[PATCH v3 2/8] iommu/arm-smmu: Delay modifying domain during init

From: Bjorn Andersson
Date: Fri Sep 04 2020 - 11:56:20 EST


Delay modifications to the domain during arm_smmu_init_domain_context()
until we've allocated a context bank. This will allow us to postpone the
special handling of identity domains until the platform specific context
bank allocator has been executed, in a later patch.

Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---

Changes since v2:
- New patch to allow us to rely on the impl specific alloc_context_bank().

drivers/iommu/arm/arm-smmu/arm-smmu.c | 40 +++++++++++++++------------
1 file changed, 23 insertions(+), 17 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index e19d7bdc7674..add2e1807e21 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -645,6 +645,9 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
irqreturn_t (*context_fault)(int irq, void *dev);
+ struct arm_smmu_cfg new_cfg = *cfg;
+ enum arm_smmu_domain_stage new_stage = smmu_domain->stage;
+ const struct iommu_flush_ops *flush_ops;

mutex_lock(&smmu_domain->init_mutex);
if (smmu_domain->smmu)
@@ -675,9 +678,9 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
* Note that you can't actually request stage-2 mappings.
*/
if (!(smmu->features & ARM_SMMU_FEAT_TRANS_S1))
- smmu_domain->stage = ARM_SMMU_DOMAIN_S2;
+ new_stage = ARM_SMMU_DOMAIN_S2;
if (!(smmu->features & ARM_SMMU_FEAT_TRANS_S2))
- smmu_domain->stage = ARM_SMMU_DOMAIN_S1;
+ new_stage = ARM_SMMU_DOMAIN_S1;

/*
* Choosing a suitable context format is even more fiddly. Until we
@@ -688,32 +691,32 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
* support to be a superset of AArch32 support...
*/
if (smmu->features & ARM_SMMU_FEAT_FMT_AARCH32_L)
- cfg->fmt = ARM_SMMU_CTX_FMT_AARCH32_L;
+ new_cfg.fmt = ARM_SMMU_CTX_FMT_AARCH32_L;
if (IS_ENABLED(CONFIG_IOMMU_IO_PGTABLE_ARMV7S) &&
!IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_ARM_LPAE) &&
(smmu->features & ARM_SMMU_FEAT_FMT_AARCH32_S) &&
- (smmu_domain->stage == ARM_SMMU_DOMAIN_S1))
- cfg->fmt = ARM_SMMU_CTX_FMT_AARCH32_S;
- if ((IS_ENABLED(CONFIG_64BIT) || cfg->fmt == ARM_SMMU_CTX_FMT_NONE) &&
+ (new_stage == ARM_SMMU_DOMAIN_S1))
+ new_cfg.fmt = ARM_SMMU_CTX_FMT_AARCH32_S;
+ if ((IS_ENABLED(CONFIG_64BIT) || new_cfg.fmt == ARM_SMMU_CTX_FMT_NONE) &&
(smmu->features & (ARM_SMMU_FEAT_FMT_AARCH64_64K |
ARM_SMMU_FEAT_FMT_AARCH64_16K |
ARM_SMMU_FEAT_FMT_AARCH64_4K)))
- cfg->fmt = ARM_SMMU_CTX_FMT_AARCH64;
+ new_cfg.fmt = ARM_SMMU_CTX_FMT_AARCH64;

- if (cfg->fmt == ARM_SMMU_CTX_FMT_NONE) {
+ if (new_cfg.fmt == ARM_SMMU_CTX_FMT_NONE) {
ret = -EINVAL;
goto out_unlock;
}

- switch (smmu_domain->stage) {
+ switch (new_stage) {
case ARM_SMMU_DOMAIN_S1:
- cfg->cbar = CBAR_TYPE_S1_TRANS_S2_BYPASS;
+ new_cfg.cbar = CBAR_TYPE_S1_TRANS_S2_BYPASS;
start = smmu->num_s2_context_banks;
ias = smmu->va_size;
oas = smmu->ipa_size;
- if (cfg->fmt == ARM_SMMU_CTX_FMT_AARCH64) {
+ if (new_cfg.fmt == ARM_SMMU_CTX_FMT_AARCH64) {
fmt = ARM_64_LPAE_S1;
- } else if (cfg->fmt == ARM_SMMU_CTX_FMT_AARCH32_L) {
+ } else if (new_cfg.fmt == ARM_SMMU_CTX_FMT_AARCH32_L) {
fmt = ARM_32_LPAE_S1;
ias = min(ias, 32UL);
oas = min(oas, 40UL);
@@ -722,7 +725,7 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
ias = min(ias, 32UL);
oas = min(oas, 32UL);
}
- smmu_domain->flush_ops = &arm_smmu_s1_tlb_ops;
+ flush_ops = &arm_smmu_s1_tlb_ops;
break;
case ARM_SMMU_DOMAIN_NESTED:
/*
@@ -730,11 +733,11 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
* involved.
*/
case ARM_SMMU_DOMAIN_S2:
- cfg->cbar = CBAR_TYPE_S2_TRANS;
+ new_cfg.cbar = CBAR_TYPE_S2_TRANS;
start = 0;
ias = smmu->ipa_size;
oas = smmu->pa_size;
- if (cfg->fmt == ARM_SMMU_CTX_FMT_AARCH64) {
+ if (new_cfg.fmt == ARM_SMMU_CTX_FMT_AARCH64) {
fmt = ARM_64_LPAE_S2;
} else {
fmt = ARM_32_LPAE_S2;
@@ -742,9 +745,9 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
oas = min(oas, 40UL);
}
if (smmu->version == ARM_SMMU_V2)
- smmu_domain->flush_ops = &arm_smmu_s2_tlb_ops_v2;
+ flush_ops = &arm_smmu_s2_tlb_ops_v2;
else
- smmu_domain->flush_ops = &arm_smmu_s2_tlb_ops_v1;
+ flush_ops = &arm_smmu_s2_tlb_ops_v1;
break;
default:
ret = -EINVAL;
@@ -757,6 +760,9 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
}

smmu_domain->smmu = smmu;
+ smmu_domain->cfg = new_cfg;
+ smmu_domain->stage = new_stage;
+ smmu_domain->flush_ops = flush_ops;

cfg->cbndx = ret;
if (smmu->version < ARM_SMMU_V2) {
--
2.28.0