1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
/*
* Copyright 2016-2018 Advanced Micro Devices, Inc.
*
* 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 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 HOLDER(S) OR AUTHOR(S) 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.
*/
#include <linux/dma-fence.h>
#include <linux/spinlock.h>
#include <linux/atomic.h>
#include <linux/stacktrace.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/sched/mm.h>
#include "amdgpu_amdkfd.h"
#include "kfd_svm.h"
static const struct dma_fence_ops amdkfd_fence_ops;
static atomic_t fence_seq = ATOMIC_INIT(0);
/* Eviction Fence
* Fence helper functions to deal with KFD memory eviction.
* Big Idea - Since KFD submissions are done by user queues, a BO cannot be
* evicted unless all the user queues for that process are evicted.
*
* All the BOs in a process share an eviction fence. When process X wants
* to map VRAM memory but TTM can't find enough space, TTM will attempt to
* evict BOs from its LRU list. TTM checks if the BO is valuable to evict
* by calling ttm_device_funcs->eviction_valuable().
*
* ttm_device_funcs->eviction_valuable() - will return false if the BO belongs
* to process X. Otherwise, it will return true to indicate BO can be
* evicted by TTM.
*
* If ttm_device_funcs->eviction_valuable returns true, then TTM will continue
* the evcition process for that BO by calling ttm_bo_evict --> amdgpu_bo_move
* --> amdgpu_copy_buffer(). This sets up job in GPU scheduler.
*
* GPU Scheduler (amd_sched_main) - sets up a cb (fence_add_callback) to
* nofity when the BO is free to move. fence_add_callback --> enable_signaling
* --> amdgpu_amdkfd_fence.enable_signaling
*
* amdgpu_amdkfd_fence.enable_signaling - Start a work item that will quiesce
* user queues and signal fence. The work item will also start another delayed
* work item to restore BOs
*/
struct amdgpu_amdkfd_fence *amdgpu_amdkfd_fence_create(u64 context,
struct mm_struct *mm,
struct svm_range_bo *svm_bo)
{
struct amdgpu_amdkfd_fence *fence;
fence = kzalloc(sizeof(*fence), GFP_KERNEL);
if (fence == NULL)
return NULL;
/* This reference gets released in amdkfd_fence_release */
mmgrab(mm);
fence->mm = mm;
get_task_comm(fence->timeline_name, current);
spin_lock_init(&fence->lock);
fence->svm_bo = svm_bo;
dma_fence_init(&fence->base, &amdkfd_fence_ops, &fence->lock,
context, atomic_inc_return(&fence_seq));
return fence;
}
struct amdgpu_amdkfd_fence *to_amdgpu_amdkfd_fence(struct dma_fence *f)
{
struct amdgpu_amdkfd_fence *fence;
if (!f)
return NULL;
fence = container_of(f, struct amdgpu_amdkfd_fence, base);
if (f->ops == &amdkfd_fence_ops)
return fence;
return NULL;
}
static const char *amdkfd_fence_get_driver_name(struct dma_fence *f)
{
return "amdgpu_amdkfd_fence";
}
static const char *amdkfd_fence_get_timeline_name(struct dma_fence *f)
{
struct amdgpu_amdkfd_fence *fence = to_amdgpu_amdkfd_fence(f);
return fence->timeline_name;
}
/**
* amdkfd_fence_enable_signaling - This gets called when TTM wants to evict
* a KFD BO and schedules a job to move the BO.
* If fence is already signaled return true.
* If fence is not signaled schedule a evict KFD process work item.
*
* @f: dma_fence
*/
static bool amdkfd_fence_enable_signaling(struct dma_fence *f)
{
struct amdgpu_amdkfd_fence *fence = to_amdgpu_amdkfd_fence(f);
if (!fence)
return false;
if (dma_fence_is_signaled(f))
return true;
if (!fence->svm_bo) {
if (!kgd2kfd_schedule_evict_and_restore_process(fence->mm, f))
return true;
} else {
if (!svm_range_schedule_evict_svm_bo(fence))
return true;
}
return false;
}
/**
* amdkfd_fence_release - callback that fence can be freed
*
* @f: dma_fence
*
* This function is called when the reference count becomes zero.
* Drops the mm_struct reference and RCU schedules freeing up the fence.
*/
static void amdkfd_fence_release(struct dma_fence *f)
{
struct amdgpu_amdkfd_fence *fence = to_amdgpu_amdkfd_fence(f);
/* Unconditionally signal the fence. The process is getting
* terminated.
*/
if (WARN_ON(!fence))
return; /* Not an amdgpu_amdkfd_fence */
mmdrop(fence->mm);
kfree_rcu(f, rcu);
}
/**
* amdkfd_fence_check_mm - Check whether to prevent eviction of @f by @mm
*
* @f: [IN] fence
* @mm: [IN] mm that needs to be verified
*
* Check if @mm is same as that of the fence @f, if same return TRUE else
* return FALSE.
* For svm bo, which support vram overcommitment, always return FALSE.
*/
bool amdkfd_fence_check_mm(struct dma_fence *f, struct mm_struct *mm)
{
struct amdgpu_amdkfd_fence *fence = to_amdgpu_amdkfd_fence(f);
if (!fence)
return false;
else if (fence->mm == mm && !fence->svm_bo)
return true;
return false;
}
static const struct dma_fence_ops amdkfd_fence_ops = {
.get_driver_name = amdkfd_fence_get_driver_name,
.get_timeline_name = amdkfd_fence_get_timeline_name,
.enable_signaling = amdkfd_fence_enable_signaling,
.release = amdkfd_fence_release,
};
|
