Initial import

1 files changed, 903 insertions, 0 deletions

diff --git a/arch/sh/mm/pmb.c b/arch/sh/mm/pmb.c
new file mode 100644
index 000000000..7160c9fd6
--- /dev/null
+++ b/arch/sh/mm/pmb.c
@@ -0,0 +1,903 @@
+/*
+ * arch/sh/mm/pmb.c
+ *
+ * Privileged Space Mapping Buffer (PMB) Support.
+ *
+ * Copyright (C) 2005 - 2011  Paul Mundt
+ * Copyright (C) 2010  Matt Fleming
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/syscore_ops.h>
+#include <linux/cpu.h>
+#include <linux/module.h>
+#include <linux/bitops.h>
+#include <linux/debugfs.h>
+#include <linux/fs.h>
+#include <linux/seq_file.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/spinlock.h>
+#include <linux/vmalloc.h>
+#include <asm/cacheflush.h>
+#include <asm/sizes.h>
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/page.h>
+#include <asm/mmu.h>
+#include <asm/mmu_context.h>
+
+struct pmb_entry;
+
+struct pmb_entry {
+	unsigned long vpn;
+	unsigned long ppn;
+	unsigned long flags;
+	unsigned long size;
+
+	raw_spinlock_t lock;
+
+	/*
+	 * 0 .. NR_PMB_ENTRIES for specific entry selection, or
+	 * PMB_NO_ENTRY to search for a free one
+	 */
+	int entry;
+
+	/* Adjacent entry link for contiguous multi-entry mappings */
+	struct pmb_entry *link;
+};
+
+static struct {
+	unsigned long size;
+	int flag;
+} pmb_sizes[] = {
+	{ .size	= SZ_512M, .flag = PMB_SZ_512M, },
+	{ .size = SZ_128M, .flag = PMB_SZ_128M, },
+	{ .size = SZ_64M,  .flag = PMB_SZ_64M,  },
+	{ .size = SZ_16M,  .flag = PMB_SZ_16M,  },
+};
+
+static void pmb_unmap_entry(struct pmb_entry *, int depth);
+
+static DEFINE_RWLOCK(pmb_rwlock);
+static struct pmb_entry pmb_entry_list[NR_PMB_ENTRIES];
+static DECLARE_BITMAP(pmb_map, NR_PMB_ENTRIES);
+
+static unsigned int pmb_iomapping_enabled;
+
+static __always_inline unsigned long mk_pmb_entry(unsigned int entry)
+{
+	return (entry & PMB_E_MASK) << PMB_E_SHIFT;
+}
+
+static __always_inline unsigned long mk_pmb_addr(unsigned int entry)
+{
+	return mk_pmb_entry(entry) | PMB_ADDR;
+}
+
+static __always_inline unsigned long mk_pmb_data(unsigned int entry)
+{
+	return mk_pmb_entry(entry) | PMB_DATA;
+}
+
+static __always_inline unsigned int pmb_ppn_in_range(unsigned long ppn)
+{
+	return ppn >= __pa(memory_start) && ppn < __pa(memory_end);
+}
+
+/*
+ * Ensure that the PMB entries match our cache configuration.
+ *
+ * When we are in 32-bit address extended mode, CCR.CB becomes
+ * invalid, so care must be taken to manually adjust cacheable
+ * translations.
