powerpc/mm: Move book3s64 specifics in subdirectory mm/book3s64

Many files in arch/powerpc/mm are only for book3S64. This patch
creates a subdirectory for them.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Update the selftest sym links, shorten new filenames, cleanup some
      whitespace and formatting in the new files.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 1946 insertions, 0 deletions

diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
new file mode 100644
index 000000000000..b21a81d42f15
--- /dev/null
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -0,0 +1,1946 @@
+/*
+ * 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
+
+#define pr_fmt(fmt) "hash-mmu: " fmt
+#include <linux/spinlock.h>
+#include <linux/errno.h>
+#include <linux/sched/mm.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 <linux/libfdt.h>
+#include <linux/pkeys.h>
+
+#include <asm/debugfs.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 <linux/uaccess.h>
+#include <asm/machdep.h>
+#include <asm/prom.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>
+#include <asm/trace.h>
+#include <asm/ps3.h>
+#include <asm/pte-walk.h>
+#include <asm/asm-prototypes.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.
+ *
+ */
+
+static unsigned long _SDR1;
+struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
+EXPORT_SYMBOL_GPL(mmu_psize_defs);
+
+u8 hpte_page_sizes[1 << LP_BITS];
+EXPORT_SYMBOL_GPL(hpte_page_sizes);
+
+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 */
+struct mmu_hash_ops mmu_hash_ops;
+EXPORT_SYMBOL(mmu_hash_ops);
+
+/*
+ * These are definitions of page sizes arrays to be used when none
+ * is provided by the firmware.
+ */
+
+/*
+ * Fallback (4k pages only)
+ */
+static struct mmu_psize_def mmu_psize_defaults[] = {
+	[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,
+	},
+};
+
+/*
+ * 'R' and 'C' update notes:
+ *  - Under pHyp or KVM, the updatepp path will not set C, thus it *will*
+ *     create writeable HPTEs without C set, because the hcall H_PROTECT
+ *     that we use in that case will not update C
+ *  - The above is however not a problem, because we also don't do that
+ *     fancy "no flush" variant of eviction and we use H_REMOVE which will
+ *     do the right thing and thus we don't have the race I described earlier
+ *
+ *    - Under bare metal,  we do have the race, so we need R and C set
+ *    - We make sure R is always set and never lost
+ *    - C is _PAGE_DIRTY, and *should* always be set for a writeable mapping
+ */
+unsigned long htab_convert_pte_flags(unsigned long pteflags)
+{
+	unsigned long rflags = 0;
+
+	/* _PAGE_EXEC -> NOEXEC */
+	if ((pteflags & _PAGE_EXEC) == 0)
+		rflags |= HPTE_R_N;
+	/*
+	 * PPP bits:
+	 * Linux uses slb key 0 for kernel and 1 for user.
+	 * kernel RW areas are mapped with PPP=0b000
+	 * User area is mapped with PPP=0b010 for read/write
+	 * or PPP=0b011 for read-only (including writeable but clean pages).
