arch/sandbox/cpu/state.c

   1 /*
   2  * Copyright (c) 2011-2012 The Chromium OS Authors.
   3  * SPDX-License-Identifier:     GPL-2.0+
   4  */
   5
   6 #include <common.h>
   7 #include <errno.h>
   8 #include <fdtdec.h>
   9 #include <os.h>
  10 #include <asm/state.h>
  11
  12 /* Main state record for the sandbox */
  13 static struct sandbox_state main_state;
  14 static struct sandbox_state *state;     /* Pointer to current state record */
  15
  16 static int state_ensure_space(int extra_size)
  17 {
  18         void *blob = state->state_fdt;
  19         int used, size, free;
  20         void *buf;
  21         int ret;
  22
  23         used = fdt_off_dt_strings(blob) + fdt_size_dt_strings(blob);
  24         size = fdt_totalsize(blob);
  25         free = size - used;
  26         if (free > extra_size)
  27                 return 0;
  28
  29         size = used + extra_size;
  30         buf = os_malloc(size);
  31         if (!buf)
  32                 return -ENOMEM;
  33
  34         ret = fdt_open_into(blob, buf, size);
  35         if (ret) {
  36                 os_free(buf);
  37                 return -EIO;
  38         }
  39
  40         os_free(blob);
  41         state->state_fdt = buf;
  42         return 0;
  43 }
  44
  45 static int state_read_file(struct sandbox_state *state, const char *fname)
  46 {
  47         loff_t size;
  48         int ret;
  49         int fd;
  50
  51         ret = os_get_filesize(fname, &size);
  52         if (ret < 0) {
  53                 printf("Cannot find sandbox state file '%s'\n", fname);
  54                 return -ENOENT;
  55         }
  56         state->state_fdt = os_malloc(size);
  57         if (!state->state_fdt) {
  58                 puts("No memory to read sandbox state\n");
  59                 return -ENOMEM;
  60         }
  61         fd = os_open(fname, OS_O_RDONLY);
  62         if (fd < 0) {
  63                 printf("Cannot open sandbox state file '%s'\n", fname);
  64                 ret = -EPERM;
  65                 goto err_open;
  66         }
  67         if (os_read(fd, state->state_fdt, size) != size) {
  68                 printf("Cannot read sandbox state file '%s'\n", fname);
  69                 ret = -EIO;
  70                 goto err_read;
  71         }
  72         os_close(fd);
  73
  74         return 0;
  75 err_read:
  76         os_close(fd);
  77 err_open:
  78         os_free(state->state_fdt);
  79         state->state_fdt = NULL;
  80
  81         return ret;
  82 }
  83
  84 /***
  85  * sandbox_read_state_nodes() - Read state associated with a driver
  86  *
  87  * This looks through all compatible nodes and calls the read function on
  88  * each one, to read in the state.
  89  *
  90  * If nothing is found, it still calls the read function once, to set up a
  91  * single global state for that driver.
  92  *
  93  * @state: Sandbox state
  94  * @io: Method to use for reading state
  95  * @blob: FDT containing state
  96  * @return 0 if OK, -EINVAL if the read function returned failure
  97  */
  98 int sandbox_read_state_nodes(struct sandbox_state *state,
  99                              struct sandbox_state_io *io, const void *blob)
 100 {
 101         int count;
 102         int node;
 103         int ret;
 104
 105         debug("   - read %s\n", io->name);
 106         if (!io->read)
 107                 return 0;
 108
 109         node = -1;
 110         count = 0;
 111         while (blob) {
 112                 node = fdt_node_offset_by_compatible(blob, node, io->compat);
 113                 if (node < 0)
 114                         return 0;       /* No more */
 115                 debug("   - read node '%s'\n", fdt_get_name(blob, node, NULL));
 116                 ret = io->read(blob, node);
 117                 if (ret) {
 118                         printf("Unable to read state for '%s'\n", io->compat);
 119                         return -EINVAL;
 120                 }
 121                 count++;
 122         }
 123
 124         /*
 125          * If we got no saved state, call the read function once without a
 126          * node, to set up the global state.
