[PATCH v5 2/5] iommu/arm-smmu-qcom: Add an adreno-smmu-priv callback to get pagefault info

Rob Clark
2021-06-10T21:44:16Z

From: Jordan Crouse <jcrouse@codeaurora.org>

Add a callback in adreno-smmu-priv to read interesting SMMU
registers to provide an opportunity for a richer debug experience
in the GPU driver.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
---
drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 17 ++++++++++++
drivers/iommu/arm/arm-smmu/arm-smmu.h | 2 ++
include/linux/adreno-smmu-priv.h | 31 +++++++++++++++++++++-
3 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
index 98b3a1c2a181..b2e31ea84128 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
@@ -32,6 +32,22 @@ static void qcom_adreno_smmu_write_sctlr(struct arm_smmu_device *smmu, int idx,
arm_smmu_cb_write(smmu, idx, ARM_SMMU_CB_SCTLR, reg);
}

+static void qcom_adreno_smmu_get_fault_info(const void *cookie,
+ struct adreno_smmu_fault_info *info)
+{
+ struct arm_smmu_domain *smmu_domain = (void *)cookie;
+ struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
+ struct arm_smmu_device *smmu = smmu_domain->smmu;
+
+ info->fsr = arm_smmu_cb_read(smmu, cfg->cbndx, ARM_SMMU_CB_FSR);
+ info->fsynr0 = arm_smmu_cb_read(smmu, cfg->cbndx, ARM_SMMU_CB_FSYNR0);
+ info->fsynr1 = arm_smmu_cb_read(smmu, cfg->cbndx, ARM_SMMU_CB_FSYNR1);
+ info->far = arm_smmu_cb_readq(smmu, cfg->cbndx, ARM_SMMU_CB_FAR);
+ info->cbfrsynra = arm_smmu_gr1_read(smmu, ARM_SMMU_GR1_CBFRSYNRA(cfg->cbndx));
+ info->ttbr0 = arm_smmu_cb_read(smmu, cfg->cbndx, ARM_SMMU_CB_TTBR0);
+ info->contextidr = arm_smmu_cb_read(smmu, cfg->cbndx, ARM_SMMU_CB_CONTEXTIDR);
+}
+
#define QCOM_ADRENO_SMMU_GPU_SID 0

static bool qcom_adreno_smmu_is_gpu_device(struct device *dev)
@@ -156,6 +172,7 @@ 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_fault_info = qcom_adreno_smmu_get_fault_info;

return 0;
}
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.h b/drivers/iommu/arm/arm-smmu/arm-smmu.h
index c31a59d35c64..84c21c4b0691 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.h
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.h
@@ -224,6 +224,8 @@ enum arm_smmu_cbar_type {
#define ARM_SMMU_CB_FSYNR0 0x68
#define ARM_SMMU_FSYNR0_WNR BIT(4)

+#define ARM_SMMU_CB_FSYNR1 0x6c
+
#define ARM_SMMU_CB_S1_TLBIVA 0x600
#define ARM_SMMU_CB_S1_TLBIASID 0x610
#define ARM_SMMU_CB_S1_TLBIVAL 0x620
diff --git a/include/linux/adreno-smmu-priv.h b/include/linux/adreno-smmu-priv.h
index a889f28afb42..53fe32fb9214 100644
--- a/include/linux/adreno-smmu-priv.h
+++ b/include/linux/adreno-smmu-priv.h
@@ -8,6 +8,32 @@

#include <linux/io-pgtable.h>

+/**
+ * struct adreno_smmu_fault_info - container for key fault information
+ *
+ * @far: The faulting IOVA from ARM_SMMU_CB_FAR
+ * @ttbr0: The current TTBR0 pagetable from ARM_SMMU_CB_TTBR0
+ * @contextidr: The value of ARM_SMMU_CB_CONTEXTIDR
+ * @fsr: The fault status from ARM_SMMU_CB_FSR
+ * @fsynr0: The value of FSYNR0 from ARM_SMMU_CB_FSYNR0
+ * @fsynr1: The value of FSYNR1 from ARM_SMMU_CB_FSYNR0
+ * @cbfrsynra: The value of CBFRSYNRA from ARM_SMMU_GR1_CBFRSYNRA(idx)
+ *
+ * This struct passes back key page fault information to the GPU driver
+ * through the get_fault_info function pointer.
+ * The GPU driver can use this information to print informative
+ * log messages and provide deeper GPU specific insight into the fault.
+ */
+struct adreno_smmu_fault_info {
+ u64 far;
+ u64 ttbr0;
+ u32 contextidr;
+ u32 fsr;
+ u32 fsynr0;
+ u32 fsynr1;
+ u32 cbfrsynra;
+};
+
/**
* struct adreno_smmu_priv - private interface between adreno-smmu and GPU
*
@@ -17,6 +43,8 @@
* @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_fault_info: Called by the GPU fault handler to get information about
+ * the fault
*
* 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
@@ -31,6 +59,7 @@ 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);
+ void (*get_fault_info)(const void *cookie, struct adreno_smmu_fault_info *info);
};

-#endif /* __ADRENO_SMMU_PRIV_H */
\ No newline at end of file
+#endif /* __ADRENO_SMMU_PRIV_H */
--
2.31.1