+	 */
+	if (pteflags & _PAGE_PRIVILEGED) {
+		/*
+		 * Kernel read only mapped with ppp bits 0b110
+		 */
+		if (!(pteflags & _PAGE_WRITE)) {
+			if (mmu_has_feature(MMU_FTR_KERNEL_RO))
+				rflags |= (HPTE_R_PP0 | 0x2);
+			else
+				rflags |= 0x3;
+		}
+	} else {
+		if (pteflags & _PAGE_RWX)
+			rflags |= 0x2;
+		if (!((pteflags & _PAGE_WRITE) && (pteflags & _PAGE_DIRTY)))
+			rflags |= 0x1;
+	}
+	/*
+	 * We can't allow hardware to update hpte bits. Hence always
+	 * set 'R' bit and set 'C' if it is a write fault
+	 */
+	rflags |=  HPTE_R_R;
+
+	if (pteflags & _PAGE_DIRTY)
+		rflags |= HPTE_R_C;
+	/*
+	 * Add in WIG bits
+	 */
+
+	if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_TOLERANT)
+		rflags |= HPTE_R_I;
+	else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_NON_IDEMPOTENT)
+		rflags |= (HPTE_R_I | HPTE_R_G);
+	else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_SAO)
+		rflags |= (HPTE_R_W | HPTE_R_I | HPTE_R_M);
+	else
+		/*
+		 * Add memory coherence if cache inhibited is not set
+		 */
+		rflags |= HPTE_R_M;
+
+	rflags |= pte_to_hpte_pkey_bits(pteflags);
+	return rflags;
+}
+
+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(!mmu_hash_ops.hpte_insert);
+		ret = mmu_hash_ops.hpte_insert(hpteg, vpn, paddr, tprot,
+					       HPTE_V_BOLTED, psize, psize,
+					       ssize);
+
+		if (ret < 0)
+			break;
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+		if (debug_pagealloc_enabled() &&
+			(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;
+}
+
+int htab_remove_mapping(unsigned long vstart, unsigned long vend,
+		      int psize, int ssize)
+{
+	unsigned long vaddr;
+	unsigned int step, shift;
+	int rc;
+	int ret = 0;
+
+	shift = mmu_psize_defs[psize].shift;
+	step = 1 << shift;
+
+	if (!mmu_hash_ops.hpte_removebolted)
+		return -ENODEV;
+
+	for (vaddr = vstart; vaddr < vend; vaddr += step) {
+		rc = mmu_hash_ops.hpte_removebolted(vaddr, psize, ssize);
+		if (rc == -ENOENT) {
+			ret = -ENOENT;
+			continue;
+		}
+		if (rc < 0)
+			return rc;
+	}
+
+	return ret;
+}
+
+static bool disable_1tb_segments = false;
+
+static int __init parse_disable_1tb_segments(char *p)
+{
+	disable_1tb_segments = true;
+	return 0;
+}
+early_param("disable_1tb_segments", parse_disable_1tb_segments);
+
+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");
+
+			if (disable_1tb_segments) {
+				DBG("1T segments disabled by command line\n");
+				break;
+			}
+
+			cur_cpu_spec->mmu_features |= MMU_FTR_1T_SEGMENT;
+			return 1;
+		}
+	}
+	cur_cpu_spec->mmu_features &= ~MMU_FTR_NO_SLBIE_B;
+	return 0;
+}
+
+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 + block_size * expected_pages <= memblock_end_of_DRAM()) {
+		memblock_reserve(phys_addr, block_size * expected_pages);
+		pseries_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) &&
+		firmware_has_feature(FW_FEATURE_SPLPAR);
+#else
+	return false;
+#endif
+}
+
+#endif /* #ifdef CONFIG_PPC_64K_PAGES */
+
+static void __init htab_scan_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,
+	       sizeof(mmu_psize_defaults));
+
+	/*
+	 * 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 && early_mmu_has_feature(MMU_FTR_16M_PAGE)) {
+		/*
+		 * Nothing in the device-tree, but the CPU supports 16M pages,
+		 * so let's fallback on a known size list for 16M capable CPUs.
+		 */
+		memcpy(mmu_psize_defs, mmu_psize_defaults_gp,
+		       sizeof(mmu_psize_defaults_gp));
+	}
+
+#ifdef CONFIG_HUGETLB_PAGE
+	if (!hugetlb_disabled) {
+		/* Reserve 16G huge page memory sections for huge pages */
+		of_scan_flat_dt(htab_dt_scan_hugepage_blocks, NULL);
+	}
+#endif /* CONFIG_HUGETLB_PAGE */
+}
+
+/*
+ * Fill in the hpte_page_sizes[] array.
+ * We go through the mmu_psize_defs[] array looking for all the
+ * supported base/actual page size combinations.  Each combination
+ * has a unique pagesize encoding (penc) value in the low bits of
+ * the LP field of the HPTE.  For actual page sizes less than 1MB,
+ * some of the upper LP bits are used for RPN bits, meaning that
+ * we need to fill in several entries in hpte_page_sizes[].
+ *
+ * In diagrammatic form, with r = RPN bits and z = page size bits:
+ *        PTE LP     actual page size
+ *    rrrr rrrz		>=8KB
+ *    rrrr rrzz		>=16KB
+ *    rrrr rzzz		>=32KB
+ *    rrrr zzzz		>=64KB
+ *    ...
