iommu/amd: Move Stoney Ridge check to detect_ivrs()

The AMD IOMMU will not be enabled on AMD Stoney Ridge systems. Bail
out even earlier and refuse to even detect the IOMMU there.

References: https://bugzilla.kernel.org/show_bug.cgi?id=212133
References: https://bugzilla.suse.com/show_bug.cgi?id=1183132
Cc: stable@vger.kernel.org # v5.11
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20210317091037.31374-2-joro@8bytes.org
Acked-by: Huang Rui <ray.huang@amd.com>

diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 9126efc..3280e6f 100644 (file)
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -2714,7 +2714,6 @@ static int __init early_amd_iommu_init(void)
        struct acpi_table_header *ivrs_base;
        int i, remap_cache_sz, ret;
        acpi_status status;
-       u32 pci_id;
 
        if (!amd_iommu_detected)
                return -ENODEV;
@@ -2804,16 +2803,6 @@ static int __init early_amd_iommu_init(void)
        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();
@@ -2880,6 +2869,7 @@ 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)
@@ -2892,6 +2882,17 @@ 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();