Rocky Phagura | afb7a81 | 2020-07-21 14:48:48 -0700 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
| 2 | |
| 3 | #include <stdint.h> |
| 4 | #include <string.h> |
| 5 | #include <rmodule.h> |
| 6 | #include <cpu/x86/smm.h> |
| 7 | #include <commonlib/helpers.h> |
| 8 | #include <console/console.h> |
| 9 | #include <security/intel/stm/SmmStm.h> |
| 10 | |
| 11 | #define FXSAVE_SIZE 512 |
| 12 | #define SMM_CODE_SEGMENT_SIZE 0x10000 |
| 13 | /* FXSAVE area during relocation. While it may not be strictly needed the |
| 14 | SMM stub code relies on the FXSAVE area being non-zero to enable SSE |
| 15 | instructions within SMM mode. */ |
| 16 | static uint8_t fxsave_area_relocation[CONFIG_MAX_CPUS][FXSAVE_SIZE] |
| 17 | __attribute__((aligned(16))); |
| 18 | |
| 19 | /* |
| 20 | * Components that make up the SMRAM: |
| 21 | * 1. Save state - the total save state memory used |
| 22 | * 2. Stack - stacks for the CPUs in the SMM handler |
| 23 | * 3. Stub - SMM stub code for calling into handler |
| 24 | * 4. Handler - C-based SMM handler. |
| 25 | * |
| 26 | * The components are assumed to consist of one consecutive region. |
| 27 | */ |
| 28 | |
| 29 | /* These parameters are used by the SMM stub code. A pointer to the params |
| 30 | * is also passed to the C-base handler. */ |
| 31 | struct smm_stub_params { |
| 32 | u32 stack_size; |
| 33 | u32 stack_top; |
| 34 | u32 c_handler; |
| 35 | u32 c_handler_arg; |
| 36 | u32 fxsave_area; |
| 37 | u32 fxsave_area_size; |
| 38 | struct smm_runtime runtime; |
| 39 | } __packed; |
| 40 | |
| 41 | /* |
| 42 | * The stub is the entry point that sets up protected mode and stacks for each |
| 43 | * CPU. It then calls into the SMM handler module. It is encoded as an rmodule. |
| 44 | */ |
| 45 | extern unsigned char _binary_smmstub_start[]; |
| 46 | |
| 47 | /* Per CPU minimum stack size. */ |
| 48 | #define SMM_MINIMUM_STACK_SIZE 32 |
| 49 | |
| 50 | struct cpu_smm_info { |
| 51 | uint8_t active; |
| 52 | uintptr_t smbase; |
| 53 | uintptr_t entry; |
| 54 | uintptr_t ss_start; |
| 55 | uintptr_t code_start; |
| 56 | uintptr_t code_end; |
| 57 | }; |
| 58 | struct cpu_smm_info cpus[CONFIG_MAX_CPUS] = { 0 }; |
| 59 | |
| 60 | /* |
| 61 | * This method creates a map of all the CPU entry points, save state locations |
| 62 | * and the beginning and end of code segments for each CPU. This map is used |
| 63 | * during relocation to properly align as many CPUs that can fit into the SMRAM |
| 64 | * region. For more information on how SMRAM works, refer to the latest Intel |
| 65 | * developer's manuals (volume 3, chapter 34). SMRAM is divided up into the |
| 66 | * following regions: |
| 67 | * +-----------------+ Top of SMRAM |
| 68 | * | | <- MSEG, FXSAVE |
| 69 | * +-----------------+ |
| 70 | * | common | |
| 71 | * | smi handler | 64K |
| 72 | * | | |
| 73 | * +-----------------+ |
| 74 | * | CPU 0 code seg | |
| 75 | * +-----------------+ |
| 76 | * | CPU 1 code seg | |
| 77 | * +-----------------+ |
| 78 | * | CPU x code seg | |
| 79 | * +-----------------+ |
| 80 | * | | |
| 81 | * | | |
| 82 | * +-----------------+ |
| 83 | * | stacks | |
| 84 | * +-----------------+ <- START of SMRAM |
| 85 | * |
| 86 | * The code below checks when a code segment is full and begins placing the remainder |
| 87 | * CPUs in the lower segments. The entry point for each CPU is smbase + 0x8000 |
| 88 | * and save state is smbase + 0x8000 + (0x8000 - state save size). Save state |
| 89 | * area grows downward into the CPUs entry point. Therefore staggering too many |
| 90 | * CPUs in one 32K block will corrupt CPU0's entry code as the save states move |
| 91 | * downward. |
