[PATCH 01/19] iommu/arm-smmu-v3: Add a type for the STE
Jason Gunthorpe
jgg at nvidia.com
Fri Oct 13 07:00:28 PDT 2023
On Fri, Oct 13, 2023 at 11:37:35AM +0100, Will Deacon wrote:
> > -static __le64 *arm_smmu_get_step_for_sid(struct arm_smmu_device *smmu, u32 sid)
> > +static struct arm_smmu_ste *
> > +arm_smmu_get_step_for_sid(struct arm_smmu_device *smmu, u32 sid)
> > {
> > - __le64 *step;
> > struct arm_smmu_strtab_cfg *cfg = &smmu->strtab_cfg;
> >
> > if (smmu->features & ARM_SMMU_FEAT_2_LVL_STRTAB) {
> > - struct arm_smmu_strtab_l1_desc *l1_desc;
> > int idx;
> >
> > /* Two-level walk */
> > idx = (sid >> STRTAB_SPLIT) * STRTAB_L1_DESC_DWORDS;
> > - l1_desc = &cfg->l1_desc[idx];
> > - idx = (sid & ((1 << STRTAB_SPLIT) - 1)) * STRTAB_STE_DWORDS;
> > - step = &l1_desc->l2ptr[idx];
> > + return &cfg->l1_desc[idx].l2ptr[sid & ((1 << STRTAB_SPLIT) - 1)];
> > } else {
> > /* Simple linear lookup */
> > - step = &cfg->strtab[sid * STRTAB_STE_DWORDS];
> > + return (struct arm_smmu_ste *)&cfg
> > + ->strtab[sid * STRTAB_STE_DWORDS];
>
> Why not change the type of 'struct arm_smmu_strtab_cfg::strtab' at the same
> time?
It doesn't always point at a STE.
arm_smmu_init_strtab_2lvl() sets strtab to:
l1size = cfg->num_l1_ents * (STRTAB_L1_DESC_DWORDS << 3);
strtab = dmam_alloc_coherent(smmu->dev, l1size, &cfg->strtab_dma,
GFP_KERNEL);
cfg->strtab = strtab;
And arm_smmu_init_strtab_linear() sets strtab to:
size = (1 << smmu->sid_bits) * (STRTAB_STE_DWORDS << 3);
strtab = dmam_alloc_coherent(smmu->dev, size, &cfg->strtab_dma,
GFP_KERNEL);
cfg->strtab = strtab;
I can add this patch if you like immediately after:
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index d5ba85034c1386..bdb559878615b8 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1559,7 +1559,7 @@ static int arm_smmu_init_l2_strtab(struct arm_smmu_device *smmu, u32 sid)
return 0;
size = 1 << (STRTAB_SPLIT + ilog2(STRTAB_STE_DWORDS) + 3);
- strtab = &cfg->strtab[(sid >> STRTAB_SPLIT) * STRTAB_L1_DESC_DWORDS];
+ strtab = &cfg->strtab.l1_desc[sid >> STRTAB_SPLIT];
desc->span = STRTAB_SPLIT + 1;
desc->l2ptr = dmam_alloc_coherent(smmu->dev, size, &desc->l2ptr_dma,
@@ -2347,8 +2347,7 @@ arm_smmu_get_step_for_sid(struct arm_smmu_device *smmu, u32 sid)
return &cfg->l1_desc[idx].l2ptr[sid & ((1 << STRTAB_SPLIT) - 1)];
} else {
/* Simple linear lookup */
- return (struct arm_smmu_ste *)&cfg
- ->strtab[sid * STRTAB_STE_DWORDS];
+ return &cfg->strtab.linear[sid * STRTAB_STE_DWORDS];
}
}
@@ -3421,17 +3420,15 @@ static int arm_smmu_init_l1_strtab(struct arm_smmu_device *smmu)
{
unsigned int i;
struct arm_smmu_strtab_cfg *cfg = &smmu->strtab_cfg;
- void *strtab = smmu->strtab_cfg.strtab;
cfg->l1_desc = devm_kcalloc(smmu->dev, cfg->num_l1_ents,
sizeof(*cfg->l1_desc), GFP_KERNEL);
if (!cfg->l1_desc)
return -ENOMEM;
- for (i = 0; i < cfg->num_l1_ents; ++i) {
- arm_smmu_write_strtab_l1_desc(strtab, &cfg->l1_desc[i]);
- strtab += STRTAB_L1_DESC_DWORDS << 3;
- }
+ for (i = 0; i < cfg->num_l1_ents; ++i)
+ arm_smmu_write_strtab_l1_desc(
+ &smmu->strtab_cfg.strtab.l1_desc[i], &cfg->l1_desc[i]);
return 0;
}
@@ -3463,7 +3460,7 @@ static int arm_smmu_init_strtab_2lvl(struct arm_smmu_device *smmu)
l1size);
return -ENOMEM;
}
- cfg->strtab = strtab;
+ cfg->strtab.l1_desc = strtab;
/* Configure strtab_base_cfg for 2 levels */
reg = FIELD_PREP(STRTAB_BASE_CFG_FMT, STRTAB_BASE_CFG_FMT_2LVL);
@@ -3490,7 +3487,7 @@ static int arm_smmu_init_strtab_linear(struct arm_smmu_device *smmu)
size);
return -ENOMEM;
}
- cfg->strtab = strtab;
+ cfg->strtab.linear = strtab;
cfg->num_l1_ents = 1 << smmu->sid_bits;
/* Configure strtab_base_cfg for a linear table covering all SIDs */
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index 74f6f9e28c6e84..6d75adb1a72b4f 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -620,7 +620,10 @@ struct arm_smmu_s2_cfg {
};
struct arm_smmu_strtab_cfg {
- __le64 *strtab;
+ union {
+ struct arm_smmu_ste *linear;
+ __le64 *l1_desc;
+ } strtab;
dma_addr_t strtab_dma;
struct arm_smmu_strtab_l1_desc *l1_desc;
unsigned int num_l1_ents;
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