xref: /openbmc/qemu/hw/dma/soc_dma.c (revision 8cf108c5)
1 /*
2  * On-chip DMA controller framework.
3  *
4  * Copyright (C) 2008 Nokia Corporation
5  * Written by Andrzej Zaborowski <andrew@openedhand.com>
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as
9  * published by the Free Software Foundation; either version 2 or
10  * (at your option) version 3 of the License.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License along
18  * with this program; if not, see <http://www.gnu.org/licenses/>.
19  */
20 #include "qemu/osdep.h"
21 #include "qemu/error-report.h"
22 #include "qemu-common.h"
23 #include "qemu/timer.h"
24 #include "hw/arm/soc_dma.h"
25 
26 static void transfer_mem2mem(struct soc_dma_ch_s *ch)
27 {
28     memcpy(ch->paddr[0], ch->paddr[1], ch->bytes);
29     ch->paddr[0] += ch->bytes;
30     ch->paddr[1] += ch->bytes;
31 }
32 
33 static void transfer_mem2fifo(struct soc_dma_ch_s *ch)
34 {
35     ch->io_fn[1](ch->io_opaque[1], ch->paddr[0], ch->bytes);
36     ch->paddr[0] += ch->bytes;
37 }
38 
39 static void transfer_fifo2mem(struct soc_dma_ch_s *ch)
40 {
41     ch->io_fn[0](ch->io_opaque[0], ch->paddr[1], ch->bytes);
42     ch->paddr[1] += ch->bytes;
43 }
44 
45 /* This is further optimisable but isn't very important because often
46  * DMA peripherals forbid this kind of transfers and even when they don't,
47  * oprating systems may not need to use them.  */
48 static void *fifo_buf;
49 static int fifo_size;
50 static void transfer_fifo2fifo(struct soc_dma_ch_s *ch)
51 {
52     if (ch->bytes > fifo_size)
53         fifo_buf = g_realloc(fifo_buf, fifo_size = ch->bytes);
54 
55     /* Implement as transfer_fifo2linear + transfer_linear2fifo.  */
56     ch->io_fn[0](ch->io_opaque[0], fifo_buf, ch->bytes);
57     ch->io_fn[1](ch->io_opaque[1], fifo_buf, ch->bytes);
58 }
59 
60 struct dma_s {
61     struct soc_dma_s soc;
62     int chnum;
63     uint64_t ch_enable_mask;
64     int64_t channel_freq;
65     int enabled_count;
66 
67     struct memmap_entry_s {
68         enum soc_dma_port_type type;
69         hwaddr addr;
70         union {
71            struct {
72                void *opaque;
73                soc_dma_io_t fn;
74                int out;
75            } fifo;
76            struct {
77                void *base;
78                size_t size;
79            } mem;
80         } u;
81     } *memmap;
82     int memmap_size;
83 
84     struct soc_dma_ch_s ch[0];
85 };
86 
87 static void soc_dma_ch_schedule(struct soc_dma_ch_s *ch, int delay_bytes)
88 {
89     int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
90     struct dma_s *dma = (struct dma_s *) ch->dma;
91 
92     timer_mod(ch->timer, now + delay_bytes / dma->channel_freq);
93 }
94 
95 static void soc_dma_ch_run(void *opaque)
96 {
97     struct soc_dma_ch_s *ch = (struct soc_dma_ch_s *) opaque;
98 
99     ch->running = 1;
100     ch->dma->setup_fn(ch);
101     ch->transfer_fn(ch);
102     ch->running = 0;
103 
104     if (ch->enable)
105         soc_dma_ch_schedule(ch, ch->bytes);
106     ch->bytes = 0;
107 }
108 
109 static inline struct memmap_entry_s *soc_dma_lookup(struct dma_s *dma,
110                 hwaddr addr)
111 {
112     struct memmap_entry_s *lo;
113     int hi;
114 
115     lo = dma->memmap;
116     hi = dma->memmap_size;
117 
118     while (hi > 1) {
119         hi /= 2;
120         if (lo[hi].addr <= addr)
121             lo += hi;
122     }
123 
124     return lo;
125 }
126 
127 static inline enum soc_dma_port_type soc_dma_ch_update_type(
128                 struct soc_dma_ch_s *ch, int port)
129 {
130     struct dma_s *dma = (struct dma_s *) ch->dma;
131     struct memmap_entry_s *entry = soc_dma_lookup(dma, ch->vaddr[port]);
132 
133     if (entry->type == soc_dma_port_fifo) {
134         while (entry < dma->memmap + dma->memmap_size &&
135                         entry->u.fifo.out != port)
136             entry ++;
137         if (entry->addr != ch->vaddr[port] || entry->u.fifo.out != port)
138             return soc_dma_port_other;
139 
140         if (ch->type[port] != soc_dma_access_const)
141             return soc_dma_port_other;
142 
