lib/efi_loader/efi_runtime.c

   1 /*
   2  *  EFI application runtime services
   3  *
   4  *  Copyright (c) 2016 Alexander Graf
   5  *
   6  *  SPDX-License-Identifier:     GPL-2.0+
   7  */
   8
   9 #include <common.h>
  10 #include <command.h>
  11 #include <dm.h>
  12 #include <efi_loader.h>
  13 #include <rtc.h>
  14 #include <asm/global_data.h>
  15
  16 /* For manual relocation support */
  17 DECLARE_GLOBAL_DATA_PTR;
  18
  19 struct efi_runtime_mmio_list {
  20         struct list_head link;
  21         void **ptr;
  22         u64 paddr;
  23         u64 len;
  24 };
  25
  26 /* This list contains all runtime available mmio regions */
  27 LIST_HEAD(efi_runtime_mmio);
  28
  29 static efi_status_t __efi_runtime EFIAPI efi_unimplemented(void);
  30 static efi_status_t __efi_runtime EFIAPI efi_device_error(void);
  31 static efi_status_t __efi_runtime EFIAPI efi_invalid_parameter(void);
  32
  33 #ifdef CONFIG_SYS_CACHELINE_SIZE
  34 #define EFI_CACHELINE_SIZE CONFIG_SYS_CACHELINE_SIZE
  35 #else
  36 /* Just use the greatest cache flush alignment requirement I'm aware of */
  37 #define EFI_CACHELINE_SIZE 128
  38 #endif
  39
  40 #if defined(CONFIG_ARM64)
  41 #define R_RELATIVE      1027
  42 #define R_MASK          0xffffffffULL
  43 #define IS_RELA         1
  44 #elif defined(CONFIG_ARM)
  45 #define R_RELATIVE      23
  46 #define R_MASK          0xffULL
  47 #elif defined(CONFIG_X86)
  48 #include <asm/elf.h>
  49 #define R_RELATIVE      R_386_RELATIVE
  50 #define R_MASK          0xffULL
  51 #else
  52 #error Need to add relocation awareness
  53 #endif
  54
  55 struct elf_rel {
  56         ulong *offset;
  57         ulong info;
  58 };
  59
  60 struct elf_rela {
  61         ulong *offset;
  62         ulong info;
  63         long addend;
  64 };
  65
  66 /*
  67  * EFI Runtime code lives in 2 stages. In the first stage, U-Boot and an EFI
  68  * payload are running concurrently at the same time. In this mode, we can
  69  * handle a good number of runtime callbacks
  70  */
  71
  72 static void EFIAPI efi_reset_system_boottime(
  73                         enum efi_reset_type reset_type,
  74                         efi_status_t reset_status,
  75                         unsigned long data_size, void *reset_data)
  76 {
  77         EFI_ENTRY("%d %lx %lx %p", reset_type, reset_status, data_size,
  78                   reset_data);
  79
  80         switch (reset_type) {
  81         case EFI_RESET_COLD:
  82         case EFI_RESET_WARM:
  83                 do_reset(NULL, 0, 0, NULL);
  84                 break;
  85         case EFI_RESET_SHUTDOWN:
  86                 /* We don't have anything to map this to */
  87                 break;
  88         }
  89
  90         while (1) { }
  91 }
  92
  93 static efi_status_t EFIAPI efi_get_time_boottime(
  94                         struct efi_time *time,
  95                         struct efi_time_cap *capabilities)
  96 {
  97 #if defined(CONFIG_CMD_DATE) && defined(CONFIG_DM_RTC)
  98         struct rtc_time tm;
  99         int r;
 100         struct udevice *dev;
 101
 102         EFI_ENTRY("%p %p", time, capabilities);
 103
 104         r = uclass_get_device(UCLASS_RTC, 0, &dev);
 105         if (r)
 106                 return EFI_EXIT(EFI_DEVICE_ERROR);
 107
 108         r = dm_rtc_get(dev, &tm);
 109         if (r)
 110                 return EFI_EXIT(EFI_DEVICE_ERROR);
 111
 112         memset(time, 0, sizeof(*time));
 113         time->year = tm.tm_year;
 114         time->month = tm.tm_mon;
 115         time->day = tm.tm_mday;
 116         time->hour = tm.tm_hour;
 117         time->minute = tm.tm_min;
 118         time->daylight = tm.tm_isdst;
 119
 120         return EFI_EXIT(EFI_SUCCESS);
 121 #else
 122         return EFI_DEVICE_ERROR;
 123 #endif
 124 }
 125
 126 /* Boards may override the helpers below to implement RTS functionality */
 127
 128 void __weak __efi_runtime EFIAPI efi_reset_system(
 129                         enum efi_reset_type reset_type,
 130                         efi_status_t reset_status,
 131                         unsigned long data_size, void *reset_data)
 132 {
 133         /* Nothing we can do */
 134         while (1) { }
 135 }
 136
 137 void __weak efi_reset_system_init(void)
 138 {
 139 }
 140
 141 efi_status_t __weak __efi_runtime EFIAPI efi_get_time(
 142                         struct efi_time *time,
 143                         struct efi_time_cap *capabilities)
 144 {
 145         /* Nothing we can do */
 146         return EFI_DEVICE_ERROR;
 147 }
 148
 149 void __weak efi_get_time_init(void)
 150 {
 151 }
 152
 153 struct efi_runtime_detach_list_struct {
 154         void *ptr;
 155         void *patchto;
 156 };
 157
