1/*
2 * Copyright 2012 Red Hat Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
21 *
22 * Authors: Ben Skeggs
23 */
24#include <core/mm.h>
25
26#define node(root, dir) ((root)->nl_entry.dir == &mm->nodes) ? NULL :          \
27	list_entry((root)->nl_entry.dir, struct nvkm_mm_node, nl_entry)
28
29static void
30nvkm_mm_dump(struct nvkm_mm *mm, const char *header)
31{
32	struct nvkm_mm_node *node;
33
34	printk(KERN_ERR "nvkm: %s\n", header);
35	printk(KERN_ERR "nvkm: node list:\n");
36	list_for_each_entry(node, &mm->nodes, nl_entry) {
37		printk(KERN_ERR "nvkm: \t%08x %08x %d\n",
38		       node->offset, node->length, node->type);
39	}
40	printk(KERN_ERR "nvkm: free list:\n");
41	list_for_each_entry(node, &mm->free, fl_entry) {
42		printk(KERN_ERR "nvkm: \t%08x %08x %d\n",
43		       node->offset, node->length, node->type);
44	}
45}
46
47void
48nvkm_mm_free(struct nvkm_mm *mm, struct nvkm_mm_node **pthis)
49{
50	struct nvkm_mm_node *this = *pthis;
51
52	if (this) {
53		struct nvkm_mm_node *prev = node(this, prev);
54		struct nvkm_mm_node *next = node(this, next);
55
56		if (prev && prev->type == NVKM_MM_TYPE_NONE) {
57			prev->length += this->length;
58			list_del(&this->nl_entry);
59			kfree(this); this = prev;
60		}
61
62		if (next && next->type == NVKM_MM_TYPE_NONE) {
63			next->offset  = this->offset;
64			next->length += this->length;
65			if (this->type == NVKM_MM_TYPE_NONE)
66				list_del(&this->fl_entry);
67			list_del(&this->nl_entry);
68			kfree(this); this = NULL;
69		}
70
71		if (this && this->type != NVKM_MM_TYPE_NONE) {
72			list_for_each_entry(prev, &mm->free, fl_entry) {
73				if (this->offset < prev->offset)
74					break;
75			}
76
77			list_add_tail(&this->fl_entry, &prev->fl_entry);
78			this->type = NVKM_MM_TYPE_NONE;
79		}
80	}
81
82	*pthis = NULL;
83}
84
85static struct nvkm_mm_node *
86region_head(struct nvkm_mm *mm, struct nvkm_mm_node *a, u32 size)
87{
88	struct nvkm_mm_node *b;
89
90	if (a->length == size)
91		return a;
92
93	b = kmalloc(sizeof(*b), GFP_KERNEL);
94	if (unlikely(b == NULL))
95		return NULL;
96
97	b->offset = a->offset;
98	b->length = size;
99	b->heap   = a->heap;
100	b->type   = a->type;
101	a->offset += size;
102	a->length -= size;
103	list_add_tail(&b->nl_entry, &a->nl_entry);
104	if (b->type == NVKM_MM_TYPE_NONE)
105		list_add_tail(&b->fl_entry, &a->fl_entry);
106
107	return b;
108}
109
110int
111nvkm_mm_head(struct nvkm_mm *mm, u8 heap, u8 type, u32 size_max, u32 size_min,
112	     u32 align, struct nvkm_mm_node **pnode)
113{
114	struct nvkm_mm_node *prev, *this, *next;
115	u32 mask = align - 1;
116	u32 splitoff;
117	u32 s, e;
118
119	BUG_ON(type == NVKM_MM_TYPE_NONE || type == NVKM_MM_TYPE_HOLE);
120
121	list_for_each_entry(this, &mm->free, fl_entry) {
122		if (unlikely(heap != NVKM_MM_HEAP_ANY)) {
123			if (this->heap != heap)
124				continue;
125		}
126		e = this->offset + this->length;
127		s = this->offset;
128
129		prev = node(this, prev);
130		if (prev && prev->type != type)
131			s = roundup(s, mm->block_size);
132
133		next = node(this, next);
134		if (next && next->type != type)
135			e = rounddown(e, mm->block_size);
136
137		s  = (s + mask) & ~mask;
138		e &= ~mask;
139		if (s > e || e - s < size_min)
140			continue;
141
142		splitoff = s - this->offset;
143		if (splitoff && !region_head(mm, this, splitoff))
144			return -ENOMEM;
145
146		this = region_head(mm, this, min(size_max, e - s));
147		if (!this)
148			return -ENOMEM;
149
150		this->type = type;
151		list_del(&this->fl_entry);
152		*pnode = this;
153		return 0;
154	}
155
156	return -ENOSPC;
