lib/efi_loader/efi_disk.c

   1 /*
   2  *  EFI application disk support
   3  *
   4  *  Copyright (c) 2016 Alexander Graf
   5  *
   6  *  SPDX-License-Identifier:     GPL-2.0+
   7  */
   8
   9 #include <common.h>
  10 #include <efi_loader.h>
  11 #include <inttypes.h>
  12 #include <part.h>
  13 #include <malloc.h>
  14
  15 static const efi_guid_t efi_block_io_guid = BLOCK_IO_GUID;
  16
  17 struct efi_disk_obj {
  18         /* Generic EFI object parent class data */
  19         struct efi_object parent;
  20         /* EFI Interface callback struct for block I/O */
  21         struct efi_block_io ops;
  22         /* U-Boot ifname for block device */
  23         const char *ifname;
  24         /* U-Boot dev_index for block device */
  25         int dev_index;
  26         /* EFI Interface Media descriptor struct, referenced by ops */
  27         struct efi_block_io_media media;
  28         /* EFI device path to this block device */
  29         struct efi_device_path_file_path *dp;
  30 };
  31
  32 static efi_status_t efi_disk_open_block(void *handle, efi_guid_t *protocol,
  33                         void **protocol_interface, void *agent_handle,
  34                         void *controller_handle, uint32_t attributes)
  35 {
  36         struct efi_disk_obj *diskobj = handle;
  37
  38         *protocol_interface = &diskobj->ops;
  39
  40         return EFI_SUCCESS;
  41 }
  42
  43 static efi_status_t efi_disk_open_dp(void *handle, efi_guid_t *protocol,
  44                         void **protocol_interface, void *agent_handle,
  45                         void *controller_handle, uint32_t attributes)
  46 {
  47         struct efi_disk_obj *diskobj = handle;
  48
  49         *protocol_interface = diskobj->dp;
  50
  51         return EFI_SUCCESS;
  52 }
  53
  54 static efi_status_t EFIAPI efi_disk_reset(struct efi_block_io *this,
  55                         char extended_verification)
  56 {
  57         EFI_ENTRY("%p, %x", this, extended_verification);
  58         return EFI_EXIT(EFI_DEVICE_ERROR);
  59 }
  60
  61 enum efi_disk_direction {
  62         EFI_DISK_READ,
  63         EFI_DISK_WRITE,
  64 };
  65
  66 static efi_status_t EFIAPI efi_disk_rw_blocks(struct efi_block_io *this,
  67                         u32 media_id, u64 lba, unsigned long buffer_size,
  68                         void *buffer, enum efi_disk_direction direction)
  69 {
  70         struct efi_disk_obj *diskobj;
  71         struct blk_desc *desc;
  72         int blksz;
  73         int blocks;
  74         unsigned long n;
  75
  76         EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
  77                   buffer_size, buffer);
  78
  79         diskobj = container_of(this, struct efi_disk_obj, ops);
  80         if (!(desc = blk_get_dev(diskobj->ifname, diskobj->dev_index)))
  81                 return EFI_EXIT(EFI_DEVICE_ERROR);
  82         blksz = desc->blksz;
  83         blocks = buffer_size / blksz;
  84
  85 #ifdef DEBUG_EFI
  86         printf("EFI: %s:%d blocks=%x lba=%"PRIx64" blksz=%x dir=%d\n", __func__,
  87                __LINE__, blocks, lba, blksz, direction);
  88 #endif
  89
  90         /* We only support full block access */
  91         if (buffer_size & (blksz - 1))
  92                 return EFI_EXIT(EFI_DEVICE_ERROR);
  93
  94         if (direction == EFI_DISK_READ)
  95                 n = desc->block_read(desc, lba, blocks, buffer);
  96         else
  97                 n = desc->block_write(desc, lba, blocks, buffer);
  98
  99         /* We don't do interrupts, so check for timers cooperatively */
 100         efi_timer_check();
 101
 102 #ifdef DEBUG_EFI
 103         printf("EFI: %s:%d n=%lx blocks=%x\n", __func__, __LINE__, n, blocks);
 104 #endif
 105         if (n != blocks)
 106                 return EFI_EXIT(EFI_DEVICE_ERROR);
 107
 108         return EFI_EXIT(EFI_SUCCESS);
 109 }
 110
 111 static efi_status_t efi_disk_read_blocks(struct efi_block_io *this,
 112                         u32 media_id, u64 lba, unsigned long buffer_size,
 113                         void *buffer)
 114 {
 115         return efi_disk_rw_blocks(this, media_id, lba, buffer_size, buffer,
 116                                   EFI_DISK_READ);
 117 }
 118
 119 static efi_status_t efi_disk_write_blocks(struct efi_block_io *this,
