From c5cca146aa03e1f60fb179df65f0dbaf17bc64ed Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 9 Oct 2009 18:31:20 +0200 Subject: x86/amd-iommu: Workaround for erratum 63 There is an erratum for IOMMU hardware which documents undefined behavior when forwarding SMI requests from peripherals and the DTE of that peripheral has a sysmgt value of 01b. This problem caused weird IO_PAGE_FAULTS in my case. This patch implements the suggested workaround for that erratum into the AMD IOMMU driver. The erratum is documented with number 63. Cc: stable@kernel.org Signed-off-by: Joerg Roedel --- arch/x86/kernel/amd_iommu.c | 2 ++ arch/x86/kernel/amd_iommu_init.c | 22 ++++++++++++++++++++++ 2 files changed, 24 insertions(+) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c index 6c99f503780..f95dfe52644 100644 --- a/arch/x86/kernel/amd_iommu.c +++ b/arch/x86/kernel/amd_iommu.c @@ -1114,6 +1114,8 @@ static void __detach_device(struct protection_domain *domain, u16 devid) amd_iommu_dev_table[devid].data[1] = 0; amd_iommu_dev_table[devid].data[2] = 0; + amd_iommu_apply_erratum_63(devid); + /* decrease reference counter */ domain->dev_cnt -= 1; diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c index c1b17e97252..498c8c79aaa 100644 --- a/arch/x86/kernel/amd_iommu_init.c +++ b/arch/x86/kernel/amd_iommu_init.c @@ -509,6 +509,26 @@ static void set_dev_entry_bit(u16 devid, u8 bit) amd_iommu_dev_table[devid].data[i] |= (1 << _bit); } +static int get_dev_entry_bit(u16 devid, u8 bit) +{ + int i = (bit >> 5) & 0x07; + int _bit = bit & 0x1f; + + return (amd_iommu_dev_table[devid].data[i] & (1 << _bit)) >> _bit; +} + + +void amd_iommu_apply_erratum_63(u16 devid) +{ + int sysmgt; + + sysmgt = get_dev_entry_bit(devid, DEV_ENTRY_SYSMGT1) | + (get_dev_entry_bit(devid, DEV_ENTRY_SYSMGT2) << 1); + + if (sysmgt == 0x01) + set_dev_entry_bit(devid, DEV_ENTRY_IW); +} + /* Writes the specific IOMMU for a device into the rlookup table */ static void __init set_iommu_for_device(struct amd_iommu *iommu, u16 devid) { @@ -537,6 +557,8 @@ static void __init set_dev_entry_from_acpi(struct amd_iommu *iommu, if (flags & ACPI_DEVFLAG_LINT1) set_dev_entry_bit(devid, DEV_ENTRY_LINT1_PASS); + amd_iommu_apply_erratum_63(devid); + set_iommu_for_device(iommu, devid); } -- cgit v1.2.3 From ca0207114f1708b563f510b7781a360ec5b98359 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Wed, 28 Oct 2009 18:02:26 +0100 Subject: x86/amd-iommu: Un__init function required on shutdown The function iommu_feature_disable is required on system shutdown to disable the IOMMU but it is marked as __init. This may result in a panic if the memory is reused. This patch fixes this bug. Signed-off-by: Joerg Roedel --- arch/x86/kernel/amd_iommu_init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c index 498c8c79aaa..1e423b2add1 100644 --- a/arch/x86/kernel/amd_iommu_init.c +++ b/arch/x86/kernel/amd_iommu_init.c @@ -240,7 +240,7 @@ static void iommu_feature_enable(struct amd_iommu *iommu, u8 bit) writel(ctrl, iommu->mmio_base + MMIO_CONTROL_OFFSET); } -static void __init iommu_feature_disable(struct amd_iommu *iommu, u8 bit) +static void iommu_feature_disable(struct amd_iommu *iommu, u8 bit) { u32 ctrl; -- cgit v1.2.3