X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fi386%2Fmm%2Fhighmem.c;h=e0fa6cb655a82574a50c3e8fc9334c2f71b9c156;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=22169861012129bb8183f6ae2487ff0fd03ba25d;hpb=6a77f38946aaee1cd85eeec6cf4229b204c15071;p=linux-2.6.git

diff --git a/arch/i386/mm/highmem.c b/arch/i386/mm/highmem.c
index 221698610..e0fa6cb65 100644
--- a/arch/i386/mm/highmem.c
+++ b/arch/i386/mm/highmem.c
@@ -1,4 +1,5 @@
 #include <linux/highmem.h>
+#include <linux/module.h>
 
 void *kmap(struct page *page)
 {
@@ -31,47 +32,57 @@ void *kmap_atomic(struct page *page, enum km_type type)
 	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(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();
 
-	if (vaddr < FIXADDR_START) { // FIXME
-		dec_preempt_count();
-		preempt_check_resched();
-		return;
-	}
-
-	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
+	 * 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(kmap_pte-idx);
-	__flush_tlb_one(vaddr);
+	if (vaddr == __fix_to_virt(FIX_KMAP_BEGIN+idx))
+		kpte_clear_flush(kmap_pte-idx, vaddr);
+	else {
+#ifdef CONFIG_DEBUG_HIGHMEM
+		BUG_ON(vaddr < PAGE_OFFSET);
+		BUG_ON(vaddr >= (unsigned long)high_memory);
 #endif
+	}
+
+	pagefault_enable();
+}
+
+/* This is the same as kmap_atomic() but can map memory that doesn't
+ * have a struct page associated with it.
+ */
+void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
+{
+	enum fixed_addresses idx;
+	unsigned long vaddr;
 
-	dec_preempt_count();
-	preempt_check_resched();
+	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));
+
+	return (void*) vaddr;
 }
 
 struct page *kmap_atomic_to_page(void *ptr)
@@ -87,3 +98,8 @@ struct page *kmap_atomic_to_page(void *ptr)
 	return pte_page(*pte);
 }
 
+EXPORT_SYMBOL(kmap);
+EXPORT_SYMBOL(kunmap);
+EXPORT_SYMBOL(kmap_atomic);
+EXPORT_SYMBOL(kunmap_atomic);
+EXPORT_SYMBOL(kmap_atomic_to_page);