Initial import

1 files changed, 1556 insertions, 0 deletions

diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
new file mode 100644
index 000000000..fda236f90
--- /dev/null
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -0,0 +1,1556 @@
+/*
+ * PowerPC64 port by Mike Corrigan and Dave Engebretsen
+ *   {mikejc|engebret}@us.ibm.com
+ *
+ *    Copyright (c) 2000 Mike Corrigan <mikejc@us.ibm.com>
+ *
+ * SMP scalability work:
+ *    Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
+ * 
+ *    Module name: htab.c
+ *
+ *    Description:
+ *      PowerPC Hashed Page Table functions
+ *
+ * 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; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#undef DEBUG
+#undef DEBUG_LOW
+
+#include <linux/spinlock.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/proc_fs.h>
+#include <linux/stat.h>
+#include <linux/sysctl.h>
+#include <linux/export.h>
+#include <linux/ctype.h>
+#include <linux/cache.h>
+#include <linux/init.h>
+#include <linux/signal.h>
+#include <linux/memblock.h>
+#include <linux/context_tracking.h>
+
+#include <asm/processor.h>
+#include <asm/pgtable.h>
+#include <asm/mmu.h>
+#include <asm/mmu_context.h>
+#include <asm/page.h>
+#include <asm/types.h>
+#include <asm/uaccess.h>
+#include <asm/machdep.h>
+#include <asm/prom.h>
+#include <asm/tlbflush.h>
+#include <asm/io.h>
+#include <asm/eeh.h>
+#include <asm/tlb.h>
+#include <asm/cacheflush.h>
+#include <asm/cputable.h>
+#include <asm/sections.h>
+#include <asm/copro.h>
+#include <asm/udbg.h>
+#include <asm/code-patching.h>
+#include <asm/fadump.h>
+#include <asm/firmware.h>
+#include <asm/tm.h>
+
+#ifdef DEBUG
+#define DBG(fmt...) udbg_printf(fmt)
+#else
+#define DBG(fmt...)
+#endif
+
+#ifdef DEBUG_LOW
+#define DBG_LOW(fmt...) udbg_printf(fmt)
+#else
+#define DBG_LOW(fmt...)
+#endif
+
+#define KB (1024)
+#define MB (1024*KB)
+#define GB (1024L*MB)
+
+/*
+ * Note:  pte   --> Linux PTE
+ *        HPTE  --> PowerPC Hashed Page Table Entry
+ *
+ * Execution context:
+ *   htab_initialize is called with the MMU off (of course), but
+ *   the kernel has been copied down to zero so it can directly
+ *   reference global data.  At this point it is very difficult
+ *   to print debug info.
+ *
+ */
+
+#ifdef CONFIG_U3_DART
+extern unsigned long dart_tablebase;
+#endif /* CONFIG_U3_DART */
+
+static unsigned long _SDR1;
+struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
+EXPORT_SYMBOL_GPL(mmu_psize_defs);
+
+struct hash_pte *htab_address;
+unsigned long htab_size_bytes;
+unsigned long htab_hash_mask;
+EXPORT_SYMBOL_GPL(htab_hash_mask);
+int mmu_linear_psize = MMU_PAGE_4K;
+EXPORT_SYMBOL_GPL(mmu_linear_psize);
+int mmu_virtual_psize = MMU_PAGE_4K;
+int mmu_vmalloc_psize = MMU_PAGE_4K;
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+int mmu_vmemmap_psize = MMU_PAGE_4K;
+#endif
+int mmu_io_psize = MMU_PAGE_4K;
+int mmu_kernel_ssize = MMU_SEGSIZE_256M;
+EXPORT_SYMBOL_GPL(mmu_kernel_ssize);
+int mmu_highuser_ssize = MMU_SEGSIZE_256M;
+u16 mmu_slb_size = 64;
+EXPORT_SYMBOL_GPL(mmu_slb_size);
+#ifdef CONFIG_PPC_64K_PAGES
+int mmu_ci_restrictions;
+#endif
+#ifdef CONFIG_DEBUG_PAGEALLOC
+static u8 *linear_map_hash_slots;
+static unsigned long linear_map_hash_count;
+static DEFINE_SPINLOCK(linear_map_hash_lock);
+#endif /* CONFIG_DEBUG_PAGEALLOC */
+
+/* There are definitions of page sizes arrays to be used when none
+ * is provided by the firmware.
+ */
+
+/* Pre-POWER4 CPUs (4k pages only)
+ */
+static struct mmu_psize_def mmu_psize_defaults_old[] = {
+	[MMU_PAGE_4K] = {
+		.shift	= 12,
+		.sllp	= 0,
+		.penc   = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1},
+		.avpnm	= 0,
+		.tlbiel = 0,
+	},
+};
+
+/* POWER4, GPUL, POWER5
+ *
+ * Support for 16Mb large pages
+ */
+static struct mmu_psize_def mmu_psize_defaults_gp[] = {
+	[MMU_PAGE_4K] = {
+		.shift	= 12,
+		.sllp	= 0,
+		.penc   = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1},
+		.avpnm	= 0,
+		.tlbiel = 1,
+	},
+	[MMU_PAGE_16M] = {
+		.shift	= 24,
+		.sllp	= SLB_VSID_L,
+		.penc   = {[0 ... MMU_PAGE_16M - 1] = -1, [MMU_PAGE_16M] = 0,
+			    [MMU_PAGE_16M + 1 ... MMU_PAGE_COUNT - 1] = -1 },
+		.avpnm	= 0x1UL,
+		.tlbiel = 0,
+	},
+};
+
+static unsigned long htab_convert_pte_flags(unsigned long pteflags)
+{
+	unsigned long rflags = pteflags & 0x1fa;
+
+	/* _PAGE_EXEC -> NOEXEC */
+	if ((pteflags & _PAGE_EXEC) == 0)
+		rflags |= HPTE_R_N;
+
+	/* PP bits. PAGE_USER is already PP bit 0x2, so we only
+	 * need to add in 0x1 if it's a read-only user page
+	 */
+	if ((pteflags & _PAGE_USER) && !((pteflags & _PAGE_RW) &&
+					 (pteflags & _PAGE_DIRTY)))
+		rflags |= 1;
+	/*
+	 * Always add "C" bit for perf. Memory coherence is always enabled
+	 */
+	return rflags | HPTE_R_C | HPTE_R_M;
+}
+
+int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
+		      unsigned long pstart, unsigned long prot,
+		      int psize, int ssize)
+{
+	unsigned long vaddr, paddr;
+	unsigned int step, shift;
+	int ret = 0;
+
+	shift = mmu_psize_defs[psize].shift;
+	step = 1 << shift;
+
+	prot = htab_convert_pte_flags(prot);
+
+	DBG("htab_bolt_mapping(%lx..%lx -> %lx (%lx,%d,%d)\n",
+	    vstart, vend, pstart, prot, psize, ssize);
+
+	for (vaddr = vstart, paddr = pstart; vaddr < vend;
+	     vaddr += step, paddr += step) {
+		unsigned long hash, hpteg;
+		unsigned long vsid = get_kernel_vsid(vaddr, ssize);
+		unsigned long vpn  = hpt_vpn(vaddr, vsid, ssize);
+		unsigned long tprot = prot;
+
+		/*
+		 * If we hit a bad address return error.
