linux/drivers/gpu/drm/nouveau/nouveau_debugfs.c
Aaron Thompson 78f88067d5 drm/nouveau: Do not fail module init on debugfs errors
If CONFIG_DEBUG_FS is enabled, nouveau_drm_init() returns an error if it
fails to create the "nouveau" directory in debugfs. One case where that
will happen is when debugfs access is restricted by
CONFIG_DEBUG_FS_ALLOW_NONE or by the boot parameter debugfs=off, which
cause the debugfs APIs to return -EPERM.

So just ignore errors from debugfs. Note that nouveau_debugfs_root may
be an error now, but that is a standard pattern for debugfs. From
include/linux/debugfs.h:

"NOTE: it's expected that most callers should _ignore_ the errors
returned by this function. Other debugfs functions handle the fact that
the "dentry" passed to them could be an error and they don't crash in
that case. Drivers should generally work fine even if debugfs fails to
init anyway."

Fixes: 97118a1816 ("drm/nouveau: create module debugfs root")
Cc: stable@vger.kernel.org
Signed-off-by: Aaron Thompson <dev@aaront.org>
Acked-by: Timur Tabi <ttabi@nvidia.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250703211949.9916-1-dev@aaront.org
2025-07-03 23:56:33 +02:00

327 lines
8.2 KiB
C

/*
* Copyright (C) 2009 Red Hat <bskeggs@redhat.com>
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
*/
/*
* Authors:
* Ben Skeggs <bskeggs@redhat.com>
*/
#include <linux/debugfs.h>
#include <nvif/class.h>
#include <nvif/if0001.h>
#include "nouveau_debugfs.h"
#include "nouveau_drv.h"
static int
nouveau_debugfs_vbios_image(struct seq_file *m, void *data)
{
struct drm_info_node *node = (struct drm_info_node *) m->private;
struct nouveau_drm *drm = nouveau_drm(node->minor->dev);
int i;
for (i = 0; i < drm->vbios.length; i++)
seq_printf(m, "%c", drm->vbios.data[i]);
return 0;
}
static int
nouveau_debugfs_strap_peek(struct seq_file *m, void *data)
{
struct drm_info_node *node = m->private;
struct nouveau_drm *drm = nouveau_drm(node->minor->dev);
int ret;
ret = pm_runtime_get_sync(drm->dev->dev);
if (ret < 0 && ret != -EACCES) {
pm_runtime_put_autosuspend(drm->dev->dev);
return ret;
}
seq_printf(m, "0x%08x\n",
nvif_rd32(&drm->client.device.object, 0x101000));
pm_runtime_mark_last_busy(drm->dev->dev);
pm_runtime_put_autosuspend(drm->dev->dev);
return 0;
}
static int
nouveau_debugfs_pstate_get(struct seq_file *m, void *data)
{
struct drm_device *drm = m->private;
struct nouveau_debugfs *debugfs = nouveau_debugfs(drm);
struct nvif_object *ctrl;
struct nvif_control_pstate_info_v0 info = {};
int ret, i;
if (!debugfs)
return -ENODEV;
ctrl = &debugfs->ctrl;
ret = nvif_mthd(ctrl, NVIF_CONTROL_PSTATE_INFO, &info, sizeof(info));
if (ret)
return ret;
for (i = 0; i < info.count + 1; i++) {
const s32 state = i < info.count ? i :
NVIF_CONTROL_PSTATE_ATTR_V0_STATE_CURRENT;
struct nvif_control_pstate_attr_v0 attr = {
.state = state,
.index = 0,
};
ret = nvif_mthd(ctrl, NVIF_CONTROL_PSTATE_ATTR,
&attr, sizeof(attr));
if (ret)
return ret;
if (i < info.count)
seq_printf(m, "%02x:", attr.state);
else
seq_printf(m, "%s:", info.pwrsrc == 0 ? "DC" :
info.pwrsrc == 1 ? "AC" : "--");
attr.index = 0;
do {
attr.state = state;
ret = nvif_mthd(ctrl, NVIF_CONTROL_PSTATE_ATTR,
&attr, sizeof(attr));
if (ret)
return ret;
seq_printf(m, " %s %d", attr.name, attr.min);
if (attr.min != attr.max)
seq_printf(m, "-%d", attr.max);
seq_printf(m, " %s", attr.unit);
} while (attr.index);
if (state >= 0) {
if (info.ustate_ac == state)
seq_puts(m, " AC");
if (info.ustate_dc == state)
seq_puts(m, " DC");
if (info.pstate == state)
seq_puts(m, " *");
} else {
if (info.ustate_ac < -1)
seq_puts(m, " AC");
if (info.ustate_dc < -1)
seq_puts(m, " DC");
}
seq_putc(m, '\n');
}
return 0;
}
static ssize_t
nouveau_debugfs_pstate_set(struct file *file, const char __user *ubuf,
size_t len, loff_t *offp)
{
struct seq_file *m = file->private_data;
struct drm_device *drm = m->private;
struct nouveau_debugfs *debugfs = nouveau_debugfs(drm);
struct nvif_control_pstate_user_v0 args = { .pwrsrc = -EINVAL };
char buf[32] = {}, *tmp, *cur = buf;
