drivers/gpu/drm/msm/msm_rd.c - arm/linux - Git at Google

 /*
  * Copyright (C) 2013 Red Hat
  * Author: Rob Clark <robdclark@gmail.com>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published by
  * the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  * more details.
  *
  * You should have received a copy of the GNU General Public License along with
  * this program.  If not, see <http://www.gnu.org/licenses/>.
  */

 /* 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.
  *
  * 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).
  */

 #ifdef CONFIG_DEBUG_FS

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

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

 static bool rd_full = false;
 MODULE_PARM_DESC(rd_full, "If true, $debugfs/.../rd will snapshot all buffer contents");
 module_param_named(rd_full, rd_full, bool, 0600);

 enum rd_sect_type {
 	RD_NONE,
 	RD_TEST,       /* ascii text */
 	RD_CMD,        /* ascii text */
 	RD_GPUADDR,    /* u32 gpuaddr, u32 size */
 	RD_CONTEXT,    /* raw dump */
 	RD_CMDSTREAM,  /* raw dump */
 	RD_CMDSTREAM_ADDR, /* gpu addr of cmdstream */
 	RD_PARAM,      /* u32 param_type, u32 param_val, u32 bitlen */
 	RD_FLUSH,      /* empty, clear previous params */
 	RD_PROGRAM,    /* shader program, raw dump */
 	RD_VERT_SHADER,
 	RD_FRAG_SHADER,
 	RD_BUFFER_CONTENTS,
 	RD_GPU_ID,
 };

 #define BUF_SZ 512  /* should be power of 2 */

 /* space used: */
 #define circ_count(circ) \
 	(CIRC_CNT((circ)->head, (circ)->tail, BUF_SZ))
 #define circ_count_to_end(circ) \
 	(CIRC_CNT_TO_END((circ)->head, (circ)->tail, BUF_SZ))
 /* space available: */
 #define circ_space(circ) \
 	(CIRC_SPACE((circ)->head, (circ)->tail, BUF_SZ))
 #define circ_space_to_end(circ) \
 	(CIRC_SPACE_TO_END((circ)->head, (circ)->tail, BUF_SZ))

 struct msm_rd_state {
 	struct drm_device *dev;

 	bool open;

 	/* current submit to read out: */
 	struct msm_gem_submit *submit;

 	/* fifo access is synchronized on the producer side by
 	 * struct_mutex held by submit code (otherwise we could
 	 * end up w/ cmds logged in different order than they
 	 * were executed).  And read_lock synchronizes the reads
 	 */
 	struct mutex read_lock;

 	wait_queue_head_t fifo_event;
 	struct circ_buf fifo;

 	char buf[BUF_SZ];
 };

 static void rd_write(struct msm_rd_state *rd, const void *buf, int sz)
 {
 	struct circ_buf *fifo = &rd->fifo;
 	const char *ptr = buf;

 	while (sz > 0) {
 		char *fptr = &fifo->buf[fifo->head];
 		int n;

 		wait_event(rd->fifo_event, circ_space(&rd->fifo) > 0);

 		/* Note that smp_load_acquire() is not strictly required
 		 * as CIRC_SPACE_TO_END() does not access the tail more
 		 * than once.
 		 */
 		n = min(sz, circ_space_to_end(&rd->fifo));
 		memcpy(fptr, ptr, n);

 		smp_store_release(&fifo->head, (fifo->head + n) & (BUF_SZ - 1));
 		sz  -= n;
 		ptr += n;

 		wake_up_all(&rd->fifo_event);
 	}
 }

 static void rd_write_section(struct msm_rd_state *rd,
 		enum rd_sect_type type, const void *buf, int sz)
 {
 	rd_write(rd, &type, 4);
 	rd_write(rd, &sz, 4);
 	rd_write(rd, buf, sz);
 }

 static ssize_t rd_read(struct file *file, char __user *buf,
 		size_t sz, loff_t *ppos)
 {
 	struct msm_rd_state *rd = file->private_data;
 	struct circ_buf *fifo = &rd->fifo;
 	const char *fptr = &fifo->buf[fifo->tail];
 	int n = 0, ret = 0;

 	mutex_lock(&rd->read_lock);

 	ret = wait_event_interruptible(rd->fifo_event,
 			circ_count(&rd->fifo) > 0);
 	if (ret)
 		goto out;