 127          */
 128         if (count == 0) {
 129                 debug("   - read global\n");
 130                 ret = io->read(NULL, -1);
 131                 if (ret) {
 132                         printf("Unable to read global state for '%s'\n",
 133                                io->name);
 134                         return -EINVAL;
 135                 }
 136         }
 137
 138         return 0;
 139 }
 140
 141 int sandbox_read_state(struct sandbox_state *state, const char *fname)
 142 {
 143         struct sandbox_state_io *io;
 144         const void *blob;
 145         bool got_err;
 146         int ret;
 147
 148         if (state->read_state && fname) {
 149                 ret = state_read_file(state, fname);
 150                 if (ret == -ENOENT && state->ignore_missing_state_on_read)
 151                         ret = 0;
 152                 if (ret)
 153                         return ret;
 154         }
 155
 156         /* Call all the state read functions */
 157         got_err = false;
 158         blob = state->state_fdt;
 159         io = ll_entry_start(struct sandbox_state_io, state_io);
 160         for (; io < ll_entry_end(struct sandbox_state_io, state_io); io++) {
 161                 ret = sandbox_read_state_nodes(state, io, blob);
 162                 if (ret < 0)
 163                         got_err = true;
 164         }
 165
 166         if (state->read_state && fname) {
 167                 debug("Read sandbox state from '%s'%s\n", fname,
 168                       got_err ? " (with errors)" : "");
 169         }
 170
 171         return got_err ? -1 : 0;
 172 }
 173
 174 /***
 175  * sandbox_write_state_node() - Write state associated with a driver
 176  *
 177  * This calls the write function to write out global state for that driver.
 178  *
 179  * TODO(sjg@chromium.org): Support writing out state from multiple drivers
 180  * of the same time. We don't need this yet,and it will be much easier to
 181  * do when driver model is available.
 182  *
 183  * @state: Sandbox state
 184  * @io: Method to use for writing state
 185  * @return 0 if OK, -EIO if there is a fatal error (such as out of space
 186  * for adding the data), -EINVAL if the write function failed.
 187  */
 188 int sandbox_write_state_node(struct sandbox_state *state,
 189                              struct sandbox_state_io *io)
 190 {
 191         void *blob;
 192         int node;
 193         int ret;
 194
 195         if (!io->write)
 196                 return 0;
 197
 198         ret = state_ensure_space(SANDBOX_STATE_MIN_SPACE);
 199         if (ret) {
 200                 printf("Failed to add more space for state\n");
 201                 return -EIO;
 202         }
 203
 204         /* The blob location can change when the size increases */
 205         blob = state->state_fdt;
 206         node = fdt_node_offset_by_compatible(blob, -1, io->compat);
 207         if (node == -FDT_ERR_NOTFOUND) {
 208                 node = fdt_add_subnode(blob, 0, io->name);
 209                 if (node < 0) {
 210                         printf("Cannot create node '%s': %s\n", io->name,
 211                                fdt_strerror(node));
 212                         return -EIO;
 213                 }
 214
 215                 if (fdt_setprop_string(blob, node, "compatible", io->compat)) {
 216                         puts("Cannot set compatible\n");
 217                         return -EIO;
 218                 }
 219         } else if (node < 0) {
 220                 printf("Cannot access node '%s': %s\n", io->name,
 221                        fdt_strerror(node));
 222                 return -EIO;
 223         }
 224         debug("Write state for '%s' to node %d\n", io->compat, node);
 225         ret = io->write(blob, node);
 226         if (ret) {
 227                 printf("Unable to write state for '%s'\n", io->compat);
 228                 return -EINVAL;
 229         }
 230
 231         return 0;
 232 }
 233
 234 int sandbox_write_state(struct sandbox_state *state, const char *fname)
 235 {
 236         struct sandbox_state_io *io;
 237         bool got_err;
 238         int size;
 239         int ret;
 240         int fd;
 241
 242         /* Create a state FDT if we don't have one */
 243         if (!state->state_fdt) {
 244                 size = 0x4000;
 245                 state->state_fdt = os_malloc(size);
 246                 if (!state->state_fdt) {
 247                         puts("No memory to create FDT\n");
 248                         return -ENOMEM;
 249                 }
 250                 ret = fdt_create_empty_tree(state->state_fdt, size);
 251                 if (ret < 0) {
 252                         printf("Cannot create empty state FDT: %s\n",
 253                                fdt_strerror(ret));
 254                         ret = -EIO;
 255                         goto err_create;
 256                 }
 257         }
 258
 259         /* Call all the state write funtcions */
