[RESEND PATCH v4 6/6] drm/msm: devcoredump iommu fault support

From: Rob Clark
Date: Wed Jun 02 2021 - 12:50:18 EST

Next message: Rob Clark: "[RESEND PATCH v4 1/6] iommu/arm-smmu: Add support for driver IOMMU fault handlers"
Previous message: Rob Clark: "[RESEND PATCH v4 4/6] iommu/arm-smmu-qcom: Add stall support"
In reply to: Rob Clark: "[RESEND PATCH v4 4/6] iommu/arm-smmu-qcom: Add stall support"
Next in thread: Rob Clark: "[RESEND PATCH v4 1/6] iommu/arm-smmu: Add support for driver IOMMU fault handlers"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

From: Rob Clark <robdclark@xxxxxxxxxxxx>

Wire up support to stall the SMMU on iova fault, and collect a devcore-
dump snapshot for easier debugging of faults.

Currently this is a6xx-only, but mostly only because so far it is the
only one using adreno-smmu-priv.

Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
---
drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 29 +++++++++++++--
drivers/gpu/drm/msm/adreno/adreno_gpu.c | 15 ++++++++
drivers/gpu/drm/msm/msm_gem.h | 1 +
drivers/gpu/drm/msm/msm_gem_submit.c | 1 +
drivers/gpu/drm/msm/msm_gpu.c | 48 +++++++++++++++++++++++++
drivers/gpu/drm/msm/msm_gpu.h | 17 +++++++++
drivers/gpu/drm/msm/msm_gpummu.c | 5 +++
drivers/gpu/drm/msm/msm_iommu.c | 11 ++++++
drivers/gpu/drm/msm/msm_mmu.h | 1 +
9 files changed, 126 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
index 094dc17fd20f..0dcde917e575 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
@@ -1008,6 +1008,16 @@ static int a6xx_fault_handler(void *arg, unsigned long iova, int flags, void *da
struct msm_gpu *gpu = arg;
struct adreno_smmu_fault_info *info = data;
const char *type = "UNKNOWN";
+ const char *block;
+ bool do_devcoredump = info && !READ_ONCE(gpu->crashstate);
+
+ /*
+ * If we aren't going to be resuming later from fault_worker, then do
+ * it now.
+ */
+ if (!do_devcoredump) {
+ gpu->aspace->mmu->funcs->resume_translation(gpu->aspace->mmu);
+ }

/*
* Print a default message if we couldn't get the data from the
@@ -1031,15 +1041,30 @@ static int a6xx_fault_handler(void *arg, unsigned long iova, int flags, void *da
else if (info->fsr & ARM_SMMU_FSR_EF)
type = "EXTERNAL";

+ block = a6xx_fault_block(gpu, info->fsynr1 & 0xff);
+
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),
+ flags & IOMMU_FAULT_WRITE ? "WRITE" : "READ",
+ type, block,
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)));

+ if (do_devcoredump) {
+ /* Turn off the hangcheck timer to keep it from bothering us */
+ del_timer(&gpu->hangcheck_timer);
+
+ gpu->fault_info.ttbr0 = info->ttbr0;
+ gpu->fault_info.iova = iova;
+ gpu->fault_info.flags = flags;
+ gpu->fault_info.type = type;
+ gpu->fault_info.block = block;
+
+ kthread_queue_work(gpu->worker, &gpu->fault_work);
+ }
+
return 0;
}

diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
index cf897297656f..4e88d4407667 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -684,6 +684,21 @@ void adreno_show(struct msm_gpu *gpu, struct msm_gpu_state *state,
adreno_gpu->info->revn, adreno_gpu->rev.core,
adreno_gpu->rev.major, adreno_gpu->rev.minor,
adreno_gpu->rev.patchid);
+ /*
+ * If this is state collected due to iova fault, so fault related info
+ *
+ * TTBR0 would not be zero, so this is a good way to distinguish
+ */
+ if (state->fault_info.ttbr0) {
+ const struct msm_gpu_fault_info *info = &state->fault_info;
+
+ drm_puts(p, "fault-info:\n");
+ drm_printf(p, " - ttbr0=%.16llx\n", info->ttbr0);
+ drm_printf(p, " - iova=%.16lx\n", info->iova);
+ drm_printf(p, " - dir=%s\n", info->flags & IOMMU_FAULT_WRITE ? "WRITE" : "READ");
+ drm_printf(p, " - type=%s\n", info->type);
+ drm_printf(p, " - source=%s\n", info->block);
+ }

drm_printf(p, "rbbm-status: 0x%08x\n", state->rbbm_status);

diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h
index 03e2cc2a2ce1..405f8411e395 100644
--- a/drivers/gpu/drm/msm/msm_gem.h
+++ b/drivers/gpu/drm/msm/msm_gem.h
@@ -328,6 +328,7 @@ struct msm_gem_submit {
struct dma_fence *fence;
struct msm_gpu_submitqueue *queue;
struct pid *pid; /* submitting process */
+ bool fault_dumped; /* Limit devcoredump dumping to one per submit */
bool valid; /* true if no cmdstream patching needed */
bool in_rb; /* "sudo" mode, copy cmds into RB */
struct msm_ringbuffer *ring;
diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index 5480852bdeda..44f84bfd0c0e 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -50,6 +50,7 @@ static struct msm_gem_submit *submit_create(struct drm_device *dev,
submit->cmd = (void *)&submit->bos[nr_bos];
submit->queue = queue;
submit->ring = gpu->rb[queue->prio];
+ submit->fault_dumped = false;

/* initially, until copy_from_user() and bo lookup succeeds: */
submit->nr_bos = 0;
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index 4d280bf446e6..4da2053c1ffb 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -401,6 +401,7 @@ static void msm_gpu_crashstate_capture(struct msm_gpu *gpu,
/* Fill in the additional crash state information */
state->comm = kstrdup(comm, GFP_KERNEL);
state->cmd = kstrdup(cmd, GFP_KERNEL);
+ state->fault_info = gpu->fault_info;

if (submit) {
int i, nr = 0;
@@ -573,6 +574,52 @@ static void recover_worker(struct kthread_work *work)
msm_gpu_retire(gpu);
}

+static void fault_worker(struct kthread_work *work)
+{
+ struct msm_gpu *gpu = container_of(work, struct msm_gpu, fault_work);
+ struct drm_device *dev = gpu->dev;
+ struct msm_gem_submit *submit;
+ struct msm_ringbuffer *cur_ring = gpu->funcs->active_ring(gpu);
+ char *comm = NULL, *cmd = NULL;
+
+ mutex_lock(&dev->struct_mutex);
+
+ submit = find_submit(cur_ring, cur_ring->memptrs->fence + 1);
+ if (submit && submit->fault_dumped)
+ goto resume_smmu;
+
+ if (submit) {
+ struct task_struct *task;
+
+ task = get_pid_task(submit->pid, PIDTYPE_PID);
+ if (task) {
+ comm = kstrdup(task->comm, GFP_KERNEL);
+ cmd = kstrdup_quotable_cmdline(task, GFP_KERNEL);
+ put_task_struct(task);
+ }
+
+ /*
+ * When we get GPU iova faults, we can get 1000s of them,
+ * but we really only want to log the first one.
+ */
+ submit->fault_dumped = true;
+ }
+
+ /* Record the crash state */
+ pm_runtime_get_sync(&gpu->pdev->dev);
+ msm_gpu_crashstate_capture(gpu, submit, comm, cmd, true);
+ pm_runtime_put_sync(&gpu->pdev->dev);
+
+ kfree(cmd);
+ kfree(comm);
+
+resume_smmu:
+ memset(&gpu->fault_info, 0, sizeof(gpu->fault_info));
+ gpu->aspace->mmu->funcs->resume_translation(gpu->aspace->mmu);
+
+ mutex_unlock(&dev->struct_mutex);
+}
+
static void hangcheck_timer_reset(struct msm_gpu *gpu)
{
mod_timer(&gpu->hangcheck_timer,
@@ -949,6 +996,7 @@ int msm_gpu_init(struct drm_device *drm, struct platform_device *pdev,
INIT_LIST_HEAD(&gpu->active_list);
kthread_init_work(&gpu->retire_work, retire_worker);
kthread_init_work(&gpu->recover_work, recover_worker);
+ kthread_init_work(&gpu->fault_work, fault_worker);

timer_setup(&gpu->hangcheck_timer, hangcheck_handler, 0);

diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index c15e5fd675d2..8dae601085ee 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -71,6 +71,15 @@ struct msm_gpu_funcs {
uint32_t (*get_rptr)(struct msm_gpu *gpu, struct msm_ringbuffer *ring);
};

+/* Additional state for iommu faults: */
+struct msm_gpu_fault_info {
+ u64 ttbr0;
+ unsigned long iova;
+ int flags;
+ const char *type;
+ const char *block;
+};
+
struct msm_gpu {
const char *name;
struct drm_device *dev;
@@ -135,6 +144,12 @@ struct msm_gpu {
#define DRM_MSM_HANGCHECK_JIFFIES msecs_to_jiffies(DRM_MSM_HANGCHECK_PERIOD)
struct timer_list hangcheck_timer;

