From 2d3e3caa2098b2d742cacfce44a275c67df6c981 Mon Sep 17 00:00:00 2001
From: Zachary Amsden <zach@vmware.com>
Date: Sat, 30 Sep 2006 23:29:35 -0700
Subject: [PATCH] --- yaml --- r: 37737 b: refs/heads/master c:
 23002d88be309a7c78db69363c9d933a29a3b0bb h: refs/heads/master i:   37735:
 665a004fc18b8e6ed27c227bfea133c46b6255d9 v: v3

---
 [refs]                           |  2 +-
 trunk/arch/i386/mm/highmem.c     | 18 +++++++-----------
 trunk/include/asm-i386/pgtable.h |  7 +++++++
 3 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/[refs] b/[refs]
index bd1154d3a661..ccfef75a3356 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 25e4df5bae333a06cd2c9b88baf14432652dc9f7
+refs/heads/master: 23002d88be309a7c78db69363c9d933a29a3b0bb
diff --git a/trunk/arch/i386/mm/highmem.c b/trunk/arch/i386/mm/highmem.c
index ba44000b9069..f9f647cdbc7b 100644
--- a/trunk/arch/i386/mm/highmem.c
+++ b/trunk/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/trunk/include/asm-i386/pgtable.h b/trunk/include/asm-i386/pgtable.h
index 94c87ff4b5ac..ee9696d2f67f 100644
--- a/trunk/include/asm-i386/pgtable.h
+++ b/trunk/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.