iommu/amd: Remove dead code for exclusion ranges in IVMD

Exclusion ranges in IVMD are treated as unity mappings with r&w
permissions since commit 0bbe4ced53e3 ("iommu/amd: Fix the
overwritten field in IVMD header"), using 1:1 mappings. And IOMMU
Exclusion Base & Range Limit Registers (0x0020/0x0028) are actually
no longer used.

As a result, several definitions and code paths became dead code:

 - exclusion_start/exclusion_length in struct amd_iommu are never
   assigned,
 - iommu_set_exclusion_range() always returns 0 now.
 - MMIO_EXCL_ENABLE_MASK & MMIO_EXCL_ALLOW_MASK are only used by
   the removed iommu_set_exclusion_range().
 - DEV_ENTRY_EX is no longer set in any DTE.
 - IOMMU_UNITY_MAP_FLAG_EXCL_RANGE is no longer set, thus the
   IOMMU_RESV_RESERVED branch in amd_iommu_get_resv_regions() is
   no longer reachable.

Just remove all of the dead code. No functional change.

Signed-off-by: Yu Zhang <zhangyu1@linux.microsoft.com>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reviewed-by: Jacob Pan <jacob.pan@linux.microsoft.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index c726d115939a6ba8ad1cd9aac3e13f5d09fd439a..9fc9e8f0887a237d44aa73c914ab841460adfdbc 100644 (file)
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -51,10 +51,6 @@
 #define MMIO_GET_BUS(x) (((x) & MMIO_RANGE_BUS_MASK) >> MMIO_RANGE_BUS_SHIFT)
 #define MMIO_MSI_NUM(x)        ((x) & 0x1f)
 
-/* Flag masks for the AMD IOMMU exclusion range */
-#define MMIO_EXCL_ENABLE_MASK 0x01ULL
-#define MMIO_EXCL_ALLOW_MASK  0x02ULL
-
 /* Used offsets into the MMIO space */
 #define MMIO_DEV_TABLE_OFFSET   0x0000
 #define MMIO_CMD_BUF_OFFSET     0x0008
@@ -231,7 +227,6 @@
 #define DEV_ENTRY_IR            0x3d
 #define DEV_ENTRY_IW            0x3e
 #define DEV_ENTRY_NO_PAGE_FAULT        0x62
-#define DEV_ENTRY_EX            0x67
 #define DEV_ENTRY_SYSMGT1       0x68
 #define DEV_ENTRY_SYSMGT2       0x69
 #define DTE_DATA1_SYSMGT_MASK  GENMASK_ULL(41, 40)
@@ -389,8 +384,6 @@
 #define IOMMU_PROT_IR 0x01
 #define IOMMU_PROT_IW 0x02
 
-#define IOMMU_UNITY_MAP_FLAG_EXCL_RANGE        (1 << 2)
-
 /* IOMMU capabilities */
 #define IOMMU_CAP_IOTLB   24
 #define IOMMU_CAP_NPCACHE 26
@@ -685,11 +678,6 @@ struct amd_iommu {
        /* pci domain of this IOMMU */
        struct amd_iommu_pci_seg *pci_seg;
 
-       /* start of exclusion range of that IOMMU */
-       u64 exclusion_start;
-       /* length of exclusion range of that IOMMU */
-       u64 exclusion_length;
-
        /* command buffer virtual address */
        u8 *cmd_buf;
        u32 cmd_buf_head;

diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 16a4567984b81f4a17d005d58ff6e7e09121c58a..d146fa2f57aede1378f27bac53677d0c967a1cee 100644 (file)
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -355,28 +355,6 @@ static void iommu_write_l2(struct amd_iommu *iommu, u8 address, u32 val)
  *
  ****************************************************************************/
 
-/*
- * This function set the exclusion range in the IOMMU. DMA accesses to the
- * exclusion range are passed through untranslated
- */
-static void iommu_set_exclusion_range(struct amd_iommu *iommu)
-{
-       u64 start = iommu->exclusion_start & PAGE_MASK;
-       u64 limit = (start + iommu->exclusion_length - 1) & PAGE_MASK;
-       u64 entry;
-
-       if (!iommu->exclusion_start)
-               return;
-
-       entry = start | MMIO_EXCL_ENABLE_MASK;
-       memcpy_toio(iommu->mmio_base + MMIO_EXCL_BASE_OFFSET,
-                       &entry, sizeof(entry));
-
-       entry = limit;
-       memcpy_toio(iommu->mmio_base + MMIO_EXCL_LIMIT_OFFSET,
-                       &entry, sizeof(entry));
-}
-
 static void iommu_set_cwwb_range(struct amd_iommu *iommu)
 {
        u64 start = iommu_virt_to_phys((void *)iommu->cmd_sem);
@@ -2905,7 +2883,6 @@ static void early_enable_iommu(struct amd_iommu *iommu)
        iommu_init_flags(iommu);
        iommu_set_device_table(iommu);
        iommu_enable_command_buffer(iommu);
-       iommu_set_exclusion_range(iommu);
        iommu_enable_gt(iommu);
        iommu_enable_ga(iommu);
        iommu_enable_xt(iommu);

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index f78e23f03938d60b3526447dc3fbbdfd321fa3a4..f1333071da103f1c37230ef438cda4052898a49a 100644 (file)
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -3082,9 +3082,6 @@ static void amd_iommu_get_resv_regions(struct device *dev,
                        prot |= IOMMU_READ;
                if (entry->prot & IOMMU_PROT_IW)
                        prot |= IOMMU_WRITE;
-               if (entry->prot & IOMMU_UNITY_MAP_FLAG_EXCL_RANGE)
-                       /* Exclusion range */
-                       type = IOMMU_RESV_RESERVED;
 
                region = iommu_alloc_resv_region(entry->address_start,
                                                 length, prot, type,