 	/* Note that smp_load_acquire() is not strictly required
 	 * as CIRC_CNT_TO_END() does not access the head more than
 	 * once.
 	 */
 	n = min_t(int, sz, circ_count_to_end(&rd->fifo));
 	if (copy_to_user(buf, fptr, n)) {
 		ret = -EFAULT;
 		goto out;
 	}

 	smp_store_release(&fifo->tail, (fifo->tail + n) & (BUF_SZ - 1));
 	*ppos += n;

 	wake_up_all(&rd->fifo_event);

 out:
 	mutex_unlock(&rd->read_lock);
 	if (ret)
 		return ret;
 	return n;
 }

 static int rd_open(struct inode *inode, struct file *file)
 {
 	struct msm_rd_state *rd = inode->i_private;
 	struct drm_device *dev = rd->dev;
 	struct msm_drm_private *priv = dev->dev_private;
 	struct msm_gpu *gpu = priv->gpu;
 	uint64_t val;
 	uint32_t gpu_id;
 	int ret = 0;

 	mutex_lock(&dev->struct_mutex);

 	if (rd->open || !gpu) {
 		ret = -EBUSY;
 		goto out;
 	}

 	file->private_data = rd;
 	rd->open = true;

 	/* the parsing tools need to know gpu-id to know which
 	 * register database to load.
 	 */
 	gpu->funcs->get_param(gpu, MSM_PARAM_GPU_ID, &val);
 	gpu_id = val;

 	rd_write_section(rd, RD_GPU_ID, &gpu_id, sizeof(gpu_id));

 out:
 	mutex_unlock(&dev->struct_mutex);
 	return ret;
 }

 static int rd_release(struct inode *inode, struct file *file)
 {
 	struct msm_rd_state *rd = inode->i_private;
 	rd->open = false;
 	return 0;
 }


 static const struct file_operations rd_debugfs_fops = {
 	.owner = THIS_MODULE,
 	.open = rd_open,
 	.read = rd_read,
 	.llseek = no_llseek,
 	.release = rd_release,
 };

 int msm_rd_debugfs_init(struct drm_minor *minor)
 {
 	struct msm_drm_private *priv = minor->dev->dev_private;
 	struct msm_rd_state *rd;
 	struct dentry *ent;

 	/* only create on first minor: */
 	if (priv->rd)
 		return 0;

 	rd = kzalloc(sizeof(*rd), GFP_KERNEL);
 	if (!rd)
 		return -ENOMEM;

 	rd->dev = minor->dev;
 	rd->fifo.buf = rd->buf;

 	mutex_init(&rd->read_lock);
 	priv->rd = rd;

 	init_waitqueue_head(&rd->fifo_event);

 	ent = debugfs_create_file("rd", S_IFREG | S_IRUGO,
 			minor->debugfs_root, rd, &rd_debugfs_fops);
 	if (!ent) {
 		DRM_ERROR("Cannot create /sys/kernel/debug/dri/%pd/rd\n",
 				minor->debugfs_root);
 		goto fail;
 	}

 	return 0;

 fail:
 	msm_rd_debugfs_cleanup(priv);
 	return -1;
 }

 void msm_rd_debugfs_cleanup(struct msm_drm_private *priv)
 {
 	struct msm_rd_state *rd = priv->rd;

 	if (!rd)
 		return;

 	priv->rd = NULL;
 	mutex_destroy(&rd->read_lock);
 	kfree(rd);
 }

 static void snapshot_buf(struct msm_rd_state *rd,
 		struct msm_gem_submit *submit, int idx,
 		uint64_t iova, uint32_t size)
 {
 	struct msm_gem_object *obj = submit->bos[idx].obj;
 	const char *buf;

 	buf = msm_gem_get_vaddr(&obj->base);
 	if (IS_ERR(buf))
 		return;

 	if (iova) {
 		buf += iova - submit->bos[idx].iova;
 	} else {
 		iova = submit->bos[idx].iova;
 		size = obj->base.size;
 	}

 	rd_write_section(rd, RD_GPUADDR,
 			(uint32_t[3]){ iova, size, iova >> 32 }, 12);
 	rd_write_section(rd, RD_BUFFER_CONTENTS, buf, size);

 	msm_gem_put_vaddr(&obj->base);
 }

 /* called under struct_mutex */
 void msm_rd_dump_submit(struct msm_gem_submit *submit)
 {
 	struct drm_device *dev = submit->dev;
 	struct msm_drm_private *priv = dev->dev_private;
 	struct msm_rd_state *rd = priv->rd;
 	char msg[128];
 	int i, n;

 	if (!rd->open)
 		return;

