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Commit 21174240 authored by Robin Murphy's avatar Robin Murphy Committed by Will Deacon
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iommu/arm-smmu: Handle stream IDs more dynamically 



Rather than assuming fixed worst-case values for stream IDs and SMR
masks, keep track of whatever implemented bits the hardware actually
reports. This also obviates the slightly questionable validation of SMR
fields in isolation - rather than aborting the whole SMMU probe for a
hardware configuration which is still architecturally valid, we can
simply refuse masters later if they try to claim an unrepresentable ID
or mask (which almost certainly implies a DT error anyway).

Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Tested-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 95fa99aa

drivers/iommu/arm-smmu.c

+22 −21
Original line number Diff line number Diff line
@@ -165,9 +165,7 @@ 
#define ARM_SMMU_GR0_SMR(n)		(0x800 + ((n) << 2))

#define SMR_VALID			(1 << 31)

#define SMR_MASK_SHIFT			16

#define SMR_MASK_MASK			0x7fff

#define SMR_ID_SHIFT			0

#define SMR_ID_MASK			0x7fff



#define ARM_SMMU_GR0_S2CR(n)		(0xc00 + ((n) << 2))

#define S2CR_CBNDX_SHIFT		0
@@ -346,6 +344,8 @@ struct arm_smmu_device { 
	atomic_t			irptndx;



	u32				num_mapping_groups;

	u16				streamid_mask;

	u16				smr_mask_mask;

	DECLARE_BITMAP(smr_map, ARM_SMMU_MAX_SMRS);



	unsigned long			va_size;
@@ -1715,39 +1715,40 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu) 
		dev_notice(smmu->dev,

			   "\t(IDR0.CTTW overridden by dma-coherent property)\n");



	/* Max. number of entries we have for stream matching/indexing */

	size = 1 << ((id >> ID0_NUMSIDB_SHIFT) & ID0_NUMSIDB_MASK);

	smmu->streamid_mask = size - 1;

	if (id & ID0_SMS) {

		u32 smr, sid, mask;

		u32 smr;



		smmu->features |= ARM_SMMU_FEAT_STREAM_MATCH;

		smmu->num_mapping_groups = (id >> ID0_NUMSMRG_SHIFT) &

					   ID0_NUMSMRG_MASK;

		if (smmu->num_mapping_groups == 0) {

		size = (id >> ID0_NUMSMRG_SHIFT) & ID0_NUMSMRG_MASK;

		if (size == 0) {

			dev_err(smmu->dev,

				"stream-matching supported, but no SMRs present!\n");

			return -ENODEV;

		}



		smr = SMR_MASK_MASK << SMR_MASK_SHIFT;

		smr |= (SMR_ID_MASK << SMR_ID_SHIFT);

		/*

		 * 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;



		mask = (smr >> SMR_MASK_SHIFT) & SMR_MASK_MASK;

		sid = (smr >> SMR_ID_SHIFT) & SMR_ID_MASK;

		if ((mask & sid) != sid) {

			dev_err(smmu->dev,

				"SMR mask bits (0x%x) insufficient for ID field (0x%x)\n",

				mask, sid);

			return -ENODEV;

		}

		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;



		dev_notice(smmu->dev,

			   "\tstream matching with %u register groups, mask 0x%x",

			   smmu->num_mapping_groups, mask);

	} else {

		smmu->num_mapping_groups = (id >> ID0_NUMSIDB_SHIFT) &

					   ID0_NUMSIDB_MASK;

			   "\tstream matching with %lu register groups, mask 0x%x",

			   size, smmu->smr_mask_mask);

	}

	smmu->num_mapping_groups = size;



	if (smmu->version < ARM_SMMU_V2 || !(id & ID0_PTFS_NO_AARCH32)) {

		smmu->features |= ARM_SMMU_FEAT_FMT_AARCH32_L;