 120                         u32 media_id, u64 lba, unsigned long buffer_size,
 121                         void *buffer)
 122 {
 123         return efi_disk_rw_blocks(this, media_id, lba, buffer_size, buffer,
 124                                   EFI_DISK_WRITE);
 125 }
 126
 127 static efi_status_t EFIAPI efi_disk_flush_blocks(struct efi_block_io *this)
 128 {
 129         /* We always write synchronously */
 130         EFI_ENTRY("%p", this);
 131         return EFI_EXIT(EFI_SUCCESS);
 132 }
 133
 134 static const struct efi_block_io block_io_disk_template = {
 135         .reset = &efi_disk_reset,
 136         .read_blocks = &efi_disk_read_blocks,
 137         .write_blocks = &efi_disk_write_blocks,
 138         .flush_blocks = &efi_disk_flush_blocks,
 139 };
 140
 141 /*
 142  * U-Boot doesn't have a list of all online disk devices. So when running our
 143  * EFI payload, we scan through all of the potentially available ones and
 144  * store them in our object pool.
 145  *
 146  * This gets called from do_bootefi_exec().
 147  */
 148 int efi_disk_register(void)
 149 {
 150         const struct block_drvr *cur_drvr;
 151         int i;
 152         int disks = 0;
 153
 154         /* Search for all available disk devices */
 155         for (cur_drvr = block_drvr; cur_drvr->name; cur_drvr++) {
 156                 printf("Scanning disks on %s...\n", cur_drvr->name);
 157                 for (i = 0; i < 4; i++) {
 158                         struct blk_desc *desc;
 159                         struct efi_disk_obj *diskobj;
 160                         struct efi_device_path_file_path *dp;
 161                         int objlen = sizeof(*diskobj) + (sizeof(*dp) * 2);
 162                         char devname[16] = { 0 }; /* dp->str is u16[16] long */
 163
 164                         desc = blk_get_dev(cur_drvr->name, i);
 165                         if (!desc)
 166                                 continue;
 167                         if (desc->type == DEV_TYPE_UNKNOWN)
 168                                 continue;
 169
 170                         diskobj = calloc(1, objlen);
 171
 172                         /* Fill in object data */
 173                         diskobj->parent.protocols[0].guid = &efi_block_io_guid;
 174                         diskobj->parent.protocols[0].open = efi_disk_open_block;
 175                         diskobj->parent.protocols[1].guid = &efi_guid_device_path;
 176                         diskobj->parent.protocols[1].open = efi_disk_open_dp;
 177                         diskobj->parent.handle = diskobj;
 178                         diskobj->ops = block_io_disk_template;
 179                         diskobj->ifname = cur_drvr->name;
 180                         diskobj->dev_index = i;
 181
 182                         /* Fill in EFI IO Media info (for read/write callbacks) */
 183                         diskobj->media.removable_media = desc->removable;
 184                         diskobj->media.media_present = 1;
 185                         diskobj->media.block_size = desc->blksz;
 186                         diskobj->media.io_align = desc->blksz;
 187                         diskobj->media.last_block = desc->lba;
 188                         diskobj->ops.media = &diskobj->media;
 189
 190                         /* Fill in device path */
 191                         dp = (void*)&diskobj[1];
 192                         diskobj->dp = dp;
 193                         dp[0].dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 194                         dp[0].dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
 195                         dp[0].dp.length = sizeof(*dp);
 196                         snprintf(devname, sizeof(devname), "%s%d",
 197                                  cur_drvr->name, i);
 198                         ascii2unicode(dp[0].str, devname);
 199
 200                         dp[1].dp.type = DEVICE_PATH_TYPE_END;
 201                         dp[1].dp.sub_type = DEVICE_PATH_SUB_TYPE_END;
 202                         dp[1].dp.length = sizeof(*dp);
 203
 204                         /* Hook up to the device list */
 205                         list_add_tail(&diskobj->parent.link, &efi_obj_list);
 206                         disks++;
 207                 }
 208         }
 209         printf("Found %d disks\n", disks);
 210
 211         return 0;
 212 }