From 0975904276552c8e201dad0ad31152ba8a21505a Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Tue, 9 Jun 2009 17:52:27 +0200 Subject: amd-iommu: disable IOMMU hardware on shutdown When the IOMMU stays enabled the BIOS may not be able to finish the machine shutdown properly. So disable the hardware on shutdown. Signed-off-by: Joerg Roedel --- arch/x86/include/asm/amd_iommu.h | 2 ++ arch/x86/kernel/amd_iommu_init.c | 5 +++++ arch/x86/kernel/pci-dma.c | 2 ++ 3 files changed, 9 insertions(+) (limited to 'arch') diff --git a/arch/x86/include/asm/amd_iommu.h b/arch/x86/include/asm/amd_iommu.h index 262e02820049..bdf96f119f06 100644 --- a/arch/x86/include/asm/amd_iommu.h +++ b/arch/x86/include/asm/amd_iommu.h @@ -29,9 +29,11 @@ extern void amd_iommu_detect(void); extern irqreturn_t amd_iommu_int_handler(int irq, void *data); extern void amd_iommu_flush_all_domains(void); extern void amd_iommu_flush_all_devices(void); +extern void amd_iommu_shutdown(void); #else static inline int amd_iommu_init(void) { return -ENODEV; } static inline void amd_iommu_detect(void) { } +static inline void amd_iommu_shutdown(void) { } #endif #endif /* _ASM_X86_AMD_IOMMU_H */ diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c index 238989ec077d..575ca46211bb 100644 --- a/arch/x86/kernel/amd_iommu_init.c +++ b/arch/x86/kernel/amd_iommu_init.c @@ -1273,6 +1273,11 @@ free: goto out; } +void amd_iommu_shutdown(void) +{ + disable_iommus(); +} + /**************************************************************************** * * Early detect code. This code runs at IOMMU detection time in the DMA diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index 745579bc8256..328592fb6044 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -290,6 +290,8 @@ static int __init pci_iommu_init(void) void pci_iommu_shutdown(void) { gart_iommu_shutdown(); + + amd_iommu_shutdown(); } /* Must execute after PCI subsystem */ fs_initcall(pci_iommu_init); -- cgit v1.2.2 From 61d047be99757fd9b0af900d7abce9a13a337488 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Tue, 9 Jun 2009 17:56:09 +0200 Subject: x86: disable IOMMUs on kernel crash If the IOMMUs are still enabled when the kexec kernel boots access to the disk is not possible. This is bad for tools like kdump or anything else which wants to use PCI devices. Signed-off-by: Joerg Roedel --- arch/x86/kernel/crash.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch') diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index ff958248e61d..5e409dc298a4 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -27,6 +27,7 @@ #include #include #include +#include #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC) @@ -103,5 +104,10 @@ void native_machine_crash_shutdown(struct pt_regs *regs) #ifdef CONFIG_HPET_TIMER hpet_disable(); #endif + +#ifdef CONFIG_X86_64 + pci_iommu_shutdown(); +#endif + crash_save_cpu(regs, safe_smp_processor_id()); } -- cgit v1.2.2 From 42a49f965a8d24ed92af04f5b564d63f17fd9c56 Mon Sep 17 00:00:00 2001 From: Chris Wright Date: Mon, 15 Jun 2009 15:42:00 +0200 Subject: amd-iommu: flush domain tlb when attaching a new device When kexec'ing to a new kernel (for example, when crashing and launching a kdump session), the AMD IOMMU may have cached translations. The kexec'd kernel, during initialization, will invalidate the IOMMU device table entries, but not the domain translations. These stale entries can cause a device's DMA to fail, makes it rough to write a dump to disk when the disk controller can't DMA ;-) Signed-off-by: Chris Wright Signed-off-by: Joerg Roedel --- arch/x86/kernel/amd_iommu.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'arch') diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c index 1c60554537c3..9372f0406ad4 100644 --- a/arch/x86/kernel/amd_iommu.c +++ b/arch/x86/kernel/amd_iommu.c @@ -434,6 +434,16 @@ static void iommu_flush_tlb(struct amd_iommu *iommu, u16 domid) iommu_queue_inv_iommu_pages(iommu, address, domid, 0, 1); } +/* Flush the whole IO/TLB for a given protection domain - including PDE */ +static void iommu_flush_tlb_pde(struct amd_iommu *iommu, u16 domid) +{ + u64 address = CMD_INV_IOMMU_ALL_PAGES_ADDRESS; + + INC_STATS_COUNTER(domain_flush_single); + + iommu_queue_inv_iommu_pages(iommu, address, domid, 