iommu/arm-smmu-v3: Test the STE S1DSS functionality

S1DSS brings in quite a few new transition pairs that are
interesting. Test to/from S1DSS_BYPASS <-> S1DSS_SSID0, and
BYPASS <-> S1DSS_SSID0.

Test a contrived non-hitless flow to make sure that the logic works.
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Michael Shavit <mshavit@google.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/12-v9-5cd718286059+79186-smmuv3_newapi_p2b_jgg@nvidia.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-test.c

@@ -144,6 +144,14 @@ static void arm_smmu_v3_test_ste_expect_transition(
 	KUNIT_EXPECT_MEMEQ(test, target->data, cur_copy.data, sizeof(cur_copy));
 }
 
+static void arm_smmu_v3_test_ste_expect_non_hitless_transition(
+	struct kunit *test, const struct arm_smmu_ste *cur,
+	const struct arm_smmu_ste *target, unsigned int num_syncs_expected)
+{
+	arm_smmu_v3_test_ste_expect_transition(test, cur, target,
+					       num_syncs_expected, false);
+}
+
 static void arm_smmu_v3_test_ste_expect_hitless_transition(
 	struct kunit *test, const struct arm_smmu_ste *cur,
 	const struct arm_smmu_ste *target, unsigned int num_syncs_expected)
@@ -155,6 +163,7 @@ static void arm_smmu_v3_test_ste_expect_hitless_transition(
 static const dma_addr_t fake_cdtab_dma_addr = 0xF0F0F0F0F0F0;
 
 static void arm_smmu_test_make_cdtable_ste(struct arm_smmu_ste *ste,
+					   unsigned int s1dss,
 					   const dma_addr_t dma_addr)
 {
 	struct arm_smmu_master master = {
@@ -164,7 +173,7 @@ static void arm_smmu_test_make_cdtable_ste(struct arm_smmu_ste *ste,
 		.smmu = &smmu,
 	};
 
-	arm_smmu_make_cdtable_ste(ste, &master, true, STRTAB_STE_1_S1DSS_SSID0);
+	arm_smmu_make_cdtable_ste(ste, &master, true, s1dss);
 }
 
 static void arm_smmu_v3_write_ste_test_bypass_to_abort(struct kunit *test)
@@ -194,7 +203,8 @@ static void arm_smmu_v3_write_ste_test_cdtable_to_abort(struct kunit *test)
 {
 	struct arm_smmu_ste ste;
 
-	arm_smmu_test_make_cdtable_ste(&ste, fake_cdtab_dma_addr);
+	arm_smmu_test_make_cdtable_ste(&ste, STRTAB_STE_1_S1DSS_SSID0,
+				       fake_cdtab_dma_addr);
 	arm_smmu_v3_test_ste_expect_hitless_transition(test, &ste, &abort_ste,
 						       NUM_EXPECTED_SYNCS(2));
 }
@@ -203,7 +213,8 @@ static void arm_smmu_v3_write_ste_test_abort_to_cdtable(struct kunit *test)
 {
 	struct arm_smmu_ste ste;
 
-	arm_smmu_test_make_cdtable_ste(&ste, fake_cdtab_dma_addr);
+	arm_smmu_test_make_cdtable_ste(&ste, STRTAB_STE_1_S1DSS_SSID0,
+				       fake_cdtab_dma_addr);
 	arm_smmu_v3_test_ste_expect_hitless_transition(test, &abort_ste, &ste,
 						       NUM_EXPECTED_SYNCS(2));
 }
@@ -212,7 +223,8 @@ static void arm_smmu_v3_write_ste_test_cdtable_to_bypass(struct kunit *test)
 {
 	struct arm_smmu_ste ste;
 
-	arm_smmu_test_make_cdtable_ste(&ste, fake_cdtab_dma_addr);
+	arm_smmu_test_make_cdtable_ste(&ste, STRTAB_STE_1_S1DSS_SSID0,
+				       fake_cdtab_dma_addr);
 	arm_smmu_v3_test_ste_expect_hitless_transition(test, &ste, &bypass_ste,
 						       NUM_EXPECTED_SYNCS(3));
 }
@@ -221,11 +233,54 @@ static void arm_smmu_v3_write_ste_test_bypass_to_cdtable(struct kunit *test)
 {
 	struct arm_smmu_ste ste;
 
-	arm_smmu_test_make_cdtable_ste(&ste, fake_cdtab_dma_addr);
+	arm_smmu_test_make_cdtable_ste(&ste, STRTAB_STE_1_S1DSS_SSID0,
+				       fake_cdtab_dma_addr);
 	arm_smmu_v3_test_ste_expect_hitless_transition(test, &bypass_ste, &ste,
 						       NUM_EXPECTED_SYNCS(3));
 }
 