| 92 | * input : smbase of first CPU (all other CPUs |
| 93 | * will go below this address) |
| 94 | * input : num_cpus in the system. The map will |
| 95 | * be created from 0 to num_cpus. |
| 96 | */ |
| 97 | static int smm_create_map(uintptr_t smbase, unsigned int num_cpus, |
| 98 | const struct smm_loader_params *params) |
| 99 | { |
| 100 | unsigned int i; |
| 101 | struct rmodule smm_stub; |
| 102 | unsigned int ss_size = params->per_cpu_save_state_size, stub_size; |
| 103 | unsigned int smm_entry_offset = params->smm_main_entry_offset; |
| 104 | unsigned int seg_count = 0, segments = 0, available; |
| 105 | unsigned int cpus_in_segment = 0; |
| 106 | unsigned int base = smbase; |
| 107 | |
| 108 | if (rmodule_parse(&_binary_smmstub_start, &smm_stub)) { |
| 109 | printk(BIOS_ERR, "%s: unable to get SMM module size\n", __func__); |
| 110 | return 0; |
| 111 | } |
| 112 | |
| 113 | stub_size = rmodule_memory_size(&smm_stub); |
| 114 | /* How many CPUs can fit into one 64K segment? */ |
| 115 | available = 0xFFFF - smm_entry_offset - ss_size - stub_size; |
| 116 | if (available > 0) { |
| 117 | cpus_in_segment = available / ss_size; |
| 118 | /* minimum segments needed will always be 1 */ |
| 119 | segments = num_cpus / cpus_in_segment + 1; |
| 120 | printk(BIOS_DEBUG, |
| 121 | "%s: cpus allowed in one segment %d\n", __func__, cpus_in_segment); |
| 122 | printk(BIOS_DEBUG, |
| 123 | "%s: min # of segments needed %d\n", __func__, segments); |
| 124 | } else { |
| 125 | printk(BIOS_ERR, "%s: not enough space in SMM to setup all CPUs\n", __func__); |
| 126 | printk(BIOS_ERR, " save state & stub size need to be reduced\n"); |
| 127 | printk(BIOS_ERR, " or increase SMRAM size\n"); |
| 128 | return 0; |
| 129 | } |
| 130 | |
| 131 | if (sizeof(cpus) / sizeof(struct cpu_smm_info) < num_cpus) { |
| 132 | printk(BIOS_ERR, |
| 133 | "%s: increase MAX_CPUS in Kconfig\n", __func__); |
| 134 | return 0; |
| 135 | } |
| 136 | |
Arthur Heymans | fd8619e | 2020-11-01 12:37:40 +0100 | [diff] [blame] | 137 | if (stub_size > ss_size) { |
| 138 | printk(BIOS_ERR, "%s: Save state larger than SMM stub size\n", __func__); |
| 139 | printk(BIOS_ERR, " Decrease stub size or increase the size allocated for the save state\n"); |
| 140 | return 0; |
| 141 | } |
| 142 | |
Rocky Phagura | afb7a81 | 2020-07-21 14:48:48 -0700 | [diff] [blame] | 143 | for (i = 0; i < num_cpus; i++) { |
| 144 | cpus[i].smbase = base; |
| 145 | cpus[i].entry = base + smm_entry_offset; |
| 146 | cpus[i].ss_start = cpus[i].entry + (smm_entry_offset - ss_size); |
| 147 | cpus[i].code_start = cpus[i].entry; |
| 148 | cpus[i].code_end = cpus[i].entry + stub_size; |
| 149 | cpus[i].active = 1; |
| 150 | base -= ss_size; |
| 151 | seg_count++; |
| 152 | if (seg_count >= cpus_in_segment) { |
| 153 | base -= smm_entry_offset; |
| 154 | seg_count = 0; |
| 155 | } |
| 156 | } |
| 157 | |
| 158 | if (CONFIG_DEFAULT_CONSOLE_LOGLEVEL >= BIOS_DEBUG) { |
| 159 | seg_count = 0; |
| 160 | for (i = 0; i < num_cpus; i++) { |
| 161 | printk(BIOS_DEBUG, "CPU 0x%x\n", i); |
| 162 | printk(BIOS_DEBUG, |
| 163 | " smbase %zx entry %zx\n", |
| 164 | cpus[i].smbase, cpus[i].entry); |
| 165 | printk(BIOS_DEBUG, |
| 166 | " ss_start %zx code_end %zx\n", |
| 167 | cpus[i].ss_start, cpus[i].code_end); |
| 168 | seg_count++; |
| 169 | if (seg_count >= cpus_in_segment) { |
| 170 | printk(BIOS_DEBUG, |
| 171 | "-------------NEW CODE SEGMENT --------------\n"); |
| 172 | seg_count = 0; |
| 173 | } |
| 174 | } |
| 175 | } |
| 176 | return 1; |
| 177 | } |
| 178 | |
| 179 | /* |
| 180 | * This method expects the smm relocation map to be complete. |
| 181 | * This method does not read any HW registers, it simply uses a |
