From bc2cea6a34fdb30f118ec75db39a46a191870607 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Sat, 21 Jul 2007 17:11:28 +0200 Subject: [PATCH] x86_64: disable the GART in shutdown For K8 system: 4G RAM with memory hole remapping enabled, or more than 4G RAM installed. when using kexec to load second kernel. In the second kernel, when mem is allocated for GART, it will do the memset for clear, it will cause restart, because some device still used that for dma. solution will be: in second kernel: disable that at first before we try to allocate mem for it. or in the first kernel: do disable that before shutdown. Andi/Eric/Alan prefer to second one for clean shutdown in first kernel. Andi also point out need to consider to AGP enable but mem less 4G case too. Signed-off-by: Yinghai Lu Cc: Alan Cox Cc: "Eric W. Biederman" Cc: Muli Ben-Yehuda Cc: Vivek Goyal Cc: Dave Jones Signed-off-by: Andrew Morton Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/x86_64/kernel/pci-dma.c | 5 +++++ arch/x86_64/kernel/pci-gart.c | 20 ++++++++++++++++++++ arch/x86_64/kernel/reboot.c | 4 ++++ include/asm-x86_64/proto.h | 7 +++++++ 4 files changed, 36 insertions(+) diff --git a/arch/x86_64/kernel/pci-dma.c b/arch/x86_64/kernel/pci-dma.c index 90f6315d02d..be8dce40f65 100644 --- a/arch/x86_64/kernel/pci-dma.c +++ b/arch/x86_64/kernel/pci-dma.c @@ -321,6 +321,11 @@ static int __init pci_iommu_init(void) return 0; } +void pci_iommu_shutdown(void) +{ + gart_iommu_shutdown(); +} + #ifdef CONFIG_PCI /* Many VIA bridges seem to corrupt data for DAC. Disable it here */ diff --git a/arch/x86_64/kernel/pci-gart.c b/arch/x86_64/kernel/pci-gart.c index e587b65e754..12acafdca79 100644 --- a/arch/x86_64/kernel/pci-gart.c +++ b/arch/x86_64/kernel/pci-gart.c @@ -571,6 +571,26 @@ static const struct dma_mapping_ops gart_dma_ops = { .unmap_sg = gart_unmap_sg, }; +void gart_iommu_shutdown(void) +{ + struct pci_dev *dev; + int i; + + if (no_agp && (dma_ops != &gart_dma_ops)) + return; + + for (i = 0; i < num_k8_northbridges; i++) { + u32 ctl; + + dev = k8_northbridges[i]; + pci_read_config_dword(dev, 0x90, &ctl); + + ctl &= ~1; + + pci_write_config_dword(dev, 0x90, ctl); + } +} + void __init gart_iommu_init(void) { struct agp_kern_info info; diff --git a/arch/x86_64/kernel/reboot.c b/arch/x86_64/kernel/reboot.c index 7503068e788..e6e65c2c63e 100644 --- a/arch/x86_64/kernel/reboot.c +++ b/arch/x86_64/kernel/reboot.c @@ -16,6 +16,7 @@ #include #include #include +#include /* * Power off function, if any @@ -81,6 +82,7 @@ static inline void kb_wait(void) void machine_shutdown(void) { unsigned long flags; + /* Stop the cpus and apics */ #ifdef CONFIG_SMP int reboot_cpu_id; @@ -111,6 +113,8 @@ void machine_shutdown(void) disable_IO_APIC(); local_irq_restore(flags); + + pci_iommu_shutdown(); } void machine_emergency_restart(void) diff --git a/include/asm-x86_64/proto.h b/include/asm-x86_64/proto.h index 85255db1e82..b70aa0ccbe2 100644 --- a/include/asm-x86_64/proto.h +++ b/include/asm-x86_64/proto.h @@ -85,11 +85,13 @@ extern int exception_trace; extern unsigned cpu_khz; extern unsigned tsc_khz; +extern void pci_iommu_shutdown(void); extern void no_iommu_init(void); extern int force_iommu, no_iommu; extern int iommu_detected; #ifdef CONFIG_IOMMU extern void gart_iommu_init(void); +extern void gart_iommu_shutdown(void); extern void __init gart_parse_options(char *); extern void iommu_hole_init(void); extern int fallback_aper_order; @@ -101,6 +103,11 @@ extern int fix_aperture; #else #define iommu_aperture 0 #define iommu_aperture_allowed 0 + +static inline void gart_iommu_shutdown(void) +{ +} + #endif extern int reboot_force; -- 2.41.1