X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fi386%2Fmm%2Fhighmem-xen.c;h=4b5d9e3dbf091b0161c94093b3a4148af6ff580f;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=23f0e1b2e926fbeb4bd1c7ed7fe62595badcf245;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git

diff --git a/arch/i386/mm/highmem-xen.c b/arch/i386/mm/highmem-xen.c
index 23f0e1b2e..4b5d9e3db 100644
--- a/arch/i386/mm/highmem-xen.c
+++ b/arch/i386/mm/highmem-xen.c
@@ -32,17 +32,15 @@ static void *__kmap_atomic(struct page *page, enum km_type type, pgprot_t prot)
 	unsigned long vaddr;
 
 	/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
-	inc_preempt_count();
+	pagefault_disable();
 	if (!PageHighMem(page))
 		return page_address(page);
 
 	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_at_sync(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot));
+	set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot));
 
 	return (void*) vaddr;
 }
@@ -60,39 +58,26 @@ void *kmap_atomic_pte(struct page *page, enum km_type type)
 
 void kunmap_atomic(void *kvaddr, enum km_type type)
 {
-#if defined(CONFIG_DEBUG_HIGHMEM) || defined(CONFIG_XEN)
 	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
 	enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();
 
-	if (vaddr < FIXADDR_START) { // FIXME
-		dec_preempt_count();
-		preempt_check_resched();
-		return;
-	}
-#endif
-
-#if defined(CONFIG_DEBUG_HIGHMEM)
-	if (vaddr != __fix_to_virt(FIX_KMAP_BEGIN+idx))
-		BUG();
-
-	/*
-	 * force other mappings to Oops if they'll try to access
-	 * this pte without first remap it
-	 */
-	pte_clear(&init_mm, vaddr, kmap_pte-idx);
-	__flush_tlb_one(vaddr);
-#elif defined(CONFIG_XEN)
 	/*
-	 * We must ensure there are no dangling pagetable references when
-	 * returning memory to Xen (decrease_reservation).
-	 * XXX TODO: We could make this faster by only zapping when
-	 * kmap_flush_unused is called but that is trickier and more invasive.
+	 * 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);
+	if (vaddr == __fix_to_virt(FIX_KMAP_BEGIN+idx)) {
+		kpte_clear_flush(kmap_pte-idx, vaddr);
+		__flush_tlb_one(vaddr);
+	} else {
+#ifdef CONFIG_DEBUG_HIGHMEM
+		BUG_ON(vaddr < PAGE_OFFSET);
+		BUG_ON(vaddr >= (unsigned long)high_memory);
 #endif
+	}
 
-	dec_preempt_count();
-	preempt_check_resched();
+	pagefault_enable();
 }
 
 /* This is the same as kmap_atomic() but can map memory that doesn't
@@ -103,12 +88,11 @@ void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
 	enum fixed_addresses idx;
 	unsigned long vaddr;
 
-	inc_preempt_count();
+	pagefault_disable();
 
 	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;
 }