| 182 | * map that was created during SMM setup. |
| 183 | * input: cpu_num - cpu number which is used as an index into the |
| 184 | * map to return the smbase |
| 185 | */ |
| 186 | u32 smm_get_cpu_smbase(unsigned int cpu_num) |
| 187 | { |
| 188 | if (cpu_num < CONFIG_MAX_CPUS) { |
| 189 | if (cpus[cpu_num].active) |
| 190 | return cpus[cpu_num].smbase; |
| 191 | } |
| 192 | return 0; |
| 193 | } |
| 194 | |
| 195 | /* |
| 196 | * This method assumes that at least 1 CPU has been set up from |
| 197 | * which it will place other CPUs below its smbase ensuring that |
| 198 | * save state does not clobber the first CPUs init code segment. The init |
| 199 | * code which is the smm stub code is the same for all CPUs. They enter |
| 200 | * smm, setup stacks (based on their apic id), enter protected mode |
| 201 | * and then jump to the common smi handler. The stack is allocated |
| 202 | * at the beginning of smram (aka tseg base, not smbase). The stack |
| 203 | * pointer for each CPU is calculated by using its apic id |
| 204 | * (code is in smm_stub.s) |
| 205 | * Each entry point will now have the same stub code which, sets up the CPU |
| 206 | * stack, enters protected mode and then jumps to the smi handler. It is |
| 207 | * important to enter protected mode before the jump because the "jump to |
| 208 | * address" might be larger than the 20bit address supported by real mode. |
| 209 | * SMI entry right now is in real mode. |
| 210 | * input: smbase - this is the smbase of the first cpu not the smbase |
| 211 | * where tseg starts (aka smram_start). All CPUs code segment |
| 212 | * and stack will be below this point except for the common |
| 213 | * SMI handler which is one segment above |
| 214 | * input: num_cpus - number of cpus that need relocation including |
| 215 | * the first CPU (though its code is already loaded) |
| 216 | * input: top of stack (stacks work downward by default in Intel HW) |
| 217 | * output: return -1, if runtime smi code could not be installed. In |
| 218 | * this case SMM will not work and any SMI's generated will |
| 219 | * cause a CPU shutdown or general protection fault because |
| 220 | * the appropriate smi handling code was not installed |
| 221 | */ |
| 222 | |
| 223 | static int smm_place_entry_code(uintptr_t smbase, unsigned int num_cpus, |
Arthur Heymans | 9ddd900 | 2020-12-03 11:02:42 +0100 | [diff] [blame^] | 224 | uintptr_t stack_top, const struct smm_loader_params *params) |
Rocky Phagura | afb7a81 | 2020-07-21 14:48:48 -0700 | [diff] [blame] | 225 | { |
| 226 | unsigned int i; |
| 227 | unsigned int size; |
| 228 | if (smm_create_map(smbase, num_cpus, params)) { |
| 229 | /* |
| 230 | * Ensure there was enough space and the last CPUs smbase |
| 231 | * did not encroach upon the stack. Stack top is smram start |
| 232 | * + size of stack. |
| 233 | */ |
| 234 | if (cpus[num_cpus].active) { |
| 235 | if (cpus[num_cpus - 1].smbase + |
| 236 | params->smm_main_entry_offset < stack_top) { |
| 237 | printk(BIOS_ERR, "%s: stack encroachment\n", __func__); |
Arthur Heymans | 9ddd900 | 2020-12-03 11:02:42 +0100 | [diff] [blame^] | 238 | printk(BIOS_ERR, "%s: smbase %zx, stack_top %lx\n", |
Rocky Phagura | afb7a81 | 2020-07-21 14:48:48 -0700 | [diff] [blame] | 239 | __func__, cpus[num_cpus].smbase, stack_top); |
| 240 | return 0; |
| 241 | } |
| 242 | } |
| 243 | } else { |
| 244 | printk(BIOS_ERR, "%s: unable to place smm entry code\n", __func__); |
| 245 | return 0; |
| 246 | } |
| 247 | |
Arthur Heymans | 9ddd900 | 2020-12-03 11:02:42 +0100 | [diff] [blame^] | 248 | printk(BIOS_INFO, "%s: smbase %zx, stack_top %lx\n", |
