powerpc/mm: Fix little-endian 4K hugetlb

When we switched to big endian page table, we never updated the hugepd
format such that it can work for both big endian and little endian
config. This patch series update hugepd format such that it is looked at
as __be64 value in big endian page table config.

This patch also switch hugepd_t.pd from signed long to unsigned long.
I did update the FSL hugepd_ok check to check for the top bit instead
of checking > 0.

Fixes: 5dc1ef858c12 ("powerpc/mm: Use big endian Linux page tables for book3s 64")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/include/asm/book3s/64/hash-4k.h b/arch/powerpc/include/asm/book3s/64/hash-4k.h
index 1c64bc6330bc0b9f70b71038e678fd110e6e1456..0c4e470571ca0faa74d3e9fa38fa57a384cab4bf 100644 (file)
--- a/arch/powerpc/include/asm/book3s/64/hash-4k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-4k.h
@@ -36,12 +36,13 @@
 #ifdef CONFIG_HUGETLB_PAGE
 static inline int hash__hugepd_ok(hugepd_t hpd)
 {
+       unsigned long hpdval = hpd_val(hpd);
        /*
         * if it is not a pte and have hugepd shift mask
         * set, then it is a hugepd directory pointer
         */
-       if (!(hpd.pd & _PAGE_PTE) &&
-           ((hpd.pd & HUGEPD_SHIFT_MASK) != 0))
+       if (!(hpdval & _PAGE_PTE) &&
+           ((hpdval & HUGEPD_SHIFT_MASK) != 0))
                return true;
        return false;
 }

diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
index ede215167d1ad4f37f4d732c0eeaeee5cbd58bd4..7f4025a6c69ea5b71b340989b35197d8f9d17b91 100644 (file)
--- a/arch/powerpc/include/asm/hugetlb.h
+++ b/arch/powerpc/include/asm/hugetlb.h
@@ -21,12 +21,12 @@ static inline pte_t *hugepd_page(hugepd_t hpd)
         * We have only four bits to encode, MMU page size
         */
        BUILD_BUG_ON((MMU_PAGE_COUNT - 1) > 0xf);
-       return __va(hpd.pd & HUGEPD_ADDR_MASK);
+       return __va(hpd_val(hpd) & HUGEPD_ADDR_MASK);
 }
 
 static inline unsigned int hugepd_mmu_psize(hugepd_t hpd)
 {
-       return (hpd.pd & HUGEPD_SHIFT_MASK) >> 2;
+       return (hpd_val(hpd) & HUGEPD_SHIFT_MASK) >> 2;
 }
 
 static inline unsigned int hugepd_shift(hugepd_t hpd)
@@ -52,18 +52,20 @@ static inline pte_t *hugepd_page(hugepd_t hpd)
 {
        BUG_ON(!hugepd_ok(hpd));
 #ifdef CONFIG_PPC_8xx
-       return (pte_t *)__va(hpd.pd & ~(_PMD_PAGE_MASK | _PMD_PRESENT_MASK));
+       return (pte_t *)__va(hpd_val(hpd) &
+                            ~(_PMD_PAGE_MASK | _PMD_PRESENT_MASK));
 #else
-       return (pte_t *)((hpd.pd & ~HUGEPD_SHIFT_MASK) | PD_HUGE);
+       return (pte_t *)((hpd_val(hpd) &
+                         ~HUGEPD_SHIFT_MASK) | PD_HUGE);
 #endif
 }
 
 static inline unsigned int hugepd_shift(hugepd_t hpd)
 {
 #ifdef CONFIG_PPC_8xx
-       return ((hpd.pd & _PMD_PAGE_MASK) >> 1) + 17;
+       return ((hpd_val(hpd) & _PMD_PAGE_MASK) >> 1) + 17;
 #else
-       return hpd.pd & HUGEPD_SHIFT_MASK;
+       return hpd_val(hpd) & HUGEPD_SHIFT_MASK;
 #endif
 }
 

diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
index 172849727054e179ea1bd58e24e2d85118ed8f91..0cd8a3852763292eabe905b33960f888e875c978 100644 (file)
--- a/arch/powerpc/include/asm/nohash/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/pgtable.h
@@ -227,9 +227,10 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 static inline int hugepd_ok(hugepd_t hpd)
 {
 #ifdef CONFIG_PPC_8xx
-       return ((hpd.pd & 0x4) != 0);
+       return ((hpd_val(hpd) & 0x4) != 0);
 #else
-       return (hpd.pd > 0);
+       /* We clear the top bit to indicate hugepd */
+       return ((hpd_val(hpd) & PD_HUGE) ==  0);
 #endif
 }
 

diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 56398e7e61004d7766f8e77627df54e73f7e75bf..47120bf2670c49f224744445c5dc154f0de60b31 100644 (file)
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -294,15 +294,12 @@ extern long long virt_phys_offset;
 #include <asm/pgtable-types.h>
 #endif
 
-typedef struct { signed long pd; } hugepd_t;
 
 #ifndef CONFIG_HUGETLB_PAGE
 #define is_hugepd(pdep)                (0)
 #define pgd_huge(pgd)          (0)
 #endif /* CONFIG_HUGETLB_PAGE */
 