+		 */
+		if (!vsid)
+			return -1;
+		/* Make kernel text executable */
+		if (overlaps_kernel_text(vaddr, vaddr + step))
+			tprot &= ~HPTE_R_N;
+
+		/* Make kvm guest trampolines executable */
+		if (overlaps_kvm_tmp(vaddr, vaddr + step))
+			tprot &= ~HPTE_R_N;
+
+		/*
+		 * If relocatable, check if it overlaps interrupt vectors that
+		 * are copied down to real 0. For relocatable kernel
+		 * (e.g. kdump case) we copy interrupt vectors down to real
+		 * address 0. Mark that region as executable. This is
+		 * because on p8 system with relocation on exception feature
+		 * enabled, exceptions are raised with MMU (IR=DR=1) ON. Hence
+		 * in order to execute the interrupt handlers in virtual
+		 * mode the vector region need to be marked as executable.
+		 */
+		if ((PHYSICAL_START > MEMORY_START) &&
+			overlaps_interrupt_vector_text(vaddr, vaddr + step))
+				tprot &= ~HPTE_R_N;
+
+		hash = hpt_hash(vpn, shift, ssize);
+		hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
+
+		BUG_ON(!ppc_md.hpte_insert);
+		ret = ppc_md.hpte_insert(hpteg, vpn, paddr, tprot,
+					 HPTE_V_BOLTED, psize, psize, ssize);
+
+		if (ret < 0)
+			break;
+#ifdef CONFIG_DEBUG_PAGEALLOC
+		if ((paddr >> PAGE_SHIFT) < linear_map_hash_count)
+			linear_map_hash_slots[paddr >> PAGE_SHIFT] = ret | 0x80;
+#endif /* CONFIG_DEBUG_PAGEALLOC */
+	}
+	return ret < 0 ? ret : 0;
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+int htab_remove_mapping(unsigned long vstart, unsigned long vend,
+		      int psize, int ssize)
+{
+	unsigned long vaddr;
+	unsigned int step, shift;
+
+	shift = mmu_psize_defs[psize].shift;
+	step = 1 << shift;
+
+	if (!ppc_md.hpte_removebolted) {
+		printk(KERN_WARNING "Platform doesn't implement "
+				"hpte_removebolted\n");
+		return -EINVAL;
+	}
+
+	for (vaddr = vstart; vaddr < vend; vaddr += step)
+		ppc_md.hpte_removebolted(vaddr, psize, ssize);
+
+	return 0;
+}
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
+static int __init htab_dt_scan_seg_sizes(unsigned long node,
+					 const char *uname, int depth,
+					 void *data)
+{
+	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+	const __be32 *prop;
+	int size = 0;
+
+	/* We are scanning "cpu" nodes only */
+	if (type == NULL || strcmp(type, "cpu") != 0)
+		return 0;
+
+	prop = of_get_flat_dt_prop(node, "ibm,processor-segment-sizes", &size);
+	if (prop == NULL)
+		return 0;
+	for (; size >= 4; size -= 4, ++prop) {
+		if (be32_to_cpu(prop[0]) == 40) {
+			DBG("1T segment support detected\n");
+			cur_cpu_spec->mmu_features |= MMU_FTR_1T_SEGMENT;
+			return 1;
+		}
+	}
+	cur_cpu_spec->mmu_features &= ~MMU_FTR_NO_SLBIE_B;
+	return 0;
+}
+
+static void __init htab_init_seg_sizes(void)
+{
+	of_scan_flat_dt(htab_dt_scan_seg_sizes, NULL);
+}
+
+static int __init get_idx_from_shift(unsigned int shift)
+{
+	int idx = -1;
+
+	switch (shift) {
+	case 0xc:
+		idx = MMU_PAGE_4K;
+		break;
+	case 0x10:
+		idx = MMU_PAGE_64K;
+		break;
+	case 0x14:
+		idx = MMU_PAGE_1M;
+		break;
+	case 0x18:
+		idx = MMU_PAGE_16M;
+		break;
+	case 0x22:
+		idx = MMU_PAGE_16G;
+		break;
+	}
+	return idx;
+}
+
+static int __init htab_dt_scan_page_sizes(unsigned long node,
+					  const char *uname, int depth,
+					  void *data)
+{
+	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+	const __be32 *prop;
+	int size = 0;
+
+	/* We are scanning "cpu" nodes only */
+	if (type == NULL || strcmp(type, "cpu") != 0)
+		return 0;
+
+	prop = of_get_flat_dt_prop(node, "ibm,segment-page-sizes", &size);
+	if (!prop)
+		return 0;
+
+	pr_info("Page sizes from device-tree:\n");
+	size /= 4;
+	cur_cpu_spec->mmu_features &= ~(MMU_FTR_16M_PAGE);
+	while(size > 0) {
+		unsigned int base_shift = be32_to_cpu(prop[0]);
+		unsigned int slbenc = be32_to_cpu(prop[1]);
+		unsigned int lpnum = be32_to_cpu(prop[2]);
+		struct mmu_psize_def *def;
+		int idx, base_idx;
+
+		size -= 3; prop += 3;
+		base_idx = get_idx_from_shift(base_shift);
+		if (base_idx < 0) {
+			/* skip the pte encoding also */
+			prop += lpnum * 2; size -= lpnum * 2;
+			continue;
+		}
+		def = &mmu_psize_defs[base_idx];
+		if (base_idx == MMU_PAGE_16M)
+			cur_cpu_spec->mmu_features |= MMU_FTR_16M_PAGE;
+
+		def->shift = base_shift;
+		if (base_shift <= 23)
+			def->avpnm = 0;
+		else
+			def->avpnm = (1 << (base_shift - 23)) - 1;
+		def->sllp = slbenc;
+		/*
+		 * We don't know for sure what's up with tlbiel, so
+		 * for now we only set it for 4K and 64K pages
+		 */
+		if (base_idx == MMU_PAGE_4K || base_idx == MMU_PAGE_64K)
+			def->tlbiel = 1;
+		else
+			def->tlbiel = 0;
+
+		while (size > 0 && lpnum) {
+			unsigned int shift = be32_to_cpu(prop[0]);
+			int penc  = be32_to_cpu(prop[1]);
+
+			prop += 2; size -= 2;
+			lpnum--;
+
+			idx = get_idx_from_shift(shift);
+			if (idx < 0)
+				continue;
+
+			if (penc == -1)
+				pr_err("Invalid penc for base_shift=%d "
+				       "shift=%d\n", base_shift, shift);
+
+			def->penc[idx] = penc;
+			pr_info("base_shift=%d: shift=%d, sllp=0x%04lx,"
+				" avpnm=0x%08lx, tlbiel=%d, penc=%d\n",
+				base_shift, shift, def->sllp,
+				def->avpnm, def->tlbiel, def->penc[idx]);
+		}
+	}
+
+	return 1;
+}
+
+#ifdef CONFIG_HUGETLB_PAGE
+/* Scan for 16G memory blocks that have been set aside for huge pages
+ * and reserve those blocks for 16G huge pages.
