iommu/amd: Fix logic to determine and checking max PASID
In reality, the spec can only support 16-bit PASID since
INVALIDATE_IOTLB_PAGES and COMPLETE_PPR_REQUEST commands only allow 16-bit
PASID. So, we updated the PASID_MASK accordingly and invoke BUG_ON
if the hardware is reporting PASmax more than 16-bit.
Besides, max PASID is defined as ((2^(PASmax+1)) - 1). The current does not
determine this correctly.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Tested-by: Jay Cornwall <Jay.Cornwall@amd.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 1dd9f81..c949520 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -963,7 +963,7 @@
address &= ~(0xfffULL);
- cmd->data[0] = pasid & PASID_MASK;
+ cmd->data[0] = pasid;
cmd->data[1] = domid;
cmd->data[2] = lower_32_bits(address);
cmd->data[3] = upper_32_bits(address);
@@ -1001,7 +1001,7 @@
cmd->data[0] = devid;
if (gn) {
- cmd->data[1] = pasid & PASID_MASK;
+ cmd->data[1] = pasid;
cmd->data[2] = CMD_INV_IOMMU_PAGES_GN_MASK;
}
cmd->data[3] = tag & 0x1ff;
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 28b4bea..b76c58d 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -150,7 +150,7 @@
bool amd_iommu_np_cache __read_mostly;
bool amd_iommu_iotlb_sup __read_mostly = true;
-u32 amd_iommu_max_pasids __read_mostly = ~0;
+u32 amd_iommu_max_pasid __read_mostly = ~0;
bool amd_iommu_v2_present __read_mostly;
bool amd_iommu_pc_present __read_mostly;
@@ -1231,14 +1231,16 @@
if (iommu_feature(iommu, FEATURE_GT)) {
int glxval;
- u32 pasids;
- u64 shift;
+ u32 max_pasid;
+ u64 pasmax;
- shift = iommu->features & FEATURE_PASID_MASK;
- shift >>= FEATURE_PASID_SHIFT;
- pasids = (1 << shift);
+ pasmax = iommu->features & FEATURE_PASID_MASK;
+ pasmax >>= FEATURE_PASID_SHIFT;
+ max_pasid = (1 << (pasmax + 1)) - 1;
- amd_iommu_max_pasids = min(amd_iommu_max_pasids, pasids);
+ amd_iommu_max_pasid = min(amd_iommu_max_pasid, max_pasid);
+
+ BUG_ON(amd_iommu_max_pasid & ~PASID_MASK);
glxval = iommu->features & FEATURE_GLXVAL_MASK;
glxval >>= FEATURE_GLXVAL_SHIFT;
diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index e400fbe..55ba46b 100644
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -98,7 +98,12 @@
#define FEATURE_GLXVAL_SHIFT 14
#define FEATURE_GLXVAL_MASK (0x03ULL << FEATURE_GLXVAL_SHIFT)
-#define PASID_MASK 0x000fffff
+/* Note:
+ * The current driver only support 16-bit PASID.
+ * Currently, hardware only implement upto 16-bit PASID
+ * even though the spec says it could have upto 20 bits.
+ */
+#define PASID_MASK 0x0000ffff
/* MMIO status bits */
#define MMIO_STATUS_EVT_INT_MASK (1 << 1)
@@ -696,8 +701,8 @@
*/
extern u32 amd_iommu_unmap_flush;
-/* Smallest number of PASIDs supported by any IOMMU in the system */
-extern u32 amd_iommu_max_pasids;
+/* Smallest max PASID supported by any IOMMU in the system */
+extern u32 amd_iommu_max_pasid;
extern bool amd_iommu_v2_present;
