[PATCH v18 3/5] iommu/arm-smmu: add support for PRR bit setup

[Bibek Kumar Patro]

Add an adreno-smmu-priv interface for drm/msm to call
into arm-smmu-qcom and initiate the 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 <robdclark at gmail.com>
Signed-off-by: Bibek Kumar Patro <quic_bibekkum at quicinc.com>
---
 drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 52 ++++++++++++++++++++++
 drivers/iommu/arm/arm-smmu/arm-smmu.h      |  2 +
 include/linux/adreno-smmu-priv.h           | 14 ++++++
 3 files changed, 68 insertions(+)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
index d26f5aea248e..818fdbd706da 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
+++ b/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;
 }
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.h b/drivers/iommu/arm/arm-smmu/arm-smmu.h
index e2aeb511ae90..2dbf3243b5ad 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.h
+++ b/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)
diff --git a/include/linux/adreno-smmu-priv.h b/include/linux/adreno-smmu-priv.h
index c637e0997f6d..614665153b3e 100644
--- a/include/linux/adreno-smmu-priv.h
+++ b/include/linux/adreno-smmu-priv.h
@@ -50,6 +50,18 @@ struct adreno_smmu_fault_info {
  *                 the GPU driver must call resume_translation()
  * @resume_translation: Resume translation after a fault
  *
+ * *CAUTION* : PRR callbacks (set_prr_bit/set_prr_addr) are NULL terminated for
+ *             targets without PRR support. Exercise caution and verify target
+ *             capabilities before invoking these callbacks to prevent potential
+ *             runtime errors or unexpected behavior.
+ *
+ * @set_prr_bit:   Extendible interface to be used by GPU to modify the
+ *		   ACTLR register bits, currently used to configure
+ *		   Partially-Resident-Region (PRR) bit for feature's
+ *		   setup and reset sequence as requested.
+ * @set_prr_addr:  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 +79,8 @@ 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 */
--
2.34.1