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-rw-r--r--arch/x86/include/asm/amd_iommu_proto.h6
-rw-r--r--arch/x86/include/asm/amd_iommu_types.h9
-rw-r--r--arch/x86/kernel/amd_iommu_init.c18
3 files changed, 33 insertions, 0 deletions
diff --git a/arch/x86/include/asm/amd_iommu_proto.h b/arch/x86/include/asm/amd_iommu_proto.h
index d2544f1..cb03037 100644
--- a/arch/x86/include/asm/amd_iommu_proto.h
+++ b/arch/x86/include/asm/amd_iommu_proto.h
@@ -38,4 +38,10 @@ static inline void amd_iommu_stats_init(void) { }
#endif /* !CONFIG_AMD_IOMMU_STATS */
+static inline bool is_rd890_iommu(struct pci_dev *pdev)
+{
+ return (pdev->vendor == PCI_VENDOR_ID_ATI) &&
+ (pdev->device == PCI_DEVICE_ID_RD890_IOMMU);
+}
+
#endif /* _ASM_X86_AMD_IOMMU_PROTO_H */
diff --git a/arch/x86/include/asm/amd_iommu_types.h b/arch/x86/include/asm/amd_iommu_types.h
index ef2d5cd..0861618 100644
--- a/arch/x86/include/asm/amd_iommu_types.h
+++ b/arch/x86/include/asm/amd_iommu_types.h
@@ -414,6 +414,15 @@ struct amd_iommu {
/* default dma_ops domain for that IOMMU */
struct dma_ops_domain *default_dom;
+
+ /*
+ * This array is required to work around a potential BIOS bug.
+ * The BIOS may miss to restore parts of the PCI configuration
+ * space when the system resumes from S3. The result is that the
+ * IOMMU does not execute commands anymore which leads to system
+ * failure.
+ */
+ u32 cache_cfg[4];
};
/*
diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index 85e9817..5a170cb 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -632,6 +632,13 @@ static void __init init_iommu_from_pci(struct amd_iommu *iommu)
iommu->last_device = calc_devid(MMIO_GET_BUS(range),
MMIO_GET_LD(range));
iommu->evt_msi_num = MMIO_MSI_NUM(misc);
+
+ if (is_rd890_iommu(iommu->dev)) {
+ pci_read_config_dword(iommu->dev, 0xf0, &iommu->cache_cfg[0]);
+ pci_read_config_dword(iommu->dev, 0xf4, &iommu->cache_cfg[1]);
+ pci_read_config_dword(iommu->dev, 0xf8, &iommu->cache_cfg[2]);
+ pci_read_config_dword(iommu->dev, 0xfc, &iommu->cache_cfg[3]);
+ }
}
/*
@@ -1120,6 +1127,16 @@ static void iommu_init_flags(struct amd_iommu *iommu)
iommu_feature_enable(iommu, CONTROL_COHERENT_EN);
}
+static void iommu_apply_quirks(struct amd_iommu *iommu)
+{
+ if (is_rd890_iommu(iommu->dev)) {
+ pci_write_config_dword(iommu->dev, 0xf0, iommu->cache_cfg[0]);
+ pci_write_config_dword(iommu->dev, 0xf4, iommu->cache_cfg[1]);
+ pci_write_config_dword(iommu->dev, 0xf8, iommu->cache_cfg[2]);
+ pci_write_config_dword(iommu->dev, 0xfc, iommu->cache_cfg[3]);
+ }
+}
+
/*
* This function finally enables all IOMMUs found in the system after
* they have been initialized
@@ -1130,6 +1147,7 @@ static void enable_iommus(void)
for_each_iommu(iommu) {
iommu_disable(iommu);
+ iommu_apply_quirks(iommu);
iommu_init_flags(iommu);
iommu_set_device_table(iommu);
iommu_enable_command_buffer(iommu);
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