x86/amd-iommu: Workaround for erratum 63

commit c5cca146aa03e1f60fb179df65f0dbaf17bc64ed upstream.

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.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/arch/x86/include/asm/amd_iommu.h b/arch/x86/include/asm/amd_iommu.h
index bdf96f119f069a8615067b33dc7e0a28fc133df2..9dbd4030f0cd87756fabfdab1fa6583266fd8c40 100644 (file)
--- 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 4607241508ca69268b0d16ea7e2d6bbbbc0ece68..f5cb46a09e6098442cc847e1a8d35549e2a3fdd1 100644 (file)
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -1112,6 +1112,8 @@ 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 c1b17e97252e08f89f2221c2228642e0ff3dad81..498c8c79aaa5549a32195510a0274b24655370fe 100644 (file)
--- 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);
 }