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Commit b92e9fac authored by Jan Beulich's avatar Jan Beulich Committed by Andi Kleen
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[PATCH] x86: fix amd64-agp aperture validation 



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.

AK: make e820 on x86-64 not initdata

Signed-off-by: default avatarJan Beulich <jbeulich@novell.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Acked-by: default avatarMark Langsdorf <mark.langsdorf@amd.com>
parent b00742d3

arch/i386/kernel/e820.c

+20 −0
Original line number Diff line number Diff line
@@ -825,6 +825,26 @@ void __init limit_regions(unsigned long long size) 
	print_memory_map("limit_regions endfunc");

}



/*

 * 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.c

+3 −2
Original line number Diff line number Diff line
@@ -25,7 +25,7 @@ 
#include <asm/bootsetup.h>

#include <asm/sections.h>



struct e820map e820 __initdata;

struct e820map e820;



/* 

 * PFN of last memory page.
@@ -98,7 +98,7 @@ static inline int bad_addr(unsigned long *addrp, unsigned long size) 
 * 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, unsigned long end, unsigned type) 
	} 

	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
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/agp_backend.h>

#include <linux/mmzone.h>

#include <asm/page.h>		/* PAGE_SIZE */

#include <asm/e820.h>

#include <asm/k8.h>

#include "agp.h"
@@ -259,7 +260,6 @@ static const struct agp_bridge_driver amd_8151_driver = { 
/* 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;
@@ -272,15 +272,10 @@ static int __devinit aperture_valid(u64 aper, u32 size) 
		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))) {

	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

	   already put a mapping in there - happens with some very broken BIOS

include/asm-i386/e820.h

+1 −0
Original line number Diff line number Diff line
@@ -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);

extern void find_max_pfn(void);

extern void register_bootmem_low_pages(unsigned long max_low_pfn);

extern void e820_register_memory(void);