[PATCH v3 06/10] iommu/arm-smmu-v3: Add bypass flag to arm_smmu_write_strtab_ent()

Shameer Kolothum shameerali.kolothum.thodi at huawei.com
Tue Apr 20 09:27:47 BST 2021


By default, disable_bypass is set and any dev without an iommu domain
installs STE with CFG_ABORT during arm_smmu_init_bypass_stes(). Introduce
a "bypass" flag to arm_smmu_write_strtab_ent() so that we can force it to
install CFG_BYPASS STE for specific SIDs. This will be useful for RMR
related SIDs.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi at huawei.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

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 29da3b681621..190285812182 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1176,7 +1176,7 @@ static void arm_smmu_sync_ste_for_sid(struct arm_smmu_device *smmu, u32 sid)
 }
 
 static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
-				      __le64 *dst)
+				      __le64 *dst, bool bypass)
 {
 	/*
 	 * This is hideously complicated, but we only really care about
@@ -1247,7 +1247,7 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
 
 	/* Bypass/fault */
 	if (!smmu_domain || !(s1_cfg || s2_cfg)) {
-		if (!smmu_domain && disable_bypass)
+		if (!smmu_domain && disable_bypass && !bypass)
 			val |= FIELD_PREP(STRTAB_STE_0_CFG, STRTAB_STE_0_CFG_ABORT);
 		else
 			val |= FIELD_PREP(STRTAB_STE_0_CFG, STRTAB_STE_0_CFG_BYPASS);
@@ -1322,7 +1322,7 @@ static void arm_smmu_init_bypass_stes(__le64 *strtab, unsigned int nent)
 	unsigned int i;
 
 	for (i = 0; i < nent; ++i) {
-		arm_smmu_write_strtab_ent(NULL, -1, strtab);
+		arm_smmu_write_strtab_ent(NULL, -1, strtab, false);
 		strtab += STRTAB_STE_DWORDS;
 	}
 }
@@ -2076,7 +2076,7 @@ static void arm_smmu_install_ste_for_dev(struct arm_smmu_master *master)
 		if (j < i)
 			continue;
 
-		arm_smmu_write_strtab_ent(master, sid, step);
+		arm_smmu_write_strtab_ent(master, sid, step, false);
 	}
 }
 
-- 
2.17.1




More information about the linux-arm-kernel mailing list