Initial import

1 files changed, 365 insertions, 0 deletions

diff --git a/arch/sh/kernel/cpu/init.c b/arch/sh/kernel/cpu/init.c
new file mode 100644
index 000000000..0d7360d54
--- /dev/null
+++ b/arch/sh/kernel/cpu/init.c
@@ -0,0 +1,365 @@
+/*
+ * arch/sh/kernel/cpu/init.c
+ *
+ * CPU init code
+ *
+ * Copyright (C) 2002 - 2009  Paul Mundt
+ * Copyright (C) 2003  Richard Curnow
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/log2.h>
+#include <asm/mmu_context.h>
+#include <asm/processor.h>
+#include <asm/uaccess.h>
+#include <asm/page.h>
+#include <asm/cacheflush.h>
+#include <asm/cache.h>
+#include <asm/elf.h>
+#include <asm/io.h>
+#include <asm/smp.h>
+#include <asm/sh_bios.h>
+#include <asm/setup.h>
+
+#ifdef CONFIG_SH_FPU
+#define cpu_has_fpu	1
+#else
+#define cpu_has_fpu	0
+#endif
+
+#ifdef CONFIG_SH_DSP
+#define cpu_has_dsp	1
+#else
+#define cpu_has_dsp	0
+#endif
+
+/*
+ * Generic wrapper for command line arguments to disable on-chip
+ * peripherals (nofpu, nodsp, and so forth).
+ */
+#define onchip_setup(x)					\
+static int x##_disabled = !cpu_has_##x;			\
+							\
+static int x##_setup(char *opts)			\
+{							\
+	x##_disabled = 1;				\
+	return 1;					\
+}							\
+__setup("no" __stringify(x), x##_setup);
+
+onchip_setup(fpu);
+onchip_setup(dsp);
+
+#ifdef CONFIG_SPECULATIVE_EXECUTION
+#define CPUOPM		0xff2f0000
+#define CPUOPM_RABD	(1 << 5)
+
+static void speculative_execution_init(void)
+{
+	/* Clear RABD */
+	__raw_writel(__raw_readl(CPUOPM) & ~CPUOPM_RABD, CPUOPM);
+
+	/* Flush the update */
+	(void)__raw_readl(CPUOPM);
+	ctrl_barrier();
+}
+#else
+#define speculative_execution_init()	do { } while (0)
+#endif
+
+#ifdef CONFIG_CPU_SH4A
+#define EXPMASK			0xff2f0004
+#define EXPMASK_RTEDS		(1 << 0)
+#define EXPMASK_BRDSSLP		(1 << 1)
+#define EXPMASK_MMCAW		(1 << 4)
+
+static void expmask_init(void)
+{
+	unsigned long expmask = __raw_readl(EXPMASK);
+
+	/*
+	 * Future proofing.
+	 *
+	 * Disable support for slottable sleep instruction, non-nop
+	 * instructions in the rte delay slot, and associative writes to
+	 * the memory-mapped cache array.
+	 */
+	expmask &= ~(EXPMASK_RTEDS | EXPMASK_BRDSSLP | EXPMASK_MMCAW);
+
+	__raw_writel(expmask, EXPMASK);
+	ctrl_barrier();
+}
+#else
+#define expmask_init()	do { } while (0)
+#endif
+
+/* 2nd-level cache init */
+void __attribute__ ((weak)) l2_cache_init(void)
+{
+}
+
+/*
+ * Generic first-level cache init
+ */
+#ifdef CONFIG_SUPERH32
+static void cache_init(void)
+{
+	unsigned long ccr, flags;
+
+	jump_to_uncached();
+	ccr = __raw_readl(SH_CCR);
+
+	/*
+	 * At this point we don't know whether the cache is enabled or not - a
+	 * bootloader may have enabled it.  There are at least 2 things that
+	 * could be dirty in the cache at this point:
+	 * 1. kernel command line set up by boot loader
+	 * 2. spilled registers from the prolog of this function
+	 * => before re-initialising the cache, we must do a purge of the whole
+	 * cache out to memory for safety.  As long as nothing is spilled
+	 * during the loop to lines that have already been done, this is safe.