+ *
+ * The zzzz bits are implementation-specific but are chosen so that
+ * no encoding for a larger page size uses the same value in its
+ * low-order N bits as the encoding for the 2^(12+N) byte page size
+ * (if it exists).
+ */
+static void init_hpte_page_sizes(void)
+{
+	long int ap, bp;
+	long int shift, penc;
+
+	for (bp = 0; bp < MMU_PAGE_COUNT; ++bp) {
+		if (!mmu_psize_defs[bp].shift)
+			continue;	/* not a supported page size */
+		for (ap = bp; ap < MMU_PAGE_COUNT; ++ap) {
+			penc = mmu_psize_defs[bp].penc[ap];
+			if (penc == -1 || !mmu_psize_defs[ap].shift)
+				continue;
+			shift = mmu_psize_defs[ap].shift - LP_SHIFT;
+			if (shift <= 0)
+				continue;	/* should never happen */
+			/*
+			 * For page sizes less than 1MB, this loop
+			 * replicates the entry for all possible values
+			 * of the rrrr bits.
+			 */
+			while (penc < (1 << LP_BITS)) {
+				hpte_page_sizes[penc] = (ap << 4) | bp;
+				penc += 1 << shift;
+			}
+		}
+	}
+}
+
+static void __init htab_init_page_sizes(void)
+{
+	init_hpte_page_sizes();
+
+	if (!debug_pagealloc_enabled()) {
+		/*
+		 * 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;
+	}
+
+#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())
+				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
+	       );
+}
+
+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;
+}
+
+unsigned htab_shift_for_mem_size(unsigned long mem_size)
+{
+	unsigned memshift = __ilog2(mem_size);
+	unsigned pshift = mmu_psize_defs[mmu_virtual_psize].shift;
+	unsigned pteg_shift;
+
+	/* round mem_size up to next power of 2 */
+	if ((1UL << memshift) < mem_size)
+		memshift += 1;
+
+	/* aim for 2 pages / pteg */
+	pteg_shift = memshift - (pshift + 1);
+
+	/*
+	 * 2^11 PTEGS of 128 bytes each, ie. 2^18 bytes is the minimum htab
+	 * size permitted by the architecture.
+	 */
+	return max(pteg_shift + 7, 18U);
+}
+
+static unsigned long __init htab_get_table_size(void)
+{
+	/*
+	 * 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;
+
+	return 1UL << htab_shift_for_mem_size(memblock_phys_mem_size());
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+int resize_hpt_for_hotplug(unsigned long new_mem_size)
+{
+	unsigned target_hpt_shift;
+
+	if (!mmu_hash_ops.resize_hpt)
+		return 0;
+
+	target_hpt_shift = htab_shift_for_mem_size(new_mem_size);
+
+	/*
+	 * To avoid lots of HPT resizes if memory size is fluctuating
+	 * across a boundary, we deliberately have some hysterisis
+	 * here: we immediately increase the HPT size if the target
+	 * shift exceeds the current shift, but we won't attempt to
+	 * reduce unless the target shift is at least 2 below the
+	 * current shift
+	 */
+	if (target_hpt_shift > ppc64_pft_size ||
+	    target_hpt_shift < ppc64_pft_size - 1)
+		return mmu_hash_ops.resize_hpt(target_hpt_shift);
+
+	return 0;
+}
+
+int hash__create_section_mapping(unsigned long start, unsigned long end, int nid)
+{
+	int rc;
+
+	if (end >= H_VMALLOC_START) {
+		pr_warn("Outside the supported range\n");
+		return -1;
+	}
+
+	rc = htab_bolt_mapping(start, end, __pa(start),
+			       pgprot_val(PAGE_KERNEL), mmu_linear_psize,
+			       mmu_kernel_ssize);
+
+	if (rc < 0) {
+		int rc2 = htab_remove_mapping(start, end, mmu_linear_psize,
+					      mmu_kernel_ssize);
+		BUG_ON(rc2 && (rc2 != -ENOENT));
+	}
+	return rc;
+}
+
+int hash__remove_section_mapping(unsigned long start, unsigned long end)
+{
+	int rc = htab_remove_mapping(start, end, mmu_linear_psize,
+				     mmu_kernel_ssize);
+	WARN_ON(rc < 0);
+	return rc;
+}
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
+static void __init hash_init_partition_table(phys_addr_t hash_table,
+					     unsigned long htab_size)
+{
+	mmu_partition_table_init();
+
+	/*
+	 * PS field (VRMA page size) is not used for LPID 0, hence set to 0.