+ */
+static __always_inline unsigned long pmb_cache_flags(void)
+{
+	unsigned long flags = 0;
+
+#if defined(CONFIG_CACHE_OFF)
+	flags |= PMB_WT | PMB_UB;
+#elif defined(CONFIG_CACHE_WRITETHROUGH)
+	flags |= PMB_C | PMB_WT | PMB_UB;
+#elif defined(CONFIG_CACHE_WRITEBACK)
+	flags |= PMB_C;
+#endif
+
+	return flags;
+}
+
+/*
+ * Convert typical pgprot value to the PMB equivalent
+ */
+static inline unsigned long pgprot_to_pmb_flags(pgprot_t prot)
+{
+	unsigned long pmb_flags = 0;
+	u64 flags = pgprot_val(prot);
+
+	if (flags & _PAGE_CACHABLE)
+		pmb_flags |= PMB_C;
+	if (flags & _PAGE_WT)
+		pmb_flags |= PMB_WT | PMB_UB;
+
+	return pmb_flags;
+}
+
+static inline bool pmb_can_merge(struct pmb_entry *a, struct pmb_entry *b)
+{
+	return (b->vpn == (a->vpn + a->size)) &&
+	       (b->ppn == (a->ppn + a->size)) &&
+	       (b->flags == a->flags);
+}
+
+static bool pmb_mapping_exists(unsigned long vaddr, phys_addr_t phys,
+			       unsigned long size)
+{
+	int i;
+
+	read_lock(&pmb_rwlock);
+
+	for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
+		struct pmb_entry *pmbe, *iter;
+		unsigned long span;
+
+		if (!test_bit(i, pmb_map))
+			continue;
+
+		pmbe = &pmb_entry_list[i];
+
+		/*
+		 * See if VPN and PPN are bounded by an existing mapping.
+		 */
+		if ((vaddr < pmbe->vpn) || (vaddr >= (pmbe->vpn + pmbe->size)))
+			continue;
+		if ((phys < pmbe->ppn) || (phys >= (pmbe->ppn + pmbe->size)))
+			continue;
+
+		/*
+		 * Now see if we're in range of a simple mapping.
+		 */
+		if (size <= pmbe->size) {
+			read_unlock(&pmb_rwlock);
+			return true;
+		}
+
+		span = pmbe->size;
+
+		/*
+		 * Finally for sizes that involve compound mappings, walk
+		 * the chain.
+		 */
+		for (iter = pmbe->link; iter; iter = iter->link)
+			span += iter->size;
+
+		/*
+		 * Nothing else to do if the range requirements are met.
+		 */
+		if (size <= span) {
+			read_unlock(&pmb_rwlock);
+			return true;
+		}
+	}
+
+	read_unlock(&pmb_rwlock);
+	return false;
+}
+
+static bool pmb_size_valid(unsigned long size)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
+		if (pmb_sizes[i].size == size)
+			return true;
+
+	return false;
+}
+
+static inline bool pmb_addr_valid(unsigned long addr, unsigned long size)
+{
+	return (addr >= P1SEG && (addr + size - 1) < P3SEG);
+}
+
+static inline bool pmb_prot_valid(pgprot_t prot)
+{
+	return (pgprot_val(prot) & _PAGE_USER) == 0;
+}
+
+static int pmb_size_to_flags(unsigned long size)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
+		if (pmb_sizes[i].size == size)
+			return pmb_sizes[i].flag;
+
+	return 0;
+}
+
+static int pmb_alloc_entry(void)
+{
+	int pos;
+
+	pos = find_first_zero_bit(pmb_map, NR_PMB_ENTRIES);
+	if (pos >= 0 && pos < NR_PMB_ENTRIES)
+		__set_bit(pos, pmb_map);
+	else
+		pos = -ENOSPC;
+
+	return pos;
+}
+
+static struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn,
+				   unsigned long flags, int entry)
+{
+	struct pmb_entry *pmbe;
+	unsigned long irqflags;
+	void *ret = NULL;
+	int pos;
+
+	write_lock_irqsave(&pmb_rwlock, irqflags);
+
+	if (entry == PMB_NO_ENTRY) {
+		pos = pmb_alloc_entry();
+		if (unlikely(pos < 0)) {
+			ret = ERR_PTR(pos);
+			goto out;
+		}
+	} else {
+		if (__test_and_set_bit(entry, pmb_map)) {
+			ret = ERR_PTR(-ENOSPC);
+			goto out;
+		}
+
+		pos = entry;
+	}
+
+	write_unlock_irqrestore(&pmb_rwlock, irqflags);
+
+	pmbe = &pmb_entry_list[pos];
+
+	memset(pmbe, 0, sizeof(struct pmb_entry));
+
+	raw_spin_lock_init(&pmbe->lock);
+
+	pmbe->vpn	= vpn;
+	pmbe->ppn	= ppn;
+	pmbe->flags	= flags;
+	pmbe->entry	= pos;
+
+	return pmbe;
+
+out:
+	write_unlock_irqrestore(&pmb_rwlock, irqflags);
+	return ret;
+}
+
+static void pmb_free(struct pmb_entry *pmbe)
+{
+	__clear_bit(pmbe->entry, pmb_map);
+
+	pmbe->entry	= PMB_NO_ENTRY;
+	pmbe->link	= NULL;
+}
+
+/*
+ * Must be run uncached.