 	/* writing into fifo is serialized by caller, and
 	 * rd->read_lock is used to serialize the reads
 	 */
 	WARN_ON(!mutex_is_locked(&dev->struct_mutex));

 	n = snprintf(msg, sizeof(msg), "%.*s/%d: fence=%u",
 			TASK_COMM_LEN, current->comm, task_pid_nr(current),
 			submit->fence->seqno);

 	rd_write_section(rd, RD_CMD, msg, ALIGN(n, 4));

 	if (rd_full) {
 		for (i = 0; i < submit->nr_bos; i++) {
 			/* buffers that are written to probably don't start out
 			 * with anything interesting:
 			 */
 			if (submit->bos[i].flags & MSM_SUBMIT_BO_WRITE)
 				continue;

 			snapshot_buf(rd, submit, i, 0, 0);
 		}
 	}

 	for (i = 0; i < submit->nr_cmds; i++) {
 		uint64_t iova = submit->cmd[i].iova;
 		uint32_t szd  = submit->cmd[i].size; /* in dwords */

 		/* snapshot cmdstream bo's (if we haven't already): */
 		if (!rd_full) {
 			snapshot_buf(rd, submit, submit->cmd[i].idx,
 					submit->cmd[i].iova, szd * 4);
 		}

 		switch (submit->cmd[i].type) {
 		case MSM_SUBMIT_CMD_IB_TARGET_BUF:
 			/* ignore IB-targets, we've logged the buffer, the
 			 * parser tool will follow the IB based on the logged
 			 * buffer/gpuaddr, so nothing more to do.
 			 */
 			break;
 		case MSM_SUBMIT_CMD_CTX_RESTORE_BUF:
 		case MSM_SUBMIT_CMD_BUF:
 			rd_write_section(rd, RD_CMDSTREAM_ADDR,
 				(uint32_t[3]){ iova, szd, iova >> 32 }, 12);
 			break;
 		}
 	}
 }
 #endif
	/*
	* Copyright (C) 2013 Red Hat
	* Author: Rob Clark <robdclark@gmail.com>
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 as published by
	* the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	* more details.
	*
	* You should have received a copy of the GNU General Public License along with
	* this program. If not, see <http://www.gnu.org/licenses/>.
	*/

	/* 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.
	*
	* 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).
	*/

	#ifdef CONFIG_DEBUG_FS

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

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

	static bool rd_full = false;
	MODULE_PARM_DESC(rd_full, "If true, $debugfs/.../rd will snapshot all buffer contents");
	module_param_named(rd_full, rd_full, bool, 0600);

	enum rd_sect_type {
	RD_NONE,
	RD_TEST, /* ascii text */
	RD_CMD, /* ascii text */
	RD_GPUADDR, /* u32 gpuaddr, u32 size */
	RD_CONTEXT, /* raw dump */
	RD_CMDSTREAM, /* raw dump */
	RD_CMDSTREAM_ADDR, /* gpu addr of cmdstream */
	RD_PARAM, /* u32 param_type, u32 param_val, u32 bitlen */
	RD_FLUSH, /* empty, clear previous params */
	RD_PROGRAM, /* shader program, raw dump */
	RD_VERT_SHADER,
	RD_FRAG_SHADER,
	RD_BUFFER_CONTENTS,
	RD_GPU_ID,
	};

	#define BUF_SZ 512 /* should be power of 2 */

	/* space used: */
	#define circ_count(circ) \
	(CIRC_CNT((circ)->head, (circ)->tail, BUF_SZ))
	#define circ_count_to_end(circ) \
	(CIRC_CNT_TO_END((circ)->head, (circ)->tail, BUF_SZ))
	/* space available: */
	#define circ_space(circ) \
	(CIRC_SPACE((circ)->head, (circ)->tail, BUF_SZ))
	#define circ_space_to_end(circ) \
	(CIRC_SPACE_TO_END((circ)->head, (circ)->tail, BUF_SZ))

	struct msm_rd_state {
	struct drm_device *dev;

	bool open;

