From c1cbebeec4a6be1c1fb54fbf2395ade2534b03c4 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Thu, 3 Jul 2008 19:35:10 +0200 Subject: [PATCH] x86, AMD IOMMU: don't try to init IOMMU if early detect code did not detect one This patch adds a check if the early detect code has found AMD IOMMU hardware descriptions and does not try to initialize hardware if the check failed. Signed-off-by: Joerg Roedel Cc: iommu@lists.linux-foundation.org Cc: bhavna.sarathy@amd.com Cc: robert.richter@amd.com Cc: Joerg Roedel Signed-off-by: Ingo Molnar --- arch/x86/kernel/amd_iommu_init.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c index c54c82305af..c970fac6fdc 100644 --- a/arch/x86/kernel/amd_iommu_init.c +++ b/arch/x86/kernel/amd_iommu_init.c @@ -101,6 +101,8 @@ struct ivmd_header { u64 range_length; } __attribute__((packed)); +static int __initdata amd_iommu_detected; + u16 amd_iommu_last_bdf; struct list_head amd_iommu_unity_map; unsigned amd_iommu_aperture_order = 26; @@ -689,6 +691,9 @@ int __init amd_iommu_init(void) return 0; } + if (!amd_iommu_detected) + return -ENODEV; + /* * First parse ACPI tables to find the largest Bus/Dev/Func * we need to handle. Upon this information the shared data @@ -831,6 +836,7 @@ void __init amd_iommu_detect(void) if (acpi_table_parse("IVRS", early_amd_iommu_detect) == 0) { iommu_detected = 1; + amd_iommu_detected = 1; #ifdef CONFIG_GART_IOMMU gart_iommu_aperture_disabled = 1; gart_iommu_aperture = 0; -- 2.41.1