+	 * For now, UPRT is 0 and we have no segment table.
+	 */
+	htab_size =  __ilog2(htab_size) - 18;
+	mmu_partition_table_set_entry(0, hash_table | htab_size, 0);
+	pr_info("Partition table %p\n", partition_tb);
+}
+
+static void __init htab_initialize(void)
+{
+	unsigned long table;
+	unsigned long pteg_count;
+	unsigned long prot;
+	unsigned long base = 0, size = 0;
+	struct memblock_region *reg;
+
+	DBG(" -> htab_initialize()\n");
+
+	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) ||
+	    firmware_has_feature(FW_FEATURE_PS3_LV1)) {
+		/* Using a hypervisor which owns the htab */
+		htab_address = NULL;
+		_SDR1 = 0; 
+		/*
+		 * On POWER9, we need to do a H_REGISTER_PROC_TBL hcall
+		 * to inform the hypervisor that we wish to use the HPT.
+		 */
+		if (cpu_has_feature(CPU_FTR_ARCH_300))
+			register_process_table(0, 0, 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() && mmu_hash_ops.hpte_clear_all)
+			mmu_hash_ops.hpte_clear_all();
+#endif
+	} else {
+		unsigned long limit = MEMBLOCK_ALLOC_ANYWHERE;
+
+#ifdef CONFIG_PPC_CELL
+		/*
+		 * Cell may require the hash table down low when using the
+		 * Axon IOMMU in order to fit the dynamic region over it, see
+		 * comments in cell/iommu.c
+		 */
+		if (fdt_subnode_offset(initial_boot_params, 0, "axon") > 0) {
+			limit = 0x80000000;
+			pr_info("Hash table forced below 2G for Axon IOMMU\n");
+		}
+#endif /* CONFIG_PPC_CELL */
+
+		table = memblock_phys_alloc_range(htab_size_bytes,
+						  htab_size_bytes,
+						  0, limit);
+		if (!table)
+			panic("ERROR: Failed to allocate %pa bytes below %pa\n",
+			      &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(htab_size_bytes) - 18;
+
+		/* Initialize the HPT with no entries */
+		memset((void *)table, 0, htab_size_bytes);
+
+		if (!cpu_has_feature(CPU_FTR_ARCH_300))
+			/* Set SDR1 */
+			mtspr(SPRN_SDR1, _SDR1);
+		else
+			hash_init_partition_table(table, htab_size_bytes);
+	}
+
+	prot = pgprot_val(PAGE_KERNEL);
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+	if (debug_pagealloc_enabled()) {
+		linear_map_hash_count = memblock_end_of_DRAM() >> PAGE_SHIFT;
+		linear_map_hash_slots = memblock_alloc_try_nid(
+				linear_map_hash_count, 1, MEMBLOCK_LOW_LIMIT,
+				ppc64_rma_size,	NUMA_NO_NODE);
+		if (!linear_map_hash_slots)
+			panic("%s: Failed to allocate %lu bytes max_addr=%pa\n",
+			      __func__, linear_map_hash_count, &ppc64_rma_size);
+	}
+#endif /* CONFIG_DEBUG_PAGEALLOC */
+
+	/* 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);
+
+		if ((base + size) >= H_VMALLOC_START) {
+			pr_warn("Outside the supported range\n");
+			continue;
+		}
+
+		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));
+	}
+
+
+	DBG(" <- htab_initialize()\n");
+}
+#undef KB
+#undef MB
+
+void __init hash__early_init_devtree(void)
+{
+	/* Initialize segment sizes */
+	of_scan_flat_dt(htab_dt_scan_seg_sizes, NULL);
+
+	/* Initialize page sizes */
+	htab_scan_page_sizes();
+}
+
+struct hash_mm_context init_hash_mm_context;
+void __init hash__early_init_mmu(void)
+{
+#ifndef CONFIG_PPC_64K_PAGES
+	/*
+	 * We have code in __hash_page_4K() and elsewhere, which assumes it can
+	 * do the following:
+	 *   new_pte |= (slot << H_PAGE_F_GIX_SHIFT) & (H_PAGE_F_SECOND | H_PAGE_F_GIX);
+	 *
+	 * Where the slot number is between 0-15, and values of 8-15 indicate
+	 * the secondary bucket. For that code to work H_PAGE_F_SECOND and
+	 * H_PAGE_F_GIX must occupy four contiguous bits in the PTE, and
+	 * H_PAGE_F_SECOND must be placed above H_PAGE_F_GIX. Assert that here
+	 * with a BUILD_BUG_ON().
