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: Pavel Machek <pavel@suse.cz>
Tested-by: Patrick <ragamuffin@datacomm.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index c07455d..aa8ec92 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -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 @@
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 @@
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 @@
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",