---

yaml --- r: 356154 b: refs/heads/master c: 0bdf525 h: refs/heads/master v: v3
git-mirror · Nov 17, 2012 · 2b12006 · 2b12006
1 parent 9fd3dd6
commit 2b12006
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Showing 4 changed files with 43 additions and 16 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: fb50b020c5331c8c4bee0eb875865f5f8be6c03a
+refs/heads/master: 0bdf525f04afd3a32c14e5a8778771f9c9e0f074
diff --git a/trunk/arch/x86/include/asm/page_64.h b/trunk/arch/x86/include/asm/page_64.h
@@ -9,7 +9,21 @@
 extern unsigned long max_pfn;
 extern unsigned long phys_base;
 
+static inline unsigned long __phys_addr_nodebug(unsigned long x)
+{
+	unsigned long y = x - __START_KERNEL_map;
+
+	/* use the carry flag to determine if x was < __START_KERNEL_map */
+	x = y + ((x > y) ? phys_base : (__START_KERNEL_map - PAGE_OFFSET));
+
+	return x;
+}
+
+#ifdef CONFIG_DEBUG_VIRTUAL
 extern unsigned long __phys_addr(unsigned long);
+#else
+#define __phys_addr(x)		__phys_addr_nodebug(x)
+#endif
 
 #define __phys_reloc_hide(x)	(x)
 

diff --git a/trunk/arch/x86/kernel/x8664_ksyms_64.c b/trunk/arch/x86/kernel/x8664_ksyms_64.c
@@ -59,6 +59,9 @@ EXPORT_SYMBOL(memcpy);
 EXPORT_SYMBOL(__memcpy);
 EXPORT_SYMBOL(memmove);
 
+#ifndef CONFIG_DEBUG_VIRTUAL
+EXPORT_SYMBOL(phys_base);
+#endif
 EXPORT_SYMBOL(empty_zero_page);
 #ifndef CONFIG_PARAVIRT
 EXPORT_SYMBOL(native_load_gs_index);

diff --git a/trunk/arch/x86/mm/physaddr.c b/trunk/arch/x86/mm/physaddr.c
@@ -8,33 +8,43 @@
 
 #ifdef CONFIG_X86_64
 
+#ifdef CONFIG_DEBUG_VIRTUAL
 unsigned long __phys_addr(unsigned long x)
 {
-	if (x >= __START_KERNEL_map) {
-		x -= __START_KERNEL_map;
-		VIRTUAL_BUG_ON(x >= KERNEL_IMAGE_SIZE);
-		x += phys_base;
+	unsigned long y = x - __START_KERNEL_map;
+
+	/* use the carry flag to determine if x was < __START_KERNEL_map */
+	if (unlikely(x > y)) {
+		x = y + phys_base;
+
+		VIRTUAL_BUG_ON(y >= KERNEL_IMAGE_SIZE);
 	} else {
-		VIRTUAL_BUG_ON(x < PAGE_OFFSET);
-		x -= PAGE_OFFSET;
-		VIRTUAL_BUG_ON(!phys_addr_valid(x));
+		x = y + (__START_KERNEL_map - PAGE_OFFSET);
+
+		/* carry flag will be set if starting x was >= PAGE_OFFSET */
+		VIRTUAL_BUG_ON((x > y) || !phys_addr_valid(x));
 	}
+
 	return x;
 }
 EXPORT_SYMBOL(__phys_addr);
+#endif
 
 bool __virt_addr_valid(unsigned long x)
 {
-	if (x >= __START_KERNEL_map) {
-		x -= __START_KERNEL_map;
-		if (x >= KERNEL_IMAGE_SIZE)
+	unsigned long y = x - __START_KERNEL_map;
+
+	/* use the carry flag to determine if x was < __START_KERNEL_map */
+	if (unlikely(x > y)) {
+		x = y + phys_base;
+
+		if (y >= KERNEL_IMAGE_SIZE)
 			return false;
-		x += phys_base;
 	} else {
-		if (x < PAGE_OFFSET)
-			return false;
-		x -= PAGE_OFFSET;
-		if (!phys_addr_valid(x))
+		x = y + (__START_KERNEL_map - PAGE_OFFSET);
+
+		/* carry flag will be set if starting x was >= PAGE_OFFSET */
+		if ((x > y) || !phys_addr_valid(x))
 			return false;
 	}