, ~__WRITE_LOCK_BIT);
+		delay_backoff(iterations++);
+		val = __insn_fetchor4(&rw->lock, __WRITE_LOCK_BIT);
+	} while (val != 0);
+}
+EXPORT_SYMBOL(__write_lock_failed);
diff --git a/arch/tile/lib/spinlock_common.h b/arch/tile/lib/spinlock_common.h
new file mode 100644
index 000000000..6ac37509f
--- /dev/null
+++ b/arch/tile/lib/spinlock_common.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ * This file is included into spinlock_32.c or _64.c.
+ */
+
+/*
+ * The mfspr in __spinlock_relax() is 5 or 6 cycles plus 2 for loop
+ * overhead.
+ */
+#ifdef __tilegx__
+#define CYCLES_PER_RELAX_LOOP 7
+#else
+#define CYCLES_PER_RELAX_LOOP 8
+#endif
+
+/*
+ * Idle the core for CYCLES_PER_RELAX_LOOP * iterations cycles.
+ */
+static inline void
+relax(int iterations)
+{
+	for (/*above*/; iterations > 0; iterations--)
+		__insn_mfspr(SPR_PASS);
+	barrier();
+}
+
+/* Perform bounded exponential backoff.*/
+static void delay_backoff(int iterations)
+{
+	u32 exponent, loops;
+
+	/*
+	 * 2^exponent is how many times we go around the loop,
+	 * which takes 8 cycles.  We want to start with a 16- to 31-cycle
+	 * loop, so we need to go around minimum 2 = 2^1 times, so we
+	 * bias the original value up by 1.
+	 */
+	exponent = iterations + 1;
+
+	/*
+	 * Don't allow exponent to exceed 7, so we have 128 loops,
+	 * or 1,024 (to 2,047) cycles, as our maximum.
+	 */
+	if (exponent > 8)
+		exponent = 8;
+
+	loops = 1 << exponent;
+
+	/* Add a randomness factor so two cpus never get in lock step. */
+	loops += __insn_crc32_32(stack_pointer, get_cycles_low()) &
+		(loops - 1);
+
+	relax(loops);
+}
diff --git a/arch/tile/lib/strchr_32.c b/arch/tile/lib/strchr_32.c
new file mode 100644
index 000000000..841fe6963
--- /dev/null
+++ b/arch/tile/lib/strchr_32.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/module.h>
+
+char *strchr(const char *s, int c)
+{
+	int z, g;
+
+	/* Get an aligned pointer. */
+	const uintptr_t s_int = (uintptr_t) s;
+	const uint32_t *p = (const uint32_t *)(s_int & -4);
+
+	/* Create four copies of the byte for which we are looking. */
+	const uint32_t goal = 0x01010101 * (uint8_t) c;
+
+	/* Read the first aligned word, but force bytes before the string to
+	 * match neither zero nor goal (we make sure the high bit of each
+	 * byte is 1, and the low 7 bits are all the opposite of the goal
+	 * byte).
+	 *
+	 * Note that this shift count expression works because we know shift
+	 * counts are taken mod 32.
+	 */
+	const uint32_t before_mask = (1 << (s_int << 3)) - 1;
+	uint32_t v = (*p | before_mask) ^ (goal & __insn_shrib(before_mask, 1));
+
+	uint32_t zero_matches, goal_matches;
+	while (1) {
+		/* Look for a terminating '\0'. */
+		zero_matches = __insn_seqb(v, 0);
+
+		/* Look for the goal byte. */
+		goal_matches = __insn_seqb(v, goal);
+
+		if (__builtin_expect(zero_matches | goal_matches, 0))
+			break;
+
+		v = *++p;
+	}
+
+	z = __insn_ctz(zero_matches);
+	g = __insn_ctz(goal_matches);
+
+	/* If we found c before '\0' we got a match. Note that if c == '\0'
+	 * then g == z, and we correctly return the address of the '\0'
+	 * rather than NULL.
