hw/soc_dma.c

   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-common.h"
  21 #include "qemu-timer.h"
  22 #include "soc_dma.h"
  23
  24 static void transfer_mem2mem(struct soc_dma_ch_s *ch)
  25 {
  26     memcpy(ch->paddr[0], ch->paddr[1], ch->bytes);
  27     ch->paddr[0] += ch->bytes;
  28     ch->paddr[1] += ch->bytes;
  29 }
  30
  31 static void transfer_mem2fifo(struct soc_dma_ch_s *ch)
  32 {
  33     ch->io_fn[1](ch->io_opaque[1], ch->paddr[0], ch->bytes);
  34     ch->paddr[0] += ch->bytes;
  35 }
  36
  37 static void transfer_fifo2mem(struct soc_dma_ch_s *ch)
  38 {
  39     ch->io_fn[0](ch->io_opaque[0], ch->paddr[1], ch->bytes);
  40     ch->paddr[1] += ch->bytes;
  41 }
  42
  43 /* This is further optimisable but isn't very important because often
  44  * DMA peripherals forbid this kind of transfers and even when they don't,
  45  * oprating systems may not need to use them.  */
  46 static void *fifo_buf;
  47 static int fifo_size;
  48 static void transfer_fifo2fifo(struct soc_dma_ch_s *ch)
  49 {
  50     if (ch->bytes > fifo_size)
  51         fifo_buf = qemu_realloc(fifo_buf, fifo_size = ch->bytes);
  52
  53     /* Implement as transfer_fifo2linear + transfer_linear2fifo.  */
  54     ch->io_fn[0](ch->io_opaque[0], fifo_buf, ch->bytes);
  55     ch->io_fn[1](ch->io_opaque[1], fifo_buf, ch->bytes);
  56 }
  57
  58 struct dma_s {
  59     struct soc_dma_s soc;
  60     int chnum;
  61     uint64_t ch_enable_mask;
  62     int64_t channel_freq;
  63     int enabled_count;
  64
  65     struct memmap_entry_s {
  66         enum soc_dma_port_type type;
  67         target_phys_addr_t addr;
  68         union {
  69            struct {
  70                void *opaque;
  71                soc_dma_io_t fn;
  72                int out;
  73            } fifo;
  74            struct {
  75                void *base;
  76                size_t size;
  77            } mem;
  78         } u;
  79     } *memmap;
  80     int memmap_size;
  81
  82     struct soc_dma_ch_s ch[0];
  83 };
  84
  85 static void soc_dma_ch_schedule(struct soc_dma_ch_s *ch, int delay_bytes)
  86 {
  87     int64_t now = qemu_get_clock(vm_clock);
  88     struct dma_s *dma = (struct dma_s *) ch->dma;
  89
  90     qemu_mod_timer(ch->timer, now + delay_bytes / dma->channel_freq);
  91 }
  92
  93 static void soc_dma_ch_run(void *opaque)
  94 {
  95     struct soc_dma_ch_s *ch = (struct soc_dma_ch_s *) opaque;
  96
  97     ch->running = 1;
  98     ch->dma->setup_fn(ch);
  99     ch->transfer_fn(ch);
 100     ch->running = 0;
 101
 102     if (ch->enable)
 103         soc_dma_ch_schedule(ch, ch->bytes);
 104     ch->bytes = 0;
 105 }
 106
 107 static inline struct memmap_entry_s *soc_dma_lookup(struct dma_s *dma,
 108                 target_phys_addr_t addr)
 109 {
 110     struct memmap_entry_s *lo;
 111     int hi;
 112
 113     lo = dma->memmap;
 114     hi = dma->memmap_size;
 115
 116     while (hi > 1) {
 117         hi /= 2;
 118         if (lo[hi].addr <= addr)
 119             lo += hi;
 120     }
 121
 122     return lo;
 123 }
 124
 125 static inline enum soc_dma_port_type soc_dma_ch_update_type(
 126                 struct soc_dma_ch_s *ch, int port)
 127 {
 128     struct dma_s *dma = (struct dma_s *) ch->dma;
 129     struct memmap_entry_s *entry = soc_dma_lookup(dma, ch->vaddr[port]);
 130
 131     if (entry->type == soc_dma_port_fifo) {
 132         while (entry < dma->memmap + dma->memmap_size &&
 133                         entry->u.fifo.out != port)
 134             entry ++;
 135         if (entry->addr != ch->vaddr[port] || entry->u.fifo.out != port)
 136             return soc_dma_port_other;
 137
 138         if (ch->type[port] != soc_dma_access_const)
 139             return soc_dma_port_other;
 140
 141         ch->io_fn[port] = entry->u.fifo.fn;
 142         ch->io_opaque[port] = entry->u.fifo.opaque;
 143         return soc_dma_port_fifo;