+ /* Fault info for most recent iova fault: */
+ struct msm_gpu_fault_info fault_info;
+
+ /* work for handling GPU ioval faults: */
+ struct kthread_work fault_work;
+
/* work for handling GPU recovery: */
struct kthread_work recover_work;

@@ -243,6 +258,8 @@ struct msm_gpu_state {
char *comm;
char *cmd;

+ struct msm_gpu_fault_info fault_info;
+
int nr_bos;
struct msm_gpu_state_bo *bos;
};
diff --git a/drivers/gpu/drm/msm/msm_gpummu.c b/drivers/gpu/drm/msm/msm_gpummu.c
index 379496186c7f..f7d1945e0c9f 100644
--- a/drivers/gpu/drm/msm/msm_gpummu.c
+++ b/drivers/gpu/drm/msm/msm_gpummu.c
@@ -68,6 +68,10 @@ static int msm_gpummu_unmap(struct msm_mmu *mmu, uint64_t iova, size_t len)
return 0;
}

+static void msm_gpummu_resume_translation(struct msm_mmu *mmu)
+{
+}
+
static void msm_gpummu_destroy(struct msm_mmu *mmu)
{
struct msm_gpummu *gpummu = to_msm_gpummu(mmu);
@@ -83,6 +87,7 @@ static const struct msm_mmu_funcs funcs = {
.map = msm_gpummu_map,
.unmap = msm_gpummu_unmap,
.destroy = msm_gpummu_destroy,
+ .resume_translation = msm_gpummu_resume_translation,
};

struct msm_mmu *msm_gpummu_new(struct device *dev, struct msm_gpu *gpu)
diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
index 6975b95c3c29..eed2a762e9dd 100644
--- a/drivers/gpu/drm/msm/msm_iommu.c
+++ b/drivers/gpu/drm/msm/msm_iommu.c
@@ -184,6 +184,9 @@ struct msm_mmu *msm_iommu_pagetable_create(struct msm_mmu *parent)
* the arm-smmu driver as a trigger to set up TTBR0
*/
if (atomic_inc_return(&iommu->pagetables) == 1) {
+ /* Enable stall on iommu fault: */
+ adreno_smmu->set_stall(adreno_smmu->cookie, true);
+
ret = adreno_smmu->set_ttbr0_cfg(adreno_smmu->cookie, &ttbr0_cfg);
if (ret) {
free_io_pgtable_ops(pagetable->pgtbl_ops);
@@ -226,6 +229,13 @@ static int msm_fault_handler(struct iommu_domain *domain, struct device *dev,
return 0;
}

+static void msm_iommu_resume_translation(struct msm_mmu *mmu)
+{
+ struct adreno_smmu_priv *adreno_smmu = dev_get_drvdata(mmu->dev);
+
+ adreno_smmu->resume_translation(adreno_smmu->cookie, true);
+}
+
static void msm_iommu_detach(struct msm_mmu *mmu)
{
struct msm_iommu *iommu = to_msm_iommu(mmu);
@@ -273,6 +283,7 @@ static const struct msm_mmu_funcs funcs = {
.map = msm_iommu_map,
.unmap = msm_iommu_unmap,
.destroy = msm_iommu_destroy,
+ .resume_translation = msm_iommu_resume_translation,
};

struct msm_mmu *msm_iommu_new(struct device *dev, struct iommu_domain *domain)
diff --git a/drivers/gpu/drm/msm/msm_mmu.h b/drivers/gpu/drm/msm/msm_mmu.h
index a88f44c3268d..de158e1bf765 100644
--- a/drivers/gpu/drm/msm/msm_mmu.h
+++ b/drivers/gpu/drm/msm/msm_mmu.h
@@ -15,6 +15,7 @@ struct msm_mmu_funcs {
size_t len, int prot);
int (*unmap)(struct msm_mmu *mmu, uint64_t iova, size_t len);
void (*destroy)(struct msm_mmu *mmu);
+ void (*resume_translation)(struct msm_mmu *mmu);
};

enum msm_mmu_type {
--
2.31.1

Next message: Rob Clark: "[RESEND PATCH v4 1/6] iommu/arm-smmu: Add support for driver IOMMU fault handlers"
Previous message: Rob Clark: "[RESEND PATCH v4 4/6] iommu/arm-smmu-qcom: Add stall support"
In reply to: Rob Clark: "[RESEND PATCH v4 4/6] iommu/arm-smmu-qcom: Add stall support"
Next in thread: Rob Clark: "[RESEND PATCH v4 1/6] iommu/arm-smmu: Add support for driver IOMMU fault handlers"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]