1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Author: Erik Kaneda <erik.kaneda@intel.com> 4 * Copyright 2020 Intel Corporation 5 * 6 * prmt.c 7 * 8 * Each PRM service is an executable that is run in a restricted environment 9 * that is invoked by writing to the PlatformRtMechanism OperationRegion from 10 * AML bytecode. 11 * 12 * init_prmt initializes the Platform Runtime Mechanism (PRM) services by 13 * processing data in the PRMT as well as registering an ACPI OperationRegion 14 * handler for the PlatformRtMechanism subtype. 15 * 16 */ 17 #include <linux/kernel.h> 18 #include <linux/efi.h> 19 #include <linux/acpi.h> 20 #include <linux/prmt.h> 21 #include <asm/efi.h> 22 23 #pragma pack(1) 24 struct prm_mmio_addr_range { 25 u64 phys_addr; 26 u64 virt_addr; 27 u32 length; 28 }; 29 30 struct prm_mmio_info { 31 u64 mmio_count; 32 struct prm_mmio_addr_range addr_ranges[]; 33 }; 34 35 struct prm_buffer { 36 u8 prm_status; 37 u64 efi_status; 38 u8 prm_cmd; 39 guid_t handler_guid; 40 }; 41 42 struct prm_context_buffer { 43 char signature[ACPI_NAMESEG_SIZE]; 44 u16 revision; 45 u16 reserved; 46 guid_t identifier; 47 u64 static_data_buffer; 48 struct prm_mmio_info *mmio_ranges; 49 }; 50 #pragma pack() 51 52 static LIST_HEAD(prm_module_list); 53 54 struct prm_handler_info { 55 efi_guid_t guid; 56 efi_status_t (__efiapi *handler_addr)(u64, void *); 57 u64 static_data_buffer_addr; 58 u64 acpi_param_buffer_addr; 59 60 struct list_head handler_list; 61 }; 62 63 struct prm_module_info { 64 guid_t guid; 65 u16 major_rev; 66 u16 minor_rev; 67 u16 handler_count; 68 struct prm_mmio_info *mmio_info; 69 bool updatable; 70 71 struct list_head module_list; 72 struct prm_handler_info handlers[] __counted_by(handler_count); 73 }; 74 75 static u64 efi_pa_va_lookup(efi_guid_t *guid, u64 pa) 76 { 77 efi_memory_desc_t *md; 78 u64 pa_offset = pa & ~PAGE_MASK; 79 u64 page = pa & PAGE_MASK; 80 81 for_each_efi_memory_desc(md) { 82 if ((md->attribute & EFI_MEMORY_RUNTIME) && 83 (md->phys_addr < pa && pa < md->phys_addr + PAGE_SIZE * md->num_pages)) { 84 return pa_offset + md->virt_addr + page - md->phys_addr; 85 } 86 } 87 88 pr_warn("Failed to find VA for GUID: %pUL, PA: 0x%llx", guid, pa); 89 90 return 0; 91 } 92 93 #define get_first_handler(a) ((struct acpi_prmt_handler_info *) ((char *) (a) + a->handler_info_offset)) 94 #define get_next_handler(a) ((struct acpi_prmt_handler_info *) (sizeof(struct acpi_prmt_handler_info) + (char *) a)) 95 96 static int __init 97 acpi_parse_prmt(union acpi_subtable_headers *header, const unsigned long end) 98 { 99 struct acpi_prmt_module_info *module_info; 100 struct acpi_prmt_handler_info *handler_info; 101 struct prm_handler_info *th; 102 struct prm_module_info *tm; 103 u64 *mmio_count; 104 u64 cur_handler = 0; 105 u32 module_info_size = 0; 106 u64 mmio_range_size = 0; 107 void *temp_mmio; 108 109 module_info = (struct acpi_prmt_module_info *) header; 110 module_info_size = struct_size(tm, handlers, module_info->handler_info_count); 111 tm = kmalloc(module_info_size, GFP_KERNEL); 112 if (!tm) 113 goto parse_prmt_out1; 114 115 guid_copy(&tm->guid, (guid_t *) module_info->module_guid); 116 tm->major_rev = module_info->major_rev; 117 tm->minor_rev = module_info->minor_rev; 118 tm->handler_count = module_info->handler_info_count; 119 tm->updatable = true; 120 121 if (module_info->mmio_list_pointer) { 122 /* 123 * Each module is associated with a list of addr 124 * ranges that it can use during the service 125 */ 126 mmio_count = (u64 *) memremap(module_info->mmio_list_pointer, 8, MEMREMAP_WB); 127 if (!mmio_count) 128 goto parse_prmt_out2; 129 130 mmio_range_size = struct_size(tm->mmio_info, addr_ranges, *mmio_count); 131 tm->mmio_info = kmalloc(mmio_range_size, GFP_KERNEL); 132 if (!tm->mmio_info) 133 goto parse_prmt_out3; 134 135 temp_mmio = memremap(module_info->mmio_list_pointer, mmio_range_size, MEMREMAP_WB); 136 if (!temp_mmio) 137 goto parse_prmt_out4; 138 memmove(tm->mmio_info, temp_mmio, mmio_range_size); 139 } else { 140 tm->mmio_info = kmalloc(sizeof(*tm->mmio_info), GFP_KERNEL); 141 if (!tm->mmio_info) 142 goto parse_prmt_out2; 143 144 tm->mmio_info->mmio_count = 0; 145 } 146 147 INIT_LIST_HEAD(&tm->module_list); 148 list_add(&tm->module_list, &prm_module_list); 149 150 handler_info = get_first_handler(module_info); 151 do { 152 th = &tm->handlers[cur_handler]; 153 154 guid_copy(&th->guid, (guid_t *)handler_info->handler_guid); 155 th->handler_addr = 156 (void *)efi_pa_va_lookup(&th->guid, handler_info->handler_address); 157 158 th->static_data_buffer_addr = 159 efi_pa_va_lookup(&th->guid, handler_info->static_data_buffer_address); 160 161 th->acpi_param_buffer_addr = 162 efi_pa_va_lookup(&th->guid, handler_info->acpi_param_buffer_address); 163 164 } while (++cur_handler < tm->handler_count && (handler_info = get_next_handler(handler_info))); 165 166 return 0; 167 168 parse_prmt_out4: 169 kfree(tm->mmio_info); 170 parse_prmt_out3: 171 memunmap(mmio_count); 172 parse_prmt_out2: 173 kfree(tm); 174 parse_prmt_out1: 175 return -ENOMEM; 176 } 177 178 #define GET_MODULE 0 179 #define GET_HANDLER 1 180 181 static void *find_guid_info(const guid_t *guid, u8 mode) 182 { 183 struct prm_handler_info *cur_handler; 184 struct prm_module_info *cur_module; 185 int i = 0; 186 187 list_for_each_entry(cur_module, &prm_module_list, module_list) { 188 for (i = 0; i < cur_module->handler_count; ++i) { 189 cur_handler = &cur_module->handlers[i]; 190 if (guid_equal(guid, &cur_handler->guid)) { 191 if (mode == GET_MODULE) 192 return (void *)cur_module; 193 else 194 return (void *)cur_handler; 195 } 196 } 197 } 198 199 return NULL; 200 } 201 202 static struct prm_module_info *find_prm_module(const guid_t *guid) 203 { 204 return (struct prm_module_info *)find_guid_info(guid, GET_MODULE); 205 } 206 207 static struct prm_handler_info *find_prm_handler(const guid_t *guid) 208 { 209 return (struct prm_handler_info *) find_guid_info(guid, GET_HANDLER); 210 } 211 212 /* In-coming PRM commands */ 213 214 #define PRM_CMD_RUN_SERVICE 0 215 #define PRM_CMD_START_TRANSACTION 1 216 #define PRM_CMD_END_TRANSACTION 2 217 218 /* statuses that can be passed back to ASL */ 219 220 #define PRM_HANDLER_SUCCESS 0 221 #define PRM_HANDLER_ERROR 1 222 #define INVALID_PRM_COMMAND 2 223 #define PRM_HANDLER_GUID_NOT_FOUND 3 224 #define UPDATE_LOCK_ALREADY_HELD 4 225 #define UPDATE_UNLOCK_WITHOUT_LOCK 5 226 227 int acpi_call_prm_handler(guid_t handler_guid, void *param_buffer) 228 { 229 struct prm_handler_info *handler = find_prm_handler(&handler_guid); 230 struct prm_module_info *module = find_prm_module(&handler_guid); 231 struct prm_context_buffer context; 232 efi_status_t status; 233 234 if (!module || !handler) 235 return -ENODEV; 236 237 memset(&context, 0, sizeof(context)); 238 ACPI_COPY_NAMESEG(context.signature, "PRMC"); 239 context.identifier = handler->guid; 240 context.static_data_buffer = handler->static_data_buffer_addr; 241 context.mmio_ranges = module->mmio_info; 242 243 status = efi_call_acpi_prm_handler(handler->handler_addr, 244 (u64)param_buffer, 245 &context); 246 247 return efi_status_to_err(status); 248 } 249 EXPORT_SYMBOL_GPL(acpi_call_prm_handler); 250 251 /* 252 * This is the PlatformRtMechanism opregion space handler. 