include/bootdev.h

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * Copyright 2021 Google LLC
   4  * Written by Simon Glass <sjg@chromium.org>
   5  */
   6
   7 #ifndef __bootdev_h
   8 #define __bootdev_h
   9
  10 #include <dm/uclass-id.h>
  11 #include <linux/list.h>
  12
  13 struct bootflow;
  14 struct bootflow_iter;
  15 struct bootstd_priv;
  16 struct udevice;
  17
  18 /**
  19  * enum bootdev_prio_t - priority of each bootdev
  20  *
  21  * These values are associated with each bootdev and set up by the driver.
  22  *
  23  * Smallest value is the highest priority. By default, bootdevs are scanned from
  24  * highest to lowest priority
  25  *
  26  * BOOTDEVP_0_NONE: Invalid value, do not use
  27  * @BOOTDEVP_6_PRE_SCAN: Scan bootdevs with this priority always, before
  28  * starting any bootflow scan
  29  * @BOOTDEVP_2_INTERNAL_FAST: Internal devices which don't need scanning and
  30  * generally very quick to access, e.g. less than 100ms
  31  * @BOOTDEVP_3_INTERNAL_SLOW: Internal devices which don't need scanning but
  32  * take a significant fraction of a second to access
  33  * @BOOTDEVP_4_SCAN_FAST: Extenal devices which need scanning or bus
  34  * enumeration to find, but this enumeration happens quickly, typically under
  35  * 100ms
  36  * @BOOTDEVP_5_SCAN_SLOW: Extenal devices which need scanning or bus
  37  * enumeration to find. The enumeration takes significant fraction of a second
  38  * to complete
  39  * @BOOTDEVP_6_NET_BASE: Basic network devices which are quickly and easily
  40  * available. Typically used for an internal Ethernet device
  41  * @BOOTDEVP_7_NET_FALLBACK: Secondary network devices which require extra time
  42  * to start up, or are less desirable. Typically used for secondary Ethernet
  43  * devices. Note that USB ethernet devices are found during USB enumeration,
  44  * so do not use this priority
  45  */
  46 enum bootdev_prio_t {
  47         BOOTDEVP_0_NONE,
  48         BOOTDEVP_1_PRE_SCAN,
  49         BOOTDEVP_2_INTERNAL_FAST,
  50         BOOTDEVP_3_INTERNAL_SLOW,
  51         BOOTDEVP_4_SCAN_FAST,
  52         BOOTDEVP_5_SCAN_SLOW,
  53         BOOTDEVP_6_NET_BASE,
  54         BOOTDEVP_7_NET_FALLBACK,
  55
  56         BOOTDEVP_COUNT,
  57 };
  58
  59 struct bootdev_hunter;
  60
  61 /**
  62  * bootdev_hunter_func - function to probe for bootdevs of a given type
  63  *
  64  * This should hunt around for bootdevs of the given type, binding them as it
  65  * finds them. This may involve bus enumeration, etc.
  66  *
  67  * @info: Info structure describing this hunter
  68  * @show: true to show information from the hunter
  69  * Returns: 0 if OK, -ENOENT on device not found, otherwise -ve on error
  70  */
  71 typedef int (*bootdev_hunter_func)(struct bootdev_hunter *info, bool show);
  72
  73 /**
  74  * struct bootdev_hunter - information about how to hunt for bootdevs
  75  *
  76  * @prio: Scanning priority of this hunter
  77  * @uclass: Uclass ID for the media associated with this bootdev
  78  * @drv: bootdev driver for the things found by this hunter
  79  * @hunt: Function to call to hunt for bootdevs of this type (NULL if none)
  80  *
  81  * Some bootdevs are not visible until other devices are enumerated. For
  82  * example, USB bootdevs only appear when the USB bus is enumerated.
  83  *
  84  * On the other hand, we don't always want to enumerate all the buses just to
  85  * find the first valid bootdev. Ideally we want to work through them in
  86  * priority order, so that the fastest bootdevs are discovered first.
