iommu/arm-smmu-v3: Reorganize struct arm_smmu_strtab_cfg

The members here are being used for both the linear and the 2 level case,
with the meaning of each item slightly different in the two cases.

Split it into a clean union where both cases have their own struct with
their own logical names and correct types.

Adjust all the users to detect linear/2lvl and use the right sub structure
and types consistently.

Remove STRTAB_STE_DWORDS by changing the last places to use
sizeof(struct arm_smmu_ste).

Tested-by: Nicolin Chen <[email protected]>
Reviewed-by: Nicolin Chen <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>

Author: jgunthorpe

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

@@ -1712,25 +1712,24 @@ static int arm_smmu_init_l2_strtab(struct arm_smmu_device *smmu, u32 sid)
 {
 	dma_addr_t l2ptr_dma;
 	struct arm_smmu_strtab_cfg *cfg = &smmu->strtab_cfg;
-	struct arm_smmu_strtab_l1_desc *desc;
-	__le64 *dst;
+	struct arm_smmu_strtab_l2 **l2table;
 
-	desc = &cfg->l1_desc[arm_smmu_strtab_l1_idx(sid)];
-	if (desc->l2ptr)
+	l2table = &cfg->l2.l2ptrs[arm_smmu_strtab_l1_idx(sid)];
+	if (*l2table)
 		return 0;
 
-	desc->l2ptr = dmam_alloc_coherent(smmu->dev, sizeof(*desc->l2ptr),
-					  &l2ptr_dma, GFP_KERNEL);
-	if (!desc->l2ptr) {
+	*l2table = dmam_alloc_coherent(smmu->dev, sizeof(**l2table),
+				       &l2ptr_dma, GFP_KERNEL);
+	if (!*l2table) {
 		dev_err(smmu->dev,
 			"failed to allocate l2 stream table for SID %u\n",
 			sid);
 		return -ENOMEM;
 	}
 
-	arm_smmu_init_initial_stes(desc->l2ptr->stes, STRTAB_NUM_L2_STES);
-	dst = &cfg->strtab[arm_smmu_strtab_l1_idx(sid)];
-	arm_smmu_write_strtab_l1_desc((struct arm_smmu_strtab_l1 *)dst,
+	arm_smmu_init_initial_stes((*l2table)->stes,
+				   ARRAY_SIZE((*l2table)->stes));
+	arm_smmu_write_strtab_l1_desc(&cfg->l2.l1tab[arm_smmu_strtab_l1_idx(sid)],
 				      l2ptr_dma);
 	return 0;
 }
@@ -2487,12 +2486,11 @@ arm_smmu_get_step_for_sid(struct arm_smmu_device *smmu, u32 sid)
 
 	if (smmu->features & ARM_SMMU_FEAT_2_LVL_STRTAB) {
 		/* Two-level walk */
-		return &cfg->l1_desc[arm_smmu_strtab_l1_idx(sid)]
-				.l2ptr->stes[arm_smmu_strtab_l2_idx(sid)];
+		return &cfg->l2.l2ptrs[arm_smmu_strtab_l1_idx(sid)]
+				->stes[arm_smmu_strtab_l2_idx(sid)];
 	} else {
 		/* Simple linear lookup */
-		return (struct arm_smmu_ste *)&cfg
-			       ->strtab[sid * STRTAB_STE_DWORDS];
+		return &cfg->linear.table[sid];
 	}
 }
 
@@ -3193,8 +3191,8 @@ struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
 static bool arm_smmu_sid_in_range(struct arm_smmu_device *smmu, u32 sid)
 {
 	if (smmu->features & ARM_SMMU_FEAT_2_LVL_STRTAB)
-		return arm_smmu_strtab_l1_idx(sid) < smmu->strtab_cfg.num_l1_ents;
-	return sid < smmu->strtab_cfg.num_l1_ents;
+		return arm_smmu_strtab_l1_idx(sid) < smmu->strtab_cfg.l2.num_l1_ents;
+	return sid < smmu->strtab_cfg.linear.num_ents;
 }
 
 static int arm_smmu_init_sid_strtab(struct arm_smmu_device *smmu, u32 sid)
@@ -3629,72 +3627,69 @@ static int arm_smmu_init_queues(struct arm_smmu_device *smmu)
 
 static int arm_smmu_init_strtab_2lvl(struct arm_smmu_device *smmu)
 {
-	void *strtab;
 	u64 reg;
 	u32 l1size;
 	struct arm_smmu_strtab_cfg *cfg = &smmu->strtab_cfg;
 	unsigned int last_sid_idx =
 		arm_smmu_strtab_l1_idx((1 << smmu->sid_bits) - 1);
 
 	/* Calculate the L1 size, capped to the SIDSIZE. */
-	cfg->num_l1_ents = min(last_sid_idx + 1, STRTAB_MAX_L1_ENTRIES);
-	if (cfg->num_l1_ents <= last_sid_idx)
+	cfg->l2.num_l1_ents = min(last_sid_idx + 1, STRTAB_MAX_L1_ENTRIES);
+	if (cfg->l2.num_l1_ents <= last_sid_idx)
 		dev_warn(smmu->dev,
 			 "2-level strtab only covers %u/%u bits of SID\n",
-			 ilog2(cfg->num_l1_ents * STRTAB_NUM_L2_STES),
+			 ilog2(cfg->l2.num_l1_ents * STRTAB_NUM_L2_STES),
 			 smmu->sid_bits);
 
