lib/efi_driver/efi_uclass.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  *  Uclass for EFI drivers
   4  *
   5  *  Copyright (c) 2017 Heinrich Schuchardt
   6  *
   7  * For each EFI driver the uclass
   8  * - creates a handle
   9  * - installs the driver binding protocol
  10  *
  11  * The uclass provides the bind, start, and stop entry points for the driver
  12  * binding protocol.
  13  *
  14  * In bind() and stop() it checks if the controller implements the protocol
  15  * supported by the EFI driver. In the start() function it calls the bind()
  16  * function of the EFI driver. In the stop() function it destroys the child
  17  * controllers.
  18  */
  19
  20 #include <efi_driver.h>
  21
  22 /**
  23  * check_node_type() - check node type
  24  *
  25  * We do not support partitions as controller handles.
  26  *
  27  * @handle:     handle to be checked
  28  * Return:      status code
  29  */
  30 static efi_status_t check_node_type(efi_handle_t handle)
  31 {
  32         efi_status_t r, ret = EFI_SUCCESS;
  33         const struct efi_device_path *dp;
  34
  35         /* Open the device path protocol */
  36         r = EFI_CALL(systab.boottime->open_protocol(
  37                         handle, &efi_guid_device_path, (void **)&dp,
  38                         NULL, NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL));
  39         if (r == EFI_SUCCESS && dp) {
  40                 /* Get the last node */
  41                 const struct efi_device_path *node = efi_dp_last_node(dp);
  42                 /* We do not support partitions as controller */
  43                 if (!node || node->type == DEVICE_PATH_TYPE_MEDIA_DEVICE)
  44                         ret = EFI_UNSUPPORTED;
  45         }
  46         return ret;
  47 }
  48
  49 /**
  50  * efi_uc_supported() - check if the driver supports the controller
  51  *
  52  * @this:                       driver binding protocol
  53  * @controller_handle:          handle of the controller
  54  * @remaining_device_path:      path specifying the child controller
  55  * Return:                      status code
  56  */
  57 static efi_status_t EFIAPI efi_uc_supported(
  58                 struct efi_driver_binding_protocol *this,
  59                 efi_handle_t controller_handle,
  60                 struct efi_device_path *remaining_device_path)
  61 {
  62         efi_status_t r, ret;
  63         void *interface;
  64         struct efi_driver_binding_extended_protocol *bp =
  65                         (struct efi_driver_binding_extended_protocol *)this;
  66
  67         EFI_ENTRY("%p, %p, %ls", this, controller_handle,
  68                   efi_dp_str(remaining_device_path));
  69
  70         ret = EFI_CALL(systab.boottime->open_protocol(
  71                         controller_handle, bp->ops->protocol,
  72                         &interface, this->driver_binding_handle,
  73                         controller_handle, EFI_OPEN_PROTOCOL_BY_DRIVER));
  74         switch (ret) {
  75         case EFI_ACCESS_DENIED:
  76         case EFI_ALREADY_STARTED:
  77                 goto out;
  78         case EFI_SUCCESS:
  79                 break;
  80         default:
  81                 ret = EFI_UNSUPPORTED;
  82                 goto out;
  83         }
  84
  85         ret = check_node_type(controller_handle);
  86
  87         r = EFI_CALL(systab.boottime->close_protocol(
  88                                 controller_handle, bp->ops->protocol,
  89                                 this->driver_binding_handle,
  90                                 controller_handle));
  91         if (r != EFI_SUCCESS)
  92                 ret = EFI_UNSUPPORTED;
  93 out:
  94         return EFI_EXIT(ret);
  95 }
  96
  97 /**
  98  * efi_uc_start() - create child controllers and attach driver
  99  *
 100  * @this:                       driver binding protocol
 101  * @controller_handle:          handle of the controller
 102  * @remaining_device_path:      path specifying the child controller
 103  * Return:                      status code
 104  */
 105 static efi_status_t EFIAPI efi_uc_start(
 106                 struct efi_driver_binding_protocol *this,
 107                 efi_handle_t controller_handle,
 108                 struct efi_device_path *remaining_device_path)
 109 {
 110         efi_status_t r, ret;
 111         void *interface = NULL;
 112         struct efi_driver_binding_extended_protocol *bp =
 113                         (struct efi_driver_binding_extended_protocol *)this;
