From: Joerg Roedel <jroedel@xxxxxxx> commit 072a03e0a0b1bc22eb5970727877264657c61fd3 upstream. The AMD IOMMU will not be enabled on AMD Stoney Ridge systems. Bail out even earlier and refuse to even detect the IOMMU there. Cc: stable@xxxxxxxxxxxxxxx # v5.11 Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> Link: https://lore.kernel.org/r/20210317091037.31374-2-joro@xxxxxxxxxx Acked-by: Huang Rui <ray.huang@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/iommu/amd/init.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -2712,7 +2712,6 @@ static int __init early_amd_iommu_init(v struct acpi_table_header *ivrs_base; acpi_status status; int i, remap_cache_sz, ret = 0; - u32 pci_id; if (!amd_iommu_detected) return -ENODEV; @@ -2802,16 +2801,6 @@ static int __init early_amd_iommu_init(v if (ret) goto out; - /* Disable IOMMU if there's Stoney Ridge graphics */ - for (i = 0; i < 32; i++) { - pci_id = read_pci_config(0, i, 0, 0); - if ((pci_id & 0xffff) == 0x1002 && (pci_id >> 16) == 0x98e4) { - pr_info("Disable IOMMU on Stoney Ridge\n"); - amd_iommu_disabled = true; - break; - } - } - /* Disable any previously enabled IOMMUs */ if (!is_kdump_kernel() || amd_iommu_disabled) disable_iommus(); @@ -2879,6 +2868,7 @@ static bool detect_ivrs(void) { struct acpi_table_header *ivrs_base; acpi_status status; + int i; status = acpi_get_table("IVRS", 0, &ivrs_base); if (status == AE_NOT_FOUND) @@ -2891,6 +2881,17 @@ static bool detect_ivrs(void) acpi_put_table(ivrs_base); + /* Don't use IOMMU if there is Stoney Ridge graphics */ + for (i = 0; i < 32; i++) { + u32 pci_id; + + pci_id = read_pci_config(0, i, 0, 0); + if ((pci_id & 0xffff) == 0x1002 && (pci_id >> 16) == 0x98e4) { + pr_info("Disable IOMMU on Stoney Ridge\n"); + return false; + } + } + /* Make sure ACS will be enabled during PCI probe */ pci_request_acs();
