1 files changed, 149 insertions, 27 deletions

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index b4e2f24a9b8f..237c8e5f2640 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -50,11 +50,69 @@ static unsigned nr_gpages;
 
 #define hugepd_none(hpd)        ((hpd).pd == 0)
 
+#ifdef CONFIG_PPC_BOOK3S_64
+/*
+ * At this point we do the placement change only for BOOK3S 64. This would
+ * possibly work on other subarchs.
+ */
+
+/*
+ * We have PGD_INDEX_SIZ = 12 and PTE_INDEX_SIZE = 8, so that we can have
+ * 16GB hugepage pte in PGD and 16MB hugepage pte at PMD;
+ */
+int pmd_huge(pmd_t pmd)
+{
+        /*
+         * leaf pte for huge page, bottom two bits != 00
+         */
+        return ((pmd_val(pmd) & 0x3) != 0x0);
+}
+
+int pud_huge(pud_t pud)
+{
+        /*
+         * leaf pte for huge page, bottom two bits != 00
+         */
+        return ((pud_val(pud) & 0x3) != 0x0);
+}
+
+int pgd_huge(pgd_t pgd)
+{
+        /*
+         * leaf pte for huge page, bottom two bits != 00
+         */
+        return ((pgd_val(pgd) & 0x3) != 0x0);
+}
+#else
+int pmd_huge(pmd_t pmd)
+{
+        return 0;
+}
+
+int pud_huge(pud_t pud)
+{
+        return 0;
+}
+
+int pgd_huge(pgd_t pgd)
+{
+        return 0;
+}
+#endif
+
+/*
+ * We have 4 cases for pgds and pmds:
+ * (1) invalid (all zeroes)
+ * (2) pointer to next table, as normal; bottom 6 bits == 0
+ * (3) leaf pte for huge page, bottom two bits != 00
+ * (4) hugepd pointer, bottom two bits == 00, next 4 bits indicate size of table
+ */
 pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift)
 {
         pgd_t *pg;
         pud_t *pu;
         pmd_t *pm;
+        pte_t *ret_pte;
         hugepd_t *hpdp = NULL;
         unsigned pdshift = PGDIR_SHIFT;
 
@@ -62,30 +120,43 @@ pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift
                 *shift = 0;
 
         pg = pgdir + pgd_index(ea);
-        if (is_hugepd(pg)) {
+
+        if (pgd_huge(*pg)) {
+                ret_pte = (pte_t *) pg;
+                goto out;
+        } else if (is_hugepd(pg))
                 hpdp = (hugepd_t *)pg;
-        } else if (!pgd_none(*pg)) {
+        else if (!pgd_none(*pg)) {
                 pdshift = PUD_SHIFT;
                 pu = pud_offset(pg, ea);
-                if (is_hugepd(pu))
+
+                if (pud_huge(*pu)) {
+                        ret_pte = (pte_t *) pu;
+                        goto out;
+                } else if (is_hugepd(pu))
                         hpdp = (hugepd_t *)pu;
                 else if (!pud_none(*pu)) {
                         pdshift = PMD_SHIFT;
                         pm = pmd_offset(pu, ea);
-                        if (is_hugepd(pm))
+
+                        if (pmd_huge(*pm)) {
+                                ret_pte = (pte_t *) pm;
+                                goto out;
+                        } else if (is_hugepd(pm))
                                 hpdp = (hugepd_t *)pm;
-                        else if (!pmd_none(*pm)) {
+                        else if (!pmd_none(*pm))
                                 return pte_offset_kernel(pm, ea);
-                        }
                 }
         }
-
         if (!hpdp)
                 return NULL;
 
+        ret_pte = hugepte_offset(hpdp, ea, pdshift);
+        pdshift = hugepd_shift(*hpdp);
+out:
         if (shift)
-                *shift = hugepd_shift(*hpdp);
-        return hugepte_offset(hpdp, ea, pdshift);
+                *shift = pdshift;
+        return ret_pte;
 }
 EXPORT_SYMBOL_GPL(find_linux_pte_or_hugepte);
 
@@ -165,6 +236,61 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
 #define HUGEPD_PUD_SHIFT PMD_SHIFT
 #endif
 