157}
158
159static struct nvkm_mm_node *
160region_tail(struct nvkm_mm *mm, struct nvkm_mm_node *a, u32 size)
161{
162	struct nvkm_mm_node *b;
163
164	if (a->length == size)
165		return a;
166
167	b = kmalloc(sizeof(*b), GFP_KERNEL);
168	if (unlikely(b == NULL))
169		return NULL;
170
171	a->length -= size;
172	b->offset  = a->offset + a->length;
173	b->length  = size;
174	b->heap    = a->heap;
175	b->type    = a->type;
176
177	list_add(&b->nl_entry, &a->nl_entry);
178	if (b->type == NVKM_MM_TYPE_NONE)
179		list_add(&b->fl_entry, &a->fl_entry);
180
181	return b;
182}
183
184int
185nvkm_mm_tail(struct nvkm_mm *mm, u8 heap, u8 type, u32 size_max, u32 size_min,
186	     u32 align, struct nvkm_mm_node **pnode)
187{
188	struct nvkm_mm_node *prev, *this, *next;
189	u32 mask = align - 1;
190
191	BUG_ON(type == NVKM_MM_TYPE_NONE || type == NVKM_MM_TYPE_HOLE);
192
193	list_for_each_entry_reverse(this, &mm->free, fl_entry) {
194		u32 e = this->offset + this->length;
195		u32 s = this->offset;
196		u32 c = 0, a;
197		if (unlikely(heap != NVKM_MM_HEAP_ANY)) {
198			if (this->heap != heap)
199				continue;
200		}
201
202		prev = node(this, prev);
203		if (prev && prev->type != type)
204			s = roundup(s, mm->block_size);
205
206		next = node(this, next);
207		if (next && next->type != type) {
208			e = rounddown(e, mm->block_size);
209			c = next->offset - e;
210		}
211
212		s = (s + mask) & ~mask;
213		a = e - s;
214		if (s > e || a < size_min)
215			continue;
216
217		a  = min(a, size_max);
218		s  = (e - a) & ~mask;
219		c += (e - s) - a;
220
221		if (c && !region_tail(mm, this, c))
222			return -ENOMEM;
223
224		this = region_tail(mm, this, a);
225		if (!this)
226			return -ENOMEM;
227
228		this->type = type;
229		list_del(&this->fl_entry);
230		*pnode = this;
231		return 0;
232	}
233
234	return -ENOSPC;
235}
236
237int
238nvkm_mm_init(struct nvkm_mm *mm, u32 offset, u32 length, u32 block)
239{
240	struct nvkm_mm_node *node, *prev;
241	u32 next;
242
243	if (nvkm_mm_initialised(mm)) {
244		prev = list_last_entry(&mm->nodes, typeof(*node), nl_entry);
245		next = prev->offset + prev->length;
246		if (next != offset) {
247			BUG_ON(next > offset);
248			if (!(node = kzalloc(sizeof(*node), GFP_KERNEL)))
249				return -ENOMEM;
250			node->type   = NVKM_MM_TYPE_HOLE;
251			node->offset = next;
252			node->length = offset - next;
253			list_add_tail(&node->nl_entry, &mm->nodes);
254		}
255		BUG_ON(block != mm->block_size);
256	} else {
257		INIT_LIST_HEAD(&mm->nodes);
258		INIT_LIST_HEAD(&mm->free);
259		mm->block_size = block;
260		mm->heap_nodes = 0;
261	}
262
263	node = kzalloc(sizeof(*node), GFP_KERNEL);
264	if (!node)
265		return -ENOMEM;
266
267	if (length) {
268		node->offset  = roundup(offset, mm->block_size);
269		node->length  = rounddown(offset + length, mm->block_size);
270		node->length -= node->offset;
271	}
272
273	list_add_tail(&node->nl_entry, &mm->nodes);
274	list_add_tail(&node->fl_entry, &mm->free);
275	node->heap = ++mm->heap_nodes;
276	return 0;
277}
278
279int
280nvkm_mm_fini(struct nvkm_mm *mm)
281{
282	struct nvkm_mm_node *node, *temp;
283	int nodes = 0;
284
285	if (!nvkm_mm_initialised(mm))
286		return 0;
287
288	list_for_each_entry(node, &mm->nodes, nl_entry) {
289		if (node->type != NVKM_MM_TYPE_HOLE) {
290			if (++nodes > mm->heap_nodes) {
291				nvkm_mm_dump(mm, "mm not clean!");
292				return -EBUSY;
293			}
294		}
295	}
296
297	list_for_each_entry_safe(node, temp, &mm->nodes, nl_entry) {
298		list_del(&node->nl_entry);
299		kfree(node);
300	}
301
302	mm->heap_nodes = 0;
303	return 0;
304}
305