diff options
| author | Joerg Roedel <joerg.roedel@amd.com> | 2009-10-09 18:31:20 +0200 |
|---|---|---|
| committer | Joerg Roedel <joerg.roedel@amd.com> | 2009-10-09 18:37:46 +0200 |
| commit | c5cca146aa03e1f60fb179df65f0dbaf17bc64ed (patch) | |
| tree | 457cdf7d8b3a12f58328d06a2bfd8665b395b9ba /arch/x86 | |
| parent | c7084b35eb1a4d3353a501508baf9d3d82822c93 (diff) | |
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 <joerg.roedel@amd.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/amd_iommu.h | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/amd_iommu.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/amd_iommu_init.c | 22 |
3 files changed, 25 insertions, 0 deletions
diff --git a/arch/x86/include/asm/amd_iommu.h b/arch/x86/include/asm/amd_iommu.h index bdf96f119f0..9dbd4030f0c 100644 --- a/arch/x86/include/asm/amd_iommu.h +++ b/arch/x86/include/asm/amd_iommu.h @@ -30,6 +30,7 @@ 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); +extern void amd_iommu_apply_erratum_63(u16 devid); #else static inline int amd_iommu_init(void) { return -ENODEV; } static inline void amd_iommu_detect(void) { } 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); } |