 144     } else if (entry->type == soc_dma_port_mem) {
 145         if (entry->addr > ch->vaddr[port] ||
 146                         entry->addr + entry->u.mem.size <= ch->vaddr[port])
 147             return soc_dma_port_other;
 148
 149         /* TODO: support constant memory address for source port as used for
 150          * drawing solid rectangles by PalmOS(R).  */
 151         if (ch->type[port] != soc_dma_access_const)
 152             return soc_dma_port_other;
 153
 154         ch->paddr[port] = (uint8_t *) entry->u.mem.base +
 155                 (ch->vaddr[port] - entry->addr);
 156         /* TODO: save bytes left to the end of the mapping somewhere so we
 157          * can check we're not reading beyond it.  */
 158         return soc_dma_port_mem;
 159     } else
 160         return soc_dma_port_other;
 161 }
 162
 163 void soc_dma_ch_update(struct soc_dma_ch_s *ch)
 164 {
 165     enum soc_dma_port_type src, dst;
 166
 167     src = soc_dma_ch_update_type(ch, 0);
 168     if (src == soc_dma_port_other) {
 169         ch->update = 0;
 170         ch->transfer_fn = ch->dma->transfer_fn;
 171         return;
 172     }
 173     dst = soc_dma_ch_update_type(ch, 1);
 174
 175     /* TODO: use src and dst as array indices.  */
 176     if (src == soc_dma_port_mem && dst == soc_dma_port_mem)
 177         ch->transfer_fn = transfer_mem2mem;
 178     else if (src == soc_dma_port_mem && dst == soc_dma_port_fifo)
 179         ch->transfer_fn = transfer_mem2fifo;
 180     else if (src == soc_dma_port_fifo && dst == soc_dma_port_mem)
 181         ch->transfer_fn = transfer_fifo2mem;
 182     else if (src == soc_dma_port_fifo && dst == soc_dma_port_fifo)
 183         ch->transfer_fn = transfer_fifo2fifo;
 184     else
 185         ch->transfer_fn = ch->dma->transfer_fn;
 186
 187     ch->update = (dst != soc_dma_port_other);
 188 }
 189
 190 static void soc_dma_ch_freq_update(struct dma_s *s)
 191 {
 192     if (s->enabled_count)
 193         /* We completely ignore channel priorities and stuff */
 194         s->channel_freq = s->soc.freq / s->enabled_count;
 195     else {
 196         /* TODO: Signal that we want to disable the functional clock and let
 197          * the platform code decide what to do with it, i.e. check that
 198          * auto-idle is enabled in the clock controller and if we are stopping
 199          * the clock, do the same with any parent clocks that had only one
 200          * user keeping them on and auto-idle enabled.  */
 201     }
 202 }
 203
 204 void soc_dma_set_request(struct soc_dma_ch_s *ch, int level)
 205 {
 206     struct dma_s *dma = (struct dma_s *) ch->dma;
 207
 208     dma->enabled_count += level - ch->enable;
 209
 210     if (level)
 211         dma->ch_enable_mask |= 1 << ch->num;
 212     else
 213         dma->ch_enable_mask &= ~(1 << ch->num);
 214
 215     if (level != ch->enable) {
 216         soc_dma_ch_freq_update(dma);
 217         ch->enable = level;
 218
 219         if (!ch->enable)
 220             qemu_del_timer(ch->timer);
 221         else if (!ch->running)
 222             soc_dma_ch_run(ch);
 223         else
 224             soc_dma_ch_schedule(ch, 1);
 225     }
 226 }
 227
 228 void soc_dma_reset(struct soc_dma_s *soc)
 229 {
 230     struct dma_s *s = (struct dma_s *) soc;
 231
 232     s->soc.drqbmp = 0;
 233     s->ch_enable_mask = 0;
 234     s->enabled_count = 0;
 235     soc_dma_ch_freq_update(s);
 236 }
 237
 238 /* TODO: take a functional-clock argument */
 239 struct soc_dma_s *soc_dma_init(int n)
 240 {
 241     int i;
 242     struct dma_s *s = qemu_mallocz(sizeof(*s) + n * sizeof(*s->ch));
 243
 244     s->chnum = n;
 245     s->soc.ch = s->ch;
 246     for (i = 0; i < n; i ++) {
 247         s->ch[i].dma = &s->soc;
 248         s->ch[i].num = i;
 249         s->ch[i].timer = qemu_new_timer(vm_clock, soc_dma_ch_run, &s->ch[i]);
 250     }
 251