+ */
+static int __init htab_dt_scan_hugepage_blocks(unsigned long node,
+					const char *uname, int depth,
+					void *data) {
+	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+	const __be64 *addr_prop;
+	const __be32 *page_count_prop;
+	unsigned int expected_pages;
+	long unsigned int phys_addr;
+	long unsigned int block_size;
+
+	/* We are scanning "memory" nodes only */
+	if (type == NULL || strcmp(type, "memory") != 0)
+		return 0;
+
+	/* This property is the log base 2 of the number of virtual pages that
+	 * will represent this memory block. */
+	page_count_prop = of_get_flat_dt_prop(node, "ibm,expected#pages", NULL);
+	if (page_count_prop == NULL)
+		return 0;
+	expected_pages = (1 << be32_to_cpu(page_count_prop[0]));
+	addr_prop = of_get_flat_dt_prop(node, "reg", NULL);
+	if (addr_prop == NULL)
+		return 0;
+	phys_addr = be64_to_cpu(addr_prop[0]);
+	block_size = be64_to_cpu(addr_prop[1]);
+	if (block_size != (16 * GB))
+		return 0;
+	printk(KERN_INFO "Huge page(16GB) memory: "
+			"addr = 0x%lX size = 0x%lX pages = %d\n",
+			phys_addr, block_size, expected_pages);
+	if (phys_addr + (16 * GB) <= memblock_end_of_DRAM()) {
+		memblock_reserve(phys_addr, block_size * expected_pages);
+		add_gpage(phys_addr, block_size, expected_pages);
+	}
+	return 0;
+}
+#endif /* CONFIG_HUGETLB_PAGE */
+
+static void mmu_psize_set_default_penc(void)
+{
+	int bpsize, apsize;
+	for (bpsize = 0; bpsize < MMU_PAGE_COUNT; bpsize++)
+		for (apsize = 0; apsize < MMU_PAGE_COUNT; apsize++)
+			mmu_psize_defs[bpsize].penc[apsize] = -1;
+}
+
+#ifdef CONFIG_PPC_64K_PAGES
+
+static bool might_have_hea(void)
+{
+	/*
+	 * The HEA ethernet adapter requires awareness of the
+	 * GX bus. Without that awareness we can easily assume
+	 * we will never see an HEA ethernet device.
+	 */
+#ifdef CONFIG_IBMEBUS
+	return !cpu_has_feature(CPU_FTR_ARCH_207S);
+#else
+	return false;
+#endif
+}
+
+#endif /* #ifdef CONFIG_PPC_64K_PAGES */
+
+static void __init htab_init_page_sizes(void)
+{
+	int rc;
+
+	/* se the invalid penc to -1 */
+	mmu_psize_set_default_penc();
+
+	/* Default to 4K pages only */
+	memcpy(mmu_psize_defs, mmu_psize_defaults_old,
+	       sizeof(mmu_psize_defaults_old));
+
+	/*
+	 * Try to find the available page sizes in the device-tree
+	 */
+	rc = of_scan_flat_dt(htab_dt_scan_page_sizes, NULL);
+	if (rc != 0)  /* Found */
+		goto found;
+
+	/*
+	 * Not in the device-tree, let's fallback on known size
+	 * list for 16M capable GP & GR
+	 */
+	if (mmu_has_feature(MMU_FTR_16M_PAGE))
+		memcpy(mmu_psize_defs, mmu_psize_defaults_gp,
+		       sizeof(mmu_psize_defaults_gp));
+ found:
+#ifndef CONFIG_DEBUG_PAGEALLOC
+	/*
+	 * Pick a size for the linear mapping. Currently, we only support
+	 * 16M, 1M and 4K which is the default
+	 */
+	if (mmu_psize_defs[MMU_PAGE_16M].shift)
+		mmu_linear_psize = MMU_PAGE_16M;
+	else if (mmu_psize_defs[MMU_PAGE_1M].shift)
+		mmu_linear_psize = MMU_PAGE_1M;
+#endif /* CONFIG_DEBUG_PAGEALLOC */
+
+#ifdef CONFIG_PPC_64K_PAGES
+	/*
+	 * Pick a size for the ordinary pages. Default is 4K, we support
+	 * 64K for user mappings and vmalloc if supported by the processor.
+	 * We only use 64k for ioremap if the processor
+	 * (and firmware) support cache-inhibited large pages.
+	 * If not, we use 4k and set mmu_ci_restrictions so that
+	 * hash_page knows to switch processes that use cache-inhibited
+	 * mappings to 4k pages.
+	 */
+	if (mmu_psize_defs[MMU_PAGE_64K].shift) {
+		mmu_virtual_psize = MMU_PAGE_64K;
+		mmu_vmalloc_psize = MMU_PAGE_64K;
+		if (mmu_linear_psize == MMU_PAGE_4K)
+			mmu_linear_psize = MMU_PAGE_64K;
+		if (mmu_has_feature(MMU_FTR_CI_LARGE_PAGE)) {
+			/*
+			 * When running on pSeries using 64k pages for ioremap
+			 * would stop us accessing the HEA ethernet. So if we
+			 * have the chance of ever seeing one, stay at 4k.
+			 */
+			if (!might_have_hea() || !machine_is(pseries))
+				mmu_io_psize = MMU_PAGE_64K;
+		} else
+			mmu_ci_restrictions = 1;
+	}
+#endif /* CONFIG_PPC_64K_PAGES */
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+	/* We try to use 16M pages for vmemmap if that is supported
+	 * and we have at least 1G of RAM at boot
+	 */
+	if (mmu_psize_defs[MMU_PAGE_16M].shift &&
+	    memblock_phys_mem_size() >= 0x40000000)
+		mmu_vmemmap_psize = MMU_PAGE_16M;
+	else if (mmu_psize_defs[MMU_PAGE_64K].shift)
+		mmu_vmemmap_psize = MMU_PAGE_64K;
+	else
+		mmu_vmemmap_psize = MMU_PAGE_4K;
+#endif /* CONFIG_SPARSEMEM_VMEMMAP */
+
+	printk(KERN_DEBUG "Page orders: linear mapping = %d, "
+	       "virtual = %d, io = %d"
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+	       ", vmemmap = %d"
+#endif
+	       "\n",
+	       mmu_psize_defs[mmu_linear_psize].shift,
+	       mmu_psize_defs[mmu_virtual_psize].shift,
+	       mmu_psize_defs[mmu_io_psize].shift
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+	       ,mmu_psize_defs[mmu_vmemmap_psize].shift
+#endif
+	       );
+
+#ifdef CONFIG_HUGETLB_PAGE
+	/* Reserve 16G huge page memory sections for huge pages */
+	of_scan_flat_dt(htab_dt_scan_hugepage_blocks, NULL);
+#endif /* CONFIG_HUGETLB_PAGE */
+}
+
+static int __init htab_dt_scan_pftsize(unsigned long node,
+				       const char *uname, int depth,
+				       void *data)
+{
+	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+	const __be32 *prop;
+
+	/* We are scanning "cpu" nodes only */
+	if (type == NULL || strcmp(type, "cpu") != 0)
+		return 0;
+
+	prop = of_get_flat_dt_prop(node, "ibm,pft-size", NULL);
+	if (prop != NULL) {
+		/* pft_size[0] is the NUMA CEC cookie */
+		ppc64_pft_size = be32_to_cpu(prop[1]);
+		return 1;
+	}
+	return 0;
+}
+