Rocky Phagura | afb7a81 | 2020-07-21 14:48:48 -0700 | [diff] [blame] | 249 | __func__, cpus[num_cpus-1].smbase, stack_top); |
| 250 | |
| 251 | /* start at 1, the first CPU stub code is already there */ |
| 252 | size = cpus[0].code_end - cpus[0].code_start; |
| 253 | for (i = 1; i < num_cpus; i++) { |
| 254 | memcpy((int *)cpus[i].code_start, (int *)cpus[0].code_start, size); |
| 255 | printk(BIOS_DEBUG, |
| 256 | "SMM Module: placing smm entry code at %zx, cpu # 0x%x\n", |
| 257 | cpus[i].code_start, i); |
| 258 | printk(BIOS_DEBUG, "%s: copying from %zx to %zx 0x%x bytes\n", |
| 259 | __func__, cpus[0].code_start, cpus[i].code_start, size); |
| 260 | } |
| 261 | return 1; |
| 262 | } |
| 263 | |
| 264 | /* |
| 265 | * Place stacks in base -> base + size region, but ensure the stacks don't |
| 266 | * overlap the staggered entry points. |
| 267 | */ |
| 268 | static void *smm_stub_place_stacks(char *base, size_t size, |
| 269 | struct smm_loader_params *params) |
| 270 | { |
| 271 | size_t total_stack_size; |
| 272 | char *stacks_top; |
| 273 | |
| 274 | /* If stack space is requested assume the space lives in the lower |
| 275 | * half of SMRAM. */ |
| 276 | total_stack_size = params->per_cpu_stack_size * |
| 277 | params->num_concurrent_stacks; |
| 278 | printk(BIOS_DEBUG, "%s: cpus: %zx : stack space: needed -> %zx\n", |
| 279 | __func__, params->num_concurrent_stacks, |
| 280 | total_stack_size); |
| 281 | printk(BIOS_DEBUG, " available -> %zx : per_cpu_stack_size : %zx\n", |
| 282 | size, params->per_cpu_stack_size); |
| 283 | |
| 284 | /* There has to be at least one stack user. */ |
| 285 | if (params->num_concurrent_stacks < 1) |
| 286 | return NULL; |
| 287 | |
| 288 | /* Total stack size cannot fit. */ |
| 289 | if (total_stack_size > size) |
| 290 | return NULL; |
| 291 | |
| 292 | /* Stacks extend down to SMBASE */ |
| 293 | stacks_top = &base[total_stack_size]; |
| 294 | printk(BIOS_DEBUG, "%s: exit, stack_top %p\n", __func__, stacks_top); |
| 295 | |
| 296 | return stacks_top; |
| 297 | } |
| 298 | |
| 299 | /* |
| 300 | * Place the staggered entry points for each CPU. The entry points are |
| 301 | * staggered by the per CPU SMM save state size extending down from |
| 302 | * SMM_ENTRY_OFFSET. |
| 303 | */ |
| 304 | static int smm_stub_place_staggered_entry_points(char *base, |
| 305 | const struct smm_loader_params *params, const struct rmodule *smm_stub) |
| 306 | { |
| 307 | size_t stub_entry_offset; |
| 308 | int rc = 1; |
| 309 | stub_entry_offset = rmodule_entry_offset(smm_stub); |
| 310 | /* Each CPU now has its own stub code, which enters protected mode, |
| 311 | * sets up the stack, and then jumps to common SMI handler |
| 312 | */ |
| 313 | if (params->num_concurrent_save_states > 1 || stub_entry_offset != 0) { |
Arthur Heymans | 9ddd900 | 2020-12-03 11:02:42 +0100 | [diff] [blame^] | 314 | rc = smm_place_entry_code((uintptr_t)base, |
| 315 | params->num_concurrent_save_states, |
| 316 | (uintptr_t)params->stack_top, params); |
Rocky Phagura | afb7a81 | 2020-07-21 14:48:48 -0700 | [diff] [blame] | 317 | } |
| 318 | return rc; |
| 319 | } |
| 320 | |
| 321 | /* |
| 322 | * The stub setup code assumes it is completely contained within the |
| 323 | * default SMRAM size (0x10000) for the default SMI handler (entry at |
| 324 | * 0x30000), but no assumption should be made for the permanent SMI handler. |
| 325 | * The placement of CPU entry points for permanent handler are determined |
| 326 | * by the number of CPUs in the system and the amount of SMRAM. |
| 327 | * There are potentially 3 regions to place |
| 328 | * within the default SMRAM size: |
| 329 | * 1. Save state areas |
