Merge branch 'v2.6.35'

4 files changed, 74 insertions, 52 deletions

diff --git a/arch/powerpc/mm/hash_low_64.S b/arch/powerpc/mm/hash_low_64.S
index a719f53921a5..3079f6b44cf5 100644
--- a/arch/powerpc/mm/hash_low_64.S
+++ b/arch/powerpc/mm/hash_low_64.S
@@ -68,9 +68,6 @@ _GLOBAL(__hash_page_4K)
         std     r8,STK_PARM(r8)(r1)
         std     r9,STK_PARM(r9)(r1)
         
-        /* Add _PAGE_PRESENT to access */
-        ori     r4,r4,_PAGE_PRESENT
-
         /* Save non-volatile registers.
          * r31 will hold "old PTE"
          * r30 is "new PTE"
@@ -347,9 +344,6 @@ _GLOBAL(__hash_page_4K)
         std     r8,STK_PARM(r8)(r1)
         std     r9,STK_PARM(r9)(r1)
 
-        /* Add _PAGE_PRESENT to access */
-        ori     r4,r4,_PAGE_PRESENT
-
         /* Save non-volatile registers.
          * r31 will hold "old PTE"
          * r30 is "new PTE"
@@ -687,9 +681,6 @@ _GLOBAL(__hash_page_64K)
         std     r8,STK_PARM(r8)(r1)
         std     r9,STK_PARM(r9)(r1)
 
-        /* Add _PAGE_PRESENT to access */
-        ori     r4,r4,_PAGE_PRESENT
-
         /* Save non-volatile registers.
          * r31 will hold "old PTE"
          * r30 is "new PTE"
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 98f262de5585..09dffe6efa46 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -871,6 +871,18 @@ static inline int subpage_protection(struct mm_struct *mm, unsigned long ea)
 }
 #endif
 
+void hash_failure_debug(unsigned long ea, unsigned long access,
+                        unsigned long vsid, unsigned long trap,
+                        int ssize, int psize, 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 psize=%d pte=0x%lx\n",
+                trap, vsid, ssize, psize, pte);
+}
+
 /* Result code is:
  *  0 - handled
  *  1 - normal page fault
@@ -955,6 +967,17 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
                 return 1;
         }
 
+        /* Add _PAGE_PRESENT to the required access perm */
+        access |= _PAGE_PRESENT;
+
+        /* Pre-check access permissions (will be re-checked atomically
+         * in __hash_page_XX but this pre-check is a fast path
+         */
+        if (access & ~pte_val(*ptep)) {
+                DBG_LOW(" no access !\n");
+                return 1;
+        }
+
 #ifdef CONFIG_HUGETLB_PAGE
         if (hugeshift)
                 return __hash_page_huge(ea, access, vsid, ptep, trap, local,
@@ -967,14 +990,6 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
         DBG_LOW(" i-pte: %016lx %016lx\n", pte_val(*ptep),
                 pte_val(*(ptep + PTRS_PER_PTE)));
 #endif
-        /* Pre-check access permissions (will be re-checked atomically
-         * in __hash_page_XX but this pre-check is a fast path
-         */
-        if (access & ~pte_val(*ptep)) {
-                DBG_LOW(" no access !\n");
-                return 1;
-        }
-
         /* Do actual hashing */
 #ifdef CONFIG_PPC_64K_PAGES
         /* If _PAGE_4K_PFN is set, make sure this is a 4k segment */
@@ -1033,6 +1048,12 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
                                             local, 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,
+                                   pte_val(*ptep));
 #ifndef CONFIG_PPC_64K_PAGES
         DBG_LOW(" o-pte: %016lx\n", pte_val(*ptep));
 #else
@@ -1051,8 +1072,7 @@ void hash_preload(struct mm_struct *mm, unsigned long ea,
         void *pgdir;
         pte_t *ptep;
         unsigned long flags;
-        int local = 0;
-        int ssize;
+        int rc, ssize, local = 0;
 
         BUG_ON(REGION_ID(ea) != USER_REGION_ID);
 
@@ -1098,11 +1118,18 @@ void hash_preload(struct mm_struct *mm, unsigned long ea,
         /* Hash it in */
 #ifdef CONFIG_PPC_HAS_HASH_64K
         if (mm->context.user_psize == MMU_PAGE_64K)
-                __hash_page_64K(ea, access, vsid, ptep, trap, local, ssize);
+                rc = __hash_page_64K(ea, access, vsid, ptep, trap, local, ssize);
         else
 #endif /* CONFIG_PPC_HAS_HASH_64K */
-                __hash_page_4K(ea, access, vsid, ptep, trap, local, ssize,
-                               subpage_protection(pgdir, ea));
+                rc = __hash_page_4K(ea, access, vsid, ptep, trap, local, ssize,
+                                    subpage_protection(pgdir, ea));
+
+        /* Dump some info in case of hash insertion failure, they should
+         * never happen so it is really useful to know if/when they do
+         */
+        if (rc == -1)
+                hash_failure_debug(ea, access, vsid, trap, ssize,
+                                   mm->context.user_psize, pte_val(*ptep));
 
         local_irq_restore(flags);
 }
diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c b/arch/powerpc/mm/hugetlbpage-hash64.c
index 199539882f92..cc5c273086cf 100644
--- a/arch/powerpc/mm/hugetlbpage-hash64.c
+++ b/arch/powerpc/mm/hugetlbpage-hash64.c
@@ -21,21 +21,13 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
         unsigned long old_pte, new_pte;
         unsigned long va, rflags, pa, sz;
         long slot;
-        int err = 1;
 
         BUG_ON(shift != mmu_psize_defs[mmu_psize].shift);
 