+static unsigned long __init htab_get_table_size(void)
+{
+	unsigned long mem_size, rnd_mem_size, pteg_count, psize;
+
+	/* If hash size isn't already provided by the platform, we try to
+	 * retrieve it from the device-tree. If it's not there neither, we
+	 * calculate it now based on the total RAM size
+	 */
+	if (ppc64_pft_size == 0)
+		of_scan_flat_dt(htab_dt_scan_pftsize, NULL);
+	if (ppc64_pft_size)
+		return 1UL << ppc64_pft_size;
+
+	/* round mem_size up to next power of 2 */
+	mem_size = memblock_phys_mem_size();
+	rnd_mem_size = 1UL << __ilog2(mem_size);
+	if (rnd_mem_size < mem_size)
+		rnd_mem_size <<= 1;
+
+	/* # pages / 2 */
+	psize = mmu_psize_defs[mmu_virtual_psize].shift;
+	pteg_count = max(rnd_mem_size >> (psize + 1), 1UL << 11);
+
+	return pteg_count << 7;
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+int create_section_mapping(unsigned long start, unsigned long end)
+{
+	return htab_bolt_mapping(start, end, __pa(start),
+				 pgprot_val(PAGE_KERNEL), mmu_linear_psize,
+				 mmu_kernel_ssize);
+}
+
+int remove_section_mapping(unsigned long start, unsigned long end)
+{
+	return htab_remove_mapping(start, end, mmu_linear_psize,
+			mmu_kernel_ssize);
+}
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
+extern u32 htab_call_hpte_insert1[];
+extern u32 htab_call_hpte_insert2[];
+extern u32 htab_call_hpte_remove[];
+extern u32 htab_call_hpte_updatepp[];
+extern u32 ht64_call_hpte_insert1[];
+extern u32 ht64_call_hpte_insert2[];
+extern u32 ht64_call_hpte_remove[];
+extern u32 ht64_call_hpte_updatepp[];
+
+static void __init htab_finish_init(void)
+{
+#ifdef CONFIG_PPC_HAS_HASH_64K
+	patch_branch(ht64_call_hpte_insert1,
+		ppc_function_entry(ppc_md.hpte_insert),
+		BRANCH_SET_LINK);
+	patch_branch(ht64_call_hpte_insert2,
+		ppc_function_entry(ppc_md.hpte_insert),
+		BRANCH_SET_LINK);
+	patch_branch(ht64_call_hpte_remove,
+		ppc_function_entry(ppc_md.hpte_remove),
+		BRANCH_SET_LINK);
+	patch_branch(ht64_call_hpte_updatepp,
+		ppc_function_entry(ppc_md.hpte_updatepp),
+		BRANCH_SET_LINK);
+#endif /* CONFIG_PPC_HAS_HASH_64K */
+
+	patch_branch(htab_call_hpte_insert1,
+		ppc_function_entry(ppc_md.hpte_insert),
+		BRANCH_SET_LINK);
+	patch_branch(htab_call_hpte_insert2,
+		ppc_function_entry(ppc_md.hpte_insert),
+		BRANCH_SET_LINK);
+	patch_branch(htab_call_hpte_remove,
+		ppc_function_entry(ppc_md.hpte_remove),
+		BRANCH_SET_LINK);
+	patch_branch(htab_call_hpte_updatepp,
+		ppc_function_entry(ppc_md.hpte_updatepp),
+		BRANCH_SET_LINK);
+}
+
+static void __init htab_initialize(void)
+{
+	unsigned long table;
+	unsigned long pteg_count;
+	unsigned long prot;
+	unsigned long base = 0, size = 0, limit;
+	struct memblock_region *reg;
+
+	DBG(" -> htab_initialize()\n");
+
+	/* Initialize segment sizes */
+	htab_init_seg_sizes();
+
+	/* Initialize page sizes */
+	htab_init_page_sizes();
+
+	if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) {
+		mmu_kernel_ssize = MMU_SEGSIZE_1T;
+		mmu_highuser_ssize = MMU_SEGSIZE_1T;
+		printk(KERN_INFO "Using 1TB segments\n");
+	}
+
+	/*
+	 * Calculate the required size of the htab.  We want the number of
+	 * PTEGs to equal one half the number of real pages.
+	 */ 
+	htab_size_bytes = htab_get_table_size();
+	pteg_count = htab_size_bytes >> 7;
+
+	htab_hash_mask = pteg_count - 1;
+
+	if (firmware_has_feature(FW_FEATURE_LPAR)) {
+		/* Using a hypervisor which owns the htab */
+		htab_address = NULL;
+		_SDR1 = 0; 
+#ifdef CONFIG_FA_DUMP
+		/*
+		 * If firmware assisted dump is active firmware preserves
+		 * the contents of htab along with entire partition memory.
+		 * Clear the htab if firmware assisted dump is active so
+		 * that we dont end up using old mappings.
+		 */
+		if (is_fadump_active() && ppc_md.hpte_clear_all)
+			ppc_md.hpte_clear_all();
+#endif
+	} else {
+		/* Find storage for the HPT.  Must be contiguous in
+		 * the absolute address space. On cell we want it to be
+		 * in the first 2 Gig so we can use it for IOMMU hacks.
+		 */
+		if (machine_is(cell))
+			limit = 0x80000000;
+		else
+			limit = MEMBLOCK_ALLOC_ANYWHERE;
+
+		table = memblock_alloc_base(htab_size_bytes, htab_size_bytes, limit);
+
+		DBG("Hash table allocated at %lx, size: %lx\n", table,
+		    htab_size_bytes);
+
+		htab_address = __va(table);
+
+		/* htab absolute addr + encoded htabsize */
+		_SDR1 = table + __ilog2(pteg_count) - 11;
+
+		/* Initialize the HPT with no entries */
+		memset((void *)table, 0, htab_size_bytes);
+
+		/* Set SDR1 */
+		mtspr(SPRN_SDR1, _SDR1);
+	}
+
+	prot = pgprot_val(PAGE_KERNEL);
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+	linear_map_hash_count = memblock_end_of_DRAM() >> PAGE_SHIFT;
+	linear_map_hash_slots = __va(memblock_alloc_base(linear_map_hash_count,
+						    1, ppc64_rma_size));
+	memset(linear_map_hash_slots, 0, linear_map_hash_count);
+#endif /* CONFIG_DEBUG_PAGEALLOC */
+
+	/* On U3 based machines, we need to reserve the DART area and
+	 * _NOT_ map it to avoid cache paradoxes as it's remapped non
+	 * cacheable later on
+	 */
+
+	/* create bolted the linear mapping in the hash table */
+	for_each_memblock(memory, reg) {
+		base = (unsigned long)__va(reg->base);
+		size = reg->size;
+
+		DBG("creating mapping for region: %lx..%lx (prot: %lx)\n",
+		    base, size, prot);
+
+#ifdef CONFIG_U3_DART
+		/* Do not map the DART space. Fortunately, it will be aligned
+		 * in such a way that it will not cross two memblock regions and
+		 * will fit within a single 16Mb page.
+		 * The DART space is assumed to be a full 16Mb region even if
+		 * we only use 2Mb of that space. We will use more of it later
+		 * for AGP GART. We have to use a full 16Mb large page.