+static void arm_smmu_v3_write_ste_test_cdtable_s1dss_change(struct kunit *test)
+{
+	struct arm_smmu_ste ste;
+	struct arm_smmu_ste s1dss_bypass;
+
+	arm_smmu_test_make_cdtable_ste(&ste, STRTAB_STE_1_S1DSS_SSID0,
+				       fake_cdtab_dma_addr);
+	arm_smmu_test_make_cdtable_ste(&s1dss_bypass, STRTAB_STE_1_S1DSS_BYPASS,
+				       fake_cdtab_dma_addr);
+
+	/*
+	 * Flipping s1dss on a CD table STE only involves changes to the second
+	 * qword of an STE and can be done in a single write.
+	 */
+	arm_smmu_v3_test_ste_expect_hitless_transition(
+		test, &ste, &s1dss_bypass, NUM_EXPECTED_SYNCS(1));
+	arm_smmu_v3_test_ste_expect_hitless_transition(
+		test, &s1dss_bypass, &ste, NUM_EXPECTED_SYNCS(1));
+}
+
+static void
+arm_smmu_v3_write_ste_test_s1dssbypass_to_stebypass(struct kunit *test)
+{
+	struct arm_smmu_ste s1dss_bypass;
+
+	arm_smmu_test_make_cdtable_ste(&s1dss_bypass, STRTAB_STE_1_S1DSS_BYPASS,
+				       fake_cdtab_dma_addr);
+	arm_smmu_v3_test_ste_expect_hitless_transition(
+		test, &s1dss_bypass, &bypass_ste, NUM_EXPECTED_SYNCS(2));
+}
+
+static void
+arm_smmu_v3_write_ste_test_stebypass_to_s1dssbypass(struct kunit *test)
+{
+	struct arm_smmu_ste s1dss_bypass;
+
+	arm_smmu_test_make_cdtable_ste(&s1dss_bypass, STRTAB_STE_1_S1DSS_BYPASS,
+				       fake_cdtab_dma_addr);
+	arm_smmu_v3_test_ste_expect_hitless_transition(
+		test, &bypass_ste, &s1dss_bypass, NUM_EXPECTED_SYNCS(2));
+}
+
 static void arm_smmu_test_make_s2_ste(struct arm_smmu_ste *ste,
 				      bool ats_enabled)
 {
@@ -285,6 +340,48 @@ static void arm_smmu_v3_write_ste_test_bypass_to_s2(struct kunit *test)
 						       NUM_EXPECTED_SYNCS(2));
 }
 
+static void arm_smmu_v3_write_ste_test_s1_to_s2(struct kunit *test)
+{
+	struct arm_smmu_ste s1_ste;
+	struct arm_smmu_ste s2_ste;
+
+	arm_smmu_test_make_cdtable_ste(&s1_ste, STRTAB_STE_1_S1DSS_SSID0,
+				       fake_cdtab_dma_addr);
+	arm_smmu_test_make_s2_ste(&s2_ste, true);
+	arm_smmu_v3_test_ste_expect_hitless_transition(test, &s1_ste, &s2_ste,
+						       NUM_EXPECTED_SYNCS(3));
+}
+
+static void arm_smmu_v3_write_ste_test_s2_to_s1(struct kunit *test)
+{
+	struct arm_smmu_ste s1_ste;
+	struct arm_smmu_ste s2_ste;
+
+	arm_smmu_test_make_cdtable_ste(&s1_ste, STRTAB_STE_1_S1DSS_SSID0,
+				       fake_cdtab_dma_addr);
+	arm_smmu_test_make_s2_ste(&s2_ste, true);
+	arm_smmu_v3_test_ste_expect_hitless_transition(test, &s2_ste, &s1_ste,
+						       NUM_EXPECTED_SYNCS(3));
+}
+
+static void arm_smmu_v3_write_ste_test_non_hitless(struct kunit *test)
+{
+	struct arm_smmu_ste ste;
+	struct arm_smmu_ste ste_2;
+
+	/*
+	 * Although no flow resembles this in practice, one way to force an STE
+	 * update to be non-hitless is to change its CD table pointer as well as
+	 * s1 dss field in the same update.
+	 */
+	arm_smmu_test_make_cdtable_ste(&ste, STRTAB_STE_1_S1DSS_SSID0,
+				       fake_cdtab_dma_addr);
+	arm_smmu_test_make_cdtable_ste(&ste_2, STRTAB_STE_1_S1DSS_BYPASS,
+				       0x4B4B4b4B4B);
+	arm_smmu_v3_test_ste_expect_non_hitless_transition(
+		test, &ste, &ste_2, NUM_EXPECTED_SYNCS(3));
+}
+
 static void arm_smmu_v3_test_cd_expect_transition(
 	struct kunit *test, const struct arm_smmu_cd *cur,
 	const struct arm_smmu_cd *target, unsigned int num_syncs_expected,
@@ -438,10 +535,16 @@ static struct kunit_case arm_smmu_v3_test_cases[] = {
 	KUNIT_CASE(arm_smmu_v3_write_ste_test_abort_to_cdtable),
 	KUNIT_CASE(arm_smmu_v3_write_ste_test_cdtable_to_bypass),
 	KUNIT_CASE(arm_smmu_v3_write_ste_test_bypass_to_cdtable),
+	KUNIT_CASE(arm_smmu_v3_write_ste_test_cdtable_s1dss_change),
+	KUNIT_CASE(arm_smmu_v3_write_ste_test_s1dssbypass_to_stebypass),
+	KUNIT_CASE(arm_smmu_v3_write_ste_test_stebypass_to_s1dssbypass),
 	KUNIT_CASE(arm_smmu_v3_write_ste_test_s2_to_abort),
 	KUNIT_CASE(arm_smmu_v3_write_ste_test_abort_to_s2),
 	KUNIT_CASE(arm_smmu_v3_write_ste_test_s2_to_bypass),
 	KUNIT_CASE(arm_smmu_v3_write_ste_test_bypass_to_s2),
+	KUNIT_CASE(arm_smmu_v3_write_ste_test_s1_to_s2),
+	KUNIT_CASE(arm_smmu_v3_write_ste_test_s2_to_s1),
+	KUNIT_CASE(arm_smmu_v3_write_ste_test_non_hitless),
 	KUNIT_CASE(arm_smmu_v3_write_cd_test_s1_clear),
 	KUNIT_CASE(arm_smmu_v3_write_cd_test_s1_change_asid),
 	KUNIT_CASE(arm_smmu_v3_write_cd_test_sva_clear),