sh: Flush only the needed range when unmapping a VMA.

[cascardo/linux.git] / arch / sh / include / asm / tlb.h

diff --git a/arch/sh/include/asm/tlb.h b/arch/sh/include/asm/tlb.h
index 88ff1ae..9c16f73 100644 (file)
--- a/arch/sh/include/asm/tlb.h
+++ b/arch/sh/include/asm/tlb.h
@@ -6,22 +6,106 @@
 #endif
 
 #ifndef __ASSEMBLY__
+#include <linux/pagemap.h>
+
+#ifdef CONFIG_MMU
+#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
+
+/*
+ * TLB handling.  This allows us to remove pages from the page
+ * tables, and efficiently handle the TLB issues.
+ */
+struct mmu_gather {
+       struct mm_struct        *mm;
+       unsigned int            fullmm;
+       unsigned long           start, end;
+};
 
-#define tlb_start_vma(tlb, vma) \
-       flush_cache_range(vma, vma->vm_start, vma->vm_end)
+DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
 
-#define tlb_end_vma(tlb, vma)  \
-       flush_tlb_range(vma, vma->vm_start, vma->vm_end)
+static inline void init_tlb_gather(struct mmu_gather *tlb)
+{
+       tlb->start = TASK_SIZE;
+       tlb->end = 0;
 
-#define __tlb_remove_tlb_entry(tlb, pte, address)      do { } while (0)
+       if (tlb->fullmm) {
+               tlb->start = 0;
+               tlb->end = TASK_SIZE;
+       }
+}
+
+static inline struct mmu_gather *
+tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
+{
+       struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);
+
+       tlb->mm = mm;
+       tlb->fullmm = full_mm_flush;
+
+       init_tlb_gather(tlb);
+
+       return tlb;
+}
+
+static inline void
+tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
+{
+       if (tlb->fullmm)
+               flush_tlb_mm(tlb->mm);
+
+       /* keep the page table cache within bounds */
+       check_pgt_cache();
+
+       put_cpu_var(mmu_gathers);
+}
+
+static inline void
+tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep, unsigned long address)
+{
+       if (tlb->start > address)
+               tlb->start = address;
+       if (tlb->end < address + PAGE_SIZE)
+               tlb->end = address + PAGE_SIZE;
+}
 
 /*
- * Flush whole TLBs for MM
+ * In the case of tlb vma handling, we can optimise these away in the
+ * case where we're doing a full MM flush.  When we're doing a munmap,
+ * the vmas are adjusted to only cover the region to be torn down.
  */
-#define tlb_flush(tlb)                         flush_tlb_mm((tlb)->mm)
+static inline void
+tlb_start_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
+{
+       if (!tlb->fullmm)
+               flush_cache_range(vma, vma->vm_start, vma->vm_end);
+}
+
+static inline void
+tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
+{
+       if (!tlb->fullmm && tlb->end) {
+               flush_tlb_range(vma, tlb->start, tlb->end);
+               init_tlb_gather(tlb);
+       }
+}
+
+#define tlb_remove_page(tlb,page)      free_page_and_swap_cache(page)
+#define pte_free_tlb(tlb, ptep)                pte_free((tlb)->mm, ptep)
+#define pmd_free_tlb(tlb, pmdp)                pmd_free((tlb)->mm, pmdp)
+#define pud_free_tlb(tlb, pudp)                pud_free((tlb)->mm, pudp)
+
+#define tlb_migrate_finish(mm)         do { } while (0)
+
+#else /* CONFIG_MMU */
+
+#define tlb_start_vma(tlb, vma)                                do { } while (0)
+#define tlb_end_vma(tlb, vma)                          do { } while (0)
+#define __tlb_remove_tlb_entry(tlb, pte, address)      do { } while (0)
+#define tlb_flush(tlb)                                 do { } while (0)
 
-#include <linux/pagemap.h>
 #include <asm-generic/tlb.h>
 
+#endif /* CONFIG_MMU */
 #endif /* __ASSEMBLY__ */
 #endif /* __ASM_SH_TLB_H */