  87  *
  88  * This struct holds information about the bootdev so we can determine the probe
  89  * order and how to hunt for bootdevs of this type
  90  */
  91 struct bootdev_hunter {
  92         enum bootdev_prio_t prio;
  93         enum uclass_id uclass;
  94         struct driver *drv;
  95         bootdev_hunter_func hunt;
  96 };
  97
  98 /* declare a new bootdev hunter */
  99 #define BOOTDEV_HUNTER(__name)                                          \
 100         ll_entry_declare(struct bootdev_hunter, __name, bootdev_hunter)
 101
 102 /* access a bootdev hunter by name */
 103 #define BOOTDEV_HUNTER_GET(__name)                                              \
 104         ll_entry_get(struct bootdev_hunter, __name, bootdev_hunter)
 105
 106 /**
 107  * struct bootdev_uc_plat - uclass information about a bootdev
 108  *
 109  * This is attached to each device in the bootdev uclass and accessible via
 110  * dev_get_uclass_plat(dev)
 111  *
 112  * @piro: Priority of this bootdev
 113  */
 114 struct bootdev_uc_plat {
 115         enum bootdev_prio_t prio;
 116 };
 117
 118 /** struct bootdev_ops - Operations for the bootdev uclass */
 119 struct bootdev_ops {
 120         /**
 121          * get_bootflow() - get a bootflow (optional)
 122          *
 123          * If this is NULL then the default implementaton is used, which is
 124          * default_get_bootflow()
 125          *
 126          * @dev:        Bootflow device to check
 127          * @iter:       Provides current dev, part, method to get. Should update
 128          *      max_part if there is a partition table. Should update state,
 129          *      subdir, fname, buf, size according to progress
 130          * @bflow:      Updated bootflow if found
 131          * Return: 0 if OK, -ESHUTDOWN if there are no more bootflows on this
 132          *      device, -ENOSYS if this device doesn't support bootflows,
 133          *      other -ve value on other error
 134          */
 135         int (*get_bootflow)(struct udevice *dev, struct bootflow_iter *iter,
 136                             struct bootflow *bflow);
 137 };
 138
 139 #define bootdev_get_ops(dev)  ((struct bootdev_ops *)(dev)->driver->ops)
 140
 141 /**
 142  * bootdev_get_bootflow() - get a bootflow
 143  *
 144  * @dev:        Bootflow device to check
 145  * @iter:       Provides current  part, method to get
 146  * @bflow:      Returns bootflow if found
 147  * Return: 0 if OK, -ESHUTDOWN if there are no more bootflows on this device,
 148  *      -ENOSYS if this device doesn't support bootflows, other -ve value on
 149  *      other error
 150  */
 151 int bootdev_get_bootflow(struct udevice *dev, struct bootflow_iter *iter,
 152                          struct bootflow *bflow);
 153
 154 /**
 155  * bootdev_bind() - Bind a new named bootdev device
 156  *
 157  * @parent:     Parent of the new device
 158  * @drv_name:   Driver name to use for the bootdev device
 159  * @name:       Name for the device (parent name is prepended)
 160  * @devp:       the new device (which has not been probed)
 161  */
 162 int bootdev_bind(struct udevice *parent, const char *drv_name, const char *name,
 163                  struct udevice **devp);
 164
 165 /**
 166  * bootdev_find_in_blk() - Find a bootdev in a block device
 167  *
 168  * @dev: Bootflow device associated with this block device
 169  * @blk: Block device to search
 170  * @iter:       Provides current dev, part, method to get. Should update
