On Thu, Jun 10, 2021 at 02:44:13PM -0700, Rob Clark wrote: > From: Rob Clark <robdcl...@chromium.org> > > 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.
Acked-by: Jordan Crouse <jor...@cosmicpenguin.net> > Signed-off-by: Rob Clark <robdcl...@chromium.org> > --- > drivers/gpu/drm/msm/adreno/a5xx_gpu.c | 19 +++++++- > drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 38 +++++++++++++++- > drivers/gpu/drm/msm/adreno/a6xx_gpu_state.c | 42 ++++++++++++++---- > 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 + > 11 files changed, 186 insertions(+), 12 deletions(-) > > diff --git a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c > b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c > index eb030b00bff4..7a271de9a212 100644 > --- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c > +++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c > @@ -1200,6 +1200,15 @@ static void a5xx_fault_detect_irq(struct msm_gpu *gpu) > struct drm_device *dev = gpu->dev; > struct msm_ringbuffer *ring = gpu->funcs->active_ring(gpu); > > + /* > + * If stalled on SMMU fault, we could trip the GPU's hang detection, > + * but the fault handler will trigger the devcore dump, and we want > + * to otherwise resume normally rather than killing the submit, so > + * just bail. > + */ > + if (gpu_read(gpu, REG_A5XX_RBBM_STATUS3) & BIT(24)) > + return; > + > DRM_DEV_ERROR(dev->dev, "gpu fault ring %d fence %x status %8.8X rb > %4.4x/%4.4x ib1 %16.16llX/%4.4x ib2 %16.16llX/%4.4x\n", > ring ? ring->id : -1, ring ? ring->seqno : 0, > gpu_read(gpu, REG_A5XX_RBBM_STATUS), > @@ -1523,6 +1532,7 @@ static struct msm_gpu_state *a5xx_gpu_state_get(struct > msm_gpu *gpu) > { > struct a5xx_gpu_state *a5xx_state = kzalloc(sizeof(*a5xx_state), > GFP_KERNEL); > + bool stalled = !!(gpu_read(gpu, REG_A5XX_RBBM_STATUS3) & BIT(24)); > > if (!a5xx_state) > return ERR_PTR(-ENOMEM); > @@ -1535,8 +1545,13 @@ static struct msm_gpu_state *a5xx_gpu_state_get(struct > msm_gpu *gpu) > > a5xx_state->base.rbbm_status = gpu_read(gpu, REG_A5XX_RBBM_STATUS); > > - /* Get the HLSQ regs with the help of the crashdumper */ > - a5xx_gpu_state_get_hlsq_regs(gpu, a5xx_state); > + /* > + * Get the HLSQ regs with the help of the crashdumper, but only if > + * we are not stalled in an iommu fault (in which case the crashdumper > + * would not have access to memory) > + */ > + if (!stalled) > + a5xx_gpu_state_get_hlsq_regs(gpu, a5xx_state); > > a5xx_set_hwcg(gpu, true); > > diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c > b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c > index fc19db10bff1..c3699408bd1f 100644 > --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c > +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c > @@ -1081,6 +1081,16 @@ 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 > @@ -1104,15 +1114,30 @@ 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; > } > > @@ -1164,6 +1189,15 @@ static void a6xx_fault_detect_irq(struct msm_gpu *gpu) > struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu); > struct msm_ringbuffer *ring = gpu->funcs->active_ring(gpu); > > + /* > + * If stalled on SMMU fault, we could trip the GPU's hang detection, > + * but the fault handler will trigger the devcore dump, and we want > + * to otherwise resume normally rather than killing the submit, so > + * just bail. > + */ > + if (gpu_read(gpu, REG_A6XX_RBBM_STATUS3) & > A6XX_RBBM_STATUS3_SMMU_STALLED_ON_FAULT) > + return; > + > /* > * Force the GPU to stay on until after we finish > * collecting information > diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu_state.c > b/drivers/gpu/drm/msm/adreno/a6xx_gpu_state.c > index 21c49c5b4519..ad4ea0ed5d99 100644 > --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu_state.c > +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu_state.c > @@ -832,6 +832,20 @@ static void a6xx_get_registers(struct msm_gpu *gpu, > a6xx_get_ahb_gpu_registers(gpu, > a6xx_state, &a6xx_vbif_reglist, > &a6xx_state->registers[index++]); > + if (!dumper) { > + /* > + * We can't use the crashdumper when the SMMU is stalled, > + * because the GPU has no memory access until we resume > + * translation (but we don't want to do that until after > + * we have captured as much useful GPU state as possible). > + * So instead collect registers via the CPU: > + */ > + for (i = 0; i < ARRAY_SIZE(a6xx_reglist); i++) > + a6xx_get_ahb_gpu_registers(gpu, > + a6xx_state, &a6xx_reglist[i], > + &a6xx_state->registers[index++]); > + return; > + } > > for (i = 0; i < ARRAY_SIZE(a6xx_reglist); i++) > a6xx_get_crashdumper_registers(gpu, > @@ -905,11 +919,13 @@ static void a6xx_get_indexed_registers(struct msm_gpu > *gpu, > > struct msm_gpu_state *a6xx_gpu_state_get(struct msm_gpu *gpu) > { > - struct a6xx_crashdumper dumper = { 0 }; > + struct a6xx_crashdumper _dumper = { 0 }, *dumper = NULL; > struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu); > struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu); > struct a6xx_gpu_state *a6xx_state = kzalloc(sizeof(*a6xx_state), > GFP_KERNEL); > + bool stalled = !!(gpu_read(gpu, REG_A6XX_RBBM_STATUS3) & > + A6XX_RBBM_STATUS3_SMMU_STALLED_ON_FAULT); > > if (!a6xx_state) > return ERR_PTR(-ENOMEM); > @@ -928,14 +944,24 @@ struct msm_gpu_state *a6xx_gpu_state_get(struct msm_gpu > *gpu) > /* Get the banks of indexed registers */ > a6xx_get_indexed_registers(gpu, a6xx_state); > > - /* Try to initialize the crashdumper */ > - if (!a6xx_crashdumper_init(gpu, &dumper)) { > - a6xx_get_registers(gpu, a6xx_state, &dumper); > - a6xx_get_shaders(gpu, a6xx_state, &dumper); > - a6xx_get_clusters(gpu, a6xx_state, &dumper); > - a6xx_get_dbgahb_clusters(gpu, a6xx_state, &dumper); > + /* > + * Try to initialize the crashdumper, if we are not dumping state > + * with the SMMU stalled. The crashdumper needs memory access to > + * write out GPU state, so we need to skip this when the SMMU is > + * stalled in response to an iova fault > + */ > + if (!stalled && !a6xx_crashdumper_init(gpu, &_dumper)) { > + dumper = &_dumper; > + } > + > + a6xx_get_registers(gpu, a6xx_state, dumper); > + > + if (dumper) { > + a6xx_get_shaders(gpu, a6xx_state, dumper); > + a6xx_get_clusters(gpu, a6xx_state, dumper); > + a6xx_get_dbgahb_clusters(gpu, a6xx_state, dumper); > > - msm_gem_kernel_put(dumper.bo, gpu->aspace, true); > + msm_gem_kernel_put(dumper->bo, gpu->aspace, true); > } > > if (snapshot_debugbus) > diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c > b/drivers/gpu/drm/msm/adreno/adreno_gpu.c > index c1b02f790804..2bfe014995c7 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 fa7691cb4614..414ba2dd34e5 100644 > --- a/drivers/gpu/drm/msm/msm_gpu.c > +++ b/drivers/gpu/drm/msm/msm_gpu.c > @@ -400,6 +400,7 @@ 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; > @@ -572,6 +573,52 @@ 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); > + 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, > @@ -948,6 +995,7 @@ 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 7a082a12d98f..8eefb3aeca10 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 > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu