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fix amd64-agp aperture validation

PATCH New Jan Beulich 1 participant 1 message Jun 19, 2007 Agpgart driver

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PATCH 1/1 fix amd64-agp aperture validation

Under Xen, pfn_valid() on a machine address makes no sense. But even on native, under CONFIG_DISCONTIGMEM, assuming that a !pfn_valid() implies all subsequent pfn-s are also invalid is wrong. Thus replace this by explicitly checking against the E820 map.

Patch is in 2.6.22-rc4, but was not tested against 2.6.18.

arch/i386/kernel/setup-xen.c +29 -0
Index: sle10sp1-2007-03-28/arch/i386/kernel/setup-xen.c
===================================================================
@@ -1029,6 +1029,35 @@ efi_memory_present_wrapper(unsigned long
 	return 0;
 }
 
+/*
+ * This function checks if any part of the range <start,end> is mapped
+ * with type.
+ */
+int
+e820_any_mapped(u64 start, u64 end, unsigned type)
+{
+	int i;
+
+#ifndef CONFIG_XEN
+	for (i = 0; i < e820.nr_map; i++) {
+		const struct e820entry *ei = &e820.map[i];
+#else
+	if (!is_initial_xendomain())
+		return 0;
+	for (i = 0; i < machine_e820.nr_map; ++i) {
+		const struct e820entry *ei = &machine_e820.map[i];
+#endif
+
+		if (type && ei->type != type)
+			continue;
+		if (ei->addr >= end || ei->addr + ei->size <= start)
+			continue;
+		return 1;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(e820_any_mapped);
+
  /*
   * This function checks if the entire range <start,end> is mapped with type.
   *
arch/i386/kernel/setup.c +22 -0
Index: sle10sp1-2007-03-28/arch/i386/kernel/setup.c
===================================================================
@@ -1029,6 +1029,28 @@ efi_memory_present_wrapper(unsigned long
 	return 0;
 }
 
+/*
+ * This function checks if any part of the range <start,end> is mapped
+ * with type.
+ */
+int
+e820_any_mapped(u64 start, u64 end, unsigned type)
+{
+	int i;
+
+	for (i = 0; i < e820.nr_map; i++) {
+		const struct e820entry *ei = &e820.map[i];
+
+		if (type && ei->type != type)
+			continue;
+		if (ei->addr >= end || ei->addr + ei->size <= start)
+			continue;
+		return 1;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(e820_any_mapped);
+
  /*
   * This function checks if the entire range <start,end> is mapped with type.
   *
arch/x86_64/kernel/e820-xen.c +13 -4
Index: sle10sp1-2007-03-28/arch/x86_64/kernel/e820-xen.c
===================================================================
@@ -88,17 +88,26 @@ static inline int bad_addr(unsigned long
 	return 0;
 } 
 
-#ifndef CONFIG_XEN
 /*
  * This function checks if any part of the range <start,end> is mapped
  * with type.
  */
-int __meminit
-e820_any_mapped(unsigned long start, unsigned long end, unsigned type)
+int e820_any_mapped(unsigned long start, unsigned long end, unsigned type)
 { 
 	int i;
+
+#ifndef CONFIG_XEN
 	for (i = 0; i < e820.nr_map; i++) { 
 		struct e820entry *ei = &e820.map[i]; 
+#else
+	extern struct e820map machine_e820;
+
+	if (!is_initial_xendomain())
+		return 0;
+	for (i = 0; i < machine_e820.nr_map; i++) {
+		const struct e820entry *ei = &machine_e820.map[i];
+#endif
+
 		if (type && ei->type != type) 
 			continue;
 		if (ei->addr >= end || ei->addr + ei->size <= start)
@@ -107,7 +116,7 @@ int __meminit e820_any_mapped(unsigned l
 	} 
 	return 0;
 }
-#endif
+EXPORT_SYMBOL_GPL(e820_any_mapped);
 
 /*
  * This function checks if the entire range <start,end> is mapped with type.
arch/x86_64/kernel/e820.c +2 -1
Index: head-2007-03-19/arch/x86_64/kernel/e820.c
===================================================================
@@ -98,7 +98,7 @@ static inline int bad_addr(unsigned long
  * This function checks if any part of the range <start,end> is mapped
  * with type.
  */
-int __meminit
+int
 e820_any_mapped(unsigned long start, unsigned long end, unsigned type)
 { 
 	int i;
@@ -112,6 +112,7 @@ e820_any_mapped(unsigned long start, uns
 	} 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(e820_any_mapped);
 
 /*
  * This function checks if the entire range <start,end> is mapped with type.
drivers/char/agp/amd64-agp.c +4 -9
Index: sle10sp1-2007-03-28/drivers/char/agp/amd64-agp.c
===================================================================
@@ -15,6 +15,7 @@
 #include <linux/mmzone.h>
 #include <asm/page.h>		/* PAGE_SIZE */
 #include <asm/k8.h>
+#include <asm/e820.h>
 #include "agp.h"
 
 /* PTE bits. */
@@ -259,7 +260,6 @@ static const struct agp_bridge_driver am
 /* Some basic sanity checks for the aperture. */
 static int __devinit aperture_valid(u64 aper, u32 size)
 {
-	u32 pfn, c;
 	if (aper == 0) {
 		printk(KERN_ERR PFX "No aperture\n");
 		return 0;
@@ -272,14 +272,9 @@ static int __devinit aperture_valid(u64 
 		printk(KERN_ERR PFX "Aperture out of bounds\n");
 		return 0;
 	}
-	pfn = aper >> PAGE_SHIFT;
-	for (c = 0; c < size/PAGE_SIZE; c++) {
-		if (!pfn_valid(pfn + c))
-			break;
-		if (!PageReserved(pfn_to_page(pfn + c))) {
-			printk(KERN_ERR PFX "Aperture pointing to RAM\n");
-			return 0;
-		}
+	if (e820_any_mapped(aper, aper + size, E820_RAM)) {
+		printk(KERN_ERR PFX "Aperture pointing to RAM\n");
+		return 0;
 	}
 
 	/* Request the Aperture. This catches cases when someone else
include/asm-i386/e820.h +1 -0
Index: sle10sp1-2007-03-28/include/asm-i386/e820.h
===================================================================
@@ -38,6 +38,7 @@ extern struct e820map e820;
 
 extern int e820_all_mapped(unsigned long start, unsigned long end,
 			   unsigned type);
+extern int e820_any_mapped(u64 start, u64 end, unsigned type);
 
 #endif/*!__ASSEMBLY__*/