+	 */
+	BUILD_BUG_ON(H_PAGE_F_SECOND != (1ul  << (H_PAGE_F_GIX_SHIFT + 3)));
+#endif /* CONFIG_PPC_64K_PAGES */
+
+	htab_init_page_sizes();
+
+	/*
+	 * initialize page table size
+	 */
+	__pte_frag_nr = H_PTE_FRAG_NR;
+	__pte_frag_size_shift = H_PTE_FRAG_SIZE_SHIFT;
+	__pmd_frag_nr = H_PMD_FRAG_NR;
+	__pmd_frag_size_shift = H_PMD_FRAG_SIZE_SHIFT;
+
+	__pte_index_size = H_PTE_INDEX_SIZE;
+	__pmd_index_size = H_PMD_INDEX_SIZE;
+	__pud_index_size = H_PUD_INDEX_SIZE;
+	__pgd_index_size = H_PGD_INDEX_SIZE;
+	__pud_cache_index = H_PUD_CACHE_INDEX;
+	__pte_table_size = H_PTE_TABLE_SIZE;
+	__pmd_table_size = H_PMD_TABLE_SIZE;
+	__pud_table_size = H_PUD_TABLE_SIZE;
+	__pgd_table_size = H_PGD_TABLE_SIZE;
+	/*
+	 * 4k use hugepd format, so for hash set then to
+	 * zero
+	 */
+	__pmd_val_bits = HASH_PMD_VAL_BITS;
+	__pud_val_bits = HASH_PUD_VAL_BITS;
+	__pgd_val_bits = HASH_PGD_VAL_BITS;
+
+	__kernel_virt_start = H_KERN_VIRT_START;
+	__vmalloc_start = H_VMALLOC_START;
+	__vmalloc_end = H_VMALLOC_END;
+	__kernel_io_start = H_KERN_IO_START;
+	__kernel_io_end = H_KERN_IO_END;
+	vmemmap = (struct page *)H_VMEMMAP_START;
+	ioremap_bot = IOREMAP_BASE;
+
+#ifdef CONFIG_PCI
+	pci_io_base = ISA_IO_BASE;
+#endif
+
+	/* Select appropriate backend */
+	if (firmware_has_feature(FW_FEATURE_PS3_LV1))
+		ps3_early_mm_init();
+	else if (firmware_has_feature(FW_FEATURE_LPAR))
+		hpte_init_pseries();
+	else if (IS_ENABLED(CONFIG_PPC_NATIVE))
+		hpte_init_native();
+
+	if (!mmu_hash_ops.hpte_insert)
+		panic("hash__early_init_mmu: No MMU hash ops defined!\n");
+
+	/*
+	 * 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();
+
+	init_mm.context.hash_context = &init_hash_mm_context;
+	init_mm.context.hash_context->slb_addr_limit = DEFAULT_MAP_WINDOW_USER64;
+
+	pr_info("Initializing hash mmu with SLB\n");
+	/* Initialize SLB management */
+	slb_initialize();
+
+	if (cpu_has_feature(CPU_FTR_ARCH_206)
+			&& cpu_has_feature(CPU_FTR_HVMODE))
+		tlbiel_all();
+}
+
+#ifdef CONFIG_SMP
+void hash__early_init_mmu_secondary(void)
+{
+	/* Initialize hash table for that CPU */
+	if (!firmware_has_feature(FW_FEATURE_LPAR)) {
+
+		if (!cpu_has_feature(CPU_FTR_ARCH_300))
+			mtspr(SPRN_SDR1, _SDR1);
+		else
+			mtspr(SPRN_PTCR,
+			      __pa(partition_tb) | (PATB_SIZE_SHIFT - 12));
+	}
+	/* Initialize SLB */
+	slb_initialize();
+
+	if (cpu_has_feature(CPU_FTR_ARCH_206)
+			&& cpu_has_feature(CPU_FTR_HVMODE))
+		tlbiel_all();
+}
+#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)
+{
+	unsigned char *psizes;
+	unsigned long index, mask_index;
+
+	if (addr < SLICE_LOW_TOP) {
+		psizes = get_paca()->mm_ctx_low_slices_psize;
+		index = GET_LOW_SLICE_INDEX(addr);
+	} else {
+		psizes = get_paca()->mm_ctx_high_slices_psize;
+		index = GET_HIGH_SLICE_INDEX(addr);
+	}
+	mask_index = index & 0x1;
+	return (psizes[index >> 1] >> (mask_index * 4)) & 0xF;
+}
+
+#else
+unsigned int get_paca_psize(unsigned long addr)
+{
+	return get_paca()->mm_ctx_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)) {
+
+		copy_mm_to_paca(mm);
+		slb_flush_and_restore_bolted();
+	}
+}
+#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_RWX: no access.