143         ch->io_fn[port] = entry->u.fifo.fn;
144         ch->io_opaque[port] = entry->u.fifo.opaque;
145         return soc_dma_port_fifo;
146     } else if (entry->type == soc_dma_port_mem) {
147         if (entry->addr > ch->vaddr[port] ||
148                         entry->addr + entry->u.mem.size <= ch->vaddr[port])
149             return soc_dma_port_other;
150 
151         /* TODO: support constant memory address for source port as used for
152          * drawing solid rectangles by PalmOS(R).  */
153         if (ch->type[port] != soc_dma_access_const)
154             return soc_dma_port_other;
155 
156         ch->paddr[port] = (uint8_t *) entry->u.mem.base +
157                 (ch->vaddr[port] - entry->addr);
158         /* TODO: save bytes left to the end of the mapping somewhere so we
159          * can check we're not reading beyond it.  */
160         return soc_dma_port_mem;
161     } else
162         return soc_dma_port_other;
163 }
164 
165 void soc_dma_ch_update(struct soc_dma_ch_s *ch)
166 {
167     enum soc_dma_port_type src, dst;
168 
169     src = soc_dma_ch_update_type(ch, 0);
170     if (src == soc_dma_port_other) {
171         ch->update = 0;
172         ch->transfer_fn = ch->dma->transfer_fn;
173         return;
174     }
175     dst = soc_dma_ch_update_type(ch, 1);
176 
177     /* TODO: use src and dst as array indices.  */
178     if (src == soc_dma_port_mem && dst == soc_dma_port_mem)
179         ch->transfer_fn = transfer_mem2mem;
180     else if (src == soc_dma_port_mem && dst == soc_dma_port_fifo)
181         ch->transfer_fn = transfer_mem2fifo;
182     else if (src == soc_dma_port_fifo && dst == soc_dma_port_mem)
183         ch->transfer_fn = transfer_fifo2mem;
184     else if (src == soc_dma_port_fifo && dst == soc_dma_port_fifo)
185         ch->transfer_fn = transfer_fifo2fifo;
186     else
187         ch->transfer_fn = ch->dma->transfer_fn;
188 
189     ch->update = (dst != soc_dma_port_other);
190 }
191 
192 static void soc_dma_ch_freq_update(struct dma_s *s)
193 {
194     if (s->enabled_count)
195         /* We completely ignore channel priorities and stuff */
196         s->channel_freq = s->soc.freq / s->enabled_count;
197     else {
198         /* TODO: Signal that we want to disable the functional clock and let
199          * the platform code decide what to do with it, i.e. check that
200          * auto-idle is enabled in the clock controller and if we are stopping
201          * the clock, do the same with any parent clocks that had only one
202          * user keeping them on and auto-idle enabled.  */
203     }
204 }
205 
206 void soc_dma_set_request(struct soc_dma_ch_s *ch, int level)
207 {
208     struct dma_s *dma = (struct dma_s *) ch->dma;
209 
210     dma->enabled_count += level - ch->enable;
211 
212     if (level)
213         dma->ch_enable_mask |= 1 << ch->num;
214     else
215         dma->ch_enable_mask &= ~(1 << ch->num);
216 
217     if (level != ch->enable) {
218         soc_dma_ch_freq_update(dma);
219         ch->enable = level;
220 
221         if (!ch->enable)
222             timer_del(ch->timer);
223         else if (!ch->running)
224             soc_dma_ch_run(ch);
225         else
226             soc_dma_ch_schedule(ch, 1);
227     }
228 }
229 
230 void soc_dma_reset(struct soc_dma_s *soc)
231 {
232     struct dma_s *s = (struct dma_s *) soc;
233 
234     s->soc.drqbmp = 0;
235     s->ch_enable_mask = 0;
236     s->enabled_count = 0;
237     soc_dma_ch_freq_update(s);
238 }
239 
240 /* TODO: take a functional-clock argument */
241 struct soc_dma_s *soc_dma_init(int n)
242 {
243     int i;
244     struct dma_s *s = g_malloc0(sizeof(*s) + n * sizeof(*s->ch));
245 
246     s->chnum = n;
247     s->soc.ch = s->ch;
248     for (i = 0; i < n; i ++) {
249         s->ch[i].dma = &s->soc;
250         s->ch[i].num = i;
251         s->ch[i].timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, soc_dma_ch_run, &s->ch[i]);
252     }
253 
254     soc_dma_reset(&s->soc);
255     fifo_size = 0;
256 
257     return &s->soc;
258 }
259 
260 void soc_dma_port_add_fifo(struct soc_dma_s *soc, hwaddr virt_base,
