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>

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index b6e26dba2dec4f1b341e94d66fe03c430d4df452..f402f9e126a8704790eb3eaf1c48b636a8f88d99 100644 (file)
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -324,6 +324,8 @@ 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_device {
        struct device                   *dev;
@@ -1090,8 +1092,8 @@ 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 */
@@ -1115,8 +1117,8 @@ 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;
 
@@ -1131,15 +1133,13 @@ err_free_smrs:
 static void arm_smmu_master_free_smes(struct arm_smmu_master_cfg *cfg)
 {
        struct arm_smmu_device *smmu = cfg->smmu;
-       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;
@@ -1151,9 +1151,9 @@ static void arm_smmu_master_free_smes(struct arm_smmu_master_cfg *cfg)
        __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;
        }
@@ -1162,7 +1162,7 @@ static void arm_smmu_master_free_smes(struct arm_smmu_master_cfg *cfg)
 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;
@@ -1182,9 +1182,7 @@ static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain,
        if (smmu_domain->domain.type == IOMMU_DOMAIN_DMA)
                type = S2CR_TYPE_BYPASS;
 
-       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;