+ */
+static int subpage_protection(struct mm_struct *mm, unsigned long ea)
+{
+	struct subpage_prot_table *spt = mm_ctx_subpage_prot(&mm->context);
+	u32 spp = 0;
+	u32 **sbpm, *sbpp;
+
+	if (!spt)
+		return 0;
+
+	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);
+
+	/*
+	 * 0 -> full premission
+	 * 1 -> Read only
+	 * 2 -> no access.
+	 * We return the flag that need to be cleared.
+	 */
+	spp = ((spp & 2) ? _PAGE_RWX : 0) | ((spp & 1) ? _PAGE_WRITE : 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)) {
+			copy_mm_to_paca(mm);
+			slb_flush_and_restore_bolted();
+		}
+	} 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)
+{
+	bool is_thp;
+	enum ctx_state prev_state = exception_enter();
+	pgd_t *pgdir;
+	unsigned long vsid;
+	pte_t *ptep;
+	unsigned hugeshift;
+	int rc, user_region = 0;
+	int psize, ssize;
+
+	DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n",
+		ea, access, trap);
+	trace_hash_fault(ea, access, trap);
+
+	/* Get region & vsid */
+	switch (get_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_user_vsid(&mm->context, ea, ssize);
+		break;
+	case VMALLOC_REGION_ID:
+		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
+		psize = mmu_vmalloc_psize;
+		ssize = mmu_kernel_ssize;
+		break;
+
+	case IO_REGION_ID:
+		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
+		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 */
+	if (user_region && mm_is_thread_local(mm))
+		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(pgdir, ea, &is_thp, &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 (!check_pte_access(access, pte_val(*ptep))) {
+		DBG_LOW(" no access !\n");
+		rc = 1;
+		goto bail;
+	}
+
+	if (hugeshift) {
+		if (is_thp)
+			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 H_PAGE_4K_PFN is set, make sure this is a 4k segment */
+	if ((pte_val(*ptep) & H_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_ci(*ptep)) {
+		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);
+		}
+	}
+
+#endif /* CONFIG_PPC_64K_PAGES */
+
+	if (current->mm == mm)
+		check_paca_psize(ea, mm, psize, user_region);
+
+#ifdef CONFIG_PPC_64K_PAGES
+	if (psize == MMU_PAGE_64K)
+		rc = __hash_page_64K(ea, access, vsid, ptep, trap,
+				     flags, ssize);
+	else
+#endif /* CONFIG_PPC_64K_PAGES */
+	{
+		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 ((get_region_id(ea) == VMALLOC_REGION_ID) ||
+	    (get_region_id(ea) == IO_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);
+
+int __hash_page(unsigned long ea, unsigned long msr, unsigned long trap,
+		unsigned long dsisr)
+{
+	unsigned long access = _PAGE_PRESENT | _PAGE_READ;
+	unsigned long flags = 0;
+	struct mm_struct *mm = current->mm;
+	unsigned int region_id = get_region_id(ea);
+
+	if ((region_id == VMALLOC_REGION_ID) || (region_id == IO_REGION_ID))
+		mm = &init_mm;
+
+	if (dsisr & DSISR_NOHPTE)
+		flags |= HPTE_NOHPTE_UPDATE;
+
+	if (dsisr & DSISR_ISSTORE)
+		access |= _PAGE_WRITE;
+	/*
+	 * We set _PAGE_PRIVILEGED only when
+	 * kernel mode access kernel space.
