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[v2,4/5] xen/arm: smmuv1: Add a stream map entry iterator

Message ID 662c4a4872e471df1d185002988700cd738080a0.1616428314.git.rahul.singh@arm.com (mailing list archive)
State New
Headers show
Series xen/arm: smmuv1: Fix stream match conflict issue | expand

Commit Message

Rahul Singh March 22, 2021, 4:11 p.m. UTC
Backport commit d3097e39302083d58922a3d1032d7d59a63d263d
"iommu/arm-smmu: Add a stream map entry iterator" from the Linux kernel.

This patch is the preparatory work to fix the stream match conflict
when two devices have the same stream-id.

Original commit message:
    iommu/arm-smmu: Add a stream map entry iterator

    We iterate over the SMEs associated with a master config quite a lot in
    various places, and are about to do so even more. Let's wrap the idiom
    in a handy iterator macro before the repetition gets out of hand.

    Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
    Signed-off-by: Robin Murphy <robin.murphy@arm.com>
    Signed-off-by: Will Deacon <will.deacon@arm.com>

Signed-off-by: Rahul Singh <rahul.singh@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
---
 xen/drivers/passthrough/arm/smmu.c | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)
diff mbox series

Patch

diff --git a/xen/drivers/passthrough/arm/smmu.c b/xen/drivers/passthrough/arm/smmu.c
index e1b937bd4b..2c1ea8e6ff 100644
--- a/xen/drivers/passthrough/arm/smmu.c
+++ b/xen/drivers/passthrough/arm/smmu.c
@@ -618,6 +618,8 @@  struct arm_smmu_master_cfg {
 	s16				smendx[MAX_MASTER_STREAMIDS];
 };
 #define INVALID_SMENDX			-1
+#define for_each_cfg_sme(cfg, i, idx) \
+	for (i = 0; idx = cfg->smendx[i], i < cfg->num_streamids; ++i)
 
 struct arm_smmu_master {
 	struct device_node		*of_node;
@@ -1457,8 +1459,8 @@  static int arm_smmu_master_alloc_smes(struct arm_smmu_device *smmu,
 	int i, idx;
 
 	/* Allocate the SMRs on the SMMU */
-	for (i = 0; i < cfg->num_streamids; ++i) {
-		if (cfg->smendx[i] != INVALID_SMENDX)
+	for_each_cfg_sme(cfg, i, idx) {
+		if (idx != INVALID_SMENDX)
 			return -EEXIST;
 
 		/* ...except on stream indexing hardware, of course */
@@ -1482,8 +1484,8 @@  static int arm_smmu_master_alloc_smes(struct arm_smmu_device *smmu,
 		return 0;
 
 	/* It worked! Now, poke the actual hardware */
-	for (i = 0; i < cfg->num_streamids; ++i)
-		arm_smmu_write_smr(smmu, cfg->smendx[i]);
+	for_each_cfg_sme(cfg, i, idx)
+		arm_smmu_write_smr(smmu, idx);
 
 	return 0;
 
@@ -1498,15 +1500,13 @@  err_free_smrs:
 static void arm_smmu_master_free_smes(struct arm_smmu_device *smmu,
 				      struct arm_smmu_master_cfg *cfg)
 {
-	int i;
+	int i, idx;
 
 	/*
 	 * We *must* clear the S2CR first, because freeing the SMR means
 	 * that it can be re-allocated immediately.
 	 */
-	for (i = 0; i < cfg->num_streamids; ++i) {
-		int idx = cfg->smendx[i];
-
+	for_each_cfg_sme(cfg, i, idx) {
 		/* An IOMMU group is torn down by the first device to be removed */
 		if (idx == INVALID_SMENDX)
 			return;
@@ -1518,9 +1518,9 @@  static void arm_smmu_master_free_smes(struct arm_smmu_device *smmu,
 	__iowmb();
 
 	/* Invalidate the SMRs before freeing back to the allocator */
-	for (i = 0; i < cfg->num_streamids; ++i) {
+	for_each_cfg_sme(cfg, i, idx) {
 		if (smmu->smrs)
-			arm_smmu_free_smr(smmu, cfg->smendx[i]);
+			arm_smmu_free_smr(smmu, idx);
 
 		cfg->smendx[i] = INVALID_SMENDX;
 	}
@@ -1529,7 +1529,7 @@  static void arm_smmu_master_free_smes(struct arm_smmu_device *smmu,
 static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain,
 				      struct arm_smmu_master_cfg *cfg)
 {
-	int i, ret = 0;
+	int i, idx, ret = 0;
 	struct arm_smmu_device *smmu = smmu_domain->smmu;
 	struct arm_smmu_s2cr *s2cr = smmu->s2crs;
 	enum arm_smmu_s2cr_type type = S2CR_TYPE_TRANS;
@@ -1540,9 +1540,7 @@  static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain,
 	if (ret)
 		return ret;
 
-	for (i = 0; i < cfg->num_streamids; ++i) {
-		int idx = cfg->smendx[i];
-
+	for_each_cfg_sme(cfg, i, idx) {
 		/* Devices in an IOMMU group may already be configured */
 		if (type == s2cr[idx].type && cbndx == s2cr[idx].cbndx)
 			break;