Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / arch / sh / mm / pmb.c
diff --git a/kernel/arch/sh/mm/pmb.c b/kernel/arch/sh/mm/pmb.c
new file mode 100644 (file)
index 0000000..7160c9f
--- /dev/null
@@ -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