+	 *
+	 * _PAGE_PRIVILEGED is NOT set
+	 * 1) when kernel mode access user space
+	 * 2) user space access kernel space.
+	 */
+	access |= _PAGE_PRIVILEGED;
+	if ((msr & MSR_PR) || (region_id == USER_REGION_ID))
+		access &= ~_PAGE_PRIVILEGED;
+
+	if (trap == 0x400)
+		access |= _PAGE_EXEC;
+
+	return hash_page_mm(mm, ea, access, trap, flags);
+}
+
+#ifdef CONFIG_PPC_MM_SLICES
+static bool should_hash_preload(struct mm_struct *mm, unsigned long ea)
+{
+	int psize = get_slice_psize(mm, ea);
+
+	/* We only prefault standard pages for now */
+	if (unlikely(psize != mm_ctx_user_psize(&mm->context)))
+		return false;
+
+	/*
+	 * Don't prefault if subpage protection is enabled for the EA.
+	 */
+	if (unlikely((psize == MMU_PAGE_4K) && subpage_protection(mm, ea)))
+		return false;
+
+	return true;
+}
+#else
+static bool should_hash_preload(struct mm_struct *mm, unsigned long ea)
+{
+	return true;
+}
+#endif
+
+void hash_preload(struct mm_struct *mm, unsigned long ea,
+		  bool is_exec, unsigned long trap)
+{
+	int hugepage_shift;
+	unsigned long vsid;
+	pgd_t *pgdir;
+	pte_t *ptep;
+	unsigned long flags;
+	int rc, ssize, update_flags = 0;
+	unsigned long access = _PAGE_PRESENT | _PAGE_READ | (is_exec ? _PAGE_EXEC : 0);
+
+	BUG_ON(get_region_id(ea) != USER_REGION_ID);
+
+	if (!should_hash_preload(mm, ea))
+		return;
+
+	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_user_vsid(&mm->context, 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_current_mm_pte(pgdir, ea, NULL, &hugepage_shift);
+	if (!ptep)
+		goto out_exit;
+
+	WARN_ON(hugepage_shift);
+#ifdef CONFIG_PPC_64K_PAGES
+	/* If either H_PAGE_4K_PFN or cache inhibited 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) & H_PAGE_4K_PFN) || pte_ci(*ptep))
+		goto out_exit;
+#endif /* CONFIG_PPC_64K_PAGES */
+
+	/* Is that local to this CPU ? */
+	if (mm_is_thread_local(mm))
+		update_flags |= HPTE_LOCAL_UPDATE;
+
+	/* Hash it in */
+#ifdef CONFIG_PPC_64K_PAGES
+	if (mm_ctx_user_psize(&mm->context) == MMU_PAGE_64K)
+		rc = __hash_page_64K(ea, access, vsid, ptep, trap,
+				     update_flags, ssize);
+	else
+#endif /* CONFIG_PPC_64K_PAGES */
+		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_ctx_user_psize(&mm->context),
+				   mm_ctx_user_psize(&mm->context),
+				   pte_val(*ptep));
+out_exit:
+	local_irq_restore(flags);
+}
+
+#ifdef CONFIG_PPC_MEM_KEYS
+/*
+ * Return the protection key associated with the given address and the
+ * mm_struct.