+ */
+static void __set_pmb_entry(struct pmb_entry *pmbe)
+{
+	unsigned long addr, data;
+
+	addr = mk_pmb_addr(pmbe->entry);
+	data = mk_pmb_data(pmbe->entry);
+
+	jump_to_uncached();
+
+	/* Set V-bit */
+	__raw_writel(pmbe->vpn | PMB_V, addr);
+	__raw_writel(pmbe->ppn | pmbe->flags | PMB_V, data);
+
+	back_to_cached();
+}
+
+static void __clear_pmb_entry(struct pmb_entry *pmbe)
+{
+	unsigned long addr, data;
+	unsigned long addr_val, data_val;
+
+	addr = mk_pmb_addr(pmbe->entry);
+	data = mk_pmb_data(pmbe->entry);
+
+	addr_val = __raw_readl(addr);
+	data_val = __raw_readl(data);
+
+	/* Clear V-bit */
+	writel_uncached(addr_val & ~PMB_V, addr);
+	writel_uncached(data_val & ~PMB_V, data);
+}
+
+#ifdef CONFIG_PM
+static void set_pmb_entry(struct pmb_entry *pmbe)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&pmbe->lock, flags);
+	__set_pmb_entry(pmbe);
+	raw_spin_unlock_irqrestore(&pmbe->lock, flags);
+}
+#endif /* CONFIG_PM */
+
+int pmb_bolt_mapping(unsigned long vaddr, phys_addr_t phys,
+		     unsigned long size, pgprot_t prot)
+{
+	struct pmb_entry *pmbp, *pmbe;
+	unsigned long orig_addr, orig_size;
+	unsigned long flags, pmb_flags;
+	int i, mapped;
+
+	if (size < SZ_16M)
+		return -EINVAL;
+	if (!pmb_addr_valid(vaddr, size))
+		return -EFAULT;
+	if (pmb_mapping_exists(vaddr, phys, size))
+		return 0;
+
+	orig_addr = vaddr;
+	orig_size = size;
+
+	flush_tlb_kernel_range(vaddr, vaddr + size);
+
+	pmb_flags = pgprot_to_pmb_flags(prot);
+	pmbp = NULL;
+
+	do {
+		for (i = mapped = 0; i < ARRAY_SIZE(pmb_sizes); i++) {
+			if (size < pmb_sizes[i].size)
+				continue;
+
+			pmbe = pmb_alloc(vaddr, phys, pmb_flags |
+					 pmb_sizes[i].flag, PMB_NO_ENTRY);
+			if (IS_ERR(pmbe)) {
+				pmb_unmap_entry(pmbp, mapped);
+				return PTR_ERR(pmbe);
+			}
+
+			raw_spin_lock_irqsave(&pmbe->lock, flags);
+
+			pmbe->size = pmb_sizes[i].size;
+
+			__set_pmb_entry(pmbe);
+
+			phys	+= pmbe->size;
+			vaddr	+= pmbe->size;
+			size	-= pmbe->size;
+
+			/*
+			 * Link adjacent entries that span multiple PMB
+			 * entries for easier tear-down.