-	l1size = cfg->num_l1_ents * sizeof(struct arm_smmu_strtab_l1);
-	strtab = dmam_alloc_coherent(smmu->dev, l1size, &cfg->strtab_dma,
-				     GFP_KERNEL);
-	if (!strtab) {
+	l1size = cfg->l2.num_l1_ents * sizeof(struct arm_smmu_strtab_l1);
+	cfg->l2.l1tab = dmam_alloc_coherent(smmu->dev, l1size, &cfg->l2.l1_dma,
+					    GFP_KERNEL);
+	if (!cfg->l2.l1tab) {
 		dev_err(smmu->dev,
 			"failed to allocate l1 stream table (%u bytes)\n",
 			l1size);
 		return -ENOMEM;
 	}
-	cfg->strtab = strtab;
 
 	/* Configure strtab_base_cfg for 2 levels */
 	reg  = FIELD_PREP(STRTAB_BASE_CFG_FMT, STRTAB_BASE_CFG_FMT_2LVL);
 	reg |= FIELD_PREP(STRTAB_BASE_CFG_LOG2SIZE,
-			  ilog2(cfg->num_l1_ents) + STRTAB_SPLIT);
+			  ilog2(cfg->l2.num_l1_ents) + STRTAB_SPLIT);
 	reg |= FIELD_PREP(STRTAB_BASE_CFG_SPLIT, STRTAB_SPLIT);
 	cfg->strtab_base_cfg = reg;
 
-	cfg->l1_desc = devm_kcalloc(smmu->dev, cfg->num_l1_ents,
-				    sizeof(*cfg->l1_desc), GFP_KERNEL);
-	if (!cfg->l1_desc)
+	cfg->l2.l2ptrs = devm_kcalloc(smmu->dev, cfg->l2.num_l1_ents,
+				      sizeof(*cfg->l2.l2ptrs), GFP_KERNEL);
+	if (!cfg->l2.l2ptrs)
 		return -ENOMEM;
 
 	return 0;
 }
 
 static int arm_smmu_init_strtab_linear(struct arm_smmu_device *smmu)
 {
-	void *strtab;
 	u64 reg;
 	u32 size;
 	struct arm_smmu_strtab_cfg *cfg = &smmu->strtab_cfg;
 
-	size = (1 << smmu->sid_bits) * (STRTAB_STE_DWORDS << 3);
-	strtab = dmam_alloc_coherent(smmu->dev, size, &cfg->strtab_dma,
-				     GFP_KERNEL);
-	if (!strtab) {
+	size = (1 << smmu->sid_bits) * sizeof(struct arm_smmu_ste);
+	cfg->linear.table = dmam_alloc_coherent(smmu->dev, size,
+						&cfg->linear.ste_dma,
+						GFP_KERNEL);
+	if (!cfg->linear.table) {
 		dev_err(smmu->dev,
 			"failed to allocate linear stream table (%u bytes)\n",
 			size);
 		return -ENOMEM;
 	}
-	cfg->strtab = strtab;
-	cfg->num_l1_ents = 1 << smmu->sid_bits;
+	cfg->linear.num_ents = 1 << smmu->sid_bits;
 
 	/* Configure strtab_base_cfg for a linear table covering all SIDs */
 	reg  = FIELD_PREP(STRTAB_BASE_CFG_FMT, STRTAB_BASE_CFG_FMT_LINEAR);
 	reg |= FIELD_PREP(STRTAB_BASE_CFG_LOG2SIZE, smmu->sid_bits);
 	cfg->strtab_base_cfg = reg;
 
-	arm_smmu_init_initial_stes(strtab, cfg->num_l1_ents);
+	arm_smmu_init_initial_stes(cfg->linear.table, cfg->linear.num_ents);
 	return 0;
 }
 
@@ -3703,16 +3698,17 @@ static int arm_smmu_init_strtab(struct arm_smmu_device *smmu)
 	u64 reg;
 	int ret;
 
-	if (smmu->features & ARM_SMMU_FEAT_2_LVL_STRTAB)
+	if (smmu->features & ARM_SMMU_FEAT_2_LVL_STRTAB) {
 		ret = arm_smmu_init_strtab_2lvl(smmu);
-	else
+		reg = smmu->strtab_cfg.l2.l1_dma & STRTAB_BASE_ADDR_MASK;
+	} else {
 		ret = arm_smmu_init_strtab_linear(smmu);
-
+		reg = smmu->strtab_cfg.linear.ste_dma & STRTAB_BASE_ADDR_MASK;
+	}
 	if (ret)
 		return ret;
 
 	/* Set the strtab base address */
-	reg  = smmu->strtab_cfg.strtab_dma & STRTAB_BASE_ADDR_MASK;
 	reg |= STRTAB_BASE_RA;
 	smmu->strtab_cfg.strtab_base = reg;
 

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h

@@ -613,10 +613,6 @@ struct arm_smmu_priq {
 };
 
 /* High-level stream table and context descriptor structures */
-struct arm_smmu_strtab_l1_desc {
-	struct arm_smmu_strtab_l2	*l2ptr;
-};
-
 struct arm_smmu_ctx_desc {
 	u16				asid;
 };
@@ -649,11 +645,19 @@ struct arm_smmu_s2_cfg {
 };
 
 struct arm_smmu_strtab_cfg {
-	__le64				*strtab;
-	dma_addr_t			strtab_dma;
-	struct arm_smmu_strtab_l1_desc	*l1_desc;
-	unsigned int			num_l1_ents;
-
+	union {
+		struct {
+			struct arm_smmu_ste *table;
+			dma_addr_t ste_dma;
+			unsigned int num_ents;
+		} linear;
+		struct {
+			struct arm_smmu_strtab_l1 *l1tab;
+			struct arm_smmu_strtab_l2 **l2ptrs;
+			dma_addr_t l1_dma;
+			unsigned int num_l1_ents;
+		} l2;
+	};
 	u64				strtab_base;
 	u32				strtab_base_cfg;
 };