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.

Signed-off-by: Andreas Herrmann <[email protected]>
---
 drivers/iommu/arm-smmu.c |   17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 6808577..4307fbc 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -207,7 +207,7 @@
 #define CBA2R_RW64_64BIT               (1 << 0)
 
 /* Translation context bank */
-#define ARM_SMMU_CB_BASE(smmu)         ((smmu)->base + ((smmu)->size >> 1))
+#define ARM_SMMU_CB_BASE(smmu)         ((smmu)->cb_base)
 #define ARM_SMMU_CB(smmu, n)           ((n) * (smmu)->pagesize)
 
 #define ARM_SMMU_CB_SCTLR              0x0
@@ -339,6 +339,7 @@ struct arm_smmu_device {
        struct device_node              *parent_of_node;
 
        void __iomem                    *base;
+       void __iomem                    *cb_base;
        unsigned long                   size;
        unsigned long                   pagesize;
 
@@ -1622,6 +1623,7 @@ static int arm_smmu_device_cfg_probe(struct 
arm_smmu_device *smmu)
        unsigned long size;
        void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
        u32 id;
+       unsigned long t;
 
        dev_notice(smmu->dev, "probing hardware configuration...\n");
 
@@ -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;
+       }
+
        smmu->num_s2_context_banks = (id >> ID1_NUMS2CB_SHIFT) &
                                      ID1_NUMS2CB_MASK;
        smmu->num_context_banks = (id >> ID1_NUMCB_SHIFT) & ID1_NUMCB_MASK;
-- 
1.7.9.5

_______________________________________________
iommu mailing list
[email protected]
https://lists.linuxfoundation.org/mailman/listinfo/iommu

Reply via email to