+			 */
+			if (likely(pmbp)) {
+				raw_spin_lock_nested(&pmbp->lock,
+						     SINGLE_DEPTH_NESTING);
+				pmbp->link = pmbe;
+				raw_spin_unlock(&pmbp->lock);
+			}
+
+			pmbp = pmbe;
+
+			/*
+			 * Instead of trying smaller sizes on every
+			 * iteration (even if we succeed in allocating
+			 * space), try using pmb_sizes[i].size again.
+			 */
+			i--;
+			mapped++;
+
+			raw_spin_unlock_irqrestore(&pmbe->lock, flags);
+		}
+	} while (size >= SZ_16M);
+
+	flush_cache_vmap(orig_addr, orig_addr + orig_size);
+
+	return 0;
+}
+
+void __iomem *pmb_remap_caller(phys_addr_t phys, unsigned long size,
+			       pgprot_t prot, void *caller)
+{
+	unsigned long vaddr;
+	phys_addr_t offset, last_addr;
+	phys_addr_t align_mask;
+	unsigned long aligned;
+	struct vm_struct *area;
+	int i, ret;
+
+	if (!pmb_iomapping_enabled)
+		return NULL;
+
+	/*
+	 * Small mappings need to go through the TLB.
+	 */
+	if (size < SZ_16M)
+		return ERR_PTR(-EINVAL);
+	if (!pmb_prot_valid(prot))
+		return ERR_PTR(-EINVAL);
+
+	for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
+		if (size >= pmb_sizes[i].size)
+			break;
+
+	last_addr = phys + size;
+	align_mask = ~(pmb_sizes[i].size - 1);
+	offset = phys & ~align_mask;
+	phys &= align_mask;
+	aligned = ALIGN(last_addr, pmb_sizes[i].size) - phys;
+
+	/*
+	 * XXX: This should really start from uncached_end, but this
+	 * causes the MMU to reset, so for now we restrict it to the
+	 * 0xb000...0xc000 range.
+	 */
+	area = __get_vm_area_caller(aligned, VM_IOREMAP, 0xb0000000,
+				    P3SEG, caller);
+	if (!area)
+		return NULL;
+
+	area->phys_addr = phys;
+	vaddr = (unsigned long)area->addr;
+
+	ret = pmb_bolt_mapping(vaddr, phys, size, prot);
+	if (unlikely(ret != 0))
+		return ERR_PTR(ret);
+
+	return (void __iomem *)(offset + (char *)vaddr);
+}
+
+int pmb_unmap(void __iomem *addr)
+{
+	struct pmb_entry *pmbe = NULL;
+	unsigned long vaddr = (unsigned long __force)addr;
+	int i, found = 0;
+
+	read_lock(&pmb_rwlock);
+
+	for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
+		if (test_bit(i, pmb_map)) {
+			pmbe = &pmb_entry_list[i];
+			if (pmbe->vpn == vaddr) {
+				found = 1;
+				break;
+			}
+		}
+	}
+
+	read_unlock(&pmb_rwlock);
+
+	if (found) {
+		pmb_unmap_entry(pmbe, NR_PMB_ENTRIES);
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static void __pmb_unmap_entry(struct pmb_entry *pmbe, int depth)
+{
+	do {
+		struct pmb_entry *pmblink = pmbe;
+
+		/*
+		 * We may be called before this pmb_entry has been
+		 * entered into the PMB table via set_pmb_entry(), but
+		 * that's OK because we've allocated a unique slot for
+		 * this entry in pmb_alloc() (even if we haven't filled
+		 * it yet).
+		 *
+		 * Therefore, calling __clear_pmb_entry() is safe as no
+		 * other mapping can be using that slot.