 252     soc_dma_reset(&s->soc);
 253     fifo_size = 0;
 254
 255     return &s->soc;
 256 }
 257
 258 void soc_dma_port_add_fifo(struct soc_dma_s *soc, target_phys_addr_t virt_base,
 259                 soc_dma_io_t fn, void *opaque, int out)
 260 {
 261     struct memmap_entry_s *entry;
 262     struct dma_s *dma = (struct dma_s *) soc;
 263
 264     dma->memmap = qemu_realloc(dma->memmap, sizeof(*entry) *
 265                     (dma->memmap_size + 1));
 266     entry = soc_dma_lookup(dma, virt_base);
 267
 268     if (dma->memmap_size) {
 269         if (entry->type == soc_dma_port_mem) {
 270             if (entry->addr <= virt_base &&
 271                             entry->addr + entry->u.mem.size > virt_base) {
 272                 fprintf(stderr, "%s: FIFO at " TARGET_FMT_lx
 273                                 " collides with RAM region at " TARGET_FMT_lx
 274                                 "-" TARGET_FMT_lx "\n", __FUNCTION__,
 275                                 (target_ulong) virt_base,
 276                                 (target_ulong) entry->addr, (target_ulong)
 277                                 (entry->addr + entry->u.mem.size));
 278                 exit(-1);
 279             }
 280
 281             if (entry->addr <= virt_base)
 282                 entry ++;
 283         } else
 284             while (entry < dma->memmap + dma->memmap_size &&
 285                             entry->addr <= virt_base) {
 286                 if (entry->addr == virt_base && entry->u.fifo.out == out) {
 287                     fprintf(stderr, "%s: FIFO at " TARGET_FMT_lx
 288                                     " collides FIFO at " TARGET_FMT_lx "\n",
 289                                     __FUNCTION__, (target_ulong) virt_base,
 290                                     (target_ulong) 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                 target_phys_addr_t 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 = qemu_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                 fprintf(stderr, "%s: RAM at " TARGET_FMT_lx "-" TARGET_FMT_lx
 326                                 " collides with RAM region at " TARGET_FMT_lx
 327                                 "-" TARGET_FMT_lx "\n", __FUNCTION__,
 328                                 (target_ulong) virt_base,
 329                                 (target_ulong) (virt_base + size),
 330                                 (target_ulong) entry->addr, (target_ulong)
 331                                 (entry->addr + entry->u.mem.size));
 332                 exit(-1);
 333             }
 334
 335             if (entry->addr <= virt_base)
 336                 entry ++;
 337         } else {
 338             if (entry->addr >= virt_base &&
 339                             entry->addr < virt_base + size) {
 340                 fprintf(stderr, "%s: RAM at " TARGET_FMT_lx "-" TARGET_FMT_lx
 341                                 " collides with FIFO at " TARGET_FMT_lx
 342                                 "\n", __FUNCTION__,
 343                                 (target_ulong) virt_base,
 344                                 (target_ulong) (virt_base + size),
 345                                 (target_ulong) entry->addr);
 346                 exit(-1);
 347             }
 348
 349             while (entry < dma->memmap + dma->memmap_size &&
 350                             entry->addr <= virt_base)
 351                 entry ++;
 352         }
 353
 354         memmove(entry + 1, entry,
 355                         (uint8_t *) (dma->memmap + dma->memmap_size ++) -
 356                         (uint8_t *) entry);
 357     } else
 358         dma->memmap_size ++;
 359
 360     entry->addr          = virt_base;
 361     entry->type          = soc_dma_port_mem;
 362     entry->u.mem.base    = phys_base;
 363     entry->u.mem.size    = size;
 364 }
 365
 366 /* TODO: port removal for ports like PCMCIA memory */