Merge tag 'arm-smmu-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into iommu/fixes

Arm SMMU fixes for 6.6 -rc

- Fix TLB range command encoding when TTL, Num and Scale are all zero

- Fix soft lockup by limiting TLB invalidation ops issued by SVA

- Fix clocks description for SDM630 platform in arm-smmu DT binding

2 files changed, 26 insertions, 7 deletions

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index 4d83edc2be99..8a16cd3ef487 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -186,6 +186,15 @@ static void arm_smmu_free_shared_cd(struct arm_smmu_ctx_desc *cd)
 	}
 }
 
+/*
+ * Cloned from the MAX_TLBI_OPS in arch/arm64/include/asm/tlbflush.h, this
+ * is used as a threshold to replace per-page TLBI commands to issue in the
+ * command queue with an address-space TLBI command, when SMMU w/o a range
+ * invalidation feature handles too many per-page TLBI commands, which will
+ * otherwise result in a soft lockup.
+ */
+#define CMDQ_MAX_TLBI_OPS		(1 << (PAGE_SHIFT - 3))
+
 static void arm_smmu_mm_arch_invalidate_secondary_tlbs(struct mmu_notifier *mn,
 						struct mm_struct *mm,
 						unsigned long start,
@@ -201,8 +210,13 @@ static void arm_smmu_mm_arch_invalidate_secondary_tlbs(struct mmu_notifier *mn,
 	 * range. So do a simple translation here by calculating size correctly.
 	 */
 	size = end - start;
-	if (size == ULONG_MAX)
-		size = 0;
+	if (!(smmu_domain->smmu->features & ARM_SMMU_FEAT_RANGE_INV)) {
+		if (size >= CMDQ_MAX_TLBI_OPS * PAGE_SIZE)
+			size = 0;
+	} else {
+		if (size == ULONG_MAX)
+			size = 0;
+	}
 
 	if (!(smmu_domain->smmu->features & ARM_SMMU_FEAT_BTM)) {
 		if (!size)
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index e82bf1c449a3..bd0a596f9863 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1895,18 +1895,23 @@ static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd,
 		/* Get the leaf page size */
 		tg = __ffs(smmu_domain->domain.pgsize_bitmap);
 
+		num_pages = size >> tg;
+
 		/* Convert page size of 12,14,16 (log2) to 1,2,3 */
 		cmd->tlbi.tg = (tg - 10) / 2;
 
 		/*
-		 * Determine what level the granule is at. For non-leaf, io-pgtable
-		 * assumes .tlb_flush_walk can invalidate multiple levels at once,
-		 * so ignore the nominal last-level granule and leave TTL=0.
+		 * Determine what level the granule is at. For non-leaf, both
+		 * io-pgtable and SVA pass a nominal last-level granule because
+		 * they don't know what level(s) actually apply, so ignore that
+		 * and leave TTL=0. However for various errata reasons we still
+		 * want to use a range command, so avoid the SVA corner case
+		 * where both scale and num could be 0 as well.
 		 */
 		if (cmd->tlbi.leaf)
 			cmd->tlbi.ttl = 4 - ((ilog2(granule) - 3) / (tg - 3));
-
-		num_pages = size >> tg;
+		else if ((num_pages & CMDQ_TLBI_RANGE_NUM_MAX) == 1)
+			num_pages++;
 	}
 
 	cmds.num = 0;