[PATCH 2/5] iommu/arm-smmu-qcom: Provide way to access current TTBR0

From: Rob Clark
Date: Sun Aug 21 2022 - 14:19:04 EST


From: Rob Clark <robdclark@xxxxxxxxxxxx>

The drm driver can skip tlbinv when unmapping from something that isn't
the current pgtables, as there is already a tlbinv on context switch.

Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
---
drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 9 +++++++++
include/linux/adreno-smmu-priv.h | 2 ++
2 files changed, 11 insertions(+)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
index 7820711c4560..59b460c1c9a5 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
@@ -157,6 +157,14 @@ static int qcom_adreno_smmu_set_ttbr0_cfg(const void *cookie,
return 0;
}

+static u64 qcom_adreno_smmu_get_ttbr0(const void *cookie)
+{
+ struct arm_smmu_domain *smmu_domain = (void *)cookie;
+ struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
+
+ return arm_smmu_cb_readq(smmu_domain->smmu, cfg->cbndx, ARM_SMMU_CB_TTBR0);
+}
+
static int qcom_adreno_smmu_alloc_context_bank(struct arm_smmu_domain *smmu_domain,
struct arm_smmu_device *smmu,
struct device *dev, int start)
@@ -217,6 +225,7 @@ static int qcom_adreno_smmu_init_context(struct arm_smmu_domain *smmu_domain,
priv->cookie = smmu_domain;
priv->get_ttbr1_cfg = qcom_adreno_smmu_get_ttbr1_cfg;
priv->set_ttbr0_cfg = qcom_adreno_smmu_set_ttbr0_cfg;
+ priv->get_ttbr0 = qcom_adreno_smmu_get_ttbr0;
priv->get_fault_info = qcom_adreno_smmu_get_fault_info;
priv->set_stall = qcom_adreno_smmu_set_stall;
priv->resume_translation = qcom_adreno_smmu_resume_translation;
diff --git a/include/linux/adreno-smmu-priv.h b/include/linux/adreno-smmu-priv.h
index ac4c2c0ab724..4ad90541a095 100644
--- a/include/linux/adreno-smmu-priv.h
+++ b/include/linux/adreno-smmu-priv.h
@@ -43,6 +43,7 @@ struct adreno_smmu_fault_info {
* @set_ttbr0_cfg: Set the TTBR0 config for the GPUs context bank. A
* NULL config disables TTBR0 translation, otherwise
* TTBR0 translation is enabled with the specified cfg
+ * @get_ttbr0: Get current TTBR0 value
* @get_fault_info: Called by the GPU fault handler to get information about
* the fault
* @set_stall: Configure whether stall on fault (CFCFG) is enabled. Call
@@ -64,6 +65,7 @@ struct adreno_smmu_priv {
const void *cookie;
const struct io_pgtable_cfg *(*get_ttbr1_cfg)(const void *cookie);
int (*set_ttbr0_cfg)(const void *cookie, const struct io_pgtable_cfg *cfg);
+ u64 (*get_ttbr0)(const void *cookie);
void (*get_fault_info)(const void *cookie, struct adreno_smmu_fault_info *info);
void (*set_stall)(const void *cookie, bool enabled);
void (*resume_translation)(const void *cookie, bool terminate);
--
2.37.2