4 files changed, 98 insertions, 34 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 33121d6c827c..2fc1fb896afc 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -685,6 +685,7 @@ and is between 256 and 4096 characters. It is defined in the file
                         See Documentation/isdn/README.HiSax.
 
         hugepages=      [HW,X86-32,IA-64] Maximal number of HugeTLB pages.
+        hugepagesz=     [HW,IA-64,PPC] The size of the HugeTLB pages.
 
         i8042.direct    [HW] Put keyboard port into non-translated mode
         i8042.dumbkbd   [HW] Pretend that controller can only read data from
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index cbbd8b0bc8f4..9326a6962b42 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -369,18 +369,11 @@ static void __init htab_init_page_sizes(void)
          * on what is available
          */
         if (mmu_psize_defs[MMU_PAGE_16M].shift)
-                mmu_huge_psize = MMU_PAGE_16M;
+                set_huge_psize(MMU_PAGE_16M);
         /* With 4k/4level pagetables, we can't (for now) cope with a
          * huge page size < PMD_SIZE */
         else if (mmu_psize_defs[MMU_PAGE_1M].shift)
-                mmu_huge_psize = MMU_PAGE_1M;
-
-        /* Calculate HPAGE_SHIFT and sanity check it */
-        if (mmu_psize_defs[mmu_huge_psize].shift > MIN_HUGEPTE_SHIFT &&
-            mmu_psize_defs[mmu_huge_psize].shift < SID_SHIFT)
-                HPAGE_SHIFT = mmu_psize_defs[mmu_huge_psize].shift;
-        else
-                HPAGE_SHIFT = 0; /* No huge pages dude ! */
+                set_huge_psize(MMU_PAGE_1M);
 #endif /* CONFIG_HUGETLB_PAGE */
 }
 
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 71efb38d599b..a02266dad215 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -24,18 +24,17 @@
 #include <asm/cputable.h>
 #include <asm/spu.h>
 
+#define HPAGE_SHIFT_64K 16
+#define HPAGE_SHIFT_16M 24
+
 #define NUM_LOW_AREAS   (0x100000000UL >> SID_SHIFT)
 #define NUM_HIGH_AREAS  (PGTABLE_RANGE >> HTLB_AREA_SHIFT)
 
-#ifdef CONFIG_PPC_64K_PAGES
-#define HUGEPTE_INDEX_SIZE      (PMD_SHIFT-HPAGE_SHIFT)
-#else
-#define HUGEPTE_INDEX_SIZE      (PUD_SHIFT-HPAGE_SHIFT)
-#endif
-#define PTRS_PER_HUGEPTE        (1 << HUGEPTE_INDEX_SIZE)
-#define HUGEPTE_TABLE_SIZE      (sizeof(pte_t) << HUGEPTE_INDEX_SIZE)
+unsigned int hugepte_shift;
+#define PTRS_PER_HUGEPTE        (1 << hugepte_shift)
+#define HUGEPTE_TABLE_SIZE      (sizeof(pte_t) << hugepte_shift)
 
-#define HUGEPD_SHIFT            (HPAGE_SHIFT + HUGEPTE_INDEX_SIZE)
+#define HUGEPD_SHIFT            (HPAGE_SHIFT + hugepte_shift)
 #define HUGEPD_SIZE             (1UL << HUGEPD_SHIFT)
 #define HUGEPD_MASK             (~(HUGEPD_SIZE-1))
 
@@ -82,11 +81,35 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
         return 0;
 }
 
+/* Base page size affects how we walk hugetlb page tables */
+#ifdef CONFIG_PPC_64K_PAGES
+#define hpmd_offset(pud, addr)          pmd_offset(pud, addr)
+#define hpmd_alloc(mm, pud, addr)       pmd_alloc(mm, pud, addr)
+#else
+static inline
+pmd_t *hpmd_offset(pud_t *pud, unsigned long addr)
+{
+        if (HPAGE_SHIFT == HPAGE_SHIFT_64K)
+                return pmd_offset(pud, addr);
+        else
+                return (pmd_t *) pud;
+}
+static inline
+pmd_t *hpmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long addr)
+{
+        if (HPAGE_SHIFT == HPAGE_SHIFT_64K)
+                return pmd_alloc(mm, pud, addr);
+        else
+                return (pmd_t *) pud;
+}
+#endif
+
 /* Modelled after find_linux_pte() */
 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
 {
         pgd_t *pg;
         pud_t *pu;
+        pmd_t *pm;
 
         BUG_ON(get_slice_psize(mm, addr) != mmu_huge_psize);
 
@@ -96,14 +119,9 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
         if (!pgd_none(*pg)) {
                 pu = pud_offset(pg, addr);
                 if (!pud_none(*pu)) {
-#ifdef CONFIG_PPC_64K_PAGES
-                        pmd_t *pm;
-                        pm = pmd_offset(pu, addr);
+                        pm = hpmd_offset(pu, addr);
                         if (!pmd_none(*pm))
                                 return hugepte_offset((hugepd_t *)pm, addr);
-#else
-                        return hugepte_offset((hugepd_t *)pu, addr);
-#endif
                 }
         }
 