+	 * - RPC
+	 */
+	if (ccr & CCR_CACHE_ENABLE) {
+		unsigned long ways, waysize, addrstart;
+
+		waysize = current_cpu_data.dcache.sets;
+
+#ifdef CCR_CACHE_ORA
+		/*
+		 * If the OC is already in RAM mode, we only have
+		 * half of the entries to flush..
+		 */
+		if (ccr & CCR_CACHE_ORA)
+			waysize >>= 1;
+#endif
+
+		waysize <<= current_cpu_data.dcache.entry_shift;
+
+#ifdef CCR_CACHE_EMODE
+		/* If EMODE is not set, we only have 1 way to flush. */
+		if (!(ccr & CCR_CACHE_EMODE))
+			ways = 1;
+		else
+#endif
+			ways = current_cpu_data.dcache.ways;
+
+		addrstart = CACHE_OC_ADDRESS_ARRAY;
+		do {
+			unsigned long addr;
+
+			for (addr = addrstart;
+			     addr < addrstart + waysize;
+			     addr += current_cpu_data.dcache.linesz)
+				__raw_writel(0, addr);
+
+			addrstart += current_cpu_data.dcache.way_incr;
+		} while (--ways);
+	}
+
+	/*
+	 * Default CCR values .. enable the caches
+	 * and invalidate them immediately..
+	 */
+	flags = CCR_CACHE_ENABLE | CCR_CACHE_INVALIDATE;
+
+#ifdef CCR_CACHE_EMODE
+	/* Force EMODE if possible */
+	if (current_cpu_data.dcache.ways > 1)
+		flags |= CCR_CACHE_EMODE;
+	else
+		flags &= ~CCR_CACHE_EMODE;
+#endif
+
+#if defined(CONFIG_CACHE_WRITETHROUGH)
+	/* Write-through */
+	flags |= CCR_CACHE_WT;
+#elif defined(CONFIG_CACHE_WRITEBACK)
+	/* Write-back */
+	flags |= CCR_CACHE_CB;
+#else
+	/* Off */
+	flags &= ~CCR_CACHE_ENABLE;
+#endif
+
+	l2_cache_init();
+
+	__raw_writel(flags, SH_CCR);
+	back_to_cached();
+}
+#else
+#define cache_init()	do { } while (0)
+#endif
+
+#define CSHAPE(totalsize, linesize, assoc) \
+	((totalsize & ~0xff) | (linesize << 4) | assoc)
+
+#define CACHE_DESC_SHAPE(desc)	\
+	CSHAPE((desc).way_size * (desc).ways, ilog2((desc).linesz), (desc).ways)
+
+static void detect_cache_shape(void)
+{
+	l1d_cache_shape = CACHE_DESC_SHAPE(current_cpu_data.dcache);
+
+	if (current_cpu_data.dcache.flags & SH_CACHE_COMBINED)
+		l1i_cache_shape = l1d_cache_shape;
+	else
+		l1i_cache_shape = CACHE_DESC_SHAPE(current_cpu_data.icache);
+
+	if (current_cpu_data.flags & CPU_HAS_L2_CACHE)
+		l2_cache_shape = CACHE_DESC_SHAPE(current_cpu_data.scache);
+	else
+		l2_cache_shape = -1; /* No S-cache */
+}
+
+static void fpu_init(void)
+{
+	/* Disable the FPU */
+	if (fpu_disabled && (current_cpu_data.flags & CPU_HAS_FPU)) {
+		printk("FPU Disabled\n");
+		current_cpu_data.flags &= ~CPU_HAS_FPU;
+	}
+
+	disable_fpu();
+	clear_used_math();
+}
+
+#ifdef CONFIG_SH_DSP
+static void release_dsp(void)
+{
+	unsigned long sr;
+
+	/* Clear SR.DSP bit */
+	__asm__ __volatile__ (
+		"stc\tsr, %0\n\t"
+		"and\t%1, %0\n\t"
+		"ldc\t%0, sr\n\t"
+		: "=&r" (sr)
+		: "r" (~SR_DSP)
+	);
+}
+
+static void dsp_init(void)
+{
+	unsigned long sr;
+
+	/*
+	 * Set the SR.DSP bit, wait for one instruction, and then read
+	 * back the SR value.