+		 */
+		__clear_pmb_entry(pmbe);
+
+		flush_cache_vunmap(pmbe->vpn, pmbe->vpn + pmbe->size);
+
+		pmbe = pmblink->link;
+
+		pmb_free(pmblink);
+	} while (pmbe && --depth);
+}
+
+static void pmb_unmap_entry(struct pmb_entry *pmbe, int depth)
+{
+	unsigned long flags;
+
+	if (unlikely(!pmbe))
+		return;
+
+	write_lock_irqsave(&pmb_rwlock, flags);
+	__pmb_unmap_entry(pmbe, depth);
+	write_unlock_irqrestore(&pmb_rwlock, flags);
+}
+
+static void __init pmb_notify(void)
+{
+	int i;
+
+	pr_info("PMB: boot mappings:\n");
+
+	read_lock(&pmb_rwlock);
+
+	for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
+		struct pmb_entry *pmbe;
+
+		if (!test_bit(i, pmb_map))
+			continue;
+
+		pmbe = &pmb_entry_list[i];
+
+		pr_info("       0x%08lx -> 0x%08lx [ %4ldMB %2scached ]\n",
+			pmbe->vpn >> PAGE_SHIFT, pmbe->ppn >> PAGE_SHIFT,
+			pmbe->size >> 20, (pmbe->flags & PMB_C) ? "" : "un");
+	}
+
+	read_unlock(&pmb_rwlock);
+}
+
+/*
+ * Sync our software copy of the PMB mappings with those in hardware. The
+ * mappings in the hardware PMB were either set up by the bootloader or
+ * very early on by the kernel.
+ */
+static void __init pmb_synchronize(void)
+{
+	struct pmb_entry *pmbp = NULL;
+	int i, j;
+
+	/*
+	 * Run through the initial boot mappings, log the established
+	 * ones, and blow away anything that falls outside of the valid
+	 * PPN range. Specifically, we only care about existing mappings
+	 * that impact the cached/uncached sections.
+	 *
+	 * Note that touching these can be a bit of a minefield; the boot
+	 * loader can establish multi-page mappings with the same caching
+	 * attributes, so we need to ensure that we aren't modifying a
+	 * mapping that we're presently executing from, or may execute
+	 * from in the case of straddling page boundaries.
+	 *
+	 * In the future we will have to tidy up after the boot loader by
+	 * jumping between the cached and uncached mappings and tearing
+	 * down alternating mappings while executing from the other.
+	 */
+	for (i = 0; i < NR_PMB_ENTRIES; i++) {
+		unsigned long addr, data;
+		unsigned long addr_val, data_val;
+		unsigned long ppn, vpn, flags;
+		unsigned long irqflags;
+		unsigned int size;
+		struct pmb_entry *pmbe;
+
+		addr = mk_pmb_addr(i);
+		data = mk_pmb_data(i);
+
+		addr_val = __raw_readl(addr);
+		data_val = __raw_readl(data);
+
+		/*
+		 * Skip over any bogus entries
+		 */
+		if (!(data_val & PMB_V) || !(addr_val & PMB_V))
+			continue;
+
+		ppn = data_val & PMB_PFN_MASK;
+		vpn = addr_val & PMB_PFN_MASK;
+
+		/*
+		 * Only preserve in-range mappings.
+		 */
+		if (!pmb_ppn_in_range(ppn)) {
+			/*
+			 * Invalidate anything out of bounds.
+			 */
+			writel_uncached(addr_val & ~PMB_V, addr);
+			writel_uncached(data_val & ~PMB_V, data);
+			continue;
+		}
+
+		/*
+		 * Update the caching attributes if necessary
+		 */
+		if (data_val & PMB_C) {
+			data_val &= ~PMB_CACHE_MASK;
+			data_val |= pmb_cache_flags();
+
+			writel_uncached(data_val, data);
+		}
+
+		size = data_val & PMB_SZ_MASK;
+		flags = size | (data_val & PMB_CACHE_MASK);
+
+		pmbe = pmb_alloc(vpn, ppn, flags, i);
+		if (IS_ERR(pmbe)) {
+			WARN_ON_ONCE(1);
+			continue;
+		}
+
+		raw_spin_lock_irqsave(&pmbe->lock, irqflags);
+
+		for (j = 0; j < ARRAY_SIZE(pmb_sizes); j++)
+			if (pmb_sizes[j].flag == size)
+				pmbe->size = pmb_sizes[j].size;
+
+		if (pmbp) {
+			raw_spin_lock_nested(&pmbp->lock, SINGLE_DEPTH_NESTING);
+			/*
+			 * Compare the previous entry against the current one to
+			 * see if the entries span a contiguous mapping. If so,
+			 * setup the entry links accordingly. Compound mappings
+			 * are later coalesced.
