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authorSuravee Suthikulpanit <suravee.suthikulpanit@amd.com>2020-09-23 12:13:47 +0000
committerJoerg Roedel <jroedel@suse.de>2020-09-24 12:46:54 +0200
commit54ce12e02e44feffa6de4f3a069b7d5c7262a966 (patch)
treed498b3d5bd3b481d97170f8e8d991f3ba3add60b /drivers/iommu
parent2818de6e87defc3103fd86bf6357658f7d2a661a (diff)
iommu/amd: Re-purpose Exclusion range registers to support SNP CWWB
When the IOMMU SNP support bit is set in the IOMMU Extended Features register, hardware re-purposes the following registers: 1. IOMMU Exclusion Base register (MMIO offset 0020h) to Completion Wait Write-Back (CWWB) Base register 2. IOMMU Exclusion Range Limit (MMIO offset 0028h) to Completion Wait Write-Back (CWWB) Range Limit register and requires the IOMMU CWWB semaphore base and range to be programmed in the register offset 0020h and 0028h accordingly. Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Link: https://lore.kernel.org/r/20200923121347.25365-4-suravee.suthikulpanit@amd.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/amd/amd_iommu_types.h1
-rw-r--r--drivers/iommu/amd/init.c26
2 files changed, 27 insertions, 0 deletions
diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index 1e7966c73707..f696ac7c5f89 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -93,6 +93,7 @@
#define FEATURE_PC (1ULL<<9)
#define FEATURE_GAM_VAPIC (1ULL<<21)
#define FEATURE_EPHSUP (1ULL<<50)
+#define FEATURE_SNP (1ULL<<63)
#define FEATURE_PASID_SHIFT 32
#define FEATURE_PASID_MASK (0x1fULL << FEATURE_PASID_SHIFT)
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 35f220704bef..662b01eaf0f2 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -359,6 +359,29 @@ static void iommu_set_exclusion_range(struct amd_iommu *iommu)
&entry, sizeof(entry));
}
+static void iommu_set_cwwb_range(struct amd_iommu *iommu)
+{
+ u64 start = iommu_virt_to_phys((void *)iommu->cmd_sem);
+ u64 entry = start & PM_ADDR_MASK;
+
+ if (!iommu_feature(iommu, FEATURE_SNP))
+ return;
+
+ /* Note:
+ * Re-purpose Exclusion base/limit registers for Completion wait
+ * write-back base/limit.
+ */
+ memcpy_toio(iommu->mmio_base + MMIO_EXCL_BASE_OFFSET,
+ &entry, sizeof(entry));
+
+ /* Note:
+ * Default to 4 Kbytes, which can be specified by setting base
+ * address equal to the limit address.
+ */
+ memcpy_toio(iommu->mmio_base + MMIO_EXCL_LIMIT_OFFSET,
+ &entry, sizeof(entry));
+}
+
/* Programs the physical address of the device table into the IOMMU hardware */
static void iommu_set_device_table(struct amd_iommu *iommu)
{
@@ -1884,6 +1907,9 @@ static int __init amd_iommu_init_pci(void)
ret = iommu_init_pci(iommu);
if (ret)
break;
+
+ /* Need to setup range after PCI init */
+ iommu_set_cwwb_range(iommu);
}
/*