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-rw-r--r--arch/i386/mm/highmem.c18
-rw-r--r--include/asm-i386/pgtable.h7
2 files changed, 14 insertions, 11 deletions
diff --git a/arch/i386/mm/highmem.c b/arch/i386/mm/highmem.c
index ba44000b906..f9f647cdbc7 100644
--- a/arch/i386/mm/highmem.c
+++ b/arch/i386/mm/highmem.c
@@ -38,22 +38,19 @@ void *kmap_atomic(struct page *page, enum km_type type)
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
if (!pte_none(*(kmap_pte-idx)))
BUG();
-#endif
set_pte(kmap_pte-idx, mk_pte(page, kmap_prot));
- __flush_tlb_one(vaddr);
return (void*) vaddr;
}
void kunmap_atomic(void *kvaddr, enum km_type type)
{
-#ifdef CONFIG_DEBUG_HIGHMEM
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();
+#ifdef CONFIG_DEBUG_HIGHMEM
if (vaddr >= PAGE_OFFSET && vaddr < (unsigned long)high_memory) {
dec_preempt_count();
preempt_check_resched();
@@ -62,14 +59,14 @@ void kunmap_atomic(void *kvaddr, enum km_type type)
if (vaddr != __fix_to_virt(FIX_KMAP_BEGIN+idx))
BUG();
-
+#endif
/*
- * force other mappings to Oops if they'll try to access
- * this pte without first remap it
+ * Force other mappings to Oops if they'll try to access this pte
+ * without first remap it. Keeping stale mappings around is a bad idea
+ * also, in case the page changes cacheability attributes or becomes
+ * a protected page in a hypervisor.
*/
- pte_clear(&init_mm, vaddr, kmap_pte-idx);
- __flush_tlb_one(vaddr);
-#endif
+ kpte_clear_flush(kmap_pte-idx, vaddr);
dec_preempt_count();
preempt_check_resched();
@@ -88,7 +85,6 @@ void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
set_pte(kmap_pte-idx, pfn_pte(pfn, kmap_prot));
- __flush_tlb_one(vaddr);
return (void*) vaddr;
}
diff --git a/include/asm-i386/pgtable.h b/include/asm-i386/pgtable.h
index 94c87ff4b5a..ee9696d2f67 100644
--- a/include/asm-i386/pgtable.h
+++ b/include/asm-i386/pgtable.h
@@ -441,6 +441,13 @@ extern pte_t *lookup_address(unsigned long address);
#define pte_unmap_nested(pte) do { } while (0)
#endif
+/* Clear a kernel PTE and flush it from the TLB */
+#define kpte_clear_flush(ptep, vaddr) \
+do { \
+ pte_clear(&init_mm, vaddr, ptep); \
+ __flush_tlb_one(vaddr); \
+} while (0)
+
/*
* The i386 doesn't have any external MMU info: the kernel page
* tables contain all the necessary information.