From 21174240e4f4439bb8ed6c116cdbdc03eba2126e Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Mon, 12 Sep 2016 17:13:48 +0100 Subject: [PATCH] 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: Will Deacon Tested-by: Lorenzo Pieralisi Signed-off-by: Robin Murphy Signed-off-by: Will Deacon --- drivers/iommu/arm-smmu.c | 43 ++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 21 deletions(-) diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index 4b1c87e947fd..f86d7887f69a 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -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; -- 2.20.1