On 18.05.2022 13:54, Rob Clark wrote:
> On Tue, May 17, 2022 at 10:42 AM Adrián Larumbe
> <adrian.larumbe@xxxxxxxxxxxxx> wrote:
> >
> > In the event of a job timeout, debug dump information will be written into
> > /sys/class/devcoredump.
> >
> > Inspired by etnaviv's similar feature.
> >
> > Signed-off-by: Adrián Larumbe <adrian.larumbe@xxxxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/panfrost/Kconfig | 1 +
> > drivers/gpu/drm/panfrost/Makefile | 3 +-
> > drivers/gpu/drm/panfrost/panfrost_dump.c | 198 +++++++++++++++++++++++
> > drivers/gpu/drm/panfrost/panfrost_dump.h | 12 ++
> > drivers/gpu/drm/panfrost/panfrost_job.c | 3 +
> > include/uapi/drm/panfrost_drm.h | 32 ++++
> > 6 files changed, 248 insertions(+), 1 deletion(-)
> > create mode 100644 drivers/gpu/drm/panfrost/panfrost_dump.c
> > create mode 100644 drivers/gpu/drm/panfrost/panfrost_dump.h
> >
> > diff --git a/drivers/gpu/drm/panfrost/Kconfig b/drivers/gpu/drm/panfrost/Kconfig
> > index 86cdc0ce79e6..079600328be1 100644
> > --- a/drivers/gpu/drm/panfrost/Kconfig
> > +++ b/drivers/gpu/drm/panfrost/Kconfig
> > @@ -11,6 +11,7 @@ config DRM_PANFROST
> > select DRM_GEM_SHMEM_HELPER
> > select PM_DEVFREQ
> > select DEVFREQ_GOV_SIMPLE_ONDEMAND
> > + select WANT_DEV_COREDUMP
> > help
> > DRM driver for ARM Mali Midgard (T6xx, T7xx, T8xx) and
> > Bifrost (G3x, G5x, G7x) GPUs.
> > diff --git a/drivers/gpu/drm/panfrost/Makefile b/drivers/gpu/drm/panfrost/Makefile
> > index b71935862417..7da2b3f02ed9 100644
> > --- a/drivers/gpu/drm/panfrost/Makefile
> > +++ b/drivers/gpu/drm/panfrost/Makefile
> > @@ -9,6 +9,7 @@ panfrost-y := \
> > panfrost_gpu.o \
> > panfrost_job.o \
> > panfrost_mmu.o \
> > - panfrost_perfcnt.o
> > + panfrost_perfcnt.o \
> > + panfrost_dump.o
> >
> > obj-$(CONFIG_DRM_PANFROST) += panfrost.o
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_dump.c b/drivers/gpu/drm/panfrost/panfrost_dump.c
> > new file mode 100644
> > index 000000000000..a76dcf4acf6f
> > --- /dev/null
> > +++ b/drivers/gpu/drm/panfrost/panfrost_dump.c
> > @@ -0,0 +1,198 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/* Copyright 2021 Collabora ltd. */
> > +
> > +#include <linux/err.h>
> > +#include <linux/device.h>
> > +#include <linux/devcoredump.h>
> > +#include <linux/moduleparam.h>
> > +#include <linux/iosys-map.h>
> > +#include <drm/panfrost_drm.h>
> > +#include <drm/drm_device.h>
> > +
> > +#include "panfrost_job.h"
> > +#include "panfrost_gem.h"
> > +#include "panfrost_regs.h"
> > +#include "panfrost_dump.h"
> > +#include "panfrost_device.h"
> > +
> > +static bool panfrost_dump_core = true;
> > +module_param_named(dump_core, panfrost_dump_core, bool, 0600);
> > +
> > +struct panfrost_dump_iterator {
> > + void *start;
> > + struct panfrost_dump_object_header *hdr;
> > + void *data;
> > +};
> > +
> > +static const unsigned short panfrost_dump_registers[] = {
> > + GPU_ID,
> > + GPU_L2_FEATURES,
> > + GPU_CORE_FEATURES,
> > + GPU_TILER_FEATURES,
> > + GPU_MEM_FEATURES,
> > + GPU_MMU_FEATURES,
> > + GPU_AS_PRESENT,
> > + GPU_JS_PRESENT,
> > + GPU_INT_RAWSTAT,
> > + GPU_INT_CLEAR,
> > + GPU_INT_MASK,
> > + GPU_INT_STAT,
> > +};
> > +
> > +static void panfrost_core_dump_header(struct panfrost_dump_iterator *iter,
> > + u32 type, void *data_end)
> > +{
> > + struct panfrost_dump_object_header *hdr = iter->hdr;
> > +
> > + hdr->magic = cpu_to_le32(PANFROSTDUMP_MAGIC);
> > + hdr->type = cpu_to_le32(type);
> > + hdr->file_offset = cpu_to_le32(iter->data - iter->start);
> > + hdr->file_size = cpu_to_le32(data_end - iter->data);
> > +
> > + iter->hdr++;
> > + iter->data += le32_to_cpu(hdr->file_size);
> > +}
> > +
> > +static void
> > +panfrost_core_dump_registers(struct panfrost_dump_iterator *iter,
> > + struct panfrost_device *pfdev)
> > +{
> > + struct panfrost_dump_registers *reg = iter->data;
> > + unsigned int i;
> > +
> > + for (i = 0; i < ARRAY_SIZE(panfrost_dump_registers); i++, reg++) {
> > + reg->reg = cpu_to_le32(panfrost_dump_registers[i]);
> > + reg->value = cpu_to_le32(gpu_read(pfdev, panfrost_dump_registers[i]));
> > + }
> > +