| 330 | * 2. Stub code |
| 331 | * 3. Stack areas |
| 332 | * |
| 333 | * The save state and smm stack are treated as contiguous for the number of |
| 334 | * concurrent areas requested. The save state always lives at the top of the |
| 335 | * the CPUS smbase (and the entry point is at offset 0x8000). This allows only a certain |
| 336 | * number of CPUs with staggered entry points until the save state area comes |
| 337 | * down far enough to overwrite/corrupt the entry code (stub code). Therefore, |
| 338 | * an SMM map is created to avoid this corruption, see smm_create_map() above. |
| 339 | * This module setup code works for the default (0x30000) SMM handler setup and the |
| 340 | * permanent SMM handler. |
| 341 | */ |
| 342 | static int smm_module_setup_stub(void *smbase, size_t smm_size, |
| 343 | struct smm_loader_params *params, |
| 344 | void *fxsave_area) |
| 345 | { |
| 346 | size_t total_save_state_size; |
| 347 | size_t smm_stub_size; |
| 348 | size_t stub_entry_offset; |
| 349 | char *smm_stub_loc; |
| 350 | void *stacks_top; |
| 351 | size_t size; |
| 352 | char *base; |
| 353 | size_t i; |
| 354 | struct smm_stub_params *stub_params; |
| 355 | struct rmodule smm_stub; |
| 356 | unsigned int total_size_all; |
| 357 | base = smbase; |
| 358 | size = smm_size; |
| 359 | |
| 360 | /* The number of concurrent stacks cannot exceed CONFIG_MAX_CPUS. */ |
| 361 | if (params->num_concurrent_stacks > CONFIG_MAX_CPUS) { |
| 362 | printk(BIOS_ERR, "%s: not enough stacks\n", __func__); |
| 363 | return -1; |
| 364 | } |
| 365 | |
| 366 | /* Fail if can't parse the smm stub rmodule. */ |
| 367 | if (rmodule_parse(&_binary_smmstub_start, &smm_stub)) { |
| 368 | printk(BIOS_ERR, "%s: unable to parse smm stub\n", __func__); |
| 369 | return -1; |
| 370 | } |
| 371 | |
| 372 | /* Adjust remaining size to account for save state. */ |
| 373 | total_save_state_size = params->per_cpu_save_state_size * |
| 374 | params->num_concurrent_save_states; |
| 375 | if (total_save_state_size > size) { |
| 376 | printk(BIOS_ERR, |
| 377 | "%s: more state save space needed:need -> %zx:available->%zx\n", |
| 378 | __func__, total_save_state_size, size); |
| 379 | return -1; |
| 380 | } |
| 381 | |
| 382 | size -= total_save_state_size; |
| 383 | |
| 384 | /* The save state size encroached over the first SMM entry point. */ |
| 385 | if (size <= params->smm_main_entry_offset) { |
| 386 | printk(BIOS_ERR, "%s: encroachment over SMM entry point\n", __func__); |
Arthur Heymans | 9ddd900 | 2020-12-03 11:02:42 +0100 | [diff] [blame^] | 387 | printk(BIOS_ERR, "%s: state save size: %zx : smm_entry_offset -> %lx\n", |
Rocky Phagura | afb7a81 | 2020-07-21 14:48:48 -0700 | [diff] [blame] | 388 | __func__, size, params->smm_main_entry_offset); |
| 389 | return -1; |
| 390 | } |
| 391 | |
| 392 | /* Need a minimum stack size and alignment. */ |
| 393 | if (params->per_cpu_stack_size <= SMM_MINIMUM_STACK_SIZE || |
| 394 | (params->per_cpu_stack_size & 3) != 0) { |
| 395 | printk(BIOS_ERR, "%s: need minimum stack size\n", __func__); |
| 396 | return -1; |
| 397 | } |
| 398 | |
| 399 | smm_stub_loc = NULL; |
| 400 | smm_stub_size = rmodule_memory_size(&smm_stub); |
| 401 | stub_entry_offset = rmodule_entry_offset(&smm_stub); |
| 402 | |
| 403 | /* Put the stub at the main entry point */ |
| 404 | smm_stub_loc = &base[params->smm_main_entry_offset]; |
| 405 | |
| 406 | /* Stub is too big to fit. */ |
| 407 | if (smm_stub_size > (size - params->smm_main_entry_offset)) { |
| 408 | printk(BIOS_ERR, "%s: stub is too big to fit\n", __func__); |
| 409 | return -1; |
| 410 | } |
| 411 | |
| 412 | /* The stacks, if requested, live in the lower half of SMRAM space |