 260         got_err = false;
 261         io = ll_entry_start(struct sandbox_state_io, state_io);
 262         ret = 0;
 263         for (; io < ll_entry_end(struct sandbox_state_io, state_io); io++) {
 264                 ret = sandbox_write_state_node(state, io);
 265                 if (ret == -EIO)
 266                         break;
 267                 else if (ret)
 268                         got_err = true;
 269         }
 270
 271         if (ret == -EIO) {
 272                 printf("Could not write sandbox state\n");
 273                 goto err_create;
 274         }
 275
 276         ret = fdt_pack(state->state_fdt);
 277         if (ret < 0) {
 278                 printf("Cannot pack state FDT: %s\n", fdt_strerror(ret));
 279                 ret = -EINVAL;
 280                 goto err_create;
 281         }
 282         size = fdt_totalsize(state->state_fdt);
 283         fd = os_open(fname, OS_O_WRONLY | OS_O_CREAT);
 284         if (fd < 0) {
 285                 printf("Cannot open sandbox state file '%s'\n", fname);
 286                 ret = -EIO;
 287                 goto err_create;
 288         }
 289         if (os_write(fd, state->state_fdt, size) != size) {
 290                 printf("Cannot write sandbox state file '%s'\n", fname);
 291                 ret = -EIO;
 292                 goto err_write;
 293         }
 294         os_close(fd);
 295
 296         debug("Wrote sandbox state to '%s'%s\n", fname,
 297               got_err ? " (with errors)" : "");
 298
 299         return 0;
 300 err_write:
 301         os_close(fd);
 302 err_create:
 303         os_free(state->state_fdt);
 304
 305         return ret;
 306 }
 307
 308 int state_setprop(int node, const char *prop_name, const void *data, int size)
 309 {
 310         void *blob;
 311         int len;
 312         int ret;
 313
 314         fdt_getprop(state->state_fdt, node, prop_name, &len);
 315
 316         /* Add space for the new property, its name and some overhead */
 317         ret = state_ensure_space(size - len + strlen(prop_name) + 32);
 318         if (ret)
 319                 return ret;
 320
 321         /* This should succeed, barring a mutiny */
 322         blob = state->state_fdt;
 323         ret = fdt_setprop(blob, node, prop_name, data, size);
 324         if (ret) {
 325                 printf("%s: Unable to set property '%s' in node '%s': %s\n",
 326                        __func__, prop_name, fdt_get_name(blob, node, NULL),
 327                         fdt_strerror(ret));
 328                 return -ENOSPC;
 329         }
 330
 331         return 0;
 332 }
 333
 334 struct sandbox_state *state_get_current(void)
 335 {
 336         assert(state);
 337         return state;
 338 }
 339
 340 void state_set_skip_delays(bool skip_delays)
 341 {
 342         struct sandbox_state *state = state_get_current();
 343
 344         state->skip_delays = skip_delays;
 345 }
 346
 347 bool state_get_skip_delays(void)
 348 {
 349         struct sandbox_state *state = state_get_current();
 350
 351         return state->skip_delays;
 352 }
 353
 354 void state_reset_for_test(struct sandbox_state *state)
 355 {
 356         /* No reset yet, so mark it as such. Always allow power reset */
 357         state->last_sysreset = SYSRESET_COUNT;
 358         state->sysreset_allowed[SYSRESET_POWER] = true;
 359
 360         memset(&state->wdt, '\0', sizeof(state->wdt));
 361         memset(state->spi, '\0', sizeof(state->spi));
 362 }
 363
 364 int state_init(void)
 365 {
 366         state = &main_state;
 367
 368         state->ram_size = CONFIG_SYS_SDRAM_SIZE;
 369         state->ram_buf = os_malloc(state->ram_size);
 370         assert(state->ram_buf);
 371
 372         state_reset_for_test(state);
 373         /*
 374          * Example of how to use GPIOs:
 375          *
 376          * sandbox_gpio_set_direction(170, 0);
 377          * sandbox_gpio_set_value(170, 0);
 378          */
 379         return 0;
 380 }
 381
 382 int state_uninit(void)
 383 {
 384         int err;
 385
 386         state = &main_state;
 387
 388         if (state->write_ram_buf && !state->ram_buf_rm) {
 389                 err = os_write_ram_buf(state->ram_buf_fname);
 390                 if (err) {
 391                         printf("Failed to write RAM buffer\n");
 392                         return err;
 393                 }
 394         }
 395
 396         if (state->write_state) {
 397                 if (sandbox_write_state(state, state->state_fname)) {
 398                         printf("Failed to write sandbox state\n");
 399                         return -1;
 400                 }
 401         }
 402
 403         /* Delete this at the last moment so as not to upset gdb too much */
 404         if (state->jumped_fname)
 405                 os_unlink(state->jumped_fname);
 406
 407         if (state->state_fdt)
 408                 os_free(state->state_fdt);
 409         memset(state, '\0', sizeof(*state));
 410
 411         return 0;
 412 }