> > + panfrost_core_dump_header(iter, PANFROSTDUMP_BUF_REG, reg);
> > +}
> > +
> > +void panfrost_core_dump(struct panfrost_job *job)
> > +{
> > + struct panfrost_device *pfdev = job->pfdev;
> > + struct panfrost_dump_iterator iter;
> > + struct drm_gem_object *dbo;
> > + unsigned int n_obj, n_bomap_pages;
> > + __le64 *bomap, *bomap_start;
> > + size_t file_size;
> > + int ret, i;
> > +
> > + /* Only catch the first event, or when manually re-armed */
> > + if (!panfrost_dump_core)
> > + return;
> > + panfrost_dump_core = false;
> > +
> > + /* At least, we dump registers and end marker */
> > + n_obj = 2;
> > + n_bomap_pages = 0;
> > + file_size = ARRAY_SIZE(panfrost_dump_registers) *
> > + sizeof(struct panfrost_dump_registers);
> > +
> > + /* Add in the active buffer objects */
> > + for (i = 0; i < job->bo_count; i++) {
> > + dbo = job->bos[i];
> > + file_size += dbo->size;
> > + n_bomap_pages += dbo->size >> PAGE_SHIFT;
> > + n_obj++;
> > + }
> > +
> > + /* If we have any buffer objects, add a bomap object */
> > + if (n_bomap_pages) {
> > + file_size += n_bomap_pages * sizeof(__le64);
> > + n_obj++;
> > + }
> > +
> > + /* Add the size of the headers */
> > + file_size += sizeof(*iter.hdr) * n_obj;
> > +
> > + /* Allocate the file in vmalloc memory, it's likely to be big */
> > + iter.start = __vmalloc(file_size, GFP_KERNEL | __GFP_NOWARN |
> > + __GFP_NORETRY);
> > + if (!iter.start) {
> > + dev_warn(pfdev->dev, "failed to allocate devcoredump file\n");
> > + return;
> > + }
> > +
> > + /* Point the data member after the headers */
> > + iter.hdr = iter.start;
> > + iter.data = &iter.hdr[n_obj];
> > +
> > + memset(iter.hdr, 0, iter.data - iter.start);
> > +
> > + /*
> > + * For now, we write the job identifier in the register dump header,
> > + * so that we can decode the entire dump later with pandecode
> > + */
> > + iter.hdr->jc = cpu_to_le64(job->jc);
> > + iter.hdr->version = cpu_to_le32(PANFROSTDUMP_VERSION_1);
> > + iter.hdr->gpu_id = cpu_to_le32(pfdev->features.id);
> > + iter.hdr->nbos = cpu_to_le64(job->bo_count);
> > +
> > + panfrost_core_dump_registers(&iter, pfdev);
> > +
> > + /* Reserve space for the bomap */
> > + if (n_bomap_pages) {
> > + bomap_start = bomap = iter.data;
> > + memset(bomap, 0, sizeof(*bomap) * n_bomap_pages);
> > + panfrost_core_dump_header(&iter, PANFROSTDUMP_BUF_BOMAP,
> > + bomap + n_bomap_pages);
> > + } else {
> > + /* Silence warning */
> > + bomap_start = bomap = NULL;
> > + }
> > +
> > + for (i = 0; i < job->bo_count; i++) {
> > + struct iosys_map map;
> > + struct panfrost_gem_mapping *mapping;
> > + struct panfrost_gem_object *bo;
> > + struct sg_page_iter page_iter;
> > + void *vaddr;
> > +
> > + bo = to_panfrost_bo(job->bos[i]);
> > + mapping = job->mappings[i];
> > +
> > + if (!bo->base.sgt) {
> > + dev_err(pfdev->dev, "Panfrost Dump: BO has no sgt, cannot dump\n");
> > + iter.hdr->valid = 0;
> > + continue;
> > + }
> > +
> > + ret = drm_gem_shmem_vmap(&bo->base, &map);
> > + if (ret) {
> > + dev_err(pfdev->dev, "Panfrost Dump: couldn't map Buffer Object\n");
> > + iter.hdr->valid = 0;
> > + continue;
> > + }
> > +
> > + WARN_ON(!mapping->active);
> > +
> > + iter.hdr->data[0] = cpu_to_le32((bomap - bomap_start));
> > +
> > + for_each_sgtable_page(bo->base.sgt, &page_iter, 0) {
> > + struct page *page = sg_page_iter_page(&page_iter);
> > +
> > + if (!IS_ERR(page))
> > + *bomap++ = cpu_to_le64(page_to_phys(page));
> > + else {
> > + dev_err(pfdev->dev, "Panfrost Dump: wrong page\n");
> > + *bomap++ = ~cpu_to_le64(0);
> > + }
> > + }
> > +
> > + iter.hdr->iova = cpu_to_le64(mapping->mmnode.start << PAGE_SHIFT);
> > +
> > + vaddr = map.vaddr;
> > + memcpy(iter.data, vaddr, bo->base.base.size);
>
> I think you are going to want to invent some way to flag which buffers
> you want to dump. For example, cmdstream and cmdstream related
> buffers, you want to capture. But things that potentially texture
> data, you do not for PII reasons, if this is ever wired up to distro
> crash telemetry. (Which is a thing that we've found very useful on
> msm/freedreno devices.)