+#ifdef CONFIG_PPC_BOOK3S_64
+/*
+ * At this point we do the placement change only for BOOK3S 64. This would
+ * possibly work on other subarchs.
+ */
+pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
+{
+        pgd_t *pg;
+        pud_t *pu;
+        pmd_t *pm;
+        hugepd_t *hpdp = NULL;
+        unsigned pshift = __ffs(sz);
+        unsigned pdshift = PGDIR_SHIFT;
+
+        addr &= ~(sz-1);
+        pg = pgd_offset(mm, addr);
+
+        if (pshift == PGDIR_SHIFT)
+                /* 16GB huge page */
+                return (pte_t *) pg;
+        else if (pshift > PUD_SHIFT)
+                /*
+                 * We need to use hugepd table
+                 */
+                hpdp = (hugepd_t *)pg;
+        else {
+                pdshift = PUD_SHIFT;
+                pu = pud_alloc(mm, pg, addr);
+                if (pshift == PUD_SHIFT)
+                        return (pte_t *)pu;
+                else if (pshift > PMD_SHIFT)
+                        hpdp = (hugepd_t *)pu;
+                else {
+                        pdshift = PMD_SHIFT;
+                        pm = pmd_alloc(mm, pu, addr);
+                        if (pshift == PMD_SHIFT)
+                                /* 16MB hugepage */
+                                return (pte_t *)pm;
+                        else
+                                hpdp = (hugepd_t *)pm;
+                }
+        }
+        if (!hpdp)
+                return NULL;
+
+        BUG_ON(!hugepd_none(*hpdp) && !hugepd_ok(*hpdp));
+
+        if (hugepd_none(*hpdp) && __hugepte_alloc(mm, hpdp, addr, pdshift, pshift))
+                return NULL;
+
+        return hugepte_offset(hpdp, addr, pdshift);
+}
+
+#else
+
 pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
 {
         pgd_t *pg;
@@ -202,6 +328,7 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz
 
         return hugepte_offset(hpdp, addr, pdshift);
 }
+#endif
 
 #ifdef CONFIG_PPC_FSL_BOOK3E
 /* Build list of addresses of gigantic pages.  This function is used in early
@@ -465,7 +592,7 @@ static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
         do {
                 pmd = pmd_offset(pud, addr);
                 next = pmd_addr_end(addr, end);
-                if (pmd_none(*pmd))
+                if (pmd_none_or_clear_bad(pmd))
                         continue;
 #ifdef CONFIG_PPC_FSL_BOOK3E
                 /*
@@ -618,16 +745,6 @@ follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
         return page;
 }
 
-int pmd_huge(pmd_t pmd)
-{
-        return 0;
-}
-
-int pud_huge(pud_t pud)
-{
-        return 0;
-}
-
 struct page *
 follow_huge_pmd(struct mm_struct *mm, unsigned long address,
                 pmd_t *pmd, int write)
@@ -636,8 +753,8 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address,
         return NULL;
 }
 
-static noinline int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
-                       unsigned long end, int write, struct page **pages, int *nr)
+int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
+                unsigned long end, int write, struct page **pages, int *nr)
 {
         unsigned long mask;
         unsigned long pte_end;
@@ -873,11 +990,16 @@ static int __init hugetlbpage_init(void)
                         pdshift = PUD_SHIFT;
                 else
                         pdshift = PGDIR_SHIFT;
-
-                pgtable_cache_add(pdshift - shift, NULL);
-                if (!PGT_CACHE(pdshift - shift))
-                        panic("hugetlbpage_init(): could not create "
-                              "pgtable cache for %d bit pagesize\n", shift);
+                /*
+                 * if we have pdshift and shift value same, we don't
+                 * use pgt cache for hugepd.
+                 */
+                if (pdshift != shift) {
+                        pgtable_cache_add(pdshift - shift, NULL);
+                        if (!PGT_CACHE(pdshift - shift))
+                                panic("hugetlbpage_init(): could not create "
+                                      "pgtable cache for %d bit pagesize\n", shift);
+                }
         }
 
         /* Set default large page size. Currently, we pick 16M or 1M