+	 */
+	return (g <= z) ? ((char *)p) + (g >> 3) : NULL;
+}
+EXPORT_SYMBOL(strchr);
diff --git a/arch/tile/lib/strchr_64.c b/arch/tile/lib/strchr_64.c
new file mode 100644
index 000000000..fe6e31c06
--- /dev/null
+++ b/arch/tile/lib/strchr_64.c
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2011 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/module.h>
+#include "string-endian.h"
+
+char *strchr(const char *s, int c)
+{
+	int z, g;
+
+	/* Get an aligned pointer. */
+	const uintptr_t s_int = (uintptr_t) s;
+	const uint64_t *p = (const uint64_t *)(s_int & -8);
+
+	/* Create eight copies of the byte for which we are looking. */
+	const uint64_t goal = copy_byte(c);
+
+	/* Read the first aligned word, but force bytes before the string to
+	 * match neither zero nor goal (we make sure the high bit of each
+	 * byte is 1, and the low 7 bits are all the opposite of the goal
+	 * byte).
+	 */
+	const uint64_t before_mask = MASK(s_int);
+	uint64_t v = (*p | before_mask) ^ (goal & __insn_v1shrui(before_mask, 1));
+
+	uint64_t zero_matches, goal_matches;
+	while (1) {
+		/* Look for a terminating '\0'. */
+		zero_matches = __insn_v1cmpeqi(v, 0);
+
+		/* Look for the goal byte. */
+		goal_matches = __insn_v1cmpeq(v, goal);
+
+		if (__builtin_expect((zero_matches | goal_matches) != 0, 0))
+			break;
+
+		v = *++p;
+	}
+
+	z = CFZ(zero_matches);
+	g = CFZ(goal_matches);
+
+	/* If we found c before '\0' we got a match. Note that if c == '\0'
+	 * then g == z, and we correctly return the address of the '\0'
+	 * rather than NULL.
+	 */
+	return (g <= z) ? ((char *)p) + (g >> 3) : NULL;
+}
+EXPORT_SYMBOL(strchr);
diff --git a/arch/tile/lib/string-endian.h b/arch/tile/lib/string-endian.h
new file mode 100644
index 000000000..2e49cbfe9
--- /dev/null
+++ b/arch/tile/lib/string-endian.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2013 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ *
+ * Provide a mask based on the pointer alignment that
+ * sets up non-zero bytes before the beginning of the string.
+ * The MASK expression works because shift counts are taken mod 64.
+ * Also, specify how to count "first" and "last" bits
+ * when the bits have been read as a word.
+ */
+
+#include <asm/byteorder.h>
+
+#ifdef __LITTLE_ENDIAN
+#define MASK(x) (__insn_shl(1ULL, (x << 3)) - 1)
+#define NULMASK(x) ((2ULL << x) - 1)
+#define CFZ(x) __insn_ctz(x)
+#define REVCZ(x) __insn_clz(x)
+#else
+#define MASK(x) (__insn_shl(-2LL, ((-x << 3) - 1)))
+#define NULMASK(x) (-2LL << (63 - x))
+#define CFZ(x) __insn_clz(x)
+#define REVCZ(x) __insn_ctz(x)
+#endif
+
+/*
+ * Create eight copies of the byte in a uint64_t.  Byte Shuffle uses
+ * the bytes of srcB as the index into the dest vector to select a
+ * byte.  With all indices of zero, the first byte is copied into all
+ * the other bytes.
+ */
+static inline uint64_t copy_byte(uint8_t byte)
+{
+	return __insn_shufflebytes(byte, 0, 0);
+}
diff --git a/arch/tile/lib/strlen_32.c b/arch/tile/lib/strlen_32.c
new file mode 100644
index 000000000..f26f88e11
--- /dev/null
+++ b/arch/tile/lib/strlen_32.c
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/module.h>
+
+size_t strlen(const char *s)
+{
+	/* Get an aligned pointer. */
+	const uintptr_t s_int = (uintptr_t) s;
+	const uint32_t *p = (const uint32_t *)(s_int & -4);
+
+	/* Read the first word, but force bytes before the string to be nonzero.