	/* current submit to read out: */
	struct msm_gem_submit *submit;

	/* fifo access is synchronized on the producer side by
	* struct_mutex held by submit code (otherwise we could
	* end up w/ cmds logged in different order than they
	* were executed). And read_lock synchronizes the reads
	*/
	struct mutex read_lock;

	wait_queue_head_t fifo_event;
	struct circ_buf fifo;

	char buf[BUF_SZ];
	};

	static void rd_write(struct msm_rd_state rd, const void buf, int sz)
	{
	struct circ_buf *fifo = &rd->fifo;
	const char *ptr = buf;

	while (sz > 0) {
	char *fptr = &fifo->buf[fifo->head];
	int n;

	wait_event(rd->fifo_event, circ_space(&rd->fifo) > 0);

	/* Note that smp_load_acquire() is not strictly required
	* as CIRC_SPACE_TO_END() does not access the tail more
	* than once.
	*/
	n = min(sz, circ_space_to_end(&rd->fifo));
	memcpy(fptr, ptr, n);

	smp_store_release(&fifo->head, (fifo->head + n) & (BUF_SZ - 1));
	sz -= n;
	ptr += n;

	wake_up_all(&rd->fifo_event);
	}
	}

	static void rd_write_section(struct msm_rd_state *rd,
	enum rd_sect_type type, const void *buf, int sz)
	{
	rd_write(rd, &type, 4);
	rd_write(rd, &sz, 4);
	rd_write(rd, buf, sz);
	}

	static ssize_t rd_read(struct file file, char __user buf,
	size_t sz, loff_t *ppos)
	{
	struct msm_rd_state *rd = file->private_data;
	struct circ_buf *fifo = &rd->fifo;
	const char *fptr = &fifo->buf[fifo->tail];
	int n = 0, ret = 0;

	mutex_lock(&rd->read_lock);

	ret = wait_event_interruptible(rd->fifo_event,
	circ_count(&rd->fifo) > 0);
	if (ret)
	goto out;

	/* Note that smp_load_acquire() is not strictly required
	* as CIRC_CNT_TO_END() does not access the head more than
	* once.
	*/
	n = min_t(int, sz, circ_count_to_end(&rd->fifo));
	if (copy_to_user(buf, fptr, n)) {
	ret = -EFAULT;
	goto out;
	}

	smp_store_release(&fifo->tail, (fifo->tail + n) & (BUF_SZ - 1));
	*ppos += n;

	wake_up_all(&rd->fifo_event);

	out:
	mutex_unlock(&rd->read_lock);
	if (ret)
	return ret;
	return n;
	}

	static int rd_open(struct inode inode, struct file file)
	{
	struct msm_rd_state *rd = inode->i_private;
	struct drm_device *dev = rd->dev;
	struct msm_drm_private *priv = dev->dev_private;
	struct msm_gpu *gpu = priv->gpu;
	uint64_t val;
	uint32_t gpu_id;
	int ret = 0;

	mutex_lock(&dev->struct_mutex);

	if (rd->open \|\| !gpu) {
	ret = -EBUSY;
	goto out;
	}

	file->private_data = rd;
	rd->open = true;

	/* the parsing tools need to know gpu-id to know which
	* register database to load.
	*/
	gpu->funcs->get_param(gpu, MSM_PARAM_GPU_ID, &val);
	gpu_id = val;

	rd_write_section(rd, RD_GPU_ID, &gpu_id, sizeof(gpu_id));

	out:
	mutex_unlock(&dev->struct_mutex);
	return ret;
	}

	static int rd_release(struct inode inode, struct file file)
	{
	struct msm_rd_state *rd = inode->i_private;
	rd->open = false;
	return 0;
	}


	static const struct file_operations rd_debugfs_fops = {
	.owner = THIS_MODULE,
	.open = rd_open,
	.read = rd_read,
	.llseek = no_llseek,
	.release = rd_release,
	};

	int msm_rd_debugfs_init(struct drm_minor *minor)
	{
	struct msm_drm_private *priv = minor->dev->dev_private;
	struct msm_rd_state *rd;
	struct dentry *ent;