 114
 115         EFI_ENTRY("%p, %pUl, %ls", this, controller_handle,
 116                   efi_dp_str(remaining_device_path));
 117
 118         /* Attach driver to controller */
 119         ret = EFI_CALL(systab.boottime->open_protocol(
 120                         controller_handle, bp->ops->protocol,
 121                         &interface, this->driver_binding_handle,
 122                         controller_handle, EFI_OPEN_PROTOCOL_BY_DRIVER));
 123         switch (ret) {
 124         case EFI_ACCESS_DENIED:
 125         case EFI_ALREADY_STARTED:
 126                 goto out;
 127         case EFI_SUCCESS:
 128                 break;
 129         default:
 130                 ret =  EFI_UNSUPPORTED;
 131                 goto out;
 132         }
 133         ret = check_node_type(controller_handle);
 134         if (ret != EFI_SUCCESS) {
 135                 r = EFI_CALL(systab.boottime->close_protocol(
 136                                 controller_handle, bp->ops->protocol,
 137                                 this->driver_binding_handle,
 138                                 controller_handle));
 139                 if (r != EFI_SUCCESS)
 140                         EFI_PRINT("Failure to close handle\n");
 141                 goto out;
 142         }
 143
 144         /* TODO: driver specific stuff */
 145         bp->ops->bind(controller_handle, interface);
 146
 147 out:
 148         return EFI_EXIT(ret);
 149 }
 150
 151 /**
 152  * disconnect_child() - remove a single child controller from the parent
 153  *                      controller
 154  *
 155  * @controller_handle:  parent controller
 156  * @child_handle:       child controller
 157  * Return:              status code
 158  */
 159 static efi_status_t disconnect_child(efi_handle_t controller_handle,
 160                                      efi_handle_t child_handle)
 161 {
 162         efi_status_t ret;
 163         efi_guid_t *guid_controller = NULL;
 164         efi_guid_t *guid_child_controller = NULL;
 165
 166         ret = EFI_CALL(systab.boottime->close_protocol(
 167                                 controller_handle, guid_controller,
 168                                 child_handle, child_handle));
 169         if (ret != EFI_SUCCESS) {
 170                 EFI_PRINT("Cannot close protocol\n");
 171                 return ret;
 172         }
 173         ret = EFI_CALL(systab.boottime->uninstall_protocol_interface(
 174                                 child_handle, guid_child_controller, NULL));
 175         if (ret != EFI_SUCCESS) {
 176                 EFI_PRINT("Cannot uninstall protocol interface\n");
 177                 return ret;
 178         }
 179         return ret;
 180 }
 181
 182 /**
 183  * efi_uc_stop() - Remove child controllers and disconnect the controller
 184  *
 185  * @this:                       driver binding protocol
 186  * @controller_handle:          handle of the controller
 187  * @number_of_children:         number of child controllers to remove
 188  * @child_handle_buffer:        handles of the child controllers to remove
 189  * Return:                      status code
 190  */
 191 static efi_status_t EFIAPI efi_uc_stop(
 192                 struct efi_driver_binding_protocol *this,
 193                 efi_handle_t controller_handle,
 194                 size_t number_of_children,
 195                 efi_handle_t *child_handle_buffer)
 196 {
 197         efi_status_t ret;
 198         efi_uintn_t count;
 199         struct efi_open_protocol_info_entry *entry_buffer;
 200         efi_guid_t *guid_controller = NULL;
 201
 202         EFI_ENTRY("%p, %pUl, %zu, %p", this, controller_handle,
 203                   number_of_children, child_handle_buffer);
 204
 205         /* Destroy provided child controllers */
 206         if (number_of_children) {
 207                 efi_uintn_t i;
 208
 209                 for (i = 0; i < number_of_children; ++i) {
 210                         ret = disconnect_child(controller_handle,
 211                                                child_handle_buffer[i]);
 212                         if (ret != EFI_SUCCESS)
 213                                 return ret;
 214                 }
 215                 return EFI_SUCCESS;
 216         }
 217
 218         /* Destroy all children */
 219         ret = EFI_CALL(systab.boottime->open_protocol_information(
 220                                         controller_handle, guid_controller,
 221                                         &entry_buffer, &count));
