[robclark:drm-next 14/15] WARNING: debugfs_remove(NULL) is safe this check is probably not required
Fengguang Wu
fengguang.wu at intel.com
Sun Aug 4 19:10:53 PDT 2013
Hi Rob,
FYI, there are new warnings show up in
tree: git://people.freedesktop.org/~robclark/linux drm-next
head: 865ff8a71f4227222fec89ebb1743b4ca9f24ab1
commit: b91c7b5f2efe902c846e315ea7d219f37ba17ef5 [14/15] WIP: drm/msm: add rd logging debugfs
scripts/checkpatch.pl 0001-WIP-drm-msm-add-rd-logging-debugfs.patch
WARNING: min() should probably be min_t(int, sz, circ_count_to_end(&rd->fifo))
#270: drivers/gpu/drm/msm/msm_rd.c:142:
+ n = min((int)sz, circ_count_to_end(&rd->fifo));
ERROR: do not use C99 // comments
#299: drivers/gpu/drm/msm/msm_rd.c:171:
+priv->rd = rd; // XXX this isn't really good..
ERROR: do not use C99 // comments
#352: drivers/gpu/drm/msm/msm_rd.c:224:
+// priv->rd = rd;
WARNING: debugfs_remove(NULL) is safe this check is probably not required
#389: drivers/gpu/drm/msm/msm_rd.c:261:
+ if (rd->ent)
+ debugfs_remove(rd->ent);
ERROR: do not use C99 // comments
#412: drivers/gpu/drm/msm/msm_rd.c:284:
+if (!rd) return; // XXX
---
0-DAY kernel build testing backend Open Source Technology Center
http://lists.01.org/mailman/listinfo/kbuild Intel Corporation
>From b91c7b5f2efe902c846e315ea7d219f37ba17ef5 Mon Sep 17 00:00:00 2001
From: Rob Clark <robdclark at gmail.com>
Date: Thu, 25 Jul 2013 12:07:04 -0400
Subject: [PATCH] WIP: drm/msm: add rd logging debugfs
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 at 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
--
1.7.10.4
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