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authorJoerg Roedel <joerg.roedel@amd.com>2009-10-09 18:31:20 +0200
committerJoerg Roedel <joerg.roedel@amd.com>2009-10-09 18:37:46 +0200
commitc5cca146aa03e1f60fb179df65f0dbaf17bc64ed (patch)
tree457cdf7d8b3a12f58328d06a2bfd8665b395b9ba /arch/x86
parentc7084b35eb1a4d3353a501508baf9d3d82822c93 (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.h1
-rw-r--r--arch/x86/kernel/amd_iommu.c2
-rw-r--r--arch/x86/kernel/amd_iommu_init.c22
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);
}