iommu/arm-smmu: Support for Extended Stream ID (16 bit)

It is the time we have the real 16-bit Stream ID user, which is the
ThunderX. Its IO topology uses 1:1 map for Requester ID to Stream ID
translation for each root complex which allows to get full 16-bit
Stream ID.  Firmware assigns bus IDs that are greater than 128 (0x80)
to some buses under PEM (external PCIe interface).  Eventually SMMU
drops devices on that buses because their Stream ID is out of range:

  pci 0006:90:00.0: stream ID 0x9000 out of range for SMMU (0x7fff)

To fix above issue enable the Extended Stream ID optional feature
when available.

Reviewed-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Tested-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

1 files changed, 48 insertions, 21 deletions

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index a60cded8a6ed..93b9177d4dfd 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -24,6 +24,7 @@
  *	- v7/v8 long-descriptor format
  *	- Non-secure access to the SMMU
  *	- Context fault reporting
+ *	- Extended Stream ID (16 bit)
  */
 
 #define pr_fmt(fmt) "arm-smmu: " fmt
@@ -87,6 +88,7 @@
 #define sCR0_CLIENTPD			(1 << 0)
 #define sCR0_GFRE			(1 << 1)
 #define sCR0_GFIE			(1 << 2)
+#define sCR0_EXIDENABLE			(1 << 3)
 #define sCR0_GCFGFRE			(1 << 4)
 #define sCR0_GCFGFIE			(1 << 5)
 #define sCR0_USFCFG			(1 << 10)
@@ -126,6 +128,7 @@
 #define ID0_NUMIRPT_MASK		0xff
 #define ID0_NUMSIDB_SHIFT		9
 #define ID0_NUMSIDB_MASK		0xf
+#define ID0_EXIDS			(1 << 8)
 #define ID0_NUMSMRG_SHIFT		0
 #define ID0_NUMSMRG_MASK		0xff
 
@@ -169,6 +172,7 @@
 #define ARM_SMMU_GR0_S2CR(n)		(0xc00 + ((n) << 2))
 #define S2CR_CBNDX_SHIFT		0
 #define S2CR_CBNDX_MASK			0xff
+#define S2CR_EXIDVALID			(1 << 10)
 #define S2CR_TYPE_SHIFT			16
 #define S2CR_TYPE_MASK			0x3
 enum arm_smmu_s2cr_type {
@@ -351,6 +355,7 @@ struct arm_smmu_device {
 #define ARM_SMMU_FEAT_FMT_AARCH64_64K	(1 << 9)
 #define ARM_SMMU_FEAT_FMT_AARCH32_L	(1 << 10)
 #define ARM_SMMU_FEAT_FMT_AARCH32_S	(1 << 11)
+#define ARM_SMMU_FEAT_EXIDS		(1 << 12)
 	u32				features;
 
 #define ARM_SMMU_OPT_SECURE_CFG_ACCESS (1 << 0)
@@ -1048,7 +1053,7 @@ static void arm_smmu_write_smr(struct arm_smmu_device *smmu, int idx)
 	struct arm_smmu_smr *smr = smmu->smrs + idx;
 	u32 reg = smr->id << SMR_ID_SHIFT | smr->mask << SMR_MASK_SHIFT;
 
-	if (smr->valid)
+	if (!(smmu->features & ARM_SMMU_FEAT_EXIDS) && smr->valid)
 		reg |= SMR_VALID;
 	writel_relaxed(reg, ARM_SMMU_GR0(smmu) + ARM_SMMU_GR0_SMR(idx));
 }
@@ -1060,6 +1065,9 @@ static void arm_smmu_write_s2cr(struct arm_smmu_device *smmu, int idx)
 		  (s2cr->cbndx & S2CR_CBNDX_MASK) << S2CR_CBNDX_SHIFT |
 		  (s2cr->privcfg & S2CR_PRIVCFG_MASK) << S2CR_PRIVCFG_SHIFT;
 
+	if (smmu->features & ARM_SMMU_FEAT_EXIDS && smmu->smrs &&
+	    smmu->smrs[idx].valid)
+		reg |= S2CR_EXIDVALID;
 	writel_relaxed(reg, ARM_SMMU_GR0(smmu) + ARM_SMMU_GR0_S2CR(idx));
 }
 
@@ -1070,6 +1078,34 @@ static void arm_smmu_write_sme(struct arm_smmu_device *smmu, int idx)
 		arm_smmu_write_smr(smmu, idx);
 }
 
