iommu/arm-smmu: Refactor master_cfg/fwspec usage

In preparation for restructuring iommu_fwspec, refactor the way we
access the arm_smmu_master_cfg private data to be less dependent on
the current layout.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20200326150841.10083-11-joro@8bytes.org

drivers/iommu/arm-smmu.c

@@ -98,12 +98,10 @@ struct arm_smmu_master_cfg {
 	s16				smendx[];
 };
 #define INVALID_SMENDX			-1
-#define __fwspec_cfg(fw) ((struct arm_smmu_master_cfg *)fw->iommu_priv)
-#define fwspec_smmu(fw)  (__fwspec_cfg(fw)->smmu)
-#define fwspec_smendx(fw, i) \
-	(i >= fw->num_ids ? INVALID_SMENDX : __fwspec_cfg(fw)->smendx[i])
-#define for_each_cfg_sme(fw, i, idx) \
-	for (i = 0; idx = fwspec_smendx(fw, i), i < fw->num_ids; ++i)
+#define cfg_smendx(cfg, fw, i) \
+	(i >= fw->num_ids ? INVALID_SMENDX : cfg->smendx[i])
+#define for_each_cfg_sme(cfg, fw, i, idx) \
+	for (i = 0; idx = cfg_smendx(cfg, fw, i), i < fw->num_ids; ++i)
 
 static bool using_legacy_binding, using_generic_binding;
 
@@ -1069,7 +1067,7 @@ static int arm_smmu_master_alloc_smes(struct device *dev)
 
 	mutex_lock(&smmu->stream_map_mutex);
 	/* Figure out a viable stream map entry allocation */
-	for_each_cfg_sme(fwspec, i, idx) {
+	for_each_cfg_sme(cfg, fwspec, i, idx) {
 		u16 sid = FIELD_GET(ARM_SMMU_SMR_ID, fwspec->ids[i]);
 		u16 mask = FIELD_GET(ARM_SMMU_SMR_MASK, fwspec->ids[i]);
 
@@ -1100,7 +1098,7 @@ static int arm_smmu_master_alloc_smes(struct device *dev)
 	iommu_group_put(group);
 
 	/* It worked! Now, poke the actual hardware */
-	for_each_cfg_sme(fwspec, i, idx) {
+	for_each_cfg_sme(cfg, fwspec, i, idx) {
 		arm_smmu_write_sme(smmu, idx);
 		smmu->s2crs[idx].group = group;
 	}
@@ -1117,14 +1115,14 @@ static int arm_smmu_master_alloc_smes(struct device *dev)
 	return ret;
 }
 
-static void arm_smmu_master_free_smes(struct iommu_fwspec *fwspec)
+static void arm_smmu_master_free_smes(struct arm_smmu_master_cfg *cfg,
+				      struct iommu_fwspec *fwspec)
 {
-	struct arm_smmu_device *smmu = fwspec_smmu(fwspec);
-	struct arm_smmu_master_cfg *cfg = fwspec->iommu_priv;
+	struct arm_smmu_device *smmu = cfg->smmu;
 	int i, idx;
 
 	mutex_lock(&smmu->stream_map_mutex);
-	for_each_cfg_sme(fwspec, i, idx) {
+	for_each_cfg_sme(cfg, fwspec, i, idx) {
 		if (arm_smmu_free_sme(smmu, idx))
 			arm_smmu_write_sme(smmu, idx);
 		cfg->smendx[i] = INVALID_SMENDX;
@@ -1133,6 +1131,7 @@ static void arm_smmu_master_free_smes(struct iommu_fwspec *fwspec)
 }
 
 static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain,
+				      struct arm_smmu_master_cfg *cfg,
 				      struct iommu_fwspec *fwspec)
 {
 	struct arm_smmu_device *smmu = smmu_domain->smmu;
@@ -1146,7 +1145,7 @@ static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain,
 	else
 		type = S2CR_TYPE_TRANS;
 
-	for_each_cfg_sme(fwspec, i, idx) {
+	for_each_cfg_sme(cfg, fwspec, i, idx) {
 		if (type == s2cr[idx].type && cbndx == s2cr[idx].cbndx)
 			continue;
 
@@ -1162,8 +1161,9 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 {
 	int ret;
 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
-	struct arm_smmu_device *smmu;
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
+	struct arm_smmu_master_cfg *cfg;
+	struct arm_smmu_device *smmu;
 
 	if (!fwspec || fwspec->ops != &arm_smmu_ops) {
 		dev_err(dev, "cannot attach to SMMU, is it on the same bus?\n");
@@ -1177,10 +1177,11 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 	 * domains, just say no (but more politely than by dereferencing NULL).
 	 * This should be at least a WARN_ON once that's sorted.
 	 */
-	if (!fwspec->iommu_priv)
+	cfg = fwspec->iommu_priv;
+	if (!cfg)
 		return -ENODEV;
 
-	smmu = fwspec_smmu(fwspec);
+	smmu = cfg->smmu;
 
 	ret = arm_smmu_rpm_get(smmu);
 	if (ret < 0)
@@ -1204,7 +1205,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 	}
 
 	/* Looks ok, so add the device to the domain */
-	ret = arm_smmu_domain_add_master(smmu_domain, fwspec);
+	ret = arm_smmu_domain_add_master(smmu_domain, cfg, fwspec);
 
 	/*
 	 * Setup an autosuspend delay to avoid bouncing runpm state.
@@ -1475,7 +1476,7 @@ static void arm_smmu_remove_device(struct device *dev)
 		return;
 
 	iommu_device_unlink(&smmu->iommu, dev);
-	arm_smmu_master_free_smes(fwspec);
+	arm_smmu_master_free_smes(cfg, fwspec);
 
 	arm_smmu_rpm_put(smmu);
 
@@ -1487,11 +1488,12 @@ static void arm_smmu_remove_device(struct device *dev)
 static struct iommu_group *arm_smmu_device_group(struct device *dev)
 {
 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
-	struct arm_smmu_device *smmu = fwspec_smmu(fwspec);
+	struct arm_smmu_master_cfg *cfg = fwspec->iommu_priv;
+	struct arm_smmu_device *smmu = cfg->smmu;
 	struct iommu_group *group = NULL;
 	int i, idx;
 
-	for_each_cfg_sme(fwspec, i, idx) {
+	for_each_cfg_sme(cfg, fwspec, i, idx) {
 		if (group && smmu->s2crs[idx].group &&
 		    group != smmu->s2crs[idx].group)
 			return ERR_PTR(-EINVAL);