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