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Commit cd76374e authored by Pavel Machek's avatar Pavel Machek Committed by Thomas Gleixner
Browse files

suspend-vs-iommu: prevent suspend if we could not resume 



iommu/gart support misses suspend/resume code, which can do bad stuff,
including memory corruption on resume.  Prevent system suspend in case we
would be unable to resume.

Signed-off-by: default avatarPavel Machek <pavel@suse.cz>
Tested-by: default avatarPatrick <ragamuffin@datacomm.ch>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent be524fb9

arch/x86/kernel/pci-gart_64.c

+30 −1
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include <linux/kdebug.h>

#include <linux/scatterlist.h>

#include <linux/iommu-helper.h>

#include <linux/sysdev.h>

#include <asm/atomic.h>

#include <asm/io.h>

#include <asm/mtrr.h>
@@ -548,6 +549,28 @@ static __init unsigned read_aperture(struct pci_dev *dev, u32 *size) 
	return aper_base;

}



static int gart_resume(struct sys_device *dev)

{

	return 0;

}



static int gart_suspend(struct sys_device *dev, pm_message_t state)

{

	return -EINVAL;

}



static struct sysdev_class gart_sysdev_class = {

	.name = "gart",

	.suspend = gart_suspend,

	.resume = gart_resume,



};



static struct sys_device device_gart = {

	.id	= 0,

	.cls	= &gart_sysdev_class,

};



/*

 * Private Northbridge GATT initialization in case we cannot use the

 * AGP driver for some reason.
@@ -558,7 +581,7 @@ static __init int init_k8_gatt(struct agp_kern_info *info) 
	unsigned aper_base, new_aper_base;

	struct pci_dev *dev;

	void *gatt;

	int i;

	int i, error;



	printk(KERN_INFO "PCI-DMA: Disabling AGP.\n");

	aper_size = aper_base = info->aper_size = 0;
@@ -606,6 +629,12 @@ static __init int init_k8_gatt(struct agp_kern_info *info) 


		pci_write_config_dword(dev, 0x90, ctl);

	}



	error = sysdev_class_register(&gart_sysdev_class);

	if (!error)

		error = sysdev_register(&device_gart);

	if (error)

		panic("Could not register gart_sysdev -- would corrupt data on next suspend");

	flush_gart();



	printk(KERN_INFO "PCI-DMA: aperture base @ %x size %u KB\n",