 222         if (ret != EFI_SUCCESS)
 223                 goto out;
 224         while (count) {
 225                 if (entry_buffer[--count].attributes &
 226                     EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER) {
 227                         ret = disconnect_child(
 228                                         controller_handle,
 229                                         entry_buffer[count].agent_handle);
 230                         if (ret != EFI_SUCCESS)
 231                                 goto out;
 232                 }
 233         }
 234         ret = EFI_CALL(systab.boottime->free_pool(entry_buffer));
 235         if (ret != EFI_SUCCESS)
 236                 printf("%s: ERROR: Cannot free pool\n", __func__);
 237
 238         /* Detach driver from controller */
 239         ret = EFI_CALL(systab.boottime->close_protocol(
 240                         controller_handle, guid_controller,
 241                         this->driver_binding_handle, controller_handle));
 242 out:
 243         return EFI_EXIT(ret);
 244 }
 245
 246 /**
 247  * efi_add_driver() - add driver
 248  *
 249  * @drv:                driver to add
 250  * Return:              status code
 251  */
 252 static efi_status_t efi_add_driver(struct driver *drv)
 253 {
 254         efi_status_t ret;
 255         const struct efi_driver_ops *ops = drv->ops;
 256         struct efi_driver_binding_extended_protocol *bp;
 257
 258         debug("EFI: Adding driver '%s'\n", drv->name);
 259         if (!ops->protocol) {
 260                 printf("EFI: ERROR: protocol GUID missing for driver '%s'\n",
 261                        drv->name);
 262                 return EFI_INVALID_PARAMETER;
 263         }
 264         bp = calloc(1, sizeof(struct efi_driver_binding_extended_protocol));
 265         if (!bp)
 266                 return EFI_OUT_OF_RESOURCES;
 267
 268         bp->bp.supported = efi_uc_supported;
 269         bp->bp.start = efi_uc_start;
 270         bp->bp.stop = efi_uc_stop;
 271         bp->bp.version = 0xffffffff;
 272         bp->ops = drv->ops;
 273
 274         ret = efi_create_handle(&bp->bp.driver_binding_handle);
 275         if (ret != EFI_SUCCESS) {
 276                 free(bp);
 277                 goto out;
 278         }
 279         bp->bp.image_handle = bp->bp.driver_binding_handle;
 280         ret = efi_add_protocol(bp->bp.driver_binding_handle,
 281                                &efi_guid_driver_binding_protocol, bp);
 282         if (ret != EFI_SUCCESS) {
 283                 efi_delete_handle(bp->bp.driver_binding_handle);
 284                 free(bp);
 285                 goto out;
 286         }
 287 out:
 288         return ret;
 289 }
 290
 291 /**
 292  * efi_driver_init() - initialize the EFI drivers
 293  *
 294  * Called by efi_init_obj_list().
 295  *
 296  * Return:      0 = success, any other value will stop further execution
 297  */
 298 efi_status_t efi_driver_init(void)
 299 {
 300         struct driver *drv;
 301         efi_status_t ret = EFI_SUCCESS;
 302
 303         /* Save 'gd' pointer */
 304         efi_save_gd();
 305
 306         debug("EFI: Initializing EFI driver framework\n");
 307         for (drv = ll_entry_start(struct driver, driver);
 308              drv < ll_entry_end(struct driver, driver); ++drv) {
 309                 if (drv->id == UCLASS_EFI) {
 310                         ret = efi_add_driver(drv);
 311                         if (ret != EFI_SUCCESS) {
 312                                 printf("EFI: ERROR: failed to add driver %s\n",
 313                                        drv->name);
 314                                 break;
 315                         }
 316                 }
 317         }
 318         return ret;
 319 }
 320
 321 /**
 322  * efi_uc_init() - initialize the EFI uclass
 323  *
 324  * @class:      the EFI uclass
 325  * Return:      0 = success
 326  */
 327 static int efi_uc_init(struct uclass *class)
 328 {
 329         printf("EFI: Initializing UCLASS_EFI\n");
 330         return 0;
 331 }
 332
 333 /**
 334  * efi_uc_destroy() - destroy the EFI uclass
 335  *
 336  * @class:      the EFI uclass
 337  * Return:      0 = success
 338  */
 339 static int efi_uc_destroy(struct uclass *class)
 340 {
 341         printf("Destroying  UCLASS_EFI\n");
 342         return 0;
 343 }
 344
 345 UCLASS_DRIVER(efi) = {
 346         .name           = "efi",
 347         .id             = UCLASS_EFI,
 348         .init           = efi_uc_init,
 349         .destroy        = efi_uc_destroy,
 350 };