aboutsummaryrefslogtreecommitdiffstats
path: root/include/nvgpu/page_allocator.h
blob: a6e0205849f9f91136be9d6dd996a9ddc6191c09 (plain) (blame)
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
/*
 * Copyright (c) 2016-2017, NVIDIA CORPORATION.  All rights reserved.
 *
 * 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 AUTHORS OR COPYRIGHT HOLDERS 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.
 */

#ifndef PAGE_ALLOCATOR_PRIV_H
#define PAGE_ALLOCATOR_PRIV_H

#include <nvgpu/allocator.h>
#include <nvgpu/nvgpu_mem.h>
#include <nvgpu/kmem.h>
#include <nvgpu/list.h>
#include <nvgpu/rbtree.h>

struct nvgpu_allocator;

/*
 * This allocator implements the ability to do SLAB style allocation since the
 * GPU has two page sizes available - 4k and 64k/128k. When the default
 * granularity is the large page size (64k/128k) small allocations become very
 * space inefficient. This is most notable in PDE and PTE blocks which are 4k
 * in size.
 *
 * Thus we need the ability to suballocate in 64k pages. The way we do this for
 * the GPU is as follows. We have several buckets for sub-64K allocations:
 *
 *   B0 - 4k
 *   B1 - 8k
 *   B3 - 16k
 *   B4 - 32k
 *   B5 - 64k (for when large pages are 128k)
 *
 * When an allocation comes in for less than the large page size (from now on
 * assumed to be 64k) the allocation is satisfied by one of the buckets.
 */
struct page_alloc_slab {
	struct nvgpu_list_node empty;
	struct nvgpu_list_node partial;
	struct nvgpu_list_node full;

	int nr_empty;
	int nr_partial;
	int nr_full;

	u32 slab_size;
};

enum slab_page_state {
	SP_EMPTY,
	SP_PARTIAL,
	SP_FULL,
	SP_NONE
};

struct page_alloc_slab_page {
	unsigned long bitmap;
	u64 page_addr;
	u32 slab_size;

	u32 nr_objects;
	u32 nr_objects_alloced;

	enum slab_page_state state;

	struct page_alloc_slab *owner;
	struct nvgpu_list_node list_entry;
};

static inline struct page_alloc_slab_page *
page_alloc_slab_page_from_list_entry(struct nvgpu_list_node *node)
{
	return (struct page_alloc_slab_page *)
	((uintptr_t)node - offsetof(struct page_alloc_slab_page, list_entry));
};

/*
 * Struct to handle internal management of page allocation. It holds a list
 * of the chunks of pages that make up the overall allocation - much like a
 * scatter gather table.
 */
struct nvgpu_page_alloc {
	/*
	 * nvgpu_sgt for describing the actual allocation. Convenient for
	 * GMMU mapping.
	 */
	struct nvgpu_sgt sgt;

	int nr_chunks;
	u64 length;

	/*
	 * Only useful for the RB tree - since the alloc may have discontiguous
	 * pages the base is essentially irrelevant except for the fact that it
	 * is guarenteed to be unique.
	 */
	u64 base;

	struct nvgpu_rbtree_node tree_entry;

	/*
	 * Set if this is a slab alloc. Points back to the slab page that owns
	 * this particular allocation. nr_chunks will always be 1 if this is
	 * set.
	 */
	struct page_alloc_slab_page *slab_page;
};

static inline struct nvgpu_page_alloc *
nvgpu_page_alloc_from_rbtree_node(struct nvgpu_rbtree_node *node)
{
	return (struct nvgpu_page_alloc *)
	      ((uintptr_t)node - offsetof(struct nvgpu_page_alloc, tree_entry));
};

struct nvgpu_page_allocator {
	struct nvgpu_allocator *owner;	/* Owner of this allocator. */

	/*
	 * Use a buddy allocator to manage the allocation of the underlying
	 * pages. This lets us abstract the discontiguous allocation handling
	 * out of the annoyingly complicated buddy allocator.
	 */
	struct nvgpu_allocator source_allocator;

	/*
	 * Page params.
	 */
	u64 base;
	u64 length;
	u64 page_size;
	u32 page_shift;

	struct nvgpu_rbtree_node *allocs;	/* Outstanding allocations. */

	struct page_alloc_slab *slabs;
	int nr_slabs;

	struct nvgpu_kmem_cache *alloc_cache;
	struct nvgpu_kmem_cache *slab_page_cache;

	u64 flags;

	/*
	 * Stat tracking.
	 */
	u64 nr_allocs;
	u64 nr_frees;
	u64 nr_fixed_allocs;
	u64 nr_fixed_frees;
	u64 nr_slab_allocs;
	u64 nr_slab_frees;
	u64 pages_alloced;
	u64 pages_freed;
};

static inline struct nvgpu_page_allocator *page_allocator(
	struct nvgpu_allocator *a)
{
	return (struct nvgpu_page_allocator *)(a)->priv;
}

static inline struct nvgpu_allocator *palloc_owner(
	struct nvgpu_page_allocator *a)
{
	return a->owner;
}

#endif