 171  *      max_part if there is a partition table
 172  * @bflow: On entry, provides information about the partition and device to
 173  *      check. On exit, returns bootflow if found
 174  * Return: 0 if found, -ESHUTDOWN if no more bootflows, other -ve on error
 175  */
 176 int bootdev_find_in_blk(struct udevice *dev, struct udevice *blk,
 177                         struct bootflow_iter *iter, struct bootflow *bflow);
 178
 179 /**
 180  * bootdev_list() - List all available bootdevs
 181  *
 182  * @probe: true to probe devices, false to leave them as is
 183  */
 184 void bootdev_list(bool probe);
 185
 186 /**
 187  * bootdev_first_bootflow() - Get the first bootflow from a bootdev
 188  *
 189  * Returns the first bootflow attached to a bootdev
 190  *
 191  * @dev: bootdev device
 192  * @bflowp: Returns a pointer to the bootflow
 193  * Return: 0 if found, -ENOENT if there are no bootflows
 194  */
 195 int bootdev_first_bootflow(struct udevice *dev, struct bootflow **bflowp);
 196
 197 /**
 198  * bootdev_next_bootflow() - Get the next bootflow from a bootdev
 199  *
 200  * Returns the next bootflow attached to a bootdev
 201  *
 202  * @bflowp: On entry, the last bootflow returned , e.g. from
 203  *      bootdev_first_bootflow()
 204  * Return: 0 if found, -ENOENT if there are no more bootflows
 205  */
 206 int bootdev_next_bootflow(struct bootflow **bflowp);
 207
 208 /**
 209  * bootdev_find_by_label() - Look up a bootdev by label
 210  *
 211  * Each bootdev has a label which contains the media-uclass name and a number,
 212  * e.g. 'mmc2'. This looks up the label and returns the associated bootdev
 213  *
 214  * The lookup is performed based on the media device's sequence number. So for
 215  * 'mmc2' this looks for a device in UCLASS_MMC with a dev_seq() of 2.
 216  *
 217  * @label: Label to look up (e.g. "mmc1" or "mmc0")
 218  * @devp: Returns the bootdev device found, or NULL if none (note it does not
 219  *      return the media device, but its bootdev child)
 220  * @method_flagsp: If non-NULL, returns any flags implied by the label
 221  * (enum bootflow_meth_flags_t), 0 if none. Unset if function fails
 222  * Return: 0 if OK, -EINVAL if the uclass is not supported by this board,
 223  * -ENOENT if there is no device with that number
 224  */
 225 int bootdev_find_by_label(const char *label, struct udevice **devp,
 226                           int *method_flagsp);
 227
 228 /**
 229  * bootdev_find_by_any() - Find a bootdev by name, label or sequence
 230  *
 231  * @name: name (e.g. "mmc2.bootdev"), label ("mmc2"), or sequence ("2") to find
 232  * @devp: returns the device found, on success
 233  * @method_flagsp: If non-NULL, returns any flags implied by the label
 234  * (enum bootflow_meth_flags_t), 0 if none. Unset if function fails
 235  * Return: 0 if OK, -EPFNOSUPPORT if the uclass is not supported by this board,
 236  * -ENOENT if there is no device with that number
 237  */
 238 int bootdev_find_by_any(const char *name, struct udevice **devp,
 239                         int *method_flagsp);
 240
 241 /**
 242  * bootdev_setup_iter() - Set up iteration through bootdevs
 243  *
 244  * This sets up the an interation, based on the provided device or label. If
 245  * neither is provided, the iteration is based on the priority of each bootdev,
 246  * the * bootdev-order property in the bootstd node (or the boot_targets env
 247  * var).