 158 static const struct efi_runtime_detach_list_struct efi_runtime_detach_list[] = {
 159         {
 160                 /* do_reset is gone */
 161                 .ptr = &efi_runtime_services.reset_system,
 162                 .patchto = efi_reset_system,
 163         }, {
 164                 /* invalidate_*cache_all are gone */
 165                 .ptr = &efi_runtime_services.set_virtual_address_map,
 166                 .patchto = &efi_invalid_parameter,
 167         }, {
 168                 /* RTC accessors are gone */
 169                 .ptr = &efi_runtime_services.get_time,
 170                 .patchto = &efi_get_time,
 171         }, {
 172                 /* Clean up system table */
 173                 .ptr = &systab.con_in,
 174                 .patchto = NULL,
 175         }, {
 176                 /* Clean up system table */
 177                 .ptr = &systab.con_out,
 178                 .patchto = NULL,
 179         }, {
 180                 /* Clean up system table */
 181                 .ptr = &systab.std_err,
 182                 .patchto = NULL,
 183         }, {
 184                 /* Clean up system table */
 185                 .ptr = &systab.boottime,
 186                 .patchto = NULL,
 187         },
 188 };
 189
 190 static bool efi_runtime_tobedetached(void *p)
 191 {
 192         int i;
 193
 194         for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++)
 195                 if (efi_runtime_detach_list[i].ptr == p)
 196                         return true;
 197
 198         return false;
 199 }
 200
 201 static void efi_runtime_detach(ulong offset)
 202 {
 203         int i;
 204         ulong patchoff = offset - (ulong)gd->relocaddr;
 205
 206         for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++) {
 207                 ulong patchto = (ulong)efi_runtime_detach_list[i].patchto;
 208                 ulong *p = efi_runtime_detach_list[i].ptr;
 209                 ulong newaddr = patchto ? (patchto + patchoff) : 0;
 210
 211                 debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
 212                 *p = newaddr;
 213         }
 214 }
 215
 216 /* Relocate EFI runtime to uboot_reloc_base = offset */
 217 void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
 218 {
 219 #ifdef IS_RELA
 220         struct elf_rela *rel = (void*)&__efi_runtime_rel_start;
 221 #else
 222         struct elf_rel *rel = (void*)&__efi_runtime_rel_start;
 223         static ulong lastoff = CONFIG_SYS_TEXT_BASE;
 224 #endif
 225
 226         debug("%s: Relocating to offset=%lx\n", __func__, offset);
 227         for (; (ulong)rel < (ulong)&__efi_runtime_rel_stop; rel++) {
 228                 ulong base = CONFIG_SYS_TEXT_BASE;
 229                 ulong *p;
 230                 ulong newaddr;
 231
 232                 p = (void*)((ulong)rel->offset - base) + gd->relocaddr;
 233
 234                 if ((rel->info & R_MASK) != R_RELATIVE) {
 235                         continue;
 236                 }
 237
 238 #ifdef IS_RELA
 239                 newaddr = rel->addend + offset - CONFIG_SYS_TEXT_BASE;
 240 #else
 241                 newaddr = *p - lastoff + offset;
 242 #endif
 243
 244                 /* Check if the relocation is inside bounds */
 245                 if (map && ((newaddr < map->virtual_start) ||
 246                     newaddr > (map->virtual_start + (map->num_pages << 12)))) {
 247                         if (!efi_runtime_tobedetached(p))
 248                                 printf("U-Boot EFI: Relocation at %p is out of "
 249                                        "range (%lx)\n", p, newaddr);
 250                         continue;
 251                 }
 252
 253                 debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
 254                 *p = newaddr;
 255                 flush_dcache_range((ulong)p & ~(EFI_CACHELINE_SIZE - 1),
 256                         ALIGN((ulong)&p[1], EFI_CACHELINE_SIZE));
 257         }
 258
 259 #ifndef IS_RELA
 260         lastoff = offset;
 261 #endif
 262
 263         invalidate_icache_all();
 264 }
 265
 266 static efi_status_t EFIAPI efi_set_virtual_address_map(
 267                         unsigned long memory_map_size,
 268                         unsigned long descriptor_size,
 269                         uint32_t descriptor_version,
 270                         struct efi_mem_desc *virtmap)
 271 {
 272         ulong runtime_start = (ulong)&__efi_runtime_start & ~0xfffULL;
 273         int n = memory_map_size / descriptor_size;
 274         int i;
 275
 276         EFI_ENTRY("%lx %lx %x %p", memory_map_size, descriptor_size,
 277                   descriptor_version, virtmap);
 278
 279         /* Rebind mmio pointers */