+	 * This expression works because we know shift counts are taken mod 32.
+	 */
+	uint32_t v = *p | ((1 << (s_int << 3)) - 1);
+
+	uint32_t bits;
+	while ((bits = __insn_seqb(v, 0)) == 0)
+		v = *++p;
+
+	return ((const char *)p) + (__insn_ctz(bits) >> 3) - s;
+}
+EXPORT_SYMBOL(strlen);
diff --git a/arch/tile/lib/strlen_64.c b/arch/tile/lib/strlen_64.c
new file mode 100644
index 000000000..9583fc336
--- /dev/null
+++ b/arch/tile/lib/strlen_64.c
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2011 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/module.h>
+#include "string-endian.h"
+
+size_t strlen(const char *s)
+{
+	/* Get an aligned pointer. */
+	const uintptr_t s_int = (uintptr_t) s;
+	const uint64_t *p = (const uint64_t *)(s_int & -8);
+
+	/* Read and MASK the first word. */
+	uint64_t v = *p | MASK(s_int);
+
+	uint64_t bits;
+	while ((bits = __insn_v1cmpeqi(v, 0)) == 0)
+		v = *++p;
+
+	return ((const char *)p) + (CFZ(bits) >> 3) - s;
+}
+EXPORT_SYMBOL(strlen);
diff --git a/arch/tile/lib/strnlen_32.c b/arch/tile/lib/strnlen_32.c
new file mode 100644
index 000000000..1434141d9
--- /dev/null
+++ b/arch/tile/lib/strnlen_32.c
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2013 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/module.h>
+
+size_t strnlen(const char *s, size_t count)
+{
+	/* Get an aligned pointer. */
+	const uintptr_t s_int = (uintptr_t) s;
+	const uint32_t *p = (const uint32_t *)(s_int & -4);
+	size_t bytes_read = sizeof(*p) - (s_int & (sizeof(*p) - 1));
+	size_t len;
+	uint32_t v, bits;
+
+	/* Avoid page fault risk by not reading any bytes when count is 0. */
+	if (count == 0)
+		return 0;
+
+	/* Read first word, but force bytes before the string to be nonzero. */
+	v = *p | ((1 << ((s_int << 3) & 31)) - 1);
+
+	while ((bits = __insn_seqb(v, 0)) == 0) {
+		if (bytes_read >= count) {
+			/* Read COUNT bytes and didn't find the terminator. */
+			return count;
+		}
+		v = *++p;
+		bytes_read += sizeof(v);
+	}
+
+	len = ((const char *) p) + (__insn_ctz(bits) >> 3) - s;
+	return (len < count ? len : count);
+}
+EXPORT_SYMBOL(strnlen);
diff --git a/arch/tile/lib/strnlen_64.c b/arch/tile/lib/strnlen_64.c
new file mode 100644
index 000000000..2e8de6a51
--- /dev/null
+++ b/arch/tile/lib/strnlen_64.c
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2013 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/module.h>
+#include "string-endian.h"
+
+size_t strnlen(const char *s, size_t count)
+{
+	/* Get an aligned pointer. */
+	const uintptr_t s_int = (uintptr_t) s;
+	const uint64_t *p = (const uint64_t *)(s_int & -8);
+	size_t bytes_read = sizeof(*p) - (s_int & (sizeof(*p) - 1));
+	size_t len;
+	uint64_t v, bits;
+
+	/* Avoid page fault risk by not reading any bytes when count is 0. */
+	if (count == 0)
+		return 0;
+
+	/* Read and MASK the first word. */
+	v = *p | MASK(s_int);
+
+	while ((bits = __insn_v1cmpeqi(v, 0)) == 0) {
+		if (bytes_read >= count) {
