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[]; 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 /* 228 * This is the PlatformRtMechanism opregion space handler. 229 * @function: indicates the read/write. In fact as the PlatformRtMechanism 230 * message is driven by command, only write is meaningful. 231 * 232 * @addr : not used 233 * @bits : not used. 234 * @value : it is an in/out parameter. It points to the PRM message buffer. 235 * @handler_context: not used 236 */ 237 static acpi_status acpi_platformrt_space_handler(u32 function, 238 acpi_physical_address addr, 239 u32 bits, acpi_integer *value, 240 void *handler_context, 241 void *region_context) 242 { 243 struct prm_buffer *buffer = ACPI_CAST_PTR(struct prm_buffer, value); 244 struct prm_handler_info *handler; 245 struct prm_module_info *module; 246 efi_status_t status; 247 struct prm_context_buffer context; 248 249 if (!efi_enabled(EFI_RUNTIME_SERVICES)) { 250 pr_err_ratelimited("PRM: EFI runtime services no longer available\n"); 251 return AE_NO_HANDLER; 252 } 253 254 /* 255 * The returned acpi_status will always be AE_OK. Error values will be 256 * saved in the first byte of the PRM message buffer to be used by ASL. 257 */ 258 switch (buffer->prm_cmd) { 259 case PRM_CMD_RUN_SERVICE: 260 261 handler = find_prm_handler(&buffer->handler_guid); 262 module = find_prm_module(&buffer->handler_guid); 263 if (!handler || !module) 264 goto invalid_guid; 265 266 if (!handler->handler_addr || 267 !handler->static_data_buffer_addr || 268 !handler->acpi_param_buffer_addr) { 269 buffer->prm_status = PRM_HANDLER_ERROR; 270 return AE_OK; 271 } 272 273 ACPI_COPY_NAMESEG(context.signature, "PRMC"); 274 context.revision = 0x0; 275 context.reserved = 0x0; 276 context.identifier = handler->guid; 277 context.static_data_buffer = handler->static_data_buffer_addr; 278 context.mmio_ranges = module->mmio_info; 279 280 status = efi_call_acpi_prm_handler(handler->handler_addr, 281 handler->acpi_param_buffer_addr, 282 &context); 283 if (status == EFI_SUCCESS) { 284 buffer->prm_status = PRM_HANDLER_SUCCESS; 285 } else { 286 buffer->prm_status = PRM_HANDLER_ERROR; 287 buffer->efi_status = status; 288 } 289 break; 290 291 case PRM_CMD_START_TRANSACTION: 292 293 module = find_prm_module(&buffer->handler_guid); 294 if (!module) 295 goto invalid_guid; 296 297 if (module->updatable) 298 module->updatable = false; 299 else 300 buffer->prm_status = UPDATE_LOCK_ALREADY_HELD; 301 break; 302 303 case PRM_CMD_END_TRANSACTION: 304 305 module = find_prm_module(&buffer->handler_guid); 306 if (!module) 307 goto invalid_guid; 308 309 if (module->updatable) 310 buffer->prm_status = UPDATE_UNLOCK_WITHOUT_LOCK; 311 else 312 module->updatable = true; 313 break; 314 315 default: 316 317 buffer->prm_status = INVALID_PRM_COMMAND; 318 break; 319 } 320 321 return AE_OK; 322 323 invalid_guid: 324 buffer->prm_status = PRM_HANDLER_GUID_NOT_FOUND; 325 return AE_OK; 326 } 327 328 void __init init_prmt(void) 329 { 330 struct acpi_table_header *tbl; 331 acpi_status status; 332 int mc; 333 334 status = acpi_get_table(ACPI_SIG_PRMT, 0, &tbl); 335 if (ACPI_FAILURE(status)) 336 return; 337 338 mc = acpi_table_parse_entries(ACPI_SIG_PRMT, sizeof(struct acpi_table_prmt) + 339 sizeof (struct acpi_table_prmt_header), 340 0, acpi_parse_prmt, 0); 341 acpi_put_table(tbl); 342 /* 343 * Return immediately if PRMT table is not present or no PRM module found. 344 */ 345 if (mc <= 0) 346 return; 347 348 pr_info("PRM: found %u modules\n", mc); 349 350 if (!efi_enabled(EFI_RUNTIME_SERVICES)) { 351 pr_err("PRM: EFI runtime services unavailable\n"); 352 return; 353 } 354 355 status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT, 356 ACPI_ADR_SPACE_PLATFORM_RT, 357 &acpi_platformrt_space_handler, 358 NULL, NULL); 359 if (ACPI_FAILURE(status)) 360 pr_alert("PRM: OperationRegion handler could not be installed\n"); 361 } 362