+			 */
+			if (pmb_can_merge(pmbp, pmbe))
+				pmbp->link = pmbe;
+			raw_spin_unlock(&pmbp->lock);
+		}
+
+		pmbp = pmbe;
+
+		raw_spin_unlock_irqrestore(&pmbe->lock, irqflags);
+	}
+}
+
+static void __init pmb_merge(struct pmb_entry *head)
+{
+	unsigned long span, newsize;
+	struct pmb_entry *tail;
+	int i = 1, depth = 0;
+
+	span = newsize = head->size;
+
+	tail = head->link;
+	while (tail) {
+		span += tail->size;
+
+		if (pmb_size_valid(span)) {
+			newsize = span;
+			depth = i;
+		}
+
+		/* This is the end of the line.. */
+		if (!tail->link)
+			break;
+
+		tail = tail->link;
+		i++;
+	}
+
+	/*
+	 * The merged page size must be valid.
+	 */
+	if (!depth || !pmb_size_valid(newsize))
+		return;
+
+	head->flags &= ~PMB_SZ_MASK;
+	head->flags |= pmb_size_to_flags(newsize);
+
+	head->size = newsize;
+
+	__pmb_unmap_entry(head->link, depth);
+	__set_pmb_entry(head);
+}
+
+static void __init pmb_coalesce(void)
+{
+	unsigned long flags;
+	int i;
+
+	write_lock_irqsave(&pmb_rwlock, flags);
+
+	for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
+		struct pmb_entry *pmbe;
+
+		if (!test_bit(i, pmb_map))
+			continue;
+
+		pmbe = &pmb_entry_list[i];
+
+		/*
+		 * We're only interested in compound mappings
+		 */
+		if (!pmbe->link)
+			continue;
+
+		/*
+		 * Nothing to do if it already uses the largest possible
+		 * page size.
+		 */
+		if (pmbe->size == SZ_512M)
+			continue;
+
+		pmb_merge(pmbe);
+	}
+
+	write_unlock_irqrestore(&pmb_rwlock, flags);
+}
+
+#ifdef CONFIG_UNCACHED_MAPPING
+static void __init pmb_resize(void)
+{
+	int i;
+
+	/*
+	 * If the uncached mapping was constructed by the kernel, it will
+	 * already be a reasonable size.
+	 */
+	if (uncached_size == SZ_16M)
+		return;
+
+	read_lock(&pmb_rwlock);
+
+	for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
+		struct pmb_entry *pmbe;
+		unsigned long flags;
+
+		if (!test_bit(i, pmb_map))
+			continue;
+
+		pmbe = &pmb_entry_list[i];
+
+		if (pmbe->vpn != uncached_start)
+			continue;
+
+		/*
+		 * Found it, now resize it.