	/* only create on first minor: */
	if (priv->rd)
	return 0;

	rd = kzalloc(sizeof(*rd), GFP_KERNEL);
	if (!rd)
	return -ENOMEM;

	rd->dev = minor->dev;
	rd->fifo.buf = rd->buf;

	mutex_init(&rd->read_lock);
	priv->rd = rd;

	init_waitqueue_head(&rd->fifo_event);

	ent = debugfs_create_file("rd", S_IFREG \| S_IRUGO,
	minor->debugfs_root, rd, &rd_debugfs_fops);
	if (!ent) {
	DRM_ERROR("Cannot create /sys/kernel/debug/dri/%pd/rd\n",
	minor->debugfs_root);
	goto fail;
	}

	return 0;

	fail:
	msm_rd_debugfs_cleanup(priv);
	return -1;
	}

	void msm_rd_debugfs_cleanup(struct msm_drm_private *priv)
	{
	struct msm_rd_state *rd = priv->rd;

	if (!rd)
	return;

	priv->rd = NULL;
	mutex_destroy(&rd->read_lock);
	kfree(rd);
	}

	static void snapshot_buf(struct msm_rd_state *rd,
	struct msm_gem_submit *submit, int idx,
	uint64_t iova, uint32_t size)
	{
	struct msm_gem_object *obj = submit->bos[idx].obj;
	const char *buf;

	buf = msm_gem_get_vaddr(&obj->base);
	if (IS_ERR(buf))
	return;

	if (iova) {
	buf += iova - submit->bos[idx].iova;
	} else {
	iova = submit->bos[idx].iova;
	size = obj->base.size;
	}

	rd_write_section(rd, RD_GPUADDR,
	(uint32_t[3]){ iova, size, iova >> 32 }, 12);
	rd_write_section(rd, RD_BUFFER_CONTENTS, buf, size);

	msm_gem_put_vaddr(&obj->base);
	}

	/* called under struct_mutex */
	void msm_rd_dump_submit(struct msm_gem_submit *submit)
	{
	struct drm_device *dev = submit->dev;
	struct msm_drm_private *priv = dev->dev_private;
	struct msm_rd_state *rd = priv->rd;
	char msg[128];
	int i, n;

	if (!rd->open)
	return;

	/* writing into fifo is serialized by caller, and
	* rd->read_lock is used to serialize the reads
	*/
	WARN_ON(!mutex_is_locked(&dev->struct_mutex));

	n = snprintf(msg, sizeof(msg), "%.*s/%d: fence=%u",
	TASK_COMM_LEN, current->comm, task_pid_nr(current),
	submit->fence->seqno);

	rd_write_section(rd, RD_CMD, msg, ALIGN(n, 4));

	if (rd_full) {
	for (i = 0; i < submit->nr_bos; i++) {
	/* buffers that are written to probably don't start out
	* with anything interesting:
	*/
	if (submit->bos[i].flags & MSM_SUBMIT_BO_WRITE)
	continue;

	snapshot_buf(rd, submit, i, 0, 0);
	}
	}

	for (i = 0; i < submit->nr_cmds; i++) {
	uint64_t iova = submit->cmd[i].iova;
	uint32_t szd = submit->cmd[i].size; /* in dwords */

	/* snapshot cmdstream bo's (if we haven't already): */
	if (!rd_full) {
	snapshot_buf(rd, submit, submit->cmd[i].idx,
	submit->cmd[i].iova, szd * 4);
	}

	switch (submit->cmd[i].type) {
	case MSM_SUBMIT_CMD_IB_TARGET_BUF:
	/* ignore IB-targets, we've logged the buffer, the
	* parser tool will follow the IB based on the logged
	* buffer/gpuaddr, so nothing more to do.
	*/
	break;
	case MSM_SUBMIT_CMD_CTX_RESTORE_BUF:
	case MSM_SUBMIT_CMD_BUF:
	rd_write_section(rd, RD_CMDSTREAM_ADDR,
	(uint32_t[3]){ iova, szd, iova >> 32 }, 12);
	break;
	}
	}
	}
	#endif