x86/amd-iommu: Work around S3 BIOS bug

[karo-tx-linux.git] / arch / x86 / kernel / amd_iommu_init.c

diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index 85e9817ead43b58397ea9df4d15bdf9688fd19da..5a170cbbbed86aa1376eb19336a5329aacc96e91 100644 (file)
--- 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);