From 42a49f965a8d24ed92af04f5b564d63f17fd9c56 Mon Sep 17 00:00:00 2001 From: Chris Wright Date: Mon, 15 Jun 2009 15:42:00 +0200 Subject: [PATCH] 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(+) 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); } /* -- GitLab