253 * @function: indicates the read/write. In fact as the PlatformRtMechanism 254 * message is driven by command, only write is meaningful. 255 * 256 * @addr : not used 257 * @bits : not used. 258 * @value : it is an in/out parameter. It points to the PRM message buffer. 259 * @handler_context: not used 260 */ 261 static acpi_status acpi_platformrt_space_handler(u32 function, 262 acpi_physical_address addr, 263 u32 bits, acpi_integer *value, 264 void *handler_context, 265 void *region_context) 266 { 267 struct prm_buffer *buffer = ACPI_CAST_PTR(struct prm_buffer, value); 268 struct prm_handler_info *handler; 269 struct prm_module_info *module; 270 efi_status_t status; 271 struct prm_context_buffer context; 272 273 if (!efi_enabled(EFI_RUNTIME_SERVICES)) { 274 pr_err_ratelimited("PRM: EFI runtime services no longer available\n"); 275 return AE_NO_HANDLER; 276 } 277 278 /* 279 * The returned acpi_status will always be AE_OK. Error values will be 280 * saved in the first byte of the PRM message buffer to be used by ASL. 281 */ 282 switch (buffer->prm_cmd) { 283 case PRM_CMD_RUN_SERVICE: 284 285 handler = find_prm_handler(&buffer->handler_guid); 286 module = find_prm_module(&buffer->handler_guid); 287 if (!handler || !module) 288 goto invalid_guid; 289 290 if (!handler->handler_addr || 291 !handler->static_data_buffer_addr || 292 !handler->acpi_param_buffer_addr) { 293 buffer->prm_status = PRM_HANDLER_ERROR; 294 return AE_OK; 295 } 296 297 ACPI_COPY_NAMESEG(context.signature, "PRMC"); 298 context.revision = 0x0; 299 context.reserved = 0x0; 300 context.identifier = handler->guid; 301 context.static_data_buffer = handler->static_data_buffer_addr; 302 context.mmio_ranges = module->mmio_info; 303 304 status = efi_call_acpi_prm_handler(handler->handler_addr, 305 handler->acpi_param_buffer_addr, 306 &context); 307 if (status == EFI_SUCCESS) { 308 buffer->prm_status = PRM_HANDLER_SUCCESS; 309 } else { 310 buffer->prm_status = PRM_HANDLER_ERROR; 311 buffer->efi_status = status; 312 } 313 break; 314 315 case PRM_CMD_START_TRANSACTION: 316 317 module = find_prm_module(&buffer->handler_guid); 318 if (!module) 319 goto invalid_guid; 320 321 if (module->updatable) 322 module->updatable = false; 323 else 324 buffer->prm_status = UPDATE_LOCK_ALREADY_HELD; 325 break; 326 327 case PRM_CMD_END_TRANSACTION: 328 329 module = find_prm_module(&buffer->handler_guid); 330 if (!module) 331 goto invalid_guid; 332 333 if (module->updatable) 334 buffer->prm_status = UPDATE_UNLOCK_WITHOUT_LOCK; 335 else 336 module->updatable = true; 337 break; 338 339 default: 340 341 buffer->prm_status = INVALID_PRM_COMMAND; 342 break; 343 } 344 345 return AE_OK; 346 347 invalid_guid: 348 buffer->prm_status = PRM_HANDLER_GUID_NOT_FOUND; 349 return AE_OK; 350 } 351 352 void __init init_prmt(void) 353 { 354 struct acpi_table_header *tbl; 355 acpi_status status; 356 int mc; 357 358 status = acpi_get_table(ACPI_SIG_PRMT, 0, &tbl); 359 if (ACPI_FAILURE(status)) 360 return; 361 362 mc = acpi_table_parse_entries(ACPI_SIG_PRMT, sizeof(struct acpi_table_prmt) + 363 sizeof (struct acpi_table_prmt_header), 364 0, acpi_parse_prmt, 0); 365 acpi_put_table(tbl); 366 /* 367 * Return immediately if PRMT table is not present or no PRM module found. 368 */ 369 if (mc <= 0) 370 return; 371 372 pr_info("PRM: found %u modules\n", mc); 373 374 if (!efi_enabled(EFI_RUNTIME_SERVICES)) { 375 pr_err("PRM: EFI runtime services unavailable\n"); 376 return; 377 } 378 379 status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT, 380 ACPI_ADR_SPACE_PLATFORM_RT, 381 &acpi_platformrt_space_handler, 382 NULL, NULL); 383 if (ACPI_FAILURE(status)) 384 pr_alert("PRM: OperationRegion handler could not be installed\n"); 385 } 386