| 413 | * for default handler, but for relocated handler it lives at the beginning |
| 414 | * of SMRAM which is TSEG base |
| 415 | */ |
Arthur Heymans | b17f11e | 2020-11-01 21:04:55 +0100 | [diff] [blame] | 416 | const size_t total_stack_size = params->num_concurrent_stacks * |
| 417 | params->per_cpu_stack_size; |
| 418 | stacks_top = smm_stub_place_stacks((char *)params->smram_start, total_stack_size, |
| 419 | params); |
Rocky Phagura | afb7a81 | 2020-07-21 14:48:48 -0700 | [diff] [blame] | 420 | if (stacks_top == NULL) { |
| 421 | printk(BIOS_ERR, "%s: not enough space for stacks\n", __func__); |
| 422 | printk(BIOS_ERR, "%s: ....need -> %p : available -> %zx\n", __func__, |
Arthur Heymans | b17f11e | 2020-11-01 21:04:55 +0100 | [diff] [blame] | 423 | base, total_stack_size); |
Rocky Phagura | afb7a81 | 2020-07-21 14:48:48 -0700 | [diff] [blame] | 424 | return -1; |
| 425 | } |
| 426 | params->stack_top = stacks_top; |
| 427 | /* Load the stub. */ |
| 428 | if (rmodule_load(smm_stub_loc, &smm_stub)) { |
| 429 | printk(BIOS_ERR, "%s: load module failed\n", __func__); |
| 430 | return -1; |
| 431 | } |
| 432 | |
| 433 | if (!smm_stub_place_staggered_entry_points(base, params, &smm_stub)) { |
| 434 | printk(BIOS_ERR, "%s: staggered entry points failed\n", __func__); |
| 435 | return -1; |
| 436 | } |
| 437 | |
| 438 | /* Setup the parameters for the stub code. */ |
| 439 | stub_params = rmodule_parameters(&smm_stub); |
| 440 | stub_params->stack_top = (uintptr_t)stacks_top; |
| 441 | stub_params->stack_size = params->per_cpu_stack_size; |
| 442 | stub_params->c_handler = (uintptr_t)params->handler; |
| 443 | stub_params->c_handler_arg = (uintptr_t)params->handler_arg; |
| 444 | stub_params->fxsave_area = (uintptr_t)fxsave_area; |
| 445 | stub_params->fxsave_area_size = FXSAVE_SIZE; |
| 446 | stub_params->runtime.smbase = (uintptr_t)smbase; |
| 447 | stub_params->runtime.smm_size = smm_size; |
| 448 | stub_params->runtime.save_state_size = params->per_cpu_save_state_size; |
| 449 | stub_params->runtime.num_cpus = params->num_concurrent_stacks; |
| 450 | |
Arthur Heymans | 81b88a1 | 2020-11-01 21:06:39 +0100 | [diff] [blame] | 451 | printk(BIOS_DEBUG, "%s: stack_end = 0x%lx\n", |
| 452 | __func__, stub_params->stack_top - total_stack_size); |
Rocky Phagura | afb7a81 | 2020-07-21 14:48:48 -0700 | [diff] [blame] | 453 | printk(BIOS_DEBUG, |
| 454 | "%s: stack_top = 0x%x\n", __func__, stub_params->stack_top); |
| 455 | printk(BIOS_DEBUG, "%s: stack_size = 0x%x\n", |
| 456 | __func__, stub_params->stack_size); |
| 457 | printk(BIOS_DEBUG, "%s: runtime.smbase = 0x%x\n", |
| 458 | __func__, stub_params->runtime.smbase); |
| 459 | printk(BIOS_DEBUG, "%s: runtime.start32_offset = 0x%x\n", __func__, |
| 460 | stub_params->runtime.start32_offset); |
| 461 | printk(BIOS_DEBUG, "%s: runtime.smm_size = 0x%zx\n", |
| 462 | __func__, smm_size); |
| 463 | printk(BIOS_DEBUG, "%s: per_cpu_save_state_size = 0x%x\n", |
| 464 | __func__, stub_params->runtime.save_state_size); |
| 465 | printk(BIOS_DEBUG, "%s: num_cpus = 0x%x\n", __func__, |
| 466 | stub_params->runtime.num_cpus); |
| 467 | printk(BIOS_DEBUG, "%s: total_save_state_size = 0x%x\n", |
| 468 | __func__, (stub_params->runtime.save_state_size * |
| 469 | stub_params->runtime.num_cpus)); |
| 470 | total_size_all = stub_params->stack_size + |
| 471 | (stub_params->runtime.save_state_size * |
| 472 | stub_params->runtime.num_cpus); |
| 473 | printk(BIOS_DEBUG, "%s: total_size_all = 0x%x\n", __func__, |
| 474 | total_size_all); |
| 475 | |
| 476 | /* Initialize the APIC id to CPU number table to be 1:1 */ |
| 477 | for (i = 0; i < params->num_concurrent_stacks; i++) |
