iommu/arm-smmu: Add support for PRR bit setup

Add an adreno-smmu-priv interface for drm/msm to call into arm-smmu-qcom
and initiate the "Partially Resident Region" (PRR) bit setup or reset
sequence as per request.

This will be used by GPU to setup the PRR bit and related configuration
registers through adreno-smmu private interface instead of directly
poking the smmu hardware.

Suggested-by: Rob Clark <[email protected]>
Signed-off-by: Bibek Kumar Patro <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>

Author: Bibek Kumar Patro

drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c

@@ -16,6 +16,8 @@
 
 #define QCOM_DUMMY_VAL	-1
 
+#define GFX_ACTLR_PRR          (1 << 5)
+
 static struct qcom_smmu *to_qcom_smmu(struct arm_smmu_device *smmu)
 {
 	return container_of(smmu, struct qcom_smmu, smmu);
@@ -99,6 +101,47 @@ static void qcom_adreno_smmu_resume_translation(const void *cookie, bool termina
 	arm_smmu_cb_write(smmu, cfg->cbndx, ARM_SMMU_CB_RESUME, reg);
 }
 
+static void qcom_adreno_smmu_set_prr_bit(const void *cookie, bool set)
+{
+	struct arm_smmu_domain *smmu_domain = (void *)cookie;
+	struct arm_smmu_device *smmu = smmu_domain->smmu;
+	struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
+	u32 reg = 0;
+	int ret;
+
+	ret = pm_runtime_resume_and_get(smmu->dev);
+	if (ret < 0) {
+		dev_err(smmu->dev, "failed to get runtime PM: %d\n", ret);
+		return;
+	}
+
+	reg =  arm_smmu_cb_read(smmu, cfg->cbndx, ARM_SMMU_CB_ACTLR);
+	reg &= ~GFX_ACTLR_PRR;
+	if (set)
+		reg |= FIELD_PREP(GFX_ACTLR_PRR, 1);
+	arm_smmu_cb_write(smmu, cfg->cbndx, ARM_SMMU_CB_ACTLR, reg);
+	pm_runtime_put_autosuspend(smmu->dev);
+}
+
+static void qcom_adreno_smmu_set_prr_addr(const void *cookie, phys_addr_t page_addr)
+{
+	struct arm_smmu_domain *smmu_domain = (void *)cookie;
+	struct arm_smmu_device *smmu = smmu_domain->smmu;
+	int ret;
+
+	ret = pm_runtime_resume_and_get(smmu->dev);
+	if (ret < 0) {
+		dev_err(smmu->dev, "failed to get runtime PM: %d\n", ret);
+		return;
+	}
+
+	writel_relaxed(lower_32_bits(page_addr),
+				smmu->base + ARM_SMMU_GFX_PRR_CFG_LADDR);
+	writel_relaxed(upper_32_bits(page_addr),
+				smmu->base + ARM_SMMU_GFX_PRR_CFG_UADDR);
+	pm_runtime_put_autosuspend(smmu->dev);
+}
+
 #define QCOM_ADRENO_SMMU_GPU_SID 0
 
 static bool qcom_adreno_smmu_is_gpu_device(struct device *dev)
@@ -210,6 +253,7 @@ static bool qcom_adreno_can_do_ttbr1(struct arm_smmu_device *smmu)
 static int qcom_adreno_smmu_init_context(struct arm_smmu_domain *smmu_domain,
 		struct io_pgtable_cfg *pgtbl_cfg, struct device *dev)
 {
+	const struct device_node *np = smmu_domain->smmu->dev->of_node;
 	struct adreno_smmu_priv *priv;
 
 	smmu_domain->cfg.flush_walk_prefer_tlbiasid = true;
@@ -239,6 +283,14 @@ static int qcom_adreno_smmu_init_context(struct arm_smmu_domain *smmu_domain,
 	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;
+	priv->set_prr_bit = NULL;
+	priv->set_prr_addr = NULL;
+
+	if (of_device_is_compatible(np, "qcom,smmu-500") &&
+			of_device_is_compatible(np, "qcom,adreno-smmu")) {
+		priv->set_prr_bit = qcom_adreno_smmu_set_prr_bit;
+		priv->set_prr_addr = qcom_adreno_smmu_set_prr_addr;
+	}
 
 	return 0;
 }

drivers/iommu/arm/arm-smmu/arm-smmu.h

@@ -154,6 +154,8 @@ enum arm_smmu_cbar_type {
 #define ARM_SMMU_SCTLR_M		BIT(0)
 
 #define ARM_SMMU_CB_ACTLR		0x4
+#define ARM_SMMU_GFX_PRR_CFG_LADDR	0x6008
+#define ARM_SMMU_GFX_PRR_CFG_UADDR	0x600C
 
 #define ARM_SMMU_CB_RESUME		0x8
 #define ARM_SMMU_RESUME_TERMINATE	BIT(0)

include/linux/adreno-smmu-priv.h

@@ -50,6 +50,11 @@ struct adreno_smmu_fault_info {
  *                 the GPU driver must call resume_translation()
  * @resume_translation: Resume translation after a fault
  *
+ * @set_prr_bit:   [optional] Configure the GPU's Partially Resident
+ *                 Region (PRR) bit in the ACTLR register.
+ * @set_prr_addr:  [optional] Configure the PRR_CFG_*ADDR register with
+ *                 the physical address of PRR page passed from GPU
+ *                 driver.
  *
  * The GPU driver (drm/msm) and adreno-smmu work together for controlling
  * the GPU's SMMU instance.  This is by necessity, as the GPU is directly
@@ -67,6 +72,8 @@ struct adreno_smmu_priv {
     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);
+    void (*set_prr_bit)(const void *cookie, bool set);
+    void (*set_prr_addr)(const void *cookie, phys_addr_t page_addr);
 };
 
 #endif /* __ADRENO_SMMU_PRIV_H */