Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
drm/xe/multi_queue: Protect priority against concurrent access
Use a spinlock to protect multi-queue priority being concurrently
updated by multiple set_priority ioctls and to protect against
concurrent read and write to this field.
v2: Update documentation, remove WRITE/READ_LOCK() (Thomas)
Use scoped_guard, reduced lock scope (Matt Brost)
v3: Fix author (checkpatch)
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patch.msgid.link/20260126174241.3470390-2-niranjana.vishwanathapura@intel.com
+22
-5
+1
drivers/gpu/drm/xe/xe_exec_queue.c
+1
drivers/gpu/drm/xe/xe_exec_queue.c
···
230
230
INIT_LIST_HEAD(&q->multi_gt_link);
231
231
INIT_LIST_HEAD(&q->hw_engine_group_link);
232
232
INIT_LIST_HEAD(&q->pxp.link);
233
+
spin_lock_init(&q->multi_queue.lock);
233
234
q->multi_queue.priority = XE_MULTI_QUEUE_PRIORITY_NORMAL;
234
235
235
236
q->sched_props.timeslice_us = hwe->eclass->sched_props.timeslice_us;
+6
-1
drivers/gpu/drm/xe/xe_exec_queue_types.h
+6
-1
drivers/gpu/drm/xe/xe_exec_queue_types.h
···
161
161
struct xe_exec_queue_group *group;
162
162
/** @multi_queue.link: Link into group's secondary queues list */
163
163
struct list_head link;
164
-
/** @multi_queue.priority: Queue priority within the multi-queue group */
164
+
/**
165
+
* @multi_queue.priority: Queue priority within the multi-queue group.
166
+
* It is protected by @multi_queue.lock.
167
+
*/
165
168
enum xe_multi_queue_priority priority;
169
+
/** @multi_queue.lock: Lock for protecting certain members */
170
+
spinlock_t lock;
166
171
/** @multi_queue.pos: Position of queue within the multi-queue group */
167
172
u8 pos;
168
173
/** @multi_queue.valid: Queue belongs to a multi queue group */
+15
-4
drivers/gpu/drm/xe/xe_guc_submit.c
+15
-4
drivers/gpu/drm/xe/xe_guc_submit.c
···
804
804
{
805
805
struct xe_exec_queue_group *group = q->multi_queue.group;
806
806
struct xe_device *xe = guc_to_xe(guc);
807
+
enum xe_multi_queue_priority priority;
807
808
long ret;
808
809
809
810
/*
···
828
827
return;
829
828
}
830
829
831
-
xe_lrc_set_multi_queue_priority(q->lrc[0], q->multi_queue.priority);
830
+
scoped_guard(spinlock, &q->multi_queue.lock)
831
+
priority = q->multi_queue.priority;
832
+
833
+
xe_lrc_set_multi_queue_priority(q->lrc[0], priority);
832
834
xe_guc_exec_queue_group_cgp_update(xe, q);
833
835
834
836
WRITE_ONCE(group->sync_pending, true);
···
2185
2181
2186
2182
xe_gt_assert(guc_to_gt(exec_queue_to_guc(q)), xe_exec_queue_is_multi_queue(q));
2187
2183
2188
-
if (q->multi_queue.priority == priority ||
2189
-
exec_queue_killed_or_banned_or_wedged(q))
2184
+
if (exec_queue_killed_or_banned_or_wedged(q))
2190
2185
return 0;
2191
2186
2192
2187
msg = kmalloc(sizeof(*msg), GFP_KERNEL);
2193
2188
if (!msg)
2194
2189
return -ENOMEM;
2195
2190
2196
-
q->multi_queue.priority = priority;
2191
+
scoped_guard(spinlock, &q->multi_queue.lock) {
2192
+
if (q->multi_queue.priority == priority) {
2193
+
kfree(msg);
2194
+
return 0;
2195
+
}
2196
+
2197
+
q->multi_queue.priority = priority;
2198
+
}
2199
+
2197
2200
guc_exec_queue_add_msg(q, msg, SET_MULTI_QUEUE_PRIORITY);
2198
2201
2199
2202
return 0;