long value, ret;
if (!debugfs)
return -ENODEV;
if (len >= sizeof(buf))
return -EINVAL;
if (copy_from_user(buf, ubuf, len))
return -EFAULT;
if ((tmp = strchr(buf, '\n')))
*tmp = '\0';
if (!strncasecmp(cur, "dc:", 3)) {
args.pwrsrc = 0;
cur += 3;
} else
if (!strncasecmp(cur, "ac:", 3)) {
args.pwrsrc = 1;
cur += 3;
}
if (!strcasecmp(cur, "none"))
args.ustate = NVIF_CONTROL_PSTATE_USER_V0_STATE_UNKNOWN;
else
if (!strcasecmp(cur, "auto"))
args.ustate = NVIF_CONTROL_PSTATE_USER_V0_STATE_PERFMON;
else {
ret = kstrtol(cur, 16, &value);
if (ret)
return ret;
args.ustate = value;
}
ret = pm_runtime_get_sync(drm->dev);
if (ret < 0 && ret != -EACCES) {
pm_runtime_put_autosuspend(drm->dev);
return ret;
}
ret = nvif_mthd(&debugfs->ctrl, NVIF_CONTROL_PSTATE_USER,
&args, sizeof(args));
pm_runtime_put_autosuspend(drm->dev);
if (ret < 0)
return ret;
return len;
}
static int
nouveau_debugfs_pstate_open(struct inode *inode, struct file *file)
{
return single_open(file, nouveau_debugfs_pstate_get, inode->i_private);
}
static void
nouveau_debugfs_gpuva_regions(struct seq_file *m, struct nouveau_uvmm *uvmm)
{
MA_STATE(mas, &uvmm->region_mt, 0, 0);
struct nouveau_uvma_region *reg;
seq_puts (m, " VA regions | start | range | end \n");
seq_puts (m, "----------------------------------------------------------------------------\n");
mas_for_each(&mas, reg, ULONG_MAX)
seq_printf(m, " | 0x%016llx | 0x%016llx | 0x%016llx\n",
reg->va.addr, reg->va.range, reg->va.addr + reg->va.range);
}
static int
nouveau_debugfs_gpuva(struct seq_file *m, void *data)
{
struct drm_info_node *node = (struct drm_info_node *) m->private;
struct nouveau_drm *drm = nouveau_drm(node->minor->dev);
struct nouveau_cli *cli;
mutex_lock(&drm->clients_lock);
list_for_each_entry(cli, &drm->clients, head) {
struct nouveau_uvmm *uvmm = nouveau_cli_uvmm(cli);
if (!uvmm)
continue;
nouveau_uvmm_lock(uvmm);
drm_debugfs_gpuva_info(m, &uvmm->base);
seq_puts(m, "\n");
nouveau_debugfs_gpuva_regions(m, uvmm);
nouveau_uvmm_unlock(uvmm);
}
mutex_unlock(&drm->clients_lock);
return 0;
}
static const struct file_operations nouveau_pstate_fops = {
.owner = THIS_MODULE,
.open = nouveau_debugfs_pstate_open,
.read = seq_read,
.write = nouveau_debugfs_pstate_set,
.release = single_release,
};
static struct drm_info_list nouveau_debugfs_list[] = {
{ "vbios.rom", nouveau_debugfs_vbios_image, 0, NULL },
{ "strap_peek", nouveau_debugfs_strap_peek, 0, NULL },
DRM_DEBUGFS_GPUVA_INFO(nouveau_debugfs_gpuva, NULL),
};
#define NOUVEAU_DEBUGFS_ENTRIES ARRAY_SIZE(nouveau_debugfs_list)
static const struct nouveau_debugfs_files {
const char *name;
const struct file_operations *fops;
} nouveau_debugfs_files[] = {
{"pstate", &nouveau_pstate_fops},
};
void
nouveau_drm_debugfs_init(struct drm_minor *minor)
{
struct nouveau_drm *drm = nouveau_drm(minor->dev);
struct dentry *dentry;
int i;
for (i = 0; i < ARRAY_SIZE(nouveau_debugfs_files); i++) {
debugfs_create_file(nouveau_debugfs_files[i].name,
S_IRUGO | S_IWUSR,
minor->debugfs_root, minor->dev,
nouveau_debugfs_files[i].fops);
}
drm_debugfs_create_files(nouveau_debugfs_list,
NOUVEAU_DEBUGFS_ENTRIES,
minor->debugfs_root, minor);
/* Set the size of the vbios since we know it, and it's confusing to
* userspace if it wants to seek() but the file has a length of 0
*/
dentry = debugfs_lookup("vbios.rom", minor->debugfs_root);
if (!dentry)
return;
d_inode(dentry)->i_size = drm->vbios.length;
dput(dentry);
}
int
nouveau_debugfs_init(struct nouveau_drm *drm)
{
drm->debugfs = kzalloc(sizeof(*drm->debugfs), GFP_KERNEL);
if (!drm->debugfs)
return -ENOMEM;
return nvif_object_ctor(&drm->client.device.object, "debugfsCtrl", 0,
NVIF_CLASS_CONTROL, NULL, 0,
&drm->debugfs->ctrl);
}
void
nouveau_debugfs_fini(struct nouveau_drm *drm)
{
if (drm->debugfs && drm->debugfs->ctrl.priv)
nvif_object_dtor(&drm->debugfs->ctrl);
kfree(drm->debugfs);
drm->debugfs = NULL;
}
void
nouveau_module_debugfs_init(void)
{
nouveau_debugfs_root = debugfs_create_dir("nouveau", NULL);
}
void
nouveau_module_debugfs_fini(void)
{
debugfs_remove(nouveau_debugfs_root);
}