iommu/amd: Consolidate feature detection and reporting logic

Currently, IOMMU driver assumes capabilities on all IOMMU instances to be
homogeneous. During early_amd_iommu_init(), the driver probes all IVHD
blocks and do sanity check to make sure that only features common among all
IOMMU instances are supported. This is tracked in the global amd_iommu_efr
and amd_iommu_efr2, which should be used whenever the driver need to check
hardware capabilities.

Therefore, introduce check_feature() and check_feature2(), and modify
the driver to adopt the new helper functions.

In addition, clean up the print_iommu_info() to avoid reporting redundant
EFR/EFR2 for each IOMMU instance.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Link: https://lore.kernel.org/r/20230921092147.5930-9-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 12 insertions, 5 deletions

diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h
index c5090e00b3aa..e1b0eeead074 100644
--- a/drivers/iommu/amd/amd_iommu.h
+++ b/drivers/iommu/amd/amd_iommu.h
@@ -87,9 +87,19 @@ static inline bool is_rd890_iommu(struct pci_dev *pdev)
 	       (pdev->device == PCI_DEVICE_ID_RD890_IOMMU);
 }
 
-static inline bool iommu_feature(struct amd_iommu *iommu, u64 mask)
+static inline bool check_feature(u64 mask)
 {
-	return !!(iommu->features & mask);
+	return (amd_iommu_efr & mask);
+}
+
+static inline bool check_feature2(u64 mask)
+{
+	return (amd_iommu_efr2 & mask);
+}
+
+static inline int check_feature_gpt_level(void)
+{
+	return ((amd_iommu_efr >> FEATURE_GATS_SHIFT) & FEATURE_GATS_MASK);
 }
 
 static inline u64 iommu_virt_to_phys(void *vaddr)
@@ -145,8 +155,5 @@ void amd_iommu_domain_set_pgtable(struct protection_domain *domain,
 				  u64 *root, int mode);
 struct dev_table_entry *get_dev_table(struct amd_iommu *iommu);
 
-extern u64 amd_iommu_efr;
-extern u64 amd_iommu_efr2;
-
 extern bool amd_iommu_snp_en;
 #endif