 248  *
 249  * @iter: Iterator to update with the order
 250  * @label: label to scan, or NULL to scan all
 251  * @devp: On entry, *devp is NULL to scan all, otherwise this is the (single)
 252  *      device to scan. Returns the first device to use, which is the passed-in
 253  *      @devp if it was non-NULL
 254  * @method_flagsp: If non-NULL, returns any flags implied by the label
 255  * (enum bootflow_meth_flags_t), 0 if none
 256  * Return: 0 if OK, -ENOENT if no bootdevs, -ENOMEM if out of memory, other -ve
 257  *      on other error
 258  */
 259 int bootdev_setup_iter(struct bootflow_iter *iter, const char *label,
 260                        struct udevice **devp, int *method_flagsp);
 261
 262 /**
 263  * bootdev_list_hunters() - List the available bootdev hunters
 264  *
 265  * These provide a way to find new bootdevs by enumerating buses, etc. This
 266  * function lists the available hunters
 267  *
 268  * @std: Pointer to bootstd private info
 269  */
 270 void bootdev_list_hunters(struct bootstd_priv *std);
 271
 272 /**
 273  * bootdev_hunt() - Hunt for bootdevs matching a particular spec
 274  *
 275  * This runs the selected hunter (or all if @spec is NULL) to try to find new
 276  * bootdevs.
 277  *
 278  * @spec: Spec to match, e.g. "mmc0", or NULL for any. If provided, this must
 279  * match a uclass name so that the hunter can be determined. Any trailing number
 280  * is ignored
 281  * @show: true to show each hunter before using it
 282  * Returns: 0 if OK, -ve on error
 283  */
 284 int bootdev_hunt(const char *spec, bool show);
 285
 286 /**
 287  * bootdev_hunt_prio() - Hunt for bootdevs of a particular priority
 288  *
 289  * This runs all hunters which can find bootdevs of the given priority.
 290  *
 291  * @prio: Priority to use
 292  * @show: true to show each hunter as it is used
 293  * Returns: 0 if OK, -ve on error
 294  */
 295 int bootdev_hunt_prio(enum bootdev_prio_t prio, bool show);
 296
 297 /**
 298  * bootdev_unhunt() - Mark a device as needing to be hunted again
 299  *
 300  * @id: uclass ID to update
 301  * Return: 0 if done, -EALREADY if already in this state, -ENOENT if no hunter
 302  * found for that uclass
 303  */
 304 int bootdev_unhunt(enum uclass_id id);
 305
 306 /**
 307  * bootdev_hunt_and_find_by_label() - Hunt for bootdevs by label
 308  *
 309  * Runs the hunter for the label, then tries to find the bootdev, possible
 310  * created by the hunter
 311  *
 312  * @label: Label to look up (e.g. "mmc1" or "mmc0")
 313  * @devp: Returns the bootdev device found, or NULL if none (note it does not
 314  *      return the media device, but its bootdev child)
 315  * @method_flagsp: If non-NULL, returns any flags implied by the label
 316  * (enum bootflow_meth_flags_t), 0 if none. Unset if function fails
 317  * Return: 0 if OK, -EINVAL if the uclass is not supported by this board,
 318  * -ENOENT if there is no device with that number
 319  */
 320 int bootdev_hunt_and_find_by_label(const char *label, struct udevice **devp,
 321                                    int *method_flagsp);
 322
 323 /**
 324  * bootdev_next_label() - Move to the next bootdev in the label sequence
 325  *
 326  * Looks through the remaining labels until it finds one that matches a bootdev.
 327  * Bootdev scanners are used as needed. For example a label "mmc1" results in
 328  * running the "mmc" bootdrv.
 329  *
 330  * @iter: Interation info, containing iter->cur_label
 331  * @devp: New bootdev found, if any was found
 332  * @method_flagsp: If non-NULL, returns any flags implied by the label
 333  * (enum bootflow_meth_flags_t), 0 if none
 334  * Returns 0 if OK, -ENODEV if no bootdev was found
 335  */
 336 int bootdev_next_label(struct bootflow_iter *iter, struct udevice **devp,
 337                        int *method_flagsp);
 338
 339 /**
 340  * bootdev_next_prio() - Find the next bootdev in priority order
 341  *
 342  * This moves @devp to the next bootdev with the current priority. If there is
 343  * none, then it moves to the next priority and scans for new bootdevs there.
