To ease debugging, add debugfs file which can be cat/tail'd to log submits, along with fence #. If GPU hangs, you can look at 'gpu' debugfs file to find last completed fence and current register state, and compare with logged rd file to narrow down the DRAW_INDX which triggered the GPU hang. --- drivers/gpu/drm/msm/Makefile | 1 + drivers/gpu/drm/msm/msm_drv.c | 3 +- drivers/gpu/drm/msm/msm_drv.h | 9 + drivers/gpu/drm/msm/msm_gem.h | 1 + drivers/gpu/drm/msm/msm_gem_submit.c | 1 + drivers/gpu/drm/msm/msm_gpu.c | 2 + drivers/gpu/drm/msm/msm_rd.c | 334 +++++++++++++++++++++++++++++++++++ 7 files changed, 350 insertions(+), 1 deletion(-) create mode 100644 drivers/gpu/drm/msm/msm_rd.c
diff --git a/drivers/gpu/drm/msm/Makefile b/drivers/gpu/drm/msm/Makefile index c3a5134..f945179 100644 --- a/drivers/gpu/drm/msm/Makefile +++ b/drivers/gpu/drm/msm/Makefile @@ -23,6 +23,7 @@ msm-y := \ msm_gem.o \ msm_gem_submit.o \ msm_gpu.o \ + msm_rd.o \ msm_ringbuffer.o
msm-$(CONFIG_DRM_MSM_FBDEV) += msm_fbdev.o diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c index 355157d..adcc68b 100644 --- a/drivers/gpu/drm/msm/msm_drv.c +++ b/drivers/gpu/drm/msm/msm_drv.c @@ -459,11 +459,12 @@ static int msm_debugfs_init(struct drm_minor *minor) return ret; }
- return ret; + return msm_rd_debugfs_init(minor); }
static void msm_debugfs_cleanup(struct drm_minor *minor) { + msm_rd_debugfs_cleanup(minor); drm_debugfs_remove_files(msm_debugfs_list, ARRAY_SIZE(msm_debugfs_list), minor); } diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h index a7426f1..ea6f1c7 100644 --- a/drivers/gpu/drm/msm/msm_drv.h +++ b/drivers/gpu/drm/msm/msm_drv.h @@ -44,6 +44,8 @@
struct msm_kms; struct msm_gpu; +struct msm_rd_state; +struct msm_gem_submit;
#define NUM_DOMAINS 2 /* one for KMS, then one per gpu core (?) */
@@ -68,6 +70,8 @@ struct msm_drm_private { uint32_t next_fence, completed_fence; wait_queue_head_t fence_event;
+ struct msm_rd_state *rd; + /* list of GEM objects: */ struct list_head inactive_list;
@@ -179,6 +183,11 @@ void __exit hdmi_unregister(void); void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m); void msm_gem_describe_objects(struct list_head *list, struct seq_file *m); void msm_framebuffer_describe(struct drm_framebuffer *fb, struct seq_file *m); +int msm_rd_debugfs_init(struct drm_minor *minor); +void msm_rd_debugfs_cleanup(struct drm_minor *minor); +void msm_rd_dump_submit(struct msm_gem_submit *submit); +#else +static inline void msm_rd_dump_submit(struct msm_gem_submit *submit) {} #endif
void __iomem *msm_ioremap(struct device *dev, resource_size_t offset, diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h index d746f13..a5dbc5c 100644 --- a/drivers/gpu/drm/msm/msm_gem.h +++ b/drivers/gpu/drm/msm/msm_gem.h @@ -88,6 +88,7 @@ struct msm_gem_submit { uint32_t type; uint32_t size; /* in dwords */ uint32_t iova; + uint32_t idx; /* cmdstream buffer idx in bos[] */ } cmd[MAX_CMDS]; struct { uint32_t flags; diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c index f62904f..d18e677 100644 --- a/drivers/gpu/drm/msm/msm_gem_submit.c +++ b/drivers/gpu/drm/msm/msm_gem_submit.c @@ -389,6 +389,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data, submit->cmd[i].type = submit_cmd.type; submit->cmd[i].size = submit_cmd.size / 4; submit->cmd[i].iova = iova + submit_cmd.submit_offset; + submit->cmd[i].idx = submit_cmd.submit_idx;
