| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright (C) 2013 Red Hat |
| * Author: Rob Clark <robdclark@gmail.com> |
| */ |
| |
| /* 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 = false; |
| MODULE_PARM_DESC(rd_full, "If true, $debugfs/.../rd will snapshot all buffer contents"); |
| module_param_named(rd_full, rd_full, bool, 0600); |
| |
| #ifdef CONFIG_DEBUG_FS |
| |
| 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 || !rd->open); |
| if (!rd->open) |
| return; |
| |
| /* 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; |
| wake_up_all(&rd->fifo_event); |
| |
| 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, |
| }; |
| |
| |
| static void rd_cleanup(struct msm_rd_state *rd) |
| { |
| if (!rd) |
| return; |
| |
| mutex_destroy(&rd->read_lock); |
| kfree(rd); |
| } |
| |
| static struct msm_rd_state *rd_init(struct drm_minor *minor, const char *name) |
| { |
| struct msm_rd_state *rd; |
| |
| rd = kzalloc(sizeof(*rd), GFP_KERNEL); |
| if (!rd) |
| return ERR_PTR(-ENOMEM); |
| |
| rd->dev = minor->dev; |
| rd->fifo.buf = rd->buf; |
| |
| mutex_init(&rd->read_lock); |
| |
| init_waitqueue_head(&rd->fifo_event); |
| |
| debugfs_create_file(name, S_IFREG | S_IRUGO, minor->debugfs_root, rd, |
| &rd_debugfs_fops); |
| |
| return rd; |
| } |
| |
| int msm_rd_debugfs_init(struct drm_minor *minor) |
| { |
| struct msm_drm_private *priv = minor->dev->dev_private; |
| struct msm_rd_state *rd; |
| int ret; |
| |
| /* only create on first minor: */ |
| if (priv->rd) |
| return 0; |
| |
| rd = rd_init(minor, "rd"); |
| if (IS_ERR(rd)) { |
| ret = PTR_ERR(rd); |
| goto fail; |
| } |
| |
| priv->rd = rd; |
| |
| rd = rd_init(minor, "hangrd"); |
| if (IS_ERR(rd)) { |
| ret = PTR_ERR(rd); |
| goto fail; |
| } |
| |
| priv->hangrd = rd; |
| |
| return 0; |
| |
| fail: |
| msm_rd_debugfs_cleanup(priv); |
| return ret; |
| } |
| |
| void msm_rd_debugfs_cleanup(struct msm_drm_private *priv) |
| { |
| rd_cleanup(priv->rd); |
| priv->rd = NULL; |
| |
| rd_cleanup(priv->hangrd); |
| priv->hangrd = NULL; |
| } |
| |
| static void snapshot_buf(struct msm_rd_state *rd, |
| struct msm_gem_submit *submit, int idx, |
| uint64_t iova, uint32_t size, bool full) |
| { |
| struct msm_gem_object *obj = submit->bos[idx].obj; |
| unsigned offset = 0; |
| const char *buf; |
| |
| if (iova) { |
| offset = iova - submit->bos[idx].iova; |
| } else { |
| iova = submit->bos[idx].iova; |
| size = obj->base.size; |
| } |
| |
| /* |
| * Always write the GPUADDR header so can get a complete list of all the |
| * buffers in the cmd |
| */ |
| rd_write_section(rd, RD_GPUADDR, |
| (uint32_t[3]){ iova, size, iova >> 32 }, 12); |
| |
| if (!full) |
| return; |
| |
| /* But only dump the contents of buffers marked READ */ |
| if (!(submit->bos[idx].flags & MSM_SUBMIT_BO_READ)) |
| return; |
| |
| buf = msm_gem_get_vaddr_active(&obj->base); |
| if (IS_ERR(buf)) |
| return; |
| |
| buf += offset; |
| |
| rd_write_section(rd, RD_BUFFER_CONTENTS, buf, size); |
| |
| msm_gem_put_vaddr_locked(&obj->base); |
| } |
| |
| /* called under struct_mutex */ |
| void msm_rd_dump_submit(struct msm_rd_state *rd, struct msm_gem_submit *submit, |
| const char *fmt, ...) |
| { |
| struct drm_device *dev = submit->dev; |
| struct task_struct *task; |
| char msg[256]; |
| 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)); |
| |
| if (fmt) { |
| va_list args; |
| |
| va_start(args, fmt); |
| n = vscnprintf(msg, sizeof(msg), fmt, args); |
| va_end(args); |
| |
| rd_write_section(rd, RD_CMD, msg, ALIGN(n, 4)); |
| } |
| |
| rcu_read_lock(); |
| task = pid_task(submit->pid, PIDTYPE_PID); |
| if (task) { |
| n = scnprintf(msg, sizeof(msg), "%.*s/%d: fence=%u", |
| TASK_COMM_LEN, task->comm, |
| pid_nr(submit->pid), submit->seqno); |
| } else { |
| n = scnprintf(msg, sizeof(msg), "???/%d: fence=%u", |
| pid_nr(submit->pid), submit->seqno); |
| } |
| rcu_read_unlock(); |
| |
| rd_write_section(rd, RD_CMD, msg, ALIGN(n, 4)); |
| |
| for (i = 0; i < submit->nr_bos; i++) |
| snapshot_buf(rd, submit, i, 0, 0, should_dump(submit, i)); |
| |
| for (i = 0; i < submit->nr_cmds; i++) { |
| uint32_t szd = submit->cmd[i].size; /* in dwords */ |
| |
| /* snapshot cmdstream bo's (if we haven't already): */ |
| if (!should_dump(submit, i)) { |
| snapshot_buf(rd, submit, submit->cmd[i].idx, |
| submit->cmd[i].iova, szd * 4, true); |
| } |
| } |
| |
| for (i = 0; i < submit->nr_cmds; i++) { |
| uint64_t iova = submit->cmd[i].iova; |
| uint32_t szd = submit->cmd[i].size; /* in dwords */ |
| |
| 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 |