@@ -114,6 +132,7 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr)
 {
         pgd_t *pg;
         pud_t *pu;
+        pmd_t *pm;
         hugepd_t *hpdp = NULL;
 
         BUG_ON(get_slice_psize(mm, addr) != mmu_huge_psize);
@@ -124,14 +143,9 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr)
         pu = pud_alloc(mm, pg, addr);
 
         if (pu) {
-#ifdef CONFIG_PPC_64K_PAGES
-                pmd_t *pm;
-                pm = pmd_alloc(mm, pu, addr);
+                pm = hpmd_alloc(mm, pu, addr);
                 if (pm)
                         hpdp = (hugepd_t *)pm;
-#else
-                hpdp = (hugepd_t *)pu;
-#endif
         }
 
         if (! hpdp)
@@ -158,7 +172,6 @@ static void free_hugepte_range(struct mmu_gather *tlb, hugepd_t *hpdp)
                                                  PGF_CACHENUM_MASK));
 }
 
-#ifdef CONFIG_PPC_64K_PAGES
 static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
                                    unsigned long addr, unsigned long end,
                                    unsigned long floor, unsigned long ceiling)
@@ -191,7 +204,6 @@ static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
         pud_clear(pud);
         pmd_free_tlb(tlb, pmd);
 }
-#endif
 
 static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
                                    unsigned long addr, unsigned long end,
@@ -210,9 +222,15 @@ static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
                         continue;
                 hugetlb_free_pmd_range(tlb, pud, addr, next, floor, ceiling);
 #else
-                if (pud_none(*pud))
-                        continue;
-                free_hugepte_range(tlb, (hugepd_t *)pud);
+                if (HPAGE_SHIFT == HPAGE_SHIFT_64K) {
+                        if (pud_none_or_clear_bad(pud))
+                                continue;
+                        hugetlb_free_pmd_range(tlb, pud, addr, next, floor, ceiling);
+                } else {
+                        if (pud_none(*pud))
+                                continue;
+                        free_hugepte_range(tlb, (hugepd_t *)pud);
+                }
 #endif
         } while (pud++, addr = next, addr != end);
 
@@ -526,6 +544,57 @@ repeat:
         return err;
 }
 
+void set_huge_psize(int psize)
+{
+        /* Check that it is a page size supported by the hardware and
+         * that it fits within pagetable limits. */
+        if (mmu_psize_defs[psize].shift && mmu_psize_defs[psize].shift < SID_SHIFT &&
+                (mmu_psize_defs[psize].shift > MIN_HUGEPTE_SHIFT ||
+                        mmu_psize_defs[psize].shift == HPAGE_SHIFT_64K)) {
+                HPAGE_SHIFT = mmu_psize_defs[psize].shift;
+                mmu_huge_psize = psize;
+#ifdef CONFIG_PPC_64K_PAGES
+                hugepte_shift = (PMD_SHIFT-HPAGE_SHIFT);
+#else
+                if (HPAGE_SHIFT == HPAGE_SHIFT_64K)
+                        hugepte_shift = (PMD_SHIFT-HPAGE_SHIFT);
+                else
+                        hugepte_shift = (PUD_SHIFT-HPAGE_SHIFT);
+#endif
+
+        } else
+                HPAGE_SHIFT = 0;
+}
+
+static int __init hugepage_setup_sz(char *str)
+{
+        unsigned long long size;
+        int mmu_psize = -1;
+        int shift;
+
+        size = memparse(str, &str);
+
+        shift = __ffs(size);
+        switch (shift) {
+#ifndef CONFIG_PPC_64K_PAGES
+        case HPAGE_SHIFT_64K:
+                mmu_psize = MMU_PAGE_64K;
+                break;
+#endif
+        case HPAGE_SHIFT_16M:
+                mmu_psize = MMU_PAGE_16M;
+                break;
+        }
+
+        if (mmu_psize >=0 && mmu_psize_defs[mmu_psize].shift)
+                set_huge_psize(mmu_psize);
+        else
+                printk(KERN_WARNING "Invalid huge page size specified(%llu)\n", size);
+
+        return 1;
+}
+__setup("hugepagesz=", hugepage_setup_sz);
+
 static void zero_ctor(struct kmem_cache *cache, void *addr)
 {
         memset(addr, 0, kmem_cache_size(cache));
diff --git a/include/asm-powerpc/mmu-hash64.h b/include/asm-powerpc/mmu-hash64.h
index f2d7d5ded2e5..2a1b4040e20d 100644
--- a/include/asm-powerpc/mmu-hash64.h
+++ b/include/asm-powerpc/mmu-hash64.h
@@ -278,6 +278,7 @@ extern int hash_huge_page(struct mm_struct *mm, unsigned long access,
 extern int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
                              unsigned long pstart, unsigned long mode,
                              int psize, int ssize);
+extern void set_huge_psize(int psize);
 
 extern void htab_initialize(void);
 extern void htab_initialize_secondary(void);