+ */
+u16 get_mm_addr_key(struct mm_struct *mm, unsigned long address)
+{
+	pte_t *ptep;
+	u16 pkey = 0;
+	unsigned long flags;
+
+	if (!mm || !mm->pgd)
+		return 0;
+
+	local_irq_save(flags);
+	ptep = find_linux_pte(mm->pgd, address, NULL, NULL);
+	if (ptep)
+		pkey = pte_to_pkey_bits(pte_val(READ_ONCE(*ptep)));
+	local_irq_restore(flags);
+
+	return pkey;
+}
+#endif /* CONFIG_PPC_MEM_KEYS */
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+static inline void tm_flush_hash_page(int local)
+{
+	/*
+	 * 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);
+	}
+}
+#else
+static inline void tm_flush_hash_page(int local)
+{
+}
+#endif
+
+/*
+ * Return the global hash slot, corresponding to the given PTE, which contains
+ * the HPTE.
+ */
+unsigned long pte_get_hash_gslot(unsigned long vpn, unsigned long shift,
+		int ssize, real_pte_t rpte, unsigned int subpg_index)
+{
+	unsigned long hash, gslot, hidx;
+
+	hash = hpt_hash(vpn, shift, ssize);
+	hidx = __rpte_to_hidx(rpte, subpg_index);
+	if (hidx & _PTEIDX_SECONDARY)
+		hash = ~hash;
+	gslot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
+	gslot += hidx & _PTEIDX_GROUP_IX;
+	return gslot;
+}
+
+/*
+ * 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 index, shift, gslot;
+	int local = flags & HPTE_LOCAL_UPDATE;
+
+	DBG_LOW("flush_hash_page(vpn=%016lx)\n", vpn);
+	pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
+		gslot = pte_get_hash_gslot(vpn, shift, ssize, pte, index);
+		DBG_LOW(" sub %ld: gslot=%lx\n", index, gslot);
+		/*
+		 * We use same base page size and actual psize, because we don't
+		 * use these functions for hugepage
+		 */
+		mmu_hash_ops.hpte_invalidate(gslot, vpn, psize, psize,
+					     ssize, local);
+	} pte_iterate_hashed_end();
+
+	tm_flush_hash_page(local);
+}
+
+#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 (mmu_hash_ops.hugepage_invalidate) {
+		mmu_hash_ops.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;
+		mmu_hash_ops.hpte_invalidate(slot, vpn, psize,
+					     MMU_PAGE_16M, ssize, local);
+	}
+tm_abort:
+	tm_flush_hash_page(local);
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+void flush_hash_range(unsigned long number, int local)
+{
+	if (mmu_hash_ops.flush_hash_range)
+		mmu_hash_ops.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;
+
+	/* Insert into the hash table, primary slot */
+	slot = mmu_hash_ops.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;
+		slot = mmu_hash_ops.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;
+
+			mmu_hash_ops.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(pgprot_val(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;
+	mmu_hash_ops.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 hash__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 virtualized systems the first entry is our RMA region aka VRMA,
+	 * non-virtualized 64-bit hash MMU systems don't have a limitation
+	 * on real mode access.
+	 *
+	 * For guests on platforms before POWER9, we clamp the it limit to 1G
+	 * to avoid some funky things such as RTAS bugs etc...
+	 */
+	if (!early_cpu_has_feature(CPU_FTR_HVMODE)) {
+		ppc64_rma_size = first_memblock_size;
+		if (!early_cpu_has_feature(CPU_FTR_ARCH_300))
+			ppc64_rma_size = min_t(u64, ppc64_rma_size, 0x40000000);
+
+		/* Finally limit subsequent allocations */
+		memblock_set_current_limit(ppc64_rma_size);
+	} else {
+		ppc64_rma_size = ULONG_MAX;
+	}
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+static int hpt_order_get(void *data, u64 *val)
+{
+	*val = ppc64_pft_size;
+	return 0;
+}
+
+static int hpt_order_set(void *data, u64 val)
+{
+	if (!mmu_hash_ops.resize_hpt)
+		return -ENODEV;
+
+	return mmu_hash_ops.resize_hpt(val);
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(fops_hpt_order, hpt_order_get, hpt_order_set, "%llu\n");
+
+static int __init hash64_debugfs(void)
+{
+	if (!debugfs_create_file_unsafe("hpt_order", 0600, powerpc_debugfs_root,
+					NULL, &fops_hpt_order)) {
+		pr_err("lpar: unable to create hpt_order debugsfs file\n");
+	}
+
+	return 0;
+}
+machine_device_initcall(pseries, hash64_debugfs);
+#endif /* CONFIG_DEBUG_FS */