[PATCH v3 3/3] drm/msm: Improve the a6xx page fault handler

[Jordan Crouse]

Use the new adreno-smmu-priv fault info function to get more SMMU
debug registers and print the current TTBR0 to debug per-instance
pagetables and figure out which GPU block generated the request.

Signed-off-by: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
---

 drivers/gpu/drm/msm/adreno/a5xx_gpu.c |  4 +-
 drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 76 +++++++++++++++++++++++++--
 drivers/gpu/drm/msm/msm_iommu.c       | 11 +++-
 drivers/gpu/drm/msm/msm_mmu.h         |  4 +-
 4 files changed, 87 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
index 7e553d3efeb2..56b548921c4e 100644
--- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
@@ -1075,7 +1075,7 @@ bool a5xx_idle(struct msm_gpu *gpu, struct msm_ringbuffer *ring)
 	return true;
 }
 
-static int a5xx_fault_handler(void *arg, unsigned long iova, int flags)
+static int a5xx_fault_handler(void *arg, unsigned long iova, int flags, void *data)
 {
 	struct msm_gpu *gpu = arg;
 	pr_warn_ratelimited("*** gpu fault: iova=%08lx, flags=%d (%u,%u,%u,%u)\n",
@@ -1085,7 +1085,7 @@ static int a5xx_fault_handler(void *arg, unsigned long iova, int flags)
 			gpu_read(gpu, REG_A5XX_CP_SCRATCH_REG(6)),
 			gpu_read(gpu, REG_A5XX_CP_SCRATCH_REG(7)));
 
-	return -EFAULT;
+	return 0;
 }
 
 static void a5xx_cp_err_irq(struct msm_gpu *gpu)
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
index 064b7face504..97eabd87740c 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
@@ -959,18 +959,88 @@ static void a6xx_recover(struct msm_gpu *gpu)
 	msm_gpu_hw_init(gpu);
 }
 
-static int a6xx_fault_handler(void *arg, unsigned long iova, int flags)
+static const char *a6xx_uche_fault_block(struct msm_gpu *gpu, u32 mid)
+{
+	static const char *uche_clients[7] = {
+		"VFD", "SP", "VSC", "VPC", "HLSQ", "PC", "LRZ",
+	};
+	u32 val;
+
+	if (mid < 1 || mid > 3)
+		return "UNKNOWN";
+
+	/*
+	 * The source of the data depends on the mid ID read from FSYNR1.
+	 * and the client ID read from the UCHE block
+	 */
+	val = gpu_read(gpu, REG_A6XX_UCHE_CLIENT_PF);
+
+	/* mid = 3 is most precise and refers to only one block per client */
+	if (mid == 3)
+		return uche_clients[val & 7];
+
+	/* For mid=2 the source is TP or VFD except when the client id is 0 */
+	if (mid == 2)
+		return ((val & 7) == 0) ? "TP" : "TP|VFD";
+
+	/* For mid=1 just return "UCHE" as a catchall for everything else */
+	return "UCHE";
+}
+
+static const char *a6xx_fault_block(struct msm_gpu *gpu, u32 id)
+{
+	if (id == 0)
+		return "CP";
+	else if (id == 4)
+		return "CCU";
+	else if (id == 6)
+		return "CDP Prefetch";
+
+	return a6xx_uche_fault_block(gpu, id);
+}
+
+#define ARM_SMMU_FSR_TF                 BIT(1)
+#define ARM_SMMU_FSR_PF			BIT(3)
+#define ARM_SMMU_FSR_EF			BIT(4)
+
+static int a6xx_fault_handler(void *arg, unsigned long iova, int flags, void *data)
 {
 	struct msm_gpu *gpu = arg;
+	struct adreno_smmu_fault_info *info = data;
+	const char *type = "UNKNOWN";
 
