iommu/arm-smmu: Rework cb_base handling

To keep register-access quirks manageable, we want to structure things
to avoid needing too many individual overrides. It seems fairly clean to
have a single interface which handles both global and context registers
in terms of the architectural pages, so the first preparatory step is to
rework cb_base into a page number rather than an absolute address.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index a877de0..1912623 100644 (file)
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -95,7 +95,7 @@
 #endif
 
 /* Translation context bank */
-#define ARM_SMMU_CB(smmu, n)   ((smmu)->cb_base + ((n) << (smmu)->pgshift))
+#define ARM_SMMU_CB(smmu, n)   ((smmu)->base + (((smmu)->numpage + (n)) << (smmu)->pgshift))
 
 #define MSI_IOVA_BASE                  0x8000000
 #define MSI_IOVA_LENGTH                        0x100000
@@ -168,8 +168,8 @@ struct arm_smmu_device {
        struct device                   *dev;
 
        void __iomem                    *base;
-       void __iomem                    *cb_base;
-       unsigned long                   pgshift;
+       unsigned int                    numpage;
+       unsigned int                    pgshift;
 
 #define ARM_SMMU_FEAT_COHERENT_WALK    (1 << 0)
 #define ARM_SMMU_FEAT_STREAM_MATCH     (1 << 1)
@@ -1815,7 +1815,7 @@ static int arm_smmu_id_size_to_bits(int size)
 
 static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
 {
-       unsigned long size;
+       unsigned int size;
        void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
        u32 id;
        bool cttw_reg, cttw_fw = smmu->features & ARM_SMMU_FEAT_COHERENT_WALK;
@@ -1899,7 +1899,7 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
                        return -ENOMEM;
 
                dev_notice(smmu->dev,
-                          "\tstream matching with %lu register groups", size);
+                          "\tstream matching with %u register groups", size);
        }
        /* s2cr->type == 0 means translation, so initialise explicitly */
        smmu->s2crs = devm_kmalloc_array(smmu->dev, size, sizeof(*smmu->s2crs),
@@ -1925,11 +1925,12 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
 
        /* Check for size mismatch of SMMU address space from mapped region */
        size = 1 << (FIELD_GET(ID1_NUMPAGENDXB, id) + 1);
-       size <<= smmu->pgshift;
-       if (smmu->cb_base != gr0_base + size)
+       if (smmu->numpage != 2 * size << smmu->pgshift)
                dev_warn(smmu->dev,
-                       "SMMU address space size (0x%lx) differs from mapped region size (0x%tx)!\n",
-                       size * 2, (smmu->cb_base - gr0_base) * 2);
+                       "SMMU address space size (0x%x) differs from mapped region size (0x%x)!\n",
+                       2 * size << smmu->pgshift, smmu->numpage);
+       /* Now properly encode NUMPAGE to subsequently derive SMMU_CB_BASE */
+       smmu->numpage = size;
 
        smmu->num_s2_context_banks = FIELD_GET(ID1_NUMS2CB, id);
        smmu->num_context_banks = FIELD_GET(ID1_NUMCB, id);
@@ -2200,7 +2201,11 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
        smmu->base = devm_ioremap_resource(dev, res);
        if (IS_ERR(smmu->base))
                return PTR_ERR(smmu->base);
-       smmu->cb_base = smmu->base + resource_size(res) / 2;
+       /*
+        * The resource size should effectively match the value of SMMU_TOP;
+        * stash that temporarily until we know PAGESIZE to validate it with.
+        */
+       smmu->numpage = resource_size(res);
 
        num_irqs = 0;
        while ((res = platform_get_resource(pdev, IORESOURCE_IRQ, num_irqs))) {