+		 */
+		DBG("DART base: %lx\n", dart_tablebase);
+
+		if (dart_tablebase != 0 && dart_tablebase >= base
+		    && dart_tablebase < (base + size)) {
+			unsigned long dart_table_end = dart_tablebase + 16 * MB;
+			if (base != dart_tablebase)
+				BUG_ON(htab_bolt_mapping(base, dart_tablebase,
+							__pa(base), prot,
+							mmu_linear_psize,
+							mmu_kernel_ssize));
+			if ((base + size) > dart_table_end)
+				BUG_ON(htab_bolt_mapping(dart_tablebase+16*MB,
+							base + size,
+							__pa(dart_table_end),
+							 prot,
+							 mmu_linear_psize,
+							 mmu_kernel_ssize));
+			continue;
+		}
+#endif /* CONFIG_U3_DART */
+		BUG_ON(htab_bolt_mapping(base, base + size, __pa(base),
+				prot, mmu_linear_psize, mmu_kernel_ssize));
+	}
+	memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
+
+	/*
+	 * If we have a memory_limit and we've allocated TCEs then we need to
+	 * explicitly map the TCE area at the top of RAM. We also cope with the
+	 * case that the TCEs start below memory_limit.
+	 * tce_alloc_start/end are 16MB aligned so the mapping should work
+	 * for either 4K or 16MB pages.
+	 */
+	if (tce_alloc_start) {
+		tce_alloc_start = (unsigned long)__va(tce_alloc_start);
+		tce_alloc_end = (unsigned long)__va(tce_alloc_end);
+
+		if (base + size >= tce_alloc_start)
+			tce_alloc_start = base + size + 1;
+
+		BUG_ON(htab_bolt_mapping(tce_alloc_start, tce_alloc_end,
+					 __pa(tce_alloc_start), prot,
+					 mmu_linear_psize, mmu_kernel_ssize));
+	}
+
+	htab_finish_init();
+
+	DBG(" <- htab_initialize()\n");
+}
+#undef KB
+#undef MB
+
+void __init early_init_mmu(void)
+{
+	/* Initialize the MMU Hash table and create the linear mapping
+	 * of memory. Has to be done before SLB initialization as this is
+	 * currently where the page size encoding is obtained.
+	 */
+	htab_initialize();
+
+	/* Initialize SLB management */
+	slb_initialize();
+}
+
+#ifdef CONFIG_SMP
+void early_init_mmu_secondary(void)
+{
+	/* Initialize hash table for that CPU */
+	if (!firmware_has_feature(FW_FEATURE_LPAR))
+		mtspr(SPRN_SDR1, _SDR1);
+
+	/* Initialize SLB */
+	slb_initialize();
+}
+#endif /* CONFIG_SMP */
+
+/*
+ * Called by asm hashtable.S for doing lazy icache flush
+ */
+unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap)
+{
+	struct page *page;
+
+	if (!pfn_valid(pte_pfn(pte)))
+		return pp;
+
+	page = pte_page(pte);
+
+	/* page is dirty */
+	if (!test_bit(PG_arch_1, &page->flags) && !PageReserved(page)) {
+		if (trap == 0x400) {
+			flush_dcache_icache_page(page);
+			set_bit(PG_arch_1, &page->flags);
+		} else
+			pp |= HPTE_R_N;
+	}
+	return pp;
+}
+
+#ifdef CONFIG_PPC_MM_SLICES
+static unsigned int get_paca_psize(unsigned long addr)
+{
+	u64 lpsizes;
+	unsigned char *hpsizes;
+	unsigned long index, mask_index;
+
+	if (addr < SLICE_LOW_TOP) {
+		lpsizes = get_paca()->context.low_slices_psize;
+		index = GET_LOW_SLICE_INDEX(addr);
+		return (lpsizes >> (index * 4)) & 0xF;
+	}
+	hpsizes = get_paca()->context.high_slices_psize;
+	index = GET_HIGH_SLICE_INDEX(addr);
+	mask_index = index & 0x1;
+	return (hpsizes[index >> 1] >> (mask_index * 4)) & 0xF;
+}
+
+#else
+unsigned int get_paca_psize(unsigned long addr)
+{
+	return get_paca()->context.user_psize;
+}
+#endif
+
+/*
+ * Demote a segment to using 4k pages.
+ * For now this makes the whole process use 4k pages.
+ */
+#ifdef CONFIG_PPC_64K_PAGES
+void demote_segment_4k(struct mm_struct *mm, unsigned long addr)
+{
+	if (get_slice_psize(mm, addr) == MMU_PAGE_4K)
+		return;
+	slice_set_range_psize(mm, addr, 1, MMU_PAGE_4K);
+	copro_flush_all_slbs(mm);
+	if ((get_paca_psize(addr) != MMU_PAGE_4K) && (current->mm == mm)) {
+		get_paca()->context = mm->context;
+		slb_flush_and_rebolt();
+	}
+}
+#endif /* CONFIG_PPC_64K_PAGES */
+
+#ifdef CONFIG_PPC_SUBPAGE_PROT
+/*
+ * This looks up a 2-bit protection code for a 4k subpage of a 64k page.
+ * Userspace sets the subpage permissions using the subpage_prot system call.
+ *
+ * Result is 0: full permissions, _PAGE_RW: read-only,
+ * _PAGE_USER or _PAGE_USER|_PAGE_RW: no access.