-	pr_warn_ratelimited("*** gpu fault: iova=%08lx, flags=%d (%u,%u,%u,%u)\n",
+	/*
+	 * Print a default message if we couldn't get the data from the
+	 * adreno-smmu-priv
+	 */
+	if (!info) {
+		pr_warn_ratelimited("*** gpu fault: iova=%.16lx flags=%d (%u,%u,%u,%u)\n",
 			iova, flags,
 			gpu_read(gpu, REG_A6XX_CP_SCRATCH_REG(4)),
 			gpu_read(gpu, REG_A6XX_CP_SCRATCH_REG(5)),
 			gpu_read(gpu, REG_A6XX_CP_SCRATCH_REG(6)),
 			gpu_read(gpu, REG_A6XX_CP_SCRATCH_REG(7)));
 
-	return -EFAULT;
+		return 0;
+	}
+
+	if (info->fsr & ARM_SMMU_FSR_TF)
+		type = "TRANSLATION";
+	else if (info->fsr & ARM_SMMU_FSR_PF)
+		type = "PERMISSION";
+	else if (info->fsr & ARM_SMMU_FSR_EF)
+		type = "EXTERNAL";
+
+	pr_warn_ratelimited("*** gpu fault: ttbr0=%.16llx iova=%.16lx dir=%s type=%s source=%s (%u,%u,%u,%u)\n",
+			info->ttbr0, iova,
+			flags & IOMMU_FAULT_WRITE ? "WRITE" : "READ", type,
+			a6xx_fault_block(gpu, info->fsynr1 & 0xff),
+			gpu_read(gpu, REG_A6XX_CP_SCRATCH_REG(4)),
+			gpu_read(gpu, REG_A6XX_CP_SCRATCH_REG(5)),
+			gpu_read(gpu, REG_A6XX_CP_SCRATCH_REG(6)),
+			gpu_read(gpu, REG_A6XX_CP_SCRATCH_REG(7)));
+
+	return 0;
 }
 
 static void a6xx_cp_hw_err_irq(struct msm_gpu *gpu)
diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
index 50d881794758..6975b95c3c29 100644
--- a/drivers/gpu/drm/msm/msm_iommu.c
+++ b/drivers/gpu/drm/msm/msm_iommu.c
@@ -211,8 +211,17 @@ static int msm_fault_handler(struct iommu_domain *domain, struct device *dev,
 		unsigned long iova, int flags, void *arg)
 {
 	struct msm_iommu *iommu = arg;
+	struct adreno_smmu_priv *adreno_smmu = dev_get_drvdata(iommu->base.dev);
+	struct adreno_smmu_fault_info info, *ptr = NULL;
+
+	if (adreno_smmu->get_fault_info) {
+		adreno_smmu->get_fault_info(adreno_smmu->cookie, &info);
+		ptr = &info;
+	}
+
 	if (iommu->base.handler)
-		return iommu->base.handler(iommu->base.arg, iova, flags);
+		return iommu->base.handler(iommu->base.arg, iova, flags, ptr);
+
 	pr_warn_ratelimited("*** fault: iova=%16lx, flags=%d\n", iova, flags);
 	return 0;
 }
diff --git a/drivers/gpu/drm/msm/msm_mmu.h b/drivers/gpu/drm/msm/msm_mmu.h
index 61ade89d9e48..a88f44c3268d 100644
--- a/drivers/gpu/drm/msm/msm_mmu.h
+++ b/drivers/gpu/drm/msm/msm_mmu.h
@@ -26,7 +26,7 @@ enum msm_mmu_type {
 struct msm_mmu {
 	const struct msm_mmu_funcs *funcs;
 	struct device *dev;
-	int (*handler)(void *arg, unsigned long iova, int flags);
+	int (*handler)(void *arg, unsigned long iova, int flags, void *data);
 	void *arg;
 	enum msm_mmu_type type;
 };
@@ -43,7 +43,7 @@ struct msm_mmu *msm_iommu_new(struct device *dev, struct iommu_domain *domain);
 struct msm_mmu *msm_gpummu_new(struct device *dev, struct msm_gpu *gpu);
 
 static inline void msm_mmu_set_fault_handler(struct msm_mmu *mmu, void *arg,
-		int (*handler)(void *arg, unsigned long iova, int flags))
+		int (*handler)(void *arg, unsigned long iova, int flags, void *data))
 {
 	mmu->arg = arg;
 	mmu->handler = handler;
-- 
2.25.1