261                 soc_dma_io_t fn, void *opaque, int out)
262 {
263     struct memmap_entry_s *entry;
264     struct dma_s *dma = (struct dma_s *) soc;
265 
266     dma->memmap = g_realloc(dma->memmap, sizeof(*entry) *
267                     (dma->memmap_size + 1));
268     entry = soc_dma_lookup(dma, virt_base);
269 
270     if (dma->memmap_size) {
271         if (entry->type == soc_dma_port_mem) {
272             if (entry->addr <= virt_base &&
273                             entry->addr + entry->u.mem.size > virt_base) {
274                 error_report("%s: FIFO at %"PRIx64
275                              " collides with RAM region at %"PRIx64
276                              "-%"PRIx64, __func__,
277                              virt_base, entry->addr,
278                              (entry->addr + entry->u.mem.size));
279                 exit(-1);
280             }
281 
282             if (entry->addr <= virt_base)
283                 entry ++;
284         } else
285             while (entry < dma->memmap + dma->memmap_size &&
286                             entry->addr <= virt_base) {
287                 if (entry->addr == virt_base && entry->u.fifo.out == out) {
288                     error_report("%s: FIFO at %"PRIx64
289                                  " collides FIFO at %"PRIx64,
290                                  __func__, virt_base, entry->addr);
291                     exit(-1);
292                 }
293 
294                 entry ++;
295             }
296 
297         memmove(entry + 1, entry,
298                         (uint8_t *) (dma->memmap + dma->memmap_size ++) -
299                         (uint8_t *) entry);
300     } else
301         dma->memmap_size ++;
302 
303     entry->addr          = virt_base;
304     entry->type          = soc_dma_port_fifo;
305     entry->u.fifo.fn     = fn;
306     entry->u.fifo.opaque = opaque;
307     entry->u.fifo.out    = out;
308 }
309 
310 void soc_dma_port_add_mem(struct soc_dma_s *soc, uint8_t *phys_base,
311                 hwaddr virt_base, size_t size)
312 {
313     struct memmap_entry_s *entry;
314     struct dma_s *dma = (struct dma_s *) soc;
315 
316     dma->memmap = g_realloc(dma->memmap, sizeof(*entry) *
317                     (dma->memmap_size + 1));
318     entry = soc_dma_lookup(dma, virt_base);
319 
320     if (dma->memmap_size) {
321         if (entry->type == soc_dma_port_mem) {
322             if ((entry->addr >= virt_base && entry->addr < virt_base + size) ||
323                             (entry->addr <= virt_base &&
324                              entry->addr + entry->u.mem.size > virt_base)) {
325                 error_report("%s: RAM at %"PRIx64 "-%"PRIx64
326                              " collides with RAM region at %"PRIx64
327                              "-%"PRIx64, __func__,
328                              virt_base, virt_base + size,
329                              entry->addr, entry->addr + entry->u.mem.size);
330                 exit(-1);
331             }
332 
333             if (entry->addr <= virt_base)
334                 entry ++;
335         } else {
336             if (entry->addr >= virt_base &&
337                             entry->addr < virt_base + size) {
338                 error_report("%s: RAM at %"PRIx64 "-%"PRIx64
339                              " collides with FIFO at %"PRIx64,
340                              __func__, virt_base, virt_base + size,
341                              entry->addr);
342                 exit(-1);
343             }
344 
345             while (entry < dma->memmap + dma->memmap_size &&
346                             entry->addr <= virt_base)
347                 entry ++;
348         }
349 
350         memmove(entry + 1, entry,
351                         (uint8_t *) (dma->memmap + dma->memmap_size ++) -
352                         (uint8_t *) entry);
353     } else
354         dma->memmap_size ++;
355 
356     entry->addr          = virt_base;
357     entry->type          = soc_dma_port_mem;
358     entry->u.mem.base    = phys_base;
359     entry->u.mem.size    = size;
360 }
361 
362 /* TODO: port removal for ports like PCMCIA memory */
363