+ */
+static int subpage_protection(struct mm_struct *mm, unsigned long ea)
+{
+	struct subpage_prot_table *spt = &mm->context.spt;
+	u32 spp = 0;
+	u32 **sbpm, *sbpp;
+
+	if (ea >= spt->maxaddr)
+		return 0;
+	if (ea < 0x100000000UL) {
+		/* addresses below 4GB use spt->low_prot */
+		sbpm = spt->low_prot;
+	} else {
+		sbpm = spt->protptrs[ea >> SBP_L3_SHIFT];
+		if (!sbpm)
+			return 0;
+	}
+	sbpp = sbpm[(ea >> SBP_L2_SHIFT) & (SBP_L2_COUNT - 1)];
+	if (!sbpp)
+		return 0;
+	spp = sbpp[(ea >> PAGE_SHIFT) & (SBP_L1_COUNT - 1)];
+
+	/* extract 2-bit bitfield for this 4k subpage */
+	spp >>= 30 - 2 * ((ea >> 12) & 0xf);
+
+	/* turn 0,1,2,3 into combination of _PAGE_USER and _PAGE_RW */
+	spp = ((spp & 2) ? _PAGE_USER : 0) | ((spp & 1) ? _PAGE_RW : 0);
+	return spp;
+}
+
+#else /* CONFIG_PPC_SUBPAGE_PROT */
+static inline int subpage_protection(struct mm_struct *mm, unsigned long ea)
+{
+	return 0;
+}
+#endif
+
+void hash_failure_debug(unsigned long ea, unsigned long access,
+			unsigned long vsid, unsigned long trap,
+			int ssize, int psize, int lpsize, unsigned long pte)
+{
+	if (!printk_ratelimit())
+		return;
+	pr_info("mm: Hashing failure ! EA=0x%lx access=0x%lx current=%s\n",
+		ea, access, current->comm);
+	pr_info("    trap=0x%lx vsid=0x%lx ssize=%d base psize=%d psize %d pte=0x%lx\n",
+		trap, vsid, ssize, psize, lpsize, pte);
+}
+
+static void check_paca_psize(unsigned long ea, struct mm_struct *mm,
+			     int psize, bool user_region)
+{
+	if (user_region) {
+		if (psize != get_paca_psize(ea)) {
+			get_paca()->context = mm->context;
+			slb_flush_and_rebolt();
+		}
+	} else if (get_paca()->vmalloc_sllp !=
+		   mmu_psize_defs[mmu_vmalloc_psize].sllp) {
+		get_paca()->vmalloc_sllp =
+			mmu_psize_defs[mmu_vmalloc_psize].sllp;
+		slb_vmalloc_update();
+	}
+}
+
+/* Result code is:
+ *  0 - handled
+ *  1 - normal page fault
+ * -1 - critical hash insertion error
+ * -2 - access not permitted by subpage protection mechanism
+ */
+int hash_page_mm(struct mm_struct *mm, unsigned long ea,
+		 unsigned long access, unsigned long trap,
+		 unsigned long flags)
+{
+	enum ctx_state prev_state = exception_enter();
+	pgd_t *pgdir;
+	unsigned long vsid;
+	pte_t *ptep;
+	unsigned hugeshift;
+	const struct cpumask *tmp;
+	int rc, user_region = 0;
+	int psize, ssize;
+
+	DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n",
+		ea, access, trap);
+
+	/* Get region & vsid */
+ 	switch (REGION_ID(ea)) {
+	case USER_REGION_ID:
+		user_region = 1;
+		if (! mm) {
+			DBG_LOW(" user region with no mm !\n");
+			rc = 1;
+			goto bail;
+		}
+		psize = get_slice_psize(mm, ea);
+		ssize = user_segment_size(ea);
+		vsid = get_vsid(mm->context.id, ea, ssize);
+		break;
+	case VMALLOC_REGION_ID:
+		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
+		if (ea < VMALLOC_END)
+			psize = mmu_vmalloc_psize;
+		else
+			psize = mmu_io_psize;
+		ssize = mmu_kernel_ssize;
+		break;
+	default:
+		/* Not a valid range
+		 * Send the problem up to do_page_fault 
+		 */
+		rc = 1;
+		goto bail;
+	}
+	DBG_LOW(" mm=%p, mm->pgdir=%p, vsid=%016lx\n", mm, mm->pgd, vsid);
+
+	/* Bad address. */
+	if (!vsid) {
+		DBG_LOW("Bad address!\n");
+		rc = 1;
+		goto bail;
+	}
+	/* Get pgdir */
+	pgdir = mm->pgd;
+	if (pgdir == NULL) {
+		rc = 1;
+		goto bail;
+	}
+
+	/* Check CPU locality */
+	tmp = cpumask_of(smp_processor_id());
+	if (user_region && cpumask_equal(mm_cpumask(mm), tmp))
+		flags |= HPTE_LOCAL_UPDATE;
+
+#ifndef CONFIG_PPC_64K_PAGES
+	/* If we use 4K pages and our psize is not 4K, then we might
+	 * be hitting a special driver mapping, and need to align the
+	 * address before we fetch the PTE.
+	 *
+	 * It could also be a hugepage mapping, in which case this is
+	 * not necessary, but it's not harmful, either.
+	 */
+	if (psize != MMU_PAGE_4K)
+		ea &= ~((1ul << mmu_psize_defs[psize].shift) - 1);
+#endif /* CONFIG_PPC_64K_PAGES */
+
+	/* Get PTE and page size from page tables */
+	ptep = __find_linux_pte_or_hugepte(pgdir, ea, &hugeshift);
+	if (ptep == NULL || !pte_present(*ptep)) {
+		DBG_LOW(" no PTE !\n");
+		rc = 1;
+		goto bail;
+	}
+
+	/* Add _PAGE_PRESENT to the required access perm */
+	access |= _PAGE_PRESENT;
+
+	/* Pre-check access permissions (will be re-checked atomically
+	 * in __hash_page_XX but this pre-check is a fast path
+	 */
+	if (access & ~pte_val(*ptep)) {
+		DBG_LOW(" no access !\n");
+		rc = 1;
+		goto bail;
+	}
+
+	if (hugeshift) {
+		if (pmd_trans_huge(*(pmd_t *)ptep))
+			rc = __hash_page_thp(ea, access, vsid, (pmd_t *)ptep,
+					     trap, flags, ssize, psize);
+#ifdef CONFIG_HUGETLB_PAGE
+		else
+			rc = __hash_page_huge(ea, access, vsid, ptep, trap,
+					      flags, ssize, hugeshift, psize);
+#else
+		else {
+			/*
+			 * if we have hugeshift, and is not transhuge with
+			 * hugetlb disabled, something is really wrong.
+			 */
+			rc = 1;
+			WARN_ON(1);
+		}
+#endif
+		if (current->mm == mm)
+			check_paca_psize(ea, mm, psize, user_region);
+
+		goto bail;
+	}
+
+#ifndef CONFIG_PPC_64K_PAGES
+	DBG_LOW(" i-pte: %016lx\n", pte_val(*ptep));
+#else
+	DBG_LOW(" i-pte: %016lx %016lx\n", pte_val(*ptep),
+		pte_val(*(ptep + PTRS_PER_PTE)));
+#endif
+	/* Do actual hashing */
+#ifdef CONFIG_PPC_64K_PAGES
+	/* If _PAGE_4K_PFN is set, make sure this is a 4k segment */
+	if ((pte_val(*ptep) & _PAGE_4K_PFN) && psize == MMU_PAGE_64K) {
+		demote_segment_4k(mm, ea);
+		psize = MMU_PAGE_4K;
+	}
+
+	/* If this PTE is non-cacheable and we have restrictions on
+	 * using non cacheable large pages, then we switch to 4k
+	 */
+	if (mmu_ci_restrictions && psize == MMU_PAGE_64K &&
+	    (pte_val(*ptep) & _PAGE_NO_CACHE)) {
+		if (user_region) {
+			demote_segment_4k(mm, ea);
+			psize = MMU_PAGE_4K;
+		} else if (ea < VMALLOC_END) {
+			/*
+			 * some driver did a non-cacheable mapping
+			 * in vmalloc space, so switch vmalloc
+			 * to 4k pages
+			 */
+			printk(KERN_ALERT "Reducing vmalloc segment "
+			       "to 4kB pages because of "
+			       "non-cacheable mapping\n");
+			psize = mmu_vmalloc_psize = MMU_PAGE_4K;
