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 <will.deacon@xxxxxxx>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
---
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;
--
2.8.1.dirty
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