+	 */
+	__asm__ __volatile__ (
+		"stc\tsr, %0\n\t"
+		"or\t%1, %0\n\t"
+		"ldc\t%0, sr\n\t"
+		"nop\n\t"
+		"stc\tsr, %0\n\t"
+		: "=&r" (sr)
+		: "r" (SR_DSP)
+	);
+
+	/* If the DSP bit is still set, this CPU has a DSP */
+	if (sr & SR_DSP)
+		current_cpu_data.flags |= CPU_HAS_DSP;
+
+	/* Disable the DSP */
+	if (dsp_disabled && (current_cpu_data.flags & CPU_HAS_DSP)) {
+		printk("DSP Disabled\n");
+		current_cpu_data.flags &= ~CPU_HAS_DSP;
+	}
+
+	/* Now that we've determined the DSP status, clear the DSP bit. */
+	release_dsp();
+}
+#else
+static inline void dsp_init(void) { }
+#endif /* CONFIG_SH_DSP */
+
+/**
+ * cpu_init
+ *
+ * This is our initial entry point for each CPU, and is invoked on the
+ * boot CPU prior to calling start_kernel(). For SMP, a combination of
+ * this and start_secondary() will bring up each processor to a ready
+ * state prior to hand forking the idle loop.
+ *
+ * We do all of the basic processor init here, including setting up
+ * the caches, FPU, DSP, etc. By the time start_kernel() is hit (and
+ * subsequently platform_setup()) things like determining the CPU
+ * subtype and initial configuration will all be done.
+ *
+ * Each processor family is still responsible for doing its own probing
+ * and cache configuration in cpu_probe().
+ */
+asmlinkage void cpu_init(void)
+{
+	current_thread_info()->cpu = hard_smp_processor_id();
+
+	/* First, probe the CPU */
+	cpu_probe();
+
+	if (current_cpu_data.type == CPU_SH_NONE)
+		panic("Unknown CPU");
+
+	/* First setup the rest of the I-cache info */
+	current_cpu_data.icache.entry_mask = current_cpu_data.icache.way_incr -
+				      current_cpu_data.icache.linesz;
+
+	current_cpu_data.icache.way_size = current_cpu_data.icache.sets *
+				    current_cpu_data.icache.linesz;
+
+	/* And the D-cache too */
+	current_cpu_data.dcache.entry_mask = current_cpu_data.dcache.way_incr -
+				      current_cpu_data.dcache.linesz;
+
+	current_cpu_data.dcache.way_size = current_cpu_data.dcache.sets *
+				    current_cpu_data.dcache.linesz;
+
+	/* Init the cache */
+	cache_init();
+
+	if (raw_smp_processor_id() == 0) {
+		shm_align_mask = max_t(unsigned long,
+				       current_cpu_data.dcache.way_size - 1,
+				       PAGE_SIZE - 1);
+
+		/* Boot CPU sets the cache shape */
+		detect_cache_shape();
+	}
+
+	fpu_init();
+	dsp_init();
+
+	/*
+	 * Initialize the per-CPU ASID cache very early, since the
+	 * TLB flushing routines depend on this being setup.
+	 */
+	current_cpu_data.asid_cache = NO_CONTEXT;
+
+	current_cpu_data.phys_bits = __in_29bit_mode() ? 29 : 32;
+
+	speculative_execution_init();
+	expmask_init();
+
+	/* Do the rest of the boot processor setup */
+	if (raw_smp_processor_id() == 0) {
+		/* Save off the BIOS VBR, if there is one */
+		sh_bios_vbr_init();
+
+		/*
+		 * Setup VBR for boot CPU. Secondary CPUs do this through
+		 * start_secondary().
+		 */
+		per_cpu_trap_init();
+
+		/*
+		 * Boot processor to setup the FP and extended state
+		 * context info.
+		 */
+		init_thread_xstate();
+	}
+}