From: Sairaj Kodilkar Date: Mon, 17 Mar 2025 05:50:20 +0000 (+0530) Subject: iommu/amd: Add support for HTRangeIgnore feature X-Git-Tag: v6.16-rc1~110^2^11~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=94a9921e2c25eedcf95b00cedbd065579406655a;p=thirdparty%2Fkernel%2Flinux.git iommu/amd: Add support for HTRangeIgnore feature AMD IOMMU reserves the address range 0xfd00000000-0xffffffffff for the hypertransport protocol (HT) and has special meaning. Hence devices cannot use this address range for the DMA. However on some AMD platforms this HT range is shifted to the very top of the address space and new feature bit `HTRangeIgnore` is introduced. When this feature bit is on, IOMMU treats the GPA access to the legacy HT range as regular GPA access. Signed-off-by: Sairaj Kodilkar Reviewed-by: Vasant Hegde Link: https://lore.kernel.org/r/20250317055020.25214-1-sarunkod@amd.com Signed-off-by: Joerg Roedel --- diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h index 220c598b7e148..29a8864381c35 100644 --- a/drivers/iommu/amd/amd_iommu.h +++ b/drivers/iommu/amd/amd_iommu.h @@ -147,6 +147,8 @@ static inline int get_pci_sbdf_id(struct pci_dev *pdev) return PCI_SEG_DEVID_TO_SBDF(seg, devid); } +bool amd_iommu_ht_range_ignore(void); + /* * This must be called after device probe completes. During probe * use rlookup_amd_iommu() get the iommu. diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h index 5089b58e528a7..11dd152cfa957 100644 --- a/drivers/iommu/amd/amd_iommu_types.h +++ b/drivers/iommu/amd/amd_iommu_types.h @@ -111,6 +111,7 @@ #define FEATURE_SNPAVICSUP GENMASK_ULL(7, 5) #define FEATURE_SNPAVICSUP_GAM(x) \ (FIELD_GET(FEATURE_SNPAVICSUP, x) == 0x1) +#define FEATURE_HT_RANGE_IGNORE BIT_ULL(11) #define FEATURE_NUM_INT_REMAP_SUP GENMASK_ULL(9, 8) #define FEATURE_NUM_INT_REMAP_SUP_2K(x) \ diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c index dd9e26b7b7184..acf8941e1ed3d 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -256,6 +256,11 @@ int amd_iommu_get_num_iommus(void) return amd_iommus_present; } +bool amd_iommu_ht_range_ignore(void) +{ + return check_feature2(FEATURE_HT_RANGE_IGNORE); +} + /* * Iterate through all the IOMMUs to get common EFR * masks among all IOMMUs and warn if found inconsistency. diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 15e3342648811..95520bcf6c0e1 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -2916,6 +2916,9 @@ static void amd_iommu_get_resv_regions(struct device *dev, return; list_add_tail(®ion->list, head); + if (amd_iommu_ht_range_ignore()) + return; + region = iommu_alloc_resv_region(HT_RANGE_START, HT_RANGE_END - HT_RANGE_START + 1, 0, IOMMU_RESV_RESERVED, GFP_KERNEL);