[PATCH 2/9] iommu/arm-smmu: Calculate SMMU_CB_BASE from smmu register values
From: Will Deacon <hidden>
Date: 2013-09-27 09:51:57
Also in:
linux-iommu
Hi Andreas, On Thu, Sep 26, 2013 at 11:36:14PM +0100, Andreas Herrmann wrote:
Currently it is derived from smmu resource size. In case of a mismatchin between the two calculations trust DT more than register values and overwrite cb_base.
I thought the driver already favoured the DT?
quoted hunk ↗ jump to hunk
@@ -1702,12 +1704,23 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu) /* Check that we ioremapped enough */ size = 1 << (((id >> ID1_NUMPAGENDXB_SHIFT) & ID1_NUMPAGENDXB_MASK) + 1); - size *= (smmu->pagesize << 1); + size *= smmu->pagesize; + smmu->cb_base = smmu->base + size; + size *= 2; + if (smmu->size < size) dev_warn(smmu->dev, "device is 0x%lx bytes but only mapped 0x%lx!\n", size, smmu->size); + t = (unsigned long) smmu->base + (smmu->size >> 1); + if ((unsigned long)smmu->cb_base != t) { + dev_warn(smmu->dev, "address space mismatch, " + "overwriting cb_base (old: 0x%lx, new: 0x%lx)\n", + (unsigned long) smmu->cb_base, t); + smmu->cb_base = (void *) t; + } +
I expect I'm just being slow here (only one coffee in), but I can't see what this gets us over the current use of resource_size (which goes and uses the DT). Will