+			/* Read COUNT bytes and didn't find the terminator. */
+			return count;
+		}
+		v = *++p;
+		bytes_read += sizeof(v);
+	}
+
+	len = ((const char *) p) + (CFZ(bits) >> 3) - s;
+	return (len < count ? len : count);
+}
+EXPORT_SYMBOL(strnlen);
diff --git a/arch/tile/lib/uaccess.c b/arch/tile/lib/uaccess.c
new file mode 100644
index 000000000..030abe3ee
--- /dev/null
+++ b/arch/tile/lib/uaccess.c
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/uaccess.h>
+#include <linux/module.h>
+
+int __range_ok(unsigned long addr, unsigned long size)
+{
+	unsigned long limit = current_thread_info()->addr_limit.seg;
+	return !((addr < limit && size <= limit - addr) ||
+		 is_arch_mappable_range(addr, size));
+}
+EXPORT_SYMBOL(__range_ok);
diff --git a/arch/tile/lib/usercopy_32.S b/arch/tile/lib/usercopy_32.S
new file mode 100644
index 000000000..1bc162224
--- /dev/null
+++ b/arch/tile/lib/usercopy_32.S
@@ -0,0 +1,135 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/linkage.h>
+#include <asm/errno.h>
+#include <asm/cache.h>
+#include <arch/chip.h>
+
+/* Access user memory, but use MMU to avoid propagating kernel exceptions. */
+
+/*
+ * strnlen_user_asm takes the pointer in r0, and the length bound in r1.
+ * It returns the length, including the terminating NUL, or zero on exception.
+ * If length is greater than the bound, returns one plus the bound.
+ */
+STD_ENTRY(strnlen_user_asm)
+	{ bz r1, 2f; addi r3, r0, -1 }  /* bias down to include NUL */
+1:      { lb_u r4, r0; addi r1, r1, -1 }
+	bz r4, 2f
+	{ bnzt r1, 1b; addi r0, r0, 1 }
+2:      { sub r0, r0, r3; jrp lr }
+	STD_ENDPROC(strnlen_user_asm)
+	.pushsection .fixup,"ax"
+strnlen_user_fault:
+	{ move r0, zero; jrp lr }
+	ENDPROC(strnlen_user_fault)
+	.section __ex_table,"a"
+	.align 4
+	.word 1b, strnlen_user_fault
+	.popsection
+
+/*
+ * strncpy_from_user_asm takes the kernel target pointer in r0,
+ * the userspace source pointer in r1, and the length bound (including
+ * the trailing NUL) in r2.  On success, it returns the string length
+ * (not including the trailing NUL), or -EFAULT on failure.
+ */
+STD_ENTRY(strncpy_from_user_asm)
+	{ bz r2, 2f; move r3, r0 }
+1:	{ lb_u r4, r1; addi r1, r1, 1; addi r2, r2, -1 }
+	{ sb r0, r4; addi r0, r0, 1 }
+	bz r4, 2f
+	bnzt r2, 1b
+	{ sub r0, r0, r3; jrp lr }
+2:	addi r0, r0, -1   /* don't count the trailing NUL */
+	{ sub r0, r0, r3; jrp lr }
+	STD_ENDPROC(strncpy_from_user_asm)
+	.pushsection .fixup,"ax"
+strncpy_from_user_fault:
+	{ movei r0, -EFAULT; jrp lr }
+	ENDPROC(strncpy_from_user_fault)
+	.section __ex_table,"a"
+	.align 4
+	.word 1b, strncpy_from_user_fault
+	.popsection
+
+/*
+ * clear_user_asm takes the user target address in r0 and the
+ * number of bytes to zero in r1.
+ * It returns the number of uncopiable bytes (hopefully zero) in r0.
+ * Note that we don't use a separate .fixup section here since we fall
+ * through into the "fixup" code as the last straight-line bundle anyway.