+			copro_flush_all_slbs(mm);
+		}
+	}
+
+	if (current->mm == mm)
+		check_paca_psize(ea, mm, psize, user_region);
+#endif /* CONFIG_PPC_64K_PAGES */
+
+#ifdef CONFIG_PPC_HAS_HASH_64K
+	if (psize == MMU_PAGE_64K)
+		rc = __hash_page_64K(ea, access, vsid, ptep, trap,
+				     flags, ssize);
+	else
+#endif /* CONFIG_PPC_HAS_HASH_64K */
+	{
+		int spp = subpage_protection(mm, ea);
+		if (access & spp)
+			rc = -2;
+		else
+			rc = __hash_page_4K(ea, access, vsid, ptep, trap,
+					    flags, ssize, spp);
+	}
+
+	/* Dump some info in case of hash insertion failure, they should
+	 * never happen so it is really useful to know if/when they do
+	 */
+	if (rc == -1)
+		hash_failure_debug(ea, access, vsid, trap, ssize, psize,
+				   psize, pte_val(*ptep));
+#ifndef CONFIG_PPC_64K_PAGES
+	DBG_LOW(" o-pte: %016lx\n", pte_val(*ptep));
+#else
+	DBG_LOW(" o-pte: %016lx %016lx\n", pte_val(*ptep),
+		pte_val(*(ptep + PTRS_PER_PTE)));
+#endif
+	DBG_LOW(" -> rc=%d\n", rc);
+
+bail:
+	exception_exit(prev_state);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(hash_page_mm);
+
+int hash_page(unsigned long ea, unsigned long access, unsigned long trap,
+	      unsigned long dsisr)
+{
+	unsigned long flags = 0;
+	struct mm_struct *mm = current->mm;
+
+	if (REGION_ID(ea) == VMALLOC_REGION_ID)
+		mm = &init_mm;
+
+	if (dsisr & DSISR_NOHPTE)
+		flags |= HPTE_NOHPTE_UPDATE;
+
+	return hash_page_mm(mm, ea, access, trap, flags);
+}
+EXPORT_SYMBOL_GPL(hash_page);
+
+void hash_preload(struct mm_struct *mm, unsigned long ea,
+		  unsigned long access, unsigned long trap)
+{
+	int hugepage_shift;
+	unsigned long vsid;
+	pgd_t *pgdir;
+	pte_t *ptep;
+	unsigned long flags;
+	int rc, ssize, update_flags = 0;
+
+	BUG_ON(REGION_ID(ea) != USER_REGION_ID);
+
+#ifdef CONFIG_PPC_MM_SLICES
+	/* We only prefault standard pages for now */
+	if (unlikely(get_slice_psize(mm, ea) != mm->context.user_psize))
+		return;
+#endif
+
+	DBG_LOW("hash_preload(mm=%p, mm->pgdir=%p, ea=%016lx, access=%lx,"
+		" trap=%lx\n", mm, mm->pgd, ea, access, trap);
+
+	/* Get Linux PTE if available */
+	pgdir = mm->pgd;
+	if (pgdir == NULL)
+		return;
+
+	/* Get VSID */
+	ssize = user_segment_size(ea);
+	vsid = get_vsid(mm->context.id, ea, ssize);
+	if (!vsid)
+		return;
+	/*
+	 * Hash doesn't like irqs. Walking linux page table with irq disabled
+	 * saves us from holding multiple locks.
+	 */
+	local_irq_save(flags);
+
+	/*
+	 * THP pages use update_mmu_cache_pmd. We don't do
+	 * hash preload there. Hence can ignore THP here
+	 */
+	ptep = find_linux_pte_or_hugepte(pgdir, ea, &hugepage_shift);
+	if (!ptep)
+		goto out_exit;
+
+	WARN_ON(hugepage_shift);
+#ifdef CONFIG_PPC_64K_PAGES
+	/* If either _PAGE_4K_PFN or _PAGE_NO_CACHE is set (and we are on
+	 * a 64K kernel), then we don't preload, hash_page() will take
+	 * care of it once we actually try to access the page.
+	 * That way we don't have to duplicate all of the logic for segment
+	 * page size demotion here
+	 */
+	if (pte_val(*ptep) & (_PAGE_4K_PFN | _PAGE_NO_CACHE))
+		goto out_exit;
+#endif /* CONFIG_PPC_64K_PAGES */
+
+	/* Is that local to this CPU ? */
+	if (cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
+		update_flags |= HPTE_LOCAL_UPDATE;
+
+	/* Hash it in */
+#ifdef CONFIG_PPC_HAS_HASH_64K
+	if (mm->context.user_psize == MMU_PAGE_64K)
+		rc = __hash_page_64K(ea, access, vsid, ptep, trap,
+				     update_flags, ssize);
+	else
+#endif /* CONFIG_PPC_HAS_HASH_64K */
+		rc = __hash_page_4K(ea, access, vsid, ptep, trap, update_flags,
+				    ssize, subpage_protection(mm, ea));
+
+	/* Dump some info in case of hash insertion failure, they should
+	 * never happen so it is really useful to know if/when they do
+	 */
+	if (rc == -1)
+		hash_failure_debug(ea, access, vsid, trap, ssize,
+				   mm->context.user_psize,
+				   mm->context.user_psize,
+				   pte_val(*ptep));
+out_exit:
+	local_irq_restore(flags);
+}
+
+/* WARNING: This is called from hash_low_64.S, if you change this prototype,
+ *          do not forget to update the assembly call site !
+ */
+void flush_hash_page(unsigned long vpn, real_pte_t pte, int psize, int ssize,
+		     unsigned long flags)
+{
+	unsigned long hash, index, shift, hidx, slot;
+	int local = flags & HPTE_LOCAL_UPDATE;
+
+	DBG_LOW("flush_hash_page(vpn=%016lx)\n", vpn);
+	pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
+		hash = hpt_hash(vpn, shift, ssize);
+		hidx = __rpte_to_hidx(pte, index);
+		if (hidx & _PTEIDX_SECONDARY)
+			hash = ~hash;
+		slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
+		slot += hidx & _PTEIDX_GROUP_IX;
+		DBG_LOW(" sub %ld: hash=%lx, hidx=%lx\n", index, slot, hidx);
+		/*
+		 * We use same base page size and actual psize, because we don't
+		 * use these functions for hugepage
+		 */
+		ppc_md.hpte_invalidate(slot, vpn, psize, psize, ssize, local);
+	} pte_iterate_hashed_end();
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	/* Transactions are not aborted by tlbiel, only tlbie.
+	 * Without, syncing a page back to a block device w/ PIO could pick up
+	 * transactional data (bad!) so we force an abort here.  Before the
+	 * sync the page will be made read-only, which will flush_hash_page.
+	 * BIG ISSUE here: if the kernel uses a page from userspace without
+	 * unmapping it first, it may see the speculated version.
+	 */
+	if (local && cpu_has_feature(CPU_FTR_TM) &&
+	    current->thread.regs &&
+	    MSR_TM_ACTIVE(current->thread.regs->msr)) {
+		tm_enable();
+		tm_abort(TM_CAUSE_TLBI);
+	}
+#endif
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+void flush_hash_hugepage(unsigned long vsid, unsigned long addr,
+			 pmd_t *pmdp, unsigned int psize, int ssize,
+			 unsigned long flags)
+{
+	int i, max_hpte_count, valid;
+	unsigned long s_addr;
+	unsigned char *hpte_slot_array;
+	unsigned long hidx, shift, vpn, hash, slot;
+	int local = flags & HPTE_LOCAL_UPDATE;
+
+	s_addr = addr & HPAGE_PMD_MASK;
+	hpte_slot_array = get_hpte_slot_array(pmdp);
+	/*
+	 * IF we try to do a HUGE PTE update after a withdraw is done.