 344  *
 345  * @iter: Interation info, containing iter->cur_prio
 346  * @devp: On entry this is the previous bootdev that was considered. On exit
 347  *      this is the new bootdev, if any was found
 348  * Returns 0 on success (*devp is updated), -ENODEV if there are no more
 349  * bootdevs at any priority
 350  */
 351 int bootdev_next_prio(struct bootflow_iter *iter, struct udevice **devp);
 352
 353 #if CONFIG_IS_ENABLED(BOOTSTD)
 354 /**
 355  * bootdev_setup_for_dev() - Bind a new bootdev device (deprecated)
 356  *
 357  * Please use bootdev_setup_for_sibling_blk() instead since it supports multiple
 358  * (child) block devices for each media device.
 359  *
 360  * Creates a bootdev device as a child of @parent. This should be called from
 361  * the driver's bind() method or its uclass' post_bind() method.
 362  *
 363  * If a child bootdev already exists, this function does nothing
 364  *
 365  * @parent: Parent device (e.g. MMC or Ethernet)
 366  * @drv_name: Name of bootdev driver to bind
 367  * Return: 0 if OK, -ve on error
 368  */
 369 int bootdev_setup_for_dev(struct udevice *parent, const char *drv_name);
 370
 371 #if CONFIG_IS_ENABLED(BOOTSTD)
 372 /**
 373  * bootdev_setup_for_sibling_blk() - Bind a new bootdev device for a blk device
 374  *
 375  * Creates a bootdev device as a sibling of @blk. This should be called from
 376  * the driver's bind() method or its uclass' post_bind() method, at the same
 377  * time as the bould device is bound
 378  *
 379  * If a device of the same name already exists, this function does nothing
 380  *
 381  * @parent: Parent device (e.g. MMC or Ethernet)
 382  * @drv_name: Name of bootdev driver to bind
 383  * Return: 0 if OK, -ve on error
 384  */
 385 int bootdev_setup_for_sibling_blk(struct udevice *blk, const char *drv_name);
 386 #else
 387 static int bootdev_setup_for_sibling_blk(struct udevice *blk,
 388                                          const char *drv_name)
 389 {
 390         return 0;
 391 }
 392 #endif
 393
 394 /**
 395  * bootdev_get_sibling_blk() - Locate the block device for a bootdev
 396  *
 397  * @dev: bootdev to check
 398  * @blkp: returns associated block device
 399  * Return: 0 if OK, -EINVAL if @dev is not a bootdev device, other -ve on other
 400  *      error
 401  */
 402 int bootdev_get_sibling_blk(struct udevice *dev, struct udevice **blkp);
 403
 404 /**
 405  * bootdev_get_from_blk() - Get the bootdev given a block device
 406  *
 407  * @blk: Block device to check
 408  * @bootdebp: Returns the bootdev found, if any
 409  * Return 0 if OK, -ve on error
 410  */
 411 int bootdev_get_from_blk(struct udevice *blk, struct udevice **bootdevp);
 412
 413 /**
 414  * bootdev_unbind_dev() - Unbind a bootdev device
 415  *
 416  * Remove and unbind a bootdev device which is a child of @parent. This should
 417  * be called from the driver's unbind() method or its uclass' post_bind()
 418  * method.
 419  *
 420  * @parent: Parent device (e.g. MMC or Ethernet)
 421  * Return: 0 if OK, -ve on error
 422  */
 423 int bootdev_unbind_dev(struct udevice *parent);
 424 #else
 425 static inline int bootdev_setup_for_dev(struct udevice *parent,
 426                                         const char *drv_name)
 427 {
 428         return 0;
 429 }
 430
 431 static inline int bootdev_setup_for_sibling_blk(struct udevice *blk,
 432                                                 const char *drv_name)
 433 {
 434         return 0;
 435 }
 436
 437 static inline int bootdev_unbind_dev(struct udevice *parent)
 438 {
 439         return 0;
 440 }
 441 #endif
 442
 443 #endif