 280         for (i = 0; i < n; i++) {
 281                 struct efi_mem_desc *map = (void*)virtmap +
 282                                            (descriptor_size * i);
 283                 struct list_head *lhandle;
 284                 efi_physical_addr_t map_start = map->physical_start;
 285                 efi_physical_addr_t map_len = map->num_pages << EFI_PAGE_SHIFT;
 286                 efi_physical_addr_t map_end = map_start + map_len;
 287
 288                 /* Adjust all mmio pointers in this region */
 289                 list_for_each(lhandle, &efi_runtime_mmio) {
 290                         struct efi_runtime_mmio_list *lmmio;
 291
 292                         lmmio = list_entry(lhandle,
 293                                            struct efi_runtime_mmio_list,
 294                                            link);
 295                         if ((map_start <= lmmio->paddr) &&
 296                             (map_end >= lmmio->paddr)) {
 297                                 u64 off = map->virtual_start - map_start;
 298                                 uintptr_t new_addr = lmmio->paddr + off;
 299                                 *lmmio->ptr = (void *)new_addr;
 300                         }
 301                 }
 302         }
 303
 304         /* Move the actual runtime code over */
 305         for (i = 0; i < n; i++) {
 306                 struct efi_mem_desc *map;
 307
 308                 map = (void*)virtmap + (descriptor_size * i);
 309                 if (map->type == EFI_RUNTIME_SERVICES_CODE) {
 310                         ulong new_offset = map->virtual_start -
 311                                            (runtime_start - gd->relocaddr);
 312
 313                         efi_runtime_relocate(new_offset, map);
 314                         /* Once we're virtual, we can no longer handle
 315                            complex callbacks */
 316                         efi_runtime_detach(new_offset);
 317                         return EFI_EXIT(EFI_SUCCESS);
 318                 }
 319         }
 320
 321         return EFI_EXIT(EFI_INVALID_PARAMETER);
 322 }
 323
 324 void efi_add_runtime_mmio(void *mmio_ptr, u64 len)
 325 {
 326         struct efi_runtime_mmio_list *newmmio;
 327
 328         u64 pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
 329         efi_add_memory_map(*(uintptr_t *)mmio_ptr, pages, EFI_MMAP_IO, false);
 330
 331         newmmio = calloc(1, sizeof(*newmmio));
 332         newmmio->ptr = mmio_ptr;
 333         newmmio->paddr = *(uintptr_t *)mmio_ptr;
 334         newmmio->len = len;
 335         list_add_tail(&newmmio->link, &efi_runtime_mmio);
 336 }
 337
 338 /*
 339  * In the second stage, U-Boot has disappeared. To isolate our runtime code
 340  * that at this point still exists from the rest, we put it into a special
 341  * section.
 342  *
 343  *        !!WARNING!!
 344  *
 345  * This means that we can not rely on any code outside of this file in any
 346  * function or variable below this line.
 347  *
 348  * Please keep everything fully self-contained and annotated with
 349  * __efi_runtime and __efi_runtime_data markers.
 350  */
 351
 352 /*
 353  * Relocate the EFI runtime stub to a different place. We need to call this
 354  * the first time we expose the runtime interface to a user and on set virtual
 355  * address map calls.
 356  */
 357
 358 static efi_status_t __efi_runtime EFIAPI efi_unimplemented(void)
 359 {
 360         return EFI_UNSUPPORTED;
 361 }
 362
 363 static efi_status_t __efi_runtime EFIAPI efi_device_error(void)
 364 {
 365         return EFI_DEVICE_ERROR;
 366 }
 367
 368 static efi_status_t __efi_runtime EFIAPI efi_invalid_parameter(void)
 369 {
 370         return EFI_INVALID_PARAMETER;
 371 }
 372
 373 struct efi_runtime_services __efi_runtime_data efi_runtime_services = {
 374         .hdr = {
 375                 .signature = EFI_RUNTIME_SERVICES_SIGNATURE,
 376                 .revision = EFI_RUNTIME_SERVICES_REVISION,
 377                 .headersize = sizeof(struct efi_table_hdr),
 378         },
 379         .get_time = &efi_get_time_boottime,
 380         .set_time = (void *)&efi_device_error,
 381         .get_wakeup_time = (void *)&efi_unimplemented,
 382         .set_wakeup_time = (void *)&efi_unimplemented,
 383         .set_virtual_address_map = &efi_set_virtual_address_map,
 384         .convert_pointer = (void *)&efi_invalid_parameter,
 385         .get_variable = (void *)&efi_device_error,
 386         .get_next_variable = (void *)&efi_device_error,
 387         .set_variable = (void *)&efi_device_error,
 388         .get_next_high_mono_count = (void *)&efi_device_error,
 389         .reset_system = &efi_reset_system_boottime,
 390 };