+ */
+STD_ENTRY(clear_user_asm)
+	{ bz r1, 2f; or r2, r0, r1 }
+	andi r2, r2, 3
+	bzt r2, .Lclear_aligned_user_asm
+1:      { sb r0, zero; addi r0, r0, 1; addi r1, r1, -1 }
+	bnzt r1, 1b
+2:      { move r0, r1; jrp lr }
+	.pushsection __ex_table,"a"
+	.align 4
+	.word 1b, 2b
+	.popsection
+
+.Lclear_aligned_user_asm:
+1:      { sw r0, zero; addi r0, r0, 4; addi r1, r1, -4 }
+	bnzt r1, 1b
+2:      { move r0, r1; jrp lr }
+	STD_ENDPROC(clear_user_asm)
+	.pushsection __ex_table,"a"
+	.align 4
+	.word 1b, 2b
+	.popsection
+
+/*
+ * flush_user_asm takes the user target address in r0 and the
+ * number of bytes to flush in r1.
+ * It returns the number of unflushable bytes (hopefully zero) in r0.
+ */
+STD_ENTRY(flush_user_asm)
+	bz r1, 2f
+	{ movei r2, L2_CACHE_BYTES; add r1, r0, r1 }
+	{ sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 }
+	{ and r0, r0, r2; and r1, r1, r2 }
+	{ sub r1, r1, r0 }
+1:      { flush r0; addi r1, r1, -CHIP_FLUSH_STRIDE() }
+	{ addi r0, r0, CHIP_FLUSH_STRIDE(); bnzt r1, 1b }
+2:      { move r0, r1; jrp lr }
+	STD_ENDPROC(flush_user_asm)
+	.pushsection __ex_table,"a"
+	.align 4
+	.word 1b, 2b
+	.popsection
+
+/*
+ * finv_user_asm takes the user target address in r0 and the
+ * number of bytes to flush-invalidate in r1.
+ * It returns the number of not finv'able bytes (hopefully zero) in r0.
+ */
+STD_ENTRY(finv_user_asm)
+	bz r1, 2f
+	{ movei r2, L2_CACHE_BYTES; add r1, r0, r1 }
+	{ sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 }
+	{ and r0, r0, r2; and r1, r1, r2 }
+	{ sub r1, r1, r0 }
+1:      { finv r0; addi r1, r1, -CHIP_FINV_STRIDE() }
+	{ addi r0, r0, CHIP_FINV_STRIDE(); bnzt r1, 1b }
+2:      { move r0, r1; jrp lr }
+	STD_ENDPROC(finv_user_asm)
+	.pushsection __ex_table,"a"
+	.align 4
+	.word 1b, 2b
+	.popsection
diff --git a/arch/tile/lib/usercopy_64.S b/arch/tile/lib/usercopy_64.S
new file mode 100644
index 000000000..b3b31a330
--- /dev/null
+++ b/arch/tile/lib/usercopy_64.S
@@ -0,0 +1,135 @@
+/*
+ * Copyright 2011 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/linkage.h>
+#include <asm/errno.h>
+#include <asm/cache.h>
+#include <arch/chip.h>
+
+/* Access user memory, but use MMU to avoid propagating kernel exceptions. */
+
+/*
+ * strnlen_user_asm takes the pointer in r0, and the length bound in r1.
+ * It returns the length, including the terminating NUL, or zero on exception.
+ * If length is greater than the bound, returns one plus the bound.
+ */
+STD_ENTRY(strnlen_user_asm)
+	{ beqz r1, 2f; addi r3, r0, -1 }  /* bias down to include NUL */
+1:      { ld1u r4, r0; addi r1, r1, -1 }
+	beqz r4, 2f
+	{ bnezt r1, 1b; addi r0, r0, 1 }
+2:      { sub r0, r0, r3; jrp lr }
+	STD_ENDPROC(strnlen_user_asm)
+	.pushsection .fixup,"ax"
+strnlen_user_fault:
+	{ move r0, zero; jrp lr }
+	ENDPROC(strnlen_user_fault)
+	.section __ex_table,"a"
+	.align 8
+	.quad 1b, strnlen_user_fault
+	.popsection
+
+/*
+ * strncpy_from_user_asm takes the kernel target pointer in r0,
+ * the userspace source pointer in r1, and the length bound (including
+ * the trailing NUL) in r2.  On success, it returns the string length
+ * (not including the trailing NUL), or -EFAULT on failure.