1, 1); +} + /* * This function is used to flush the IO/TLB for a given protection domain * on every IOMMU in the system @@ -1078,7 +1088,13 @@ static void attach_device(struct amd_iommu *iommu, amd_iommu_pd_table[devid] = domain; write_unlock_irqrestore(&amd_iommu_devtable_lock, flags); + /* + * We might boot into a crash-kernel here. The crashed kernel + * left the caches in the IOMMU dirty. So we have to flush + * here to evict all dirty stuff. + */ iommu_queue_inv_dev_entry(iommu, devid); + iommu_flush_tlb_pde(iommu, domain->id); } /* -- cgit v1.2.2 From a8c485bb6857811807d42f9fd1fde2f5f89cc5c9 Mon Sep 17 00:00:00 2001 From: Chris Wright Date: Mon, 15 Jun 2009 15:53:45 +0200 Subject: amd-iommu: disable cmd buffer and evt logging before reprogramming iommu The IOMMU spec states that IOMMU behavior may be undefined when the IOMMU registers are rewritten while command or event buffer is enabled. Disable them in IOMMU disable path. Signed-off-by: Chris Wright Signed-off-by: Joerg Roedel --- arch/x86/kernel/amd_iommu_init.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'arch') diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c index 575ca46211bb..48a79b9b2f9e 100644 --- a/arch/x86/kernel/amd_iommu_init.c +++ b/arch/x86/kernel/amd_iommu_init.c @@ -260,6 +260,14 @@ static void iommu_enable(struct amd_iommu *iommu) static void iommu_disable(struct amd_iommu *iommu) { + /* Disable command buffer */ + iommu_feature_disable(iommu, CONTROL_CMDBUF_EN); + + /* Disable event logging and event interrupts */ + iommu_feature_disable(iommu, CONTROL_EVT_INT_EN); + iommu_feature_disable(iommu, CONTROL_EVT_LOG_EN); + + /* Disable IOMMU hardware itself */ iommu_feature_disable(iommu, CONTROL_IOMMU_EN); } @@ -1042,6 +1050,7 @@ static void enable_iommus(void) struct amd_iommu *iommu; for_each_iommu(iommu) { + iommu_disable(iommu); iommu_set_device_table(iommu); iommu_enable_command_buffer(iommu); iommu_enable_event_buffer(iommu); -- cgit v1.2.2 From 09067207f6eacb7f00c8f7f0623c3696083ce042 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Mon, 15 Jun 2009 16:06:48 +0200 Subject: amd-iommu: set event buffer head and tail to 0 manually These registers may contain values from previous kernels. So reset them to known values before enable the event buffer again. Signed-off-by: Joerg Roedel --- arch/x86/kernel/amd_iommu_init.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch') diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c index 48a79b9b2f9e..068a3569f837 100644 --- a/arch/x86/kernel/amd_iommu_init.c +++ b/arch/x86/kernel/amd_iommu_init.c @@ -486,6 +486,10 @@ static void iommu_enable_event_buffer(struct amd_iommu *iommu) memcpy_toio(iommu->mmio_base + MMIO_EVT_BUF_OFFSET, &entry, sizeof(entry)); + /* set head and tail to zero manually */ + writel(0x00, iommu->mmio_base + MMIO_EVT_HEAD_OFFSET); + writel(0x00, iommu->mmio_base + MMIO_EVT_TAIL_OFFSET); + iommu_feature_enable(iommu, CONTROL_EVT_LOG_EN); } -- cgit v1.2.2 From 6a047d8b9efc4b7d0c57ca4835f7e519e5c90d3f Mon Sep 17 00:00:00 2001 From: Chris Wright Date: Tue, 16 Jun 2009 03:01:37 -0400 Subject: amd-iommu: resume cleanup Now that enable_iommus() will call iommu_disable() for each iommu, the call to disable_iommus() during resume is redundant. Also, the order for an invalidation is to invalidate device table entries first, then domain translations. Signed-off-by: Chris Wright Signed-off-by: Joerg Roedel --- arch/x86/kernel/amd_iommu_init.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c index 068a3569f837..10b2accd12ea 100644 --- a/arch/x86/kernel/amd_iommu_init.c +++ b/arch/x86/kernel/amd_iommu_init.c @@ -1079,12 +1079,6 @@ static void disable_iommus(void) static int amd_iommu_resume(struct sys_device *dev) { - /* - * Disable IOMMUs before reprogramming the hardware registers. - * IOMMU is still enabled from the resume kernel. - */ - disable_iommus(); - /* re-load the hardware */ enable_iommus(); @@ -1092,8 +1086,8 @@ static int amd_iommu_resume(struct sys_device *dev) * we have to flush after the IOMMUs are enabled because a * disabled IOMMU will never execute the commands we send */ - amd_iommu_flush_all_domains(); amd_iommu_flush_all_devices(); + amd_iommu_flush_all_domains(); return 0; } -- cgit v1.2.2