         /* Search the Linux page table for a match with va */
         va = hpt_va(ea, vsid, ssize);
 
-        /*
-         * Check the user's access rights to the page.  If access should be
-         * prevented then send the problem up to do_page_fault.
-         */
-        if (unlikely(access & ~pte_val(*ptep)))
-                goto out;
-        /*
-         * At this point, we have a pte (old_pte) which can be used to build
+        /* At this point, we have a pte (old_pte) which can be used to build
          * or update an HPTE. There are 2 cases:
          *
          * 1. There is a valid (present) pte with no associated HPTE (this is
@@ -49,9 +41,17 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
 
         do {
                 old_pte = pte_val(*ptep);
-                if (old_pte & _PAGE_BUSY)
-                        goto out;
+                /* If PTE busy, retry the access */
+                if (unlikely(old_pte & _PAGE_BUSY))
+                        return 0;
+                /* If PTE permissions don't match, take page fault */
+                if (unlikely(access & ~old_pte))
+                        return 1;
+                /* Try to lock the PTE, add ACCESSED and DIRTY if it was
+                 * a write access */
                 new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED;
+                if (access & _PAGE_RW)
+                        new_pte |= _PAGE_DIRTY;
         } while(old_pte != __cmpxchg_u64((unsigned long *)ptep,
                                          old_pte, new_pte));
 
@@ -121,8 +121,16 @@ repeat:
                         }
                 }
 
-                if (unlikely(slot == -2))
-                        panic("hash_huge_page: pte_insert failed\n");
+                /*
+                 * Hypervisor failure. Restore old pte and return -1
+                 * similar to __hash_page_*
+                 */
+                if (unlikely(slot == -2)) {
+                        *ptep = __pte(old_pte);
+                        hash_failure_debug(ea, access, vsid, trap, ssize,
+                                           mmu_psize, old_pte);
+                        return -1;
+                }
 
                 new_pte |= (slot << 12) & (_PAGE_F_SECOND | _PAGE_F_GIX);
         }
@@ -131,9 +139,5 @@ repeat:
          * No need to use ldarx/stdcx here
          */
         *ptep = __pte(new_pte & ~_PAGE_BUSY);
-
-        err = 0;
-
- out:
-        return err;
+        return 0;
 }
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index f47364585ecd..aa731af720c0 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -398,15 +398,15 @@ static int of_get_drconf_memory(struct device_node *memory, const u32 **dm)
 }
 
 /*
- * Retreive and validate the ibm,memblock-size property for drconf memory
+ * Retreive and validate the ibm,lmb-size property for drconf memory
  * from the device tree.
  */
-static u64 of_get_memblock_size(struct device_node *memory)
+static u64 of_get_lmb_size(struct device_node *memory)
 {
         const u32 *prop;
         u32 len;
 
-        prop = of_get_property(memory, "ibm,memblock-size", &len);
+        prop = of_get_property(memory, "ibm,lmb-size", &len);
         if (!prop || len < sizeof(unsigned int))
                 return 0;
 
@@ -562,7 +562,7 @@ static unsigned long __init numa_enforce_memory_limit(unsigned long start,
 static inline int __init read_usm_ranges(const u32 **usm)
 {
         /*
-         * For each memblock in ibm,dynamic-memory a corresponding
+         * For each lmb in ibm,dynamic-memory a corresponding
          * entry in linux,drconf-usable-memory property contains
          * a counter followed by that many (base, size) duple.
          * read the counter from linux,drconf-usable-memory
@@ -578,7 +578,7 @@ static void __init parse_drconf_memory(struct device_node *memory)
 {
         const u32 *dm, *usm;
         unsigned int n, rc, ranges, is_kexec_kdump = 0;
-        unsigned long memblock_size, base, size, sz;
+        unsigned long lmb_size, base, size, sz;
         int nid;
         struct assoc_arrays aa;
 
@@ -586,8 +586,8 @@ static void __init parse_drconf_memory(struct device_node *memory)
         if (!n)
                 return;
 
-        memblock_size = of_get_memblock_size(memory);
-        if (!memblock_size)
+        lmb_size = of_get_lmb_size(memory);
+        if (!lmb_size)
                 return;
 
         rc = of_get_assoc_arrays(memory, &aa);
@@ -611,7 +611,7 @@ static void __init parse_drconf_memory(struct device_node *memory)
                         continue;
 
                 base = drmem.base_addr;
-                size = memblock_size;
+                size = lmb_size;
                 ranges = 1;
 
                 if (is_kexec_kdump) {
@@ -1072,7 +1072,7 @@ static int hot_add_drconf_scn_to_nid(struct device_node *memory,
 {
         const u32 *dm;
         unsigned int drconf_cell_cnt, rc;
-        unsigned long memblock_size;
+        unsigned long lmb_size;
         struct assoc_arrays aa;
         int nid = -1;
 
@@ -1080,8 +1080,8 @@ static int hot_add_drconf_scn_to_nid(struct device_node *memory,
         if (!drconf_cell_cnt)
                 return -1;
 
-        memblock_size = of_get_memblock_size(memory);
-        if (!memblock_size)
+        lmb_size = of_get_lmb_size(memory);
+        if (!lmb_size)
                 return -1;
 
         rc = of_get_assoc_arrays(memory, &aa);
@@ -1100,7 +1100,7 @@ static int hot_add_drconf_scn_to_nid(struct device_node *memory,
                         continue;
 
                 if ((scn_addr < drmem.base_addr)
-                    || (scn_addr >= (drmem.base_addr + memblock_size)))
+                    || (scn_addr >= (drmem.base_addr + lmb_size)))
                         continue;
 
                 nid = of_drconf_to_nid_single(&drmem, &aa);