linux-loongson/drivers/gpu/drm/xe/xe_guc_debugfs.c
Aradhya Bhatia e22d7acf9f drm/xe/guc: Make creation of SLPC debugfs files conditional
Platforms that do not support SLPC are exempted from the GuC PC support.
The GuC PC does not get initialized, and neither do its BOs get created.

This causes a problem because the GuC PC debugfs file is still being
created. Whenever the file is attempted to read, it causes a NULL
pointer dereference on the supposed BO of the GuC PC.

So, make the creation of SLPC debugfs files conditional to when SLPC
features are supported.

Fixes: aaab5404b1 ("drm/xe: Introduce GuC PC debugfs")
Suggested-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
Reviewed-by: Stuart Summers <stuart.summers@intel.com>
Signed-off-by: Aradhya Bhatia <aradhya.bhatia@intel.com>
Link: https://lore.kernel.org/r/20250516141902.5614-1-aradhya.bhatia@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
(cherry picked from commit 17486cf3df)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
2025-05-23 09:40:55 +02:00

147 lines
4.2 KiB
C

// SPDX-License-Identifier: MIT
/*
* Copyright © 2022 Intel Corporation
*/
#include "xe_guc_debugfs.h"
#include <drm/drm_debugfs.h>
#include <drm/drm_managed.h>
#include "xe_device.h"
#include "xe_gt.h"
#include "xe_guc.h"
#include "xe_guc_ct.h"
#include "xe_guc_log.h"
#include "xe_guc_pc.h"
#include "xe_macros.h"
#include "xe_pm.h"
/*
* guc_debugfs_show - A show callback for struct drm_info_list
* @m: the &seq_file
* @data: data used by the drm debugfs helpers
*
* This callback can be used in struct drm_info_list to describe debugfs
* files that are &xe_guc specific in similar way how we handle &xe_gt
* specific files using &xe_gt_debugfs_simple_show.
*
* It is assumed that those debugfs files will be created on directory entry
* which grandparent struct dentry d_inode->i_private points to &xe_gt.
*
* /sys/kernel/debug/dri/0/
* ├── gt0 # dent->d_parent->d_parent (d_inode->i_private == gt)
* │   ├── uc # dent->d_parent
* │   │   ├── guc_info # dent
* │   │   ├── guc_...
*
* This function assumes that &m->private will be set to the &struct
* drm_info_node corresponding to the instance of the info on a given &struct
* drm_minor (see struct drm_info_list.show for details).
*
* This function also assumes that struct drm_info_list.data will point to the
* function code that will actually print a file content::
*
* int (*print)(struct xe_guc *, struct drm_printer *)
*
* Example::
*
* int foo(struct xe_guc *guc, struct drm_printer *p)
* {
* drm_printf(p, "enabled %d\n", guc->submission_state.enabled);
* return 0;
* }
*
* static const struct drm_info_list bar[] = {
* { name = "foo", .show = guc_debugfs_show, .data = foo },
* };
*
* parent = debugfs_create_dir("uc", gtdir);
* drm_debugfs_create_files(bar, ARRAY_SIZE(bar), parent, minor);
*
* Return: 0 on success or a negative error code on failure.
*/
static int guc_debugfs_show(struct seq_file *m, void *data)
{
struct drm_printer p = drm_seq_file_printer(m);
struct drm_info_node *node = m->private;
struct dentry *parent = node->dent->d_parent;
struct dentry *grandparent = parent->d_parent;
struct xe_gt *gt = grandparent->d_inode->i_private;
struct xe_device *xe = gt_to_xe(gt);
int (*print)(struct xe_guc *, struct drm_printer *) = node->info_ent->data;
int ret;
xe_pm_runtime_get(xe);
ret = print(&gt->uc.guc, &p);
xe_pm_runtime_put(xe);
return ret;
}
static int guc_log(struct xe_guc *guc, struct drm_printer *p)
{
xe_guc_log_print(&guc->log, p);
return 0;
}
static int guc_log_dmesg(struct xe_guc *guc, struct drm_printer *p)
{
xe_guc_log_print_dmesg(&guc->log);
return 0;
}
static int guc_ctb(struct xe_guc *guc, struct drm_printer *p)
{
xe_guc_ct_print(&guc->ct, p, true);
return 0;
}
static int guc_pc(struct xe_guc *guc, struct drm_printer *p)
{
xe_guc_pc_print(&guc->pc, p);
return 0;
}
/*
* only for GuC debugfs files which can be safely used on the VF as well:
* - without access to the GuC privileged registers
* - without access to the PF specific GuC objects
*/
static const struct drm_info_list vf_safe_debugfs_list[] = {
{ "guc_info", .show = guc_debugfs_show, .data = xe_guc_print_info },
{ "guc_ctb", .show = guc_debugfs_show, .data = guc_ctb },
};
/* For GuC debugfs files that require the SLPC support */
static const struct drm_info_list slpc_debugfs_list[] = {
{ "guc_pc", .show = guc_debugfs_show, .data = guc_pc },
};
/* everything else should be added here */
static const struct drm_info_list pf_only_debugfs_list[] = {
{ "guc_log", .show = guc_debugfs_show, .data = guc_log },
{ "guc_log_dmesg", .show = guc_debugfs_show, .data = guc_log_dmesg },
};
void xe_guc_debugfs_register(struct xe_guc *guc, struct dentry *parent)
{
struct xe_device *xe = guc_to_xe(guc);
struct drm_minor *minor = xe->drm.primary;
drm_debugfs_create_files(vf_safe_debugfs_list,
ARRAY_SIZE(vf_safe_debugfs_list),
parent, minor);
if (!IS_SRIOV_VF(xe)) {
drm_debugfs_create_files(pf_only_debugfs_list,
ARRAY_SIZE(pf_only_debugfs_list),
parent, minor);
if (!xe->info.skip_guc_pc)
drm_debugfs_create_files(slpc_debugfs_list,
ARRAY_SIZE(slpc_debugfs_list),
parent, minor);
}
}