| 478 | stub_params->runtime.apic_id_to_cpu[i] = i; |
| 479 | |
| 480 | /* Allow the initiator to manipulate SMM stub parameters. */ |
| 481 | params->runtime = &stub_params->runtime; |
| 482 | |
| 483 | printk(BIOS_DEBUG, "SMM Module: stub loaded at %p. Will call %p(%p)\n", |
| 484 | smm_stub_loc, params->handler, params->handler_arg); |
| 485 | return 0; |
| 486 | } |
| 487 | |
| 488 | /* |
| 489 | * smm_setup_relocation_handler assumes the callback is already loaded in |
| 490 | * memory. i.e. Another SMM module isn't chained to the stub. The other |
| 491 | * assumption is that the stub will be entered from the default SMRAM |
| 492 | * location: 0x30000 -> 0x40000. |
| 493 | */ |
| 494 | int smm_setup_relocation_handler(struct smm_loader_params *params) |
| 495 | { |
| 496 | void *smram = (void *)(SMM_DEFAULT_BASE); |
| 497 | printk(BIOS_SPEW, "%s: enter\n", __func__); |
| 498 | /* There can't be more than 1 concurrent save state for the relocation |
| 499 | * handler because all CPUs default to 0x30000 as SMBASE. */ |
| 500 | if (params->num_concurrent_save_states > 1) |
| 501 | return -1; |
| 502 | |
| 503 | /* A handler has to be defined to call for relocation. */ |
| 504 | if (params->handler == NULL) |
| 505 | return -1; |
| 506 | |
| 507 | /* Since the relocation handler always uses stack, adjust the number |
| 508 | * of concurrent stack users to be CONFIG_MAX_CPUS. */ |
| 509 | if (params->num_concurrent_stacks == 0) |
| 510 | params->num_concurrent_stacks = CONFIG_MAX_CPUS; |
| 511 | |
| 512 | params->smm_main_entry_offset = SMM_ENTRY_OFFSET; |
| 513 | params->smram_start = SMM_DEFAULT_BASE; |
| 514 | params->smram_end = SMM_DEFAULT_BASE + SMM_DEFAULT_SIZE; |
| 515 | return smm_module_setup_stub(smram, SMM_DEFAULT_SIZE, |
| 516 | params, fxsave_area_relocation); |
| 517 | printk(BIOS_SPEW, "%s: exit\n", __func__); |
| 518 | } |
| 519 | |
| 520 | /* |
| 521 | *The SMM module is placed within the provided region in the following |
| 522 | * manner: |
| 523 | * +-----------------+ <- smram + size |
| 524 | * | BIOS resource | |
| 525 | * | list (STM) | |
| 526 | * +-----------------+ |
| 527 | * | fxsave area | |
| 528 | * +-----------------+ |
| 529 | * | smi handler | |
| 530 | * | ... | |
| 531 | * +-----------------+ <- cpu0 |
| 532 | * | stub code | <- cpu1 |
| 533 | * | stub code | <- cpu2 |
| 534 | * | stub code | <- cpu3, etc |
| 535 | * | | |
| 536 | * | | |
| 537 | * | | |
| 538 | * | stacks | |
| 539 | * +-----------------+ <- smram start |
| 540 | |
| 541 | * It should be noted that this algorithm will not work for |
| 542 | * SMM_DEFAULT_SIZE SMRAM regions such as the A segment. This algorithm |
| 543 | * expects a region large enough to encompass the handler and stacks |
| 544 | * as well as the SMM_DEFAULT_SIZE. |
| 545 | */ |
| 546 | int smm_load_module(void *smram, size_t size, struct smm_loader_params *params) |
| 547 | { |
| 548 | struct rmodule smm_mod; |
| 549 | size_t total_stack_size; |
| 550 | size_t handler_size; |
| 551 | size_t module_alignment; |
| 552 | size_t alignment_size; |
| 553 | size_t fxsave_size; |
| 554 | void *fxsave_area; |
| 555 | size_t total_size = 0; |
| 556 | char *base; |
| 557 | |
| 558 | if (size <= SMM_DEFAULT_SIZE) |
| 559 | return -1; |
| 560 | |
| 561 | /* Load main SMI handler at the top of SMRAM |
| 562 | * everything else will go below |
| 563 | */ |
| 564 | base = smram; |
| 565 | base += size; |
| 566 | params->smram_start = (uintptr_t)smram; |
| 567 | params->smram_end = params->smram_start + size; |
| 568 | params->smm_main_entry_offset = SMM_ENTRY_OFFSET; |
| 569 | |
| 570 | /* Fail if can't parse the smm rmodule. */ |