+	 * we will find the below NULL. This happens when we do
+	 * split_huge_page_pmd
+	 */
+	if (!hpte_slot_array)
+		return;
+
+	if (ppc_md.hugepage_invalidate) {
+		ppc_md.hugepage_invalidate(vsid, s_addr, hpte_slot_array,
+					   psize, ssize, local);
+		goto tm_abort;
+	}
+	/*
+	 * No bluk hpte removal support, invalidate each entry
+	 */
+	shift = mmu_psize_defs[psize].shift;
+	max_hpte_count = HPAGE_PMD_SIZE >> shift;
+	for (i = 0; i < max_hpte_count; i++) {
+		/*
+		 * 8 bits per each hpte entries
+		 * 000| [ secondary group (one bit) | hidx (3 bits) | valid bit]
+		 */
+		valid = hpte_valid(hpte_slot_array, i);
+		if (!valid)
+			continue;
+		hidx =  hpte_hash_index(hpte_slot_array, i);
+
+		/* get the vpn */
+		addr = s_addr + (i * (1ul << shift));
+		vpn = hpt_vpn(addr, vsid, ssize);
+		hash = hpt_hash(vpn, shift, ssize);
+		if (hidx & _PTEIDX_SECONDARY)
+			hash = ~hash;
+
+		slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
+		slot += hidx & _PTEIDX_GROUP_IX;
+		ppc_md.hpte_invalidate(slot, vpn, psize,
+				       MMU_PAGE_16M, ssize, local);
+	}
+tm_abort:
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	/* Transactions are not aborted by tlbiel, only tlbie.
+	 * Without, syncing a page back to a block device w/ PIO could pick up
+	 * transactional data (bad!) so we force an abort here.  Before the
+	 * sync the page will be made read-only, which will flush_hash_page.
+	 * BIG ISSUE here: if the kernel uses a page from userspace without
+	 * unmapping it first, it may see the speculated version.
+	 */
+	if (local && cpu_has_feature(CPU_FTR_TM) &&
+	    current->thread.regs &&
+	    MSR_TM_ACTIVE(current->thread.regs->msr)) {
+		tm_enable();
+		tm_abort(TM_CAUSE_TLBI);
+	}
+#endif
+	return;
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+void flush_hash_range(unsigned long number, int local)
+{
+	if (ppc_md.flush_hash_range)
+		ppc_md.flush_hash_range(number, local);
+	else {
+		int i;
+		struct ppc64_tlb_batch *batch =
+			this_cpu_ptr(&ppc64_tlb_batch);
+
+		for (i = 0; i < number; i++)
+			flush_hash_page(batch->vpn[i], batch->pte[i],
+					batch->psize, batch->ssize, local);
+	}
+}
+
+/*
+ * low_hash_fault is called when we the low level hash code failed
+ * to instert a PTE due to an hypervisor error
+ */
+void low_hash_fault(struct pt_regs *regs, unsigned long address, int rc)
+{
+	enum ctx_state prev_state = exception_enter();
+
+	if (user_mode(regs)) {
+#ifdef CONFIG_PPC_SUBPAGE_PROT
+		if (rc == -2)
+			_exception(SIGSEGV, regs, SEGV_ACCERR, address);
+		else
+#endif
+			_exception(SIGBUS, regs, BUS_ADRERR, address);
+	} else
+		bad_page_fault(regs, address, SIGBUS);
+
+	exception_exit(prev_state);
+}
+
+long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
+			   unsigned long pa, unsigned long rflags,
+			   unsigned long vflags, int psize, int ssize)
+{
+	unsigned long hpte_group;
+	long slot;
+
+repeat:
+	hpte_group = ((hash & htab_hash_mask) *
+		       HPTES_PER_GROUP) & ~0x7UL;
+
+	/* Insert into the hash table, primary slot */
+	slot = ppc_md.hpte_insert(hpte_group, vpn, pa, rflags, vflags,
+				  psize, psize, ssize);
+
+	/* Primary is full, try the secondary */
+	if (unlikely(slot == -1)) {
+		hpte_group = ((~hash & htab_hash_mask) *
+			      HPTES_PER_GROUP) & ~0x7UL;
+		slot = ppc_md.hpte_insert(hpte_group, vpn, pa, rflags,
+					  vflags | HPTE_V_SECONDARY,
+					  psize, psize, ssize);
+		if (slot == -1) {
+			if (mftb() & 0x1)
+				hpte_group = ((hash & htab_hash_mask) *
+					      HPTES_PER_GROUP)&~0x7UL;
+
+			ppc_md.hpte_remove(hpte_group);
+			goto repeat;
+		}
+	}
+
+	return slot;
+}
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi)
+{
+	unsigned long hash;
+	unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
+	unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
+	unsigned long mode = htab_convert_pte_flags(PAGE_KERNEL);
+	long ret;
+
+	hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
+
+	/* Don't create HPTE entries for bad address */
+	if (!vsid)
+		return;
+
+	ret = hpte_insert_repeating(hash, vpn, __pa(vaddr), mode,
+				    HPTE_V_BOLTED,
+				    mmu_linear_psize, mmu_kernel_ssize);
+
+	BUG_ON (ret < 0);
+	spin_lock(&linear_map_hash_lock);
+	BUG_ON(linear_map_hash_slots[lmi] & 0x80);
+	linear_map_hash_slots[lmi] = ret | 0x80;
+	spin_unlock(&linear_map_hash_lock);
+}
+
+static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi)
+{
+	unsigned long hash, hidx, slot;
+	unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
+	unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
+
+	hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
+	spin_lock(&linear_map_hash_lock);
+	BUG_ON(!(linear_map_hash_slots[lmi] & 0x80));
+	hidx = linear_map_hash_slots[lmi] & 0x7f;
+	linear_map_hash_slots[lmi] = 0;
+	spin_unlock(&linear_map_hash_lock);
+	if (hidx & _PTEIDX_SECONDARY)
+		hash = ~hash;
+	slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
+	slot += hidx & _PTEIDX_GROUP_IX;
+	ppc_md.hpte_invalidate(slot, vpn, mmu_linear_psize, mmu_linear_psize,
+			       mmu_kernel_ssize, 0);
+}
+
+void __kernel_map_pages(struct page *page, int numpages, int enable)
+{
+	unsigned long flags, vaddr, lmi;
+	int i;
+
+	local_irq_save(flags);
+	for (i = 0; i < numpages; i++, page++) {
+		vaddr = (unsigned long)page_address(page);
+		lmi = __pa(vaddr) >> PAGE_SHIFT;
+		if (lmi >= linear_map_hash_count)
+			continue;
+		if (enable)
+			kernel_map_linear_page(vaddr, lmi);
+		else
+			kernel_unmap_linear_page(vaddr, lmi);
+	}
+	local_irq_restore(flags);
+}
+#endif /* CONFIG_DEBUG_PAGEALLOC */
+
+void setup_initial_memory_limit(phys_addr_t first_memblock_base,
+				phys_addr_t first_memblock_size)
+{
+	/* We don't currently support the first MEMBLOCK not mapping 0
+	 * physical on those processors
+	 */
+	BUG_ON(first_memblock_base != 0);
+
+	/* On LPAR systems, the first entry is our RMA region,
+	 * non-LPAR 64-bit hash MMU systems don't have a limitation
+	 * on real mode access, but using the first entry works well
+	 * enough. We also clamp it to 1G to avoid some funky things
+	 * such as RTAS bugs etc...
+	 */
+	ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000);
+
+	/* Finally limit subsequent allocations */
+	memblock_set_current_limit(ppc64_rma_size);
+}