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21#include <linux/init.h>
22#include <linux/module.h>
23#include <linux/errno.h>
24#include <linux/sched.h>
25#include <linux/wait.h>
26#include <linux/bitmap.h>
27#include <linux/slab.h>
28#include "tcm.h"
29
30static unsigned long mask[8];
31
32
33
34
35
36
37
38static void free_slots(unsigned long pos, uint16_t w, uint16_t h,
39 unsigned long *map, uint16_t stride)
40{
41 int i;
42
43 for (i = 0; i < h; i++, pos += stride)
44 bitmap_clear(map, pos, w);
45}
46
47
48
49
50
51
52
53static int r2l_b2t_1d(uint16_t w, unsigned long *pos, unsigned long *map,
54 size_t num_bits)
55{
56 unsigned long search_count = 0;
57 unsigned long bit;
58 bool area_found = false;
59
60 *pos = num_bits - w;
61
62 while (search_count < num_bits) {
63 bit = find_next_bit(map, num_bits, *pos);
64
65 if (bit - *pos >= w) {
66
67 bitmap_set(map, *pos, w);
68 area_found = true;
69 break;
70 }
71
72 search_count = num_bits - bit + w;
73 *pos = bit - w;
74 }
75
76 return (area_found) ? 0 : -ENOMEM;
77}
78
79
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87
88
89static int l2r_t2b(uint16_t w, uint16_t h, uint16_t a, int16_t offset,
90 unsigned long *pos, unsigned long slot_bytes,
91 unsigned long *map, size_t num_bits, size_t slot_stride)
92{
93 int i;
94 unsigned long index;
95 bool area_free;
96 unsigned long slots_per_band = PAGE_SIZE / slot_bytes;
97 unsigned long bit_offset = (offset > 0) ? offset / slot_bytes : 0;
98 unsigned long curr_bit = bit_offset;
99
100
101
102 a = (offset > 0) ? 0 : a - 1;
103
104
105
106 while (curr_bit < num_bits) {
107 *pos = bitmap_find_next_zero_area(map, num_bits, curr_bit, w,
108 a);
109
110
111 if (bit_offset > 0 && (*pos % slots_per_band != bit_offset)) {
112 curr_bit = ALIGN(*pos, slots_per_band) + bit_offset;
113 continue;
114 }
115
116
117 if ((*pos % slot_stride) + w > slot_stride) {
118 curr_bit = ALIGN(*pos, slot_stride) + bit_offset;
119 continue;
120 }
121
122
123
124
125 if ((*pos + slot_stride * h) > num_bits)
126 break;
127
128
129 bitmap_clear(mask, 0, slot_stride);
130 bitmap_set(mask, (*pos % BITS_PER_LONG), w);
131
132
133 area_free = true;
134
135
136 for (i = 1; i < h; i++) {
137 index = *pos / BITS_PER_LONG + i * 8;
138 if (bitmap_intersects(&map[index], mask,
139 (*pos % BITS_PER_LONG) + w)) {
140 area_free = false;
141 break;
142 }
143 }
144
145 if (area_free)
146 break;
147
148
149 if (bit_offset > 0)
150 curr_bit = ALIGN(*pos, slots_per_band) + bit_offset;
151 else
152 curr_bit = *pos + a + 1;
153 }
154
155 if (area_free) {
156
157 for (i = 0, index = *pos; i < h; i++, index += slot_stride)
158 bitmap_set(map, index, w);
159 }
160
161 return (area_free) ? 0 : -ENOMEM;
162}
163
164static s32 sita_reserve_1d(struct tcm *tcm, u32 num_slots,
165 struct tcm_area *area)
166{
167 unsigned long pos;
168 int ret;
169
170 spin_lock(&(tcm->lock));
171 ret = r2l_b2t_1d(num_slots, &pos, tcm->bitmap, tcm->map_size);
172 if (!ret) {
173 area->p0.x = pos % tcm->width;
174 area->p0.y = pos / tcm->width;
175 area->p1.x = (pos + num_slots - 1) % tcm->width;
176 area->p1.y = (pos + num_slots - 1) / tcm->width;
177 }
178 spin_unlock(&(tcm->lock));
179
180 return ret;
181}
182
183static s32 sita_reserve_2d(struct tcm *tcm, u16 h, u16 w, u16 align,
184 int16_t offset, uint16_t slot_bytes,
185 struct tcm_area *area)
186{
187 unsigned long pos;
188 int ret;
189
190 spin_lock(&(tcm->lock));
191 ret = l2r_t2b(w, h, align, offset, &pos, slot_bytes, tcm->bitmap,
192 tcm->map_size, tcm->width);
193
194 if (!ret) {
195 area->p0.x = pos % tcm->width;
196 area->p0.y = pos / tcm->width;
197 area->p1.x = area->p0.x + w - 1;
198 area->p1.y = area->p0.y + h - 1;
199 }
200 spin_unlock(&(tcm->lock));
201
202 return ret;
203}
204
205static void sita_deinit(struct tcm *tcm)
206{
207 kfree(tcm);
208}
209
210static s32 sita_free(struct tcm *tcm, struct tcm_area *area)
211{
212 unsigned long pos;
213 uint16_t w, h;
214
215 pos = area->p0.x + area->p0.y * tcm->width;
216 if (area->is2d) {
217 w = area->p1.x - area->p0.x + 1;
218 h = area->p1.y - area->p0.y + 1;
219 } else {
220 w = area->p1.x + area->p1.y * tcm->width - pos + 1;
221 h = 1;
222 }
223
224 spin_lock(&(tcm->lock));
225 free_slots(pos, w, h, tcm->bitmap, tcm->width);
226 spin_unlock(&(tcm->lock));
227 return 0;
228}
229
230struct tcm *sita_init(u16 width, u16 height)
231{
232 struct tcm *tcm;
233 size_t map_size = BITS_TO_LONGS(width*height) * sizeof(unsigned long);
234
235 if (width == 0 || height == 0)
236 return NULL;
237
238 tcm = kzalloc(sizeof(*tcm) + map_size, GFP_KERNEL);
239 if (!tcm)
240 goto error;
241
242
243 tcm->height = height;
244 tcm->width = width;
245 tcm->reserve_2d = sita_reserve_2d;
246 tcm->reserve_1d = sita_reserve_1d;
247 tcm->free = sita_free;
248 tcm->deinit = sita_deinit;
249
250 spin_lock_init(&tcm->lock);
251 tcm->bitmap = (unsigned long *)(tcm + 1);
252 bitmap_clear(tcm->bitmap, 0, width*height);
253
254 tcm->map_size = width*height;
255
256 return tcm;
257
258error:
259 kfree(tcm);
260 return NULL;
261}
262