+/*
+ * The width of SMR's mask field depends on sCR0_EXIDENABLE, so this function
+ * should be called after sCR0 is written.
+ */
+static void arm_smmu_test_smr_masks(struct arm_smmu_device *smmu)
+{
+	void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
+	u32 smr;
+
+	if (!smmu->smrs)
+		return;
+
+	/*
+	 * SMR.ID bits may not be preserved if the corresponding MASK
+	 * bits are set, so check each one separately. We can reject
+	 * masters later if they try to claim IDs outside these masks.
+	 */
+	smr = smmu->streamid_mask << SMR_ID_SHIFT;
+	writel_relaxed(smr, gr0_base + ARM_SMMU_GR0_SMR(0));
+	smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(0));
+	smmu->streamid_mask = smr >> SMR_ID_SHIFT;
+
+	smr = smmu->streamid_mask << SMR_MASK_SHIFT;
+	writel_relaxed(smr, gr0_base + ARM_SMMU_GR0_SMR(0));
+	smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(0));
+	smmu->smr_mask_mask = smr >> SMR_MASK_SHIFT;
+}
+
 static int arm_smmu_find_sme(struct arm_smmu_device *smmu, u16 id, u16 mask)
 {
 	struct arm_smmu_smr *smrs = smmu->smrs;
@@ -1648,6 +1684,9 @@ static void arm_smmu_device_reset(struct arm_smmu_device *smmu)
 	if (smmu->features & ARM_SMMU_FEAT_VMID16)
 		reg |= sCR0_VMID16EN;
 
+	if (smmu->features & ARM_SMMU_FEAT_EXIDS)
+		reg |= sCR0_EXIDENABLE;
+
 	/* Push the button */
 	__arm_smmu_tlb_sync(smmu);
 	writel(reg, ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0);
@@ -1735,11 +1774,14 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
 			   "\t(IDR0.CTTW overridden by FW configuration)\n");
 
 	/* Max. number of entries we have for stream matching/indexing */
-	size = 1 << ((id >> ID0_NUMSIDB_SHIFT) & ID0_NUMSIDB_MASK);
+	if (smmu->version == ARM_SMMU_V2 && id & ID0_EXIDS) {
+		smmu->features |= ARM_SMMU_FEAT_EXIDS;
+		size = 1 << 16;
+	} else {
+		size = 1 << ((id >> ID0_NUMSIDB_SHIFT) & ID0_NUMSIDB_MASK);
+	}
 	smmu->streamid_mask = size - 1;
 	if (id & ID0_SMS) {
-		u32 smr;
-
 		smmu->features |= ARM_SMMU_FEAT_STREAM_MATCH;
 		size = (id >> ID0_NUMSMRG_SHIFT) & ID0_NUMSMRG_MASK;
 		if (size == 0) {
@@ -1748,21 +1790,6 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
 			return -ENODEV;
 		}
 
-		/*
-		 * SMR.ID bits may not be preserved if the corresponding MASK
-		 * bits are set, so check each one separately. We can reject
-		 * masters later if they try to claim IDs outside these masks.
-		 */
-		smr = smmu->streamid_mask << SMR_ID_SHIFT;
-		writel_relaxed(smr, gr0_base + ARM_SMMU_GR0_SMR(0));
-		smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(0));
-		smmu->streamid_mask = smr >> SMR_ID_SHIFT;
-
-		smr = smmu->streamid_mask << SMR_MASK_SHIFT;
-		writel_relaxed(smr, gr0_base + ARM_SMMU_GR0_SMR(0));
-		smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(0));
-		smmu->smr_mask_mask = smr >> SMR_MASK_SHIFT;
-
 		/* Zero-initialised to mark as invalid */
 		smmu->smrs = devm_kcalloc(smmu->dev, size, sizeof(*smmu->smrs),
 					  GFP_KERNEL);
@@ -1770,8 +1797,7 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
 			return -ENOMEM;
 
 		dev_notice(smmu->dev,
-			   "\tstream matching with %lu register groups, mask 0x%x",
-			   size, smmu->smr_mask_mask);
+			   "\tstream matching with %lu register groups", size);
 	}
 	/* s2cr->type == 0 means translation, so initialise explicitly */
 	smmu->s2crs = devm_kmalloc_array(smmu->dev, size, sizeof(*smmu->s2crs),
@@ -2094,6 +2120,7 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 	iommu_register_instance(dev->fwnode, &arm_smmu_ops);
 	platform_set_drvdata(pdev, smmu);
 	arm_smmu_device_reset(smmu);
+	arm_smmu_test_smr_masks(smmu);
 
 	/* Oh, for a proper bus abstraction */
 	if (!iommu_present(&platform_bus_type))