powerpc/book3s64/mm: Simplify the rcu callback for page table free

Instead of encoding shift in the table address, use an enumerated index value.
This allow us to do different things in the callback for pte and pmd.

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/pgalloc.h b/arch/powerpc/include/asm/book3s/64/pgalloc.h
index 826171568192ed576f45b2c711eacb726c01ea51..ed313b8d3facdf11d5556dbe74e923f07e6c57de 100644 (file)
--- a/arch/powerpc/include/asm/book3s/64/pgalloc.h
+++ b/arch/powerpc/include/asm/book3s/64/pgalloc.h
@@ -124,14 +124,14 @@ static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
 }
 
 static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
-                                  unsigned long address)
+                                 unsigned long address)
 {
        /*
         * By now all the pud entries should be none entries. So go
         * ahead and flush the page walk cache
         */
        flush_tlb_pgtable(tlb, address);
-       pgtable_free_tlb(tlb, pud, PUD_CACHE_INDEX);
+       pgtable_free_tlb(tlb, pud, PUD_INDEX);
 }
 
 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
@@ -146,14 +146,14 @@ static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
 }
 
 static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
-                                  unsigned long address)
+                                 unsigned long address)
 {
        /*
         * By now all the pud entries should be none entries. So go
         * ahead and flush the page walk cache
         */
        flush_tlb_pgtable(tlb, address);
-        return pgtable_free_tlb(tlb, pmd, PMD_CACHE_INDEX);
+       return pgtable_free_tlb(tlb, pmd, PMD_INDEX);
 }
 
 static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
@@ -203,7 +203,7 @@ static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
         * ahead and flush the page walk cache
         */
        flush_tlb_pgtable(tlb, address);
-       pgtable_free_tlb(tlb, table, 0);
+       pgtable_free_tlb(tlb, table, PTE_INDEX);
 }
 
 #define check_pgt_cache()      do { } while (0)

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 47b5ffc8715d9c02e342c31459f201d66c7de399..9462bc18806c5e74211edc5800b715c4c6dcce15 100644 (file)
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -273,6 +273,16 @@ extern unsigned long __pte_frag_size_shift;
 /* Bits to mask out from a PGD to get to the PUD page */
 #define PGD_MASKED_BITS                0xc0000000000000ffUL
 
+/*
+ * Used as an indicator for rcu callback functions
+ */
+enum pgtable_index {
+       PTE_INDEX = 0,
+       PMD_INDEX,
+       PUD_INDEX,
+       PGD_INDEX,
+};
+
 extern unsigned long __vmalloc_start;
 extern unsigned long __vmalloc_end;
 #define VMALLOC_START  __vmalloc_start

diff --git a/arch/powerpc/mm/pgtable-book3s64.c b/arch/powerpc/mm/pgtable-book3s64.c
index fc42cccb96c7c8bba4742b64eea88d18f5f4c71b..0a05e99b54a1d81ecd111be3ff7291fc4d7bc189 100644 (file)
--- a/arch/powerpc/mm/pgtable-book3s64.c
+++ b/arch/powerpc/mm/pgtable-book3s64.c
@@ -309,38 +309,45 @@ void pte_fragment_free(unsigned long *table, int kernel)
        }
 }
 
+static inline void pgtable_free(void *table, int index)
+{
+       switch (index) {
+       case PTE_INDEX:
+               pte_fragment_free(table, 0);
+               break;
+       case PMD_INDEX:
+               kmem_cache_free(PGT_CACHE(PMD_CACHE_INDEX), table);
+               break;
+       case PUD_INDEX:
+               kmem_cache_free(PGT_CACHE(PUD_CACHE_INDEX), table);
+               break;
+               /* We don't free pgd table via RCU callback */
+       default:
+               BUG();
+       }
+}
+
 #ifdef CONFIG_SMP
-void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
+void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int index)
 {
        unsigned long pgf = (unsigned long)table;
 
-       BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
-       pgf |= shift;
+       BUG_ON(index > MAX_PGTABLE_INDEX_SIZE);
+       pgf |= index;
        tlb_remove_table(tlb, (void *)pgf);
 }
 
 void __tlb_remove_table(void *_table)
 {
        void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
-       unsigned int shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
+       unsigned int index = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
 
-       if (!shift)
-               /* PTE page needs special handling */
-               pte_fragment_free(table, 0);
-       else {
-               BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
-               kmem_cache_free(PGT_CACHE(shift), table);
-       }
+       return pgtable_free(table, index);
 }
 #else
-void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
+void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int index)
 {
-       if (!shift) {
-               /* PTE page needs special handling */
-               pte_fragment_free(table, 0);
-       } else {
-               BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
-               kmem_cache_free(PGT_CACHE(shift), table);
-       }
+
+       return pgtable_free(table, index);
 }
 #endif