if (submit->valid) continue; diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c index 047be07..4775415 100644 --- a/drivers/gpu/drm/msm/msm_gpu.c +++ b/drivers/gpu/drm/msm/msm_gpu.c @@ -254,6 +254,8 @@ int msm_gpu_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit,
submit->fence = ++priv->next_fence;
+ msm_rd_dump_submit(submit); + ret = gpu->funcs->submit(gpu, submit, ctx); priv->lastctx = ctx;
diff --git a/drivers/gpu/drm/msm/msm_rd.c b/drivers/gpu/drm/msm/msm_rd.c new file mode 100644 index 0000000..9aaa681 --- /dev/null +++ b/drivers/gpu/drm/msm/msm_rd.c @@ -0,0 +1,334 @@ +/* + * 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. + */ + +#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" + +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; + + struct dentry *ent; + struct drm_info_node *node; + + /* 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); + + n = min(sz, circ_space_to_end(&rd->fifo)); + memcpy(fptr, ptr, n); + + 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; + + n = min((int)sz, circ_count_to_end(&rd->fifo)); + ret = copy_to_user(buf, fptr, n); + if (ret) + goto out; + + 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); + +priv->rd = rd; // XXX this isn't really good.. + + 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; + + rd = kzalloc(sizeof(*rd), GFP_KERNEL); + if (!rd) + return -ENOMEM; + + rd->dev = minor->dev; + rd->fifo.buf = rd->buf; + + mutex_init(&rd->read_lock); +DBG("********** rd->dev=%p, priv=%p", rd->dev, priv); +// priv->rd = rd; + + init_waitqueue_head(&rd->fifo_event); + + rd->node = kzalloc(sizeof(*rd->node), GFP_KERNEL); + if (!rd->node) + goto fail; + + rd->ent = debugfs_create_file("rd", S_IFREG | S_IRUGO, + minor->debugfs_root, rd, &rd_debugfs_fops); + if (!rd->ent) { + DRM_ERROR("Cannot create /sys/kernel/debug/dri/%s/rd\n", + minor->debugfs_root->d_name.name); + goto fail; + } + + rd->node->minor = minor; + rd->node->dent = rd->ent; + rd->node->info_ent = NULL; + + mutex_lock(&minor->debugfs_lock); + list_add(&rd->node->list, &minor->debugfs_list); + mutex_unlock(&minor->debugfs_lock); + + return 0; + +fail: + msm_rd_debugfs_cleanup(minor); + return -1; +} + +void msm_rd_debugfs_cleanup(struct drm_minor *minor) +{ + struct msm_drm_private *priv = minor->dev->dev_private; + struct msm_rd_state *rd = priv->rd; + + if (rd->ent) + debugfs_remove(rd->ent); + + if (rd->node) { + mutex_lock(&minor->debugfs_lock); + list_del(&rd->node->list); + mutex_unlock(&minor->debugfs_lock); + kfree(rd->node); + } + + mutex_destroy(&rd->read_lock); + + kfree(rd); +} + +/* 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) return; // XXX + + 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); + + rd_write_section(rd, RD_CMD, msg, ALIGN(n, 4)); + + /* could be nice to have an option (module-param?) to snapshot + * all the bo's associated with the submit. Handy to see vtx + * buffers, etc. For now just the cmdstream bo's is enough. + */ + + for (i = 0; i < submit->nr_cmds; i++) { + uint32_t idx = submit->cmd[i].idx; + uint32_t iova = submit->cmd[i].iova; + uint32_t szd = submit->cmd[i].size; /* in dwords */ + struct msm_gem_object *obj = submit->bos[idx].obj; + const char *buf = msm_gem_vaddr_locked(&obj->base); + + buf += iova - submit->bos[idx].iova; + + rd_write_section(rd, RD_GPUADDR, + (uint32_t[2]){ iova, szd * 4 }, 8); + rd_write_section(rd, RD_BUFFER_CONTENTS, + buf, 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[2]){ iova, szd }, 8); + break; + } + } +} +#endif