sparc64: use RCU page table freeing
David S. Miller [Tue, 26 Jul 2011 00:12:21 +0000 (17:12 -0700)]
Make use of the generic RCU page table freeing on Sparc64, doing so allows
for race-free software page-table walkers like gup_fast().

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/sparc/Kconfig
arch/sparc/include/asm/pgalloc_64.h

index af64348..1074ddd 100644 (file)
@@ -41,6 +41,7 @@ config SPARC64
        select HAVE_FUNCTION_TRACE_MCOUNT_TEST
        select HAVE_KRETPROBES
        select HAVE_KPROBES
+       select HAVE_RCU_TABLE_FREE if SMP
        select HAVE_MEMBLOCK
        select HAVE_SYSCALL_WRAPPERS
        select HAVE_DYNAMIC_FTRACE
index cb4867d..40b2d7a 100644 (file)
@@ -76,7 +76,51 @@ static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
 
 #define check_pgt_cache()      do { } while (0)
 
-#define __pte_free_tlb(tlb, pte, addr) pte_free((tlb)->mm, pte)
-#define __pmd_free_tlb(tlb, pmd, addr) pmd_free((tlb)->mm, pmd)
+static inline void pgtable_free(void *table, bool is_page)
+{
+       if (is_page)
+               free_page((unsigned long)table);
+       else
+               kmem_cache_free(pgtable_cache, table);
+}
+
+#ifdef CONFIG_SMP
+
+struct mmu_gather;
+extern void tlb_remove_table(struct mmu_gather *, void *);
+
+static inline void pgtable_free_tlb(struct mmu_gather *tlb, void *table, bool is_page)
+{
+       unsigned long pgf = (unsigned long)table;
+       if (is_page)
+               pgf |= 0x1UL;
+       tlb_remove_table(tlb, (void *)pgf);
+}
+
+static inline void __tlb_remove_table(void *_table)
+{
+       void *table = (void *)((unsigned long)_table & ~0x1UL);
+       bool is_page = false;
+
+       if ((unsigned long)_table & 0x1UL)
+               is_page = true;
+       pgtable_free(table, is_page);
+}
+#else /* CONFIG_SMP */
+static inline void pgtable_free_tlb(struct mmu_gather *tlb, void *table, bool is_page)
+{
+       pgtable_free(table, is_page);
+}
+#endif /* !CONFIG_SMP */
+
+static inline void __pte_free_tlb(struct mmu_gather *tlb, struct page *ptepage,
+                                 unsigned long address)
+{
+       pgtable_page_dtor(ptepage);
+       pgtable_free_tlb(tlb, page_address(ptepage), true);
+}
+
+#define __pmd_free_tlb(tlb, pmd, addr)               \
+       pgtable_free_tlb(tlb, pmd, false)
 
 #endif /* _SPARC64_PGALLOC_H */