+ */
+STD_ENTRY(strncpy_from_user_asm)
+	{ beqz r2, 2f; move r3, r0 }
+1:	{ ld1u r4, r1; addi r1, r1, 1; addi r2, r2, -1 }
+	{ st1 r0, r4; addi r0, r0, 1 }
+	beqz r4, 2f
+	bnezt r2, 1b
+	{ sub r0, r0, r3; jrp lr }
+2:	addi r0, r0, -1   /* don't count the trailing NUL */
+	{ sub r0, r0, r3; jrp lr }
+	STD_ENDPROC(strncpy_from_user_asm)
+	.pushsection .fixup,"ax"
+strncpy_from_user_fault:
+	{ movei r0, -EFAULT; jrp lr }
+	ENDPROC(strncpy_from_user_fault)
+	.section __ex_table,"a"
+	.align 8
+	.quad 1b, strncpy_from_user_fault
+	.popsection
+
+/*
+ * clear_user_asm takes the user target address in r0 and the
+ * number of bytes to zero in r1.
+ * It returns the number of uncopiable bytes (hopefully zero) in r0.
+ * Note that we don't use a separate .fixup section here since we fall
+ * through into the "fixup" code as the last straight-line bundle anyway.
+ */
+STD_ENTRY(clear_user_asm)
+	{ beqz r1, 2f; or r2, r0, r1 }
+	andi r2, r2, 7
+	beqzt r2, .Lclear_aligned_user_asm
+1:      { st1 r0, zero; addi r0, r0, 1; addi r1, r1, -1 }
+	bnezt r1, 1b
+2:      { move r0, r1; jrp lr }
+	.pushsection __ex_table,"a"
+	.align 8
+	.quad 1b, 2b
+	.popsection
+
+.Lclear_aligned_user_asm:
+1:      { st r0, zero; addi r0, r0, 8; addi r1, r1, -8 }
+	bnezt r1, 1b
+2:      { move r0, r1; jrp lr }
+	STD_ENDPROC(clear_user_asm)
+	.pushsection __ex_table,"a"
+	.align 8
+	.quad 1b, 2b
+	.popsection
+
+/*
+ * flush_user_asm takes the user target address in r0 and the
+ * number of bytes to flush in r1.
+ * It returns the number of unflushable bytes (hopefully zero) in r0.
+ */
+STD_ENTRY(flush_user_asm)
+	beqz r1, 2f
+	{ movei r2, L2_CACHE_BYTES; add r1, r0, r1 }
+	{ sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 }
+	{ and r0, r0, r2; and r1, r1, r2 }
+	{ sub r1, r1, r0 }
+1:      { flush r0; addi r1, r1, -CHIP_FLUSH_STRIDE() }
+	{ addi r0, r0, CHIP_FLUSH_STRIDE(); bnezt r1, 1b }
+2:      { move r0, r1; jrp lr }
+	STD_ENDPROC(flush_user_asm)
+	.pushsection __ex_table,"a"
+	.align 8
+	.quad 1b, 2b
+	.popsection
+
+/*
+ * finv_user_asm takes the user target address in r0 and the
+ * number of bytes to flush-invalidate in r1.
+ * It returns the number of not finv'able bytes (hopefully zero) in r0.
+ */
+STD_ENTRY(finv_user_asm)
+	beqz r1, 2f
+	{ movei r2, L2_CACHE_BYTES; add r1, r0, r1 }
+	{ sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 }
+	{ and r0, r0, r2; and r1, r1, r2 }
+	{ sub r1, r1, r0 }
+1:      { finv r0; addi r1, r1, -CHIP_FINV_STRIDE() }
+	{ addi r0, r0, CHIP_FINV_STRIDE(); bnezt r1, 1b }
+2:      { move r0, r1; jrp lr }
+	STD_ENDPROC(finv_user_asm)
+	.pushsection __ex_table,"a"
+	.align 8
+	.quad 1b, 2b
+	.popsection