+		 */
+		raw_spin_lock_irqsave(&pmbe->lock, flags);
+
+		pmbe->size = SZ_16M;
+		pmbe->flags &= ~PMB_SZ_MASK;
+		pmbe->flags |= pmb_size_to_flags(pmbe->size);
+
+		uncached_resize(pmbe->size);
+
+		__set_pmb_entry(pmbe);
+
+		raw_spin_unlock_irqrestore(&pmbe->lock, flags);
+	}
+
+	read_unlock(&pmb_rwlock);
+}
+#endif
+
+static int __init early_pmb(char *p)
+{
+	if (!p)
+		return 0;
+
+	if (strstr(p, "iomap"))
+		pmb_iomapping_enabled = 1;
+
+	return 0;
+}
+early_param("pmb", early_pmb);
+
+void __init pmb_init(void)
+{
+	/* Synchronize software state */
+	pmb_synchronize();
+
+	/* Attempt to combine compound mappings */
+	pmb_coalesce();
+
+#ifdef CONFIG_UNCACHED_MAPPING
+	/* Resize initial mappings, if necessary */
+	pmb_resize();
+#endif
+
+	/* Log them */
+	pmb_notify();
+
+	writel_uncached(0, PMB_IRMCR);
+
+	/* Flush out the TLB */
+	local_flush_tlb_all();
+	ctrl_barrier();
+}
+
+bool __in_29bit_mode(void)
+{
+        return (__raw_readl(PMB_PASCR) & PASCR_SE) == 0;
+}
+
+static int pmb_seq_show(struct seq_file *file, void *iter)
+{
+	int i;
+
+	seq_printf(file, "V: Valid, C: Cacheable, WT: Write-Through\n"
+			 "CB: Copy-Back, B: Buffered, UB: Unbuffered\n");
+	seq_printf(file, "ety   vpn  ppn  size   flags\n");
+
+	for (i = 0; i < NR_PMB_ENTRIES; i++) {
+		unsigned long addr, data;
+		unsigned int size;
+		char *sz_str = NULL;
+
+		addr = __raw_readl(mk_pmb_addr(i));
+		data = __raw_readl(mk_pmb_data(i));
+
+		size = data & PMB_SZ_MASK;
+		sz_str = (size == PMB_SZ_16M)  ? " 16MB":
+			 (size == PMB_SZ_64M)  ? " 64MB":
+			 (size == PMB_SZ_128M) ? "128MB":
+					         "512MB";
+
+		/* 02: V 0x88 0x08 128MB C CB  B */
+		seq_printf(file, "%02d: %c 0x%02lx 0x%02lx %s %c %s %s\n",
+			   i, ((addr & PMB_V) && (data & PMB_V)) ? 'V' : ' ',
+			   (addr >> 24) & 0xff, (data >> 24) & 0xff,
+			   sz_str, (data & PMB_C) ? 'C' : ' ',
+			   (data & PMB_WT) ? "WT" : "CB",
+			   (data & PMB_UB) ? "UB" : " B");
+	}
+
+	return 0;
+}
+
+static int pmb_debugfs_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, pmb_seq_show, NULL);
+}
+
+static const struct file_operations pmb_debugfs_fops = {
+	.owner		= THIS_MODULE,
+	.open		= pmb_debugfs_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int __init pmb_debugfs_init(void)
+{
+	struct dentry *dentry;
+
+	dentry = debugfs_create_file("pmb", S_IFREG | S_IRUGO,
+				     arch_debugfs_dir, NULL, &pmb_debugfs_fops);
+	if (!dentry)
+		return -ENOMEM;
+
+	return 0;
+}
+subsys_initcall(pmb_debugfs_init);
+
+#ifdef CONFIG_PM
+static void pmb_syscore_resume(void)
+{
+	struct pmb_entry *pmbe;
+	int i;
+
+	read_lock(&pmb_rwlock);
+
+	for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
+		if (test_bit(i, pmb_map)) {
+			pmbe = &pmb_entry_list[i];
+			set_pmb_entry(pmbe);
+		}
+	}
+
+	read_unlock(&pmb_rwlock);
+}
+
+static struct syscore_ops pmb_syscore_ops = {
+	.resume = pmb_syscore_resume,
+};
+
+static int __init pmb_sysdev_init(void)
+{
+	register_syscore_ops(&pmb_syscore_ops);
+	return 0;
+}
+subsys_initcall(pmb_sysdev_init);
+#endif