> Looks like the panfrost submit ioctl doesn't already have per-bo
> flags, but perhaps that dump flag could be a property of the GEM
> object?
I guess flagging what kind of BO one is creating inside the ioctl params might
require quite a few changes in both the uAPI and Mesa, which I don't know that
much about anyway.
I'll see how I can go about figuring it out inside the kernel driver instead,
but from a quick look at it, it seems that it cannot learn it without userspace
intervention.
> BR,
> -R
>
> > +
> > + drm_gem_shmem_vunmap(&bo->base, &map);
> > +
> > + iter.hdr->valid = cpu_to_le32(1);
> > +
> > + panfrost_core_dump_header(&iter, PANFROSTDUMP_BUF_BO, iter.data +
> > + bo->base.base.size);
> > + }
> > + panfrost_core_dump_header(&iter, PANFROSTDUMP_BUF_END, iter.data);
> > +
> > + dev_coredumpv(pfdev->dev, iter.start, iter.data - iter.start, GFP_KERNEL);
> > +}
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_dump.h b/drivers/gpu/drm/panfrost/panfrost_dump.h
> > new file mode 100644
> > index 000000000000..7d9bcefa5346
> > --- /dev/null
> > +++ b/drivers/gpu/drm/panfrost/panfrost_dump.h
> > @@ -0,0 +1,12 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * Copyright 2021 Collabora ltd.
> > + */
> > +
> > +#ifndef PANFROST_DUMP_H
> > +#define PANFROST_DUMP_H
> > +
> > +struct panfrost_job;
> > +void panfrost_core_dump(struct panfrost_job *job);
> > +
> > +#endif
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
> > index fda5871aebe3..f506d0ea067c 100644
> > --- a/drivers/gpu/drm/panfrost/panfrost_job.c
> > +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
> > @@ -20,6 +20,7 @@
> > #include "panfrost_regs.h"
> > #include "panfrost_gpu.h"
> > #include "panfrost_mmu.h"
> > +#include "panfrost_dump.h"
> >
> > #define JOB_TIMEOUT_MS 500
> >
> > @@ -727,6 +728,8 @@ static enum drm_gpu_sched_stat panfrost_job_timedout(struct drm_sched_job
> > job_read(pfdev, JS_TAIL_LO(js)),
> > sched_job);
> >
> > + panfrost_core_dump(job);
> > +
> > atomic_set(&pfdev->reset.pending, 1);
> > panfrost_reset(pfdev, sched_job);
> >
> > diff --git a/include/uapi/drm/panfrost_drm.h b/include/uapi/drm/panfrost_drm.h
> > index 9e40277d8185..a4e988be8478 100644
> > --- a/include/uapi/drm/panfrost_drm.h
> > +++ b/include/uapi/drm/panfrost_drm.h
> > @@ -224,6 +224,38 @@ struct drm_panfrost_madvise {
> > __u32 retained; /* out, whether backing store still exists */
> > };
> >
> > +/* Definitions for coredump decoding in user space */
> > +enum {
> > + PANFROSTDUMP_MAGIC = 0xCAFECAFE,
> > + PANFROSTDUMP_BUF_REG = 0,
> > + PANFROSTDUMP_BUF_BOMAP,
> > + PANFROSTDUMP_BUF_BO,
> > + PANFROSTDUMP_BUF_END,
> > +};
> > +
> > +#define PANFROSTDUMP_VERSION_1 1
> > +
> > +struct panfrost_dump_object_header {
> > + __le32 magic;
> > + __le32 type;
> > + __le32 version;
> > + __le32 bifrost;
> > + __le64 nbos;
> > + __le64 jc;
> > + __le32 file_offset;
> > + __le32 file_size;
> > + __le64 iova;
> > + __le32 gpu_id;
> > + __le32 valid;
> > + __le32 data[2];
> > +};
> > +
> > +/* Registers object, an array of these */
> > +struct panfrost_dump_registers {
> > + __le32 reg;
> > + __le32 value;
> > +};
> > +
> > #if defined(__cplusplus)
> > }
> > #endif
> > --
> > 2.35.1
Adrian Larumbe