-#define __hugepd(x) ((hugepd_t) { (x) })
-
 struct page;
 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
 extern void copy_user_page(void *to, void *from, unsigned long vaddr,

diff --git a/arch/powerpc/include/asm/pgtable-be-types.h b/arch/powerpc/include/asm/pgtable-be-types.h
index 49c0a5a80efa2948764e247d3cbd76fc6fdf06a0..9c0f5db5cf461a92e72185701b4cbc1df168dfcc 100644 (file)
--- a/arch/powerpc/include/asm/pgtable-be-types.h
+++ b/arch/powerpc/include/asm/pgtable-be-types.h
@@ -104,4 +104,12 @@ static inline bool pmd_xchg(pmd_t *pmdp, pmd_t old, pmd_t new)
        return pmd_raw(old) == prev;
 }
 
+typedef struct { __be64 pdbe; } hugepd_t;
+#define __hugepd(x) ((hugepd_t) { cpu_to_be64(x) })
+
+static inline unsigned long hpd_val(hugepd_t x)
+{
+       return be64_to_cpu(x.pdbe);
+}
+
 #endif /* _ASM_POWERPC_PGTABLE_BE_TYPES_H */

diff --git a/arch/powerpc/include/asm/pgtable-types.h b/arch/powerpc/include/asm/pgtable-types.h
index e7f4f3e0fcde94ba237fa2a269c32d40458cc8f2..8bd3b13fe2fb2e8bd1c5762c4e080c9cd921edaa 100644 (file)
--- a/arch/powerpc/include/asm/pgtable-types.h
+++ b/arch/powerpc/include/asm/pgtable-types.h
@@ -66,4 +66,11 @@ static inline bool pte_xchg(pte_t *ptep, pte_t old, pte_t new)
 }
 #endif
 
+typedef struct { unsigned long pd; } hugepd_t;
+#define __hugepd(x) ((hugepd_t) { (x) })
+static inline unsigned long hpd_val(hugepd_t x)
+{
+       return x.pd;
+}
+
 #endif /* _ASM_POWERPC_PGTABLE_TYPES_H */

diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c b/arch/powerpc/mm/hugetlbpage-hash64.c
index d5026f3800b6129bc4c05ef303b4c37d80065cc0..37b5f91e381b77d545b5c336e60aecb0194dcd7d 100644 (file)
--- a/arch/powerpc/mm/hugetlbpage-hash64.c
+++ b/arch/powerpc/mm/hugetlbpage-hash64.c
@@ -125,11 +125,14 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
 int hugepd_ok(hugepd_t hpd)
 {
        bool is_hugepd;
+       unsigned long hpdval;
+
+       hpdval = hpd_val(hpd);
 
        /*
         * We should not find this format in page directory, warn otherwise.
         */
-       is_hugepd = (((hpd.pd & 0x3) == 0x0) && ((hpd.pd & HUGEPD_SHIFT_MASK) != 0));
+       is_hugepd = (((hpdval & 0x3) == 0x0) && ((hpdval & HUGEPD_SHIFT_MASK) != 0));
        WARN(is_hugepd, "Found wrong page directory format\n");
        return 0;
 }

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 8797df11c51f6b08d34ad2c11cec9778652a788e..8c3389cbcd12216ef7b71884163322255f76ea68 100644 (file)
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -53,7 +53,7 @@ static u64 gpage_freearray[MAX_NUMBER_GPAGES];
 static unsigned nr_gpages;
 #endif
 
-#define hugepd_none(hpd)       ((hpd).pd == 0)
+#define hugepd_none(hpd)       (hpd_val(hpd) == 0)
 
 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
 {
@@ -103,24 +103,24 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
        for (i = 0; i < num_hugepd; i++, hpdp++) {
                if (unlikely(!hugepd_none(*hpdp)))
                        break;
-               else
+               else {
 #ifdef CONFIG_PPC_BOOK3S_64
-                       hpdp->pd = __pa(new) |
-                                  (shift_to_mmu_psize(pshift) << 2);
+                       *hpdp = __hugepd(__pa(new) |
+                                        (shift_to_mmu_psize(pshift) << 2));
 #elif defined(CONFIG_PPC_8xx)
-                       hpdp->pd = __pa(new) |
-                                  (pshift == PAGE_SHIFT_8M ? _PMD_PAGE_8M :
-                                                             _PMD_PAGE_512K) |
-                                  _PMD_PRESENT;
+                       *hpdp = __hugepd(__pa(new) |
+                                        (pshift == PAGE_SHIFT_8M ? _PMD_PAGE_8M :
+                                         _PMD_PAGE_512K) | _PMD_PRESENT);
 #else
                        /* We use the old format for PPC_FSL_BOOK3E */
-                       hpdp->pd = ((unsigned long)new & ~PD_HUGE) | pshift;
+                       *hpdp = __hugepd(((unsigned long)new & ~PD_HUGE) | pshift);
 #endif
+               }
        }
        /* If we bailed from the for loop early, an error occurred, clean up */
        if (i < num_hugepd) {
                for (i = i - 1 ; i >= 0; i--, hpdp--)
-                       hpdp->pd = 0;
+                       *hpdp = __hugepd(0);
                kmem_cache_free(cachep, new);
        }
        spin_unlock(&mm->page_table_lock);
@@ -454,7 +454,7 @@ static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshif
                return;
 
        for (i = 0; i < num_hugepd; i++, hpdp++)
-               hpdp->pd = 0;
+               *hpdp = __hugepd(0);
 
        if (shift >= pdshift)
                hugepd_free(tlb, hugepte);