msm_rd.c | Explore in Territory

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2013 Red Hat
 * Author: Rob Clark <[email protected]>
 */

/* For debugging crashes, userspace can:
 *
 *   tail -f /sys/kernel/debug/dri/<minor>/rd > logfile.rd
 *
 * to log the cmdstream in a format that is understood by freedreno/cffdump
 * utility.  By comparing the last successfully completed fence #, to the
 * cmdstream for the next fence, you can narrow down which process and submit
 * caused the gpu crash/lockup.
 *
 * Additionally:
 *
 *   tail -f /sys/kernel/debug/dri/<minor>/hangrd > logfile.rd
 *
 * will capture just the cmdstream from submits which triggered a GPU hang.
 *
 * This bypasses drm_debugfs_create_files() mainly because we need to use
 * our own fops for a bit more control.  In particular, we don't want to
 * do anything if userspace doesn't have the debugfs file open.
 *
 * The module-param "rd_full", which defaults to false, enables snapshotting
 * all (non-written) buffers in the submit, rather than just cmdstream bo's.
 * This is useful to capture the contents of (for example) vbo's or textures,
 * or shader programs (if not emitted inline in cmdstream).
 */

#include <linux/circ_buf.h>
#include <linux/debugfs.h>
#include <linux/kfifo.h>
#include <linux/uaccess.h>
#include <linux/wait.h>

#include <drm/drm_file.h>

#include "msm_drv.h"
#include "msm_gpu.h"
#include "msm_gem.h"

bool rd_full = …;
MODULE_PARM_DESC(…) …;
module_param_named(rd_full, rd_full, bool, 0600);

#ifdef CONFIG_DEBUG_FS

enum rd_sect_type { … };

#define BUF_SZ …

/* space used: */
#define circ_count(circ) …
#define circ_count_to_end(circ) …
/* space available: */
#define circ_space(circ) …
#define circ_space_to_end(circ) …

struct msm_rd_state { … };

static void rd_write(struct msm_rd_state *rd, const void *buf, int sz)
{ … }

static void rd_write_section(struct msm_rd_state *rd,
		enum rd_sect_type type, const void *buf, int sz)
{ … }

static ssize_t rd_read(struct file *file, char __user *buf,
		size_t sz, loff_t *ppos)
{ … }

static int rd_open(struct inode *inode, struct file *file)
{ … }

static int rd_release(struct inode *inode, struct file *file)
{ … }


static const struct file_operations rd_debugfs_fops = …;


static void rd_cleanup(struct msm_rd_state *rd)
{ … }

static struct msm_rd_state *rd_init(struct drm_minor *minor, const char *name)
{ … }

int msm_rd_debugfs_init(struct drm_minor *minor)
{ … }

void msm_rd_debugfs_cleanup(struct msm_drm_private *priv)
{ … }

static void snapshot_buf(struct msm_rd_state *rd,
		struct msm_gem_submit *submit, int idx,
		uint64_t iova, uint32_t size, bool full)
{ … }

/* called under gpu->lock */
void msm_rd_dump_submit(struct msm_rd_state *rd, struct msm_gem_submit *submit,
		const char *fmt, ...)
{ … }
#endif
linux/drivers/gpu/drm/msm/msm_rd.c