| 571 | if (rmodule_parse(&_binary_smm_start, &smm_mod)) |
| 572 | return -1; |
| 573 | |
| 574 | /* Clear SMM region */ |
| 575 | if (CONFIG(DEBUG_SMI)) |
| 576 | memset(smram, 0xcd, size); |
| 577 | |
| 578 | total_stack_size = params->per_cpu_stack_size * |
| 579 | params->num_concurrent_stacks; |
| 580 | total_size += total_stack_size; |
| 581 | /* Stacks are the base of SMRAM */ |
| 582 | params->stack_top = smram + total_stack_size; |
| 583 | |
| 584 | /* MSEG starts at the top of SMRAM and works down */ |
| 585 | if (CONFIG(STM)) { |
| 586 | base -= CONFIG_MSEG_SIZE + CONFIG_BIOS_RESOURCE_LIST_SIZE; |
| 587 | total_size += CONFIG_MSEG_SIZE + CONFIG_BIOS_RESOURCE_LIST_SIZE; |
| 588 | } |
| 589 | |
| 590 | /* FXSAVE goes below MSEG */ |
| 591 | if (CONFIG(SSE)) { |
| 592 | fxsave_size = FXSAVE_SIZE * params->num_concurrent_stacks; |
| 593 | fxsave_area = base - fxsave_size; |
| 594 | base -= fxsave_size; |
| 595 | total_size += fxsave_size; |
| 596 | } else { |
| 597 | fxsave_size = 0; |
| 598 | fxsave_area = NULL; |
| 599 | } |
| 600 | |
Rocky Phagura | afb7a81 | 2020-07-21 14:48:48 -0700 | [diff] [blame] | 601 | handler_size = rmodule_memory_size(&smm_mod); |
| 602 | base -= handler_size; |
| 603 | total_size += handler_size; |
| 604 | module_alignment = rmodule_load_alignment(&smm_mod); |
| 605 | alignment_size = module_alignment - |
| 606 | ((uintptr_t)base % module_alignment); |
| 607 | if (alignment_size != module_alignment) { |
| 608 | handler_size += alignment_size; |
| 609 | base += alignment_size; |
| 610 | } |
| 611 | |
| 612 | printk(BIOS_DEBUG, |
| 613 | "%s: total_smm_space_needed %zx, available -> %zx\n", |
| 614 | __func__, total_size, size); |
| 615 | |
| 616 | /* Does the required amount of memory exceed the SMRAM region size? */ |
| 617 | if (total_size > size) { |
| 618 | printk(BIOS_ERR, "%s: need more SMRAM\n", __func__); |
| 619 | return -1; |
| 620 | } |
| 621 | if (handler_size > SMM_CODE_SEGMENT_SIZE) { |
| 622 | printk(BIOS_ERR, "%s: increase SMM_CODE_SEGMENT_SIZE: handler_size = %zx\n", |
| 623 | __func__, handler_size); |
| 624 | return -1; |
| 625 | } |
| 626 | |
| 627 | if (rmodule_load(base, &smm_mod)) |
| 628 | return -1; |
| 629 | |
| 630 | params->handler = rmodule_entry(&smm_mod); |
| 631 | params->handler_arg = rmodule_parameters(&smm_mod); |
| 632 | |
| 633 | printk(BIOS_DEBUG, "%s: smram_start: 0x%p\n", |
| 634 | __func__, smram); |
| 635 | printk(BIOS_DEBUG, "%s: smram_end: %p\n", |
| 636 | __func__, smram + size); |
| 637 | printk(BIOS_DEBUG, "%s: stack_top: %p\n", |
| 638 | __func__, params->stack_top); |
| 639 | printk(BIOS_DEBUG, "%s: handler start %p\n", |
| 640 | __func__, params->handler); |
| 641 | printk(BIOS_DEBUG, "%s: handler_size %zx\n", |
| 642 | __func__, handler_size); |
| 643 | printk(BIOS_DEBUG, "%s: handler_arg %p\n", |
| 644 | __func__, params->handler_arg); |
| 645 | printk(BIOS_DEBUG, "%s: fxsave_area %p\n", |
| 646 | __func__, fxsave_area); |
| 647 | printk(BIOS_DEBUG, "%s: fxsave_size %zx\n", |
| 648 | __func__, fxsave_size); |
| 649 | printk(BIOS_DEBUG, "%s: CONFIG_MSEG_SIZE 0x%x\n", |
| 650 | __func__, CONFIG_MSEG_SIZE); |
| 651 | printk(BIOS_DEBUG, "%s: CONFIG_BIOS_RESOURCE_LIST_SIZE 0x%x\n", |
| 652 | __func__, CONFIG_BIOS_RESOURCE_LIST_SIZE); |
| 653 | |
| 654 | /* CPU 0 smbase goes first, all other CPUs |
| 655 | * will be staggered below |
| 656 | */ |
| 657 | base -= SMM_CODE_SEGMENT_SIZE; |
| 658 | printk(BIOS_DEBUG, "%s: cpu0 entry: %p\n", |
| 659 | __func__, base); |
| 660 | params->smm_entry = (uintptr_t)base + params->smm_main_entry_offset; |
| 661 | return smm_module_setup_stub(base, size, params, fxsave_area); |
| 662 | } |