1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * ARM Specific GTDT table Support 4 * 5 * Copyright (C) 2016, Linaro Ltd. 6 * Author: Daniel Lezcano <daniel.lezcano@linaro.org> 7 * Fu Wei <fu.wei@linaro.org> 8 * Hanjun Guo <hanjun.guo@linaro.org> 9 */ 10 11 #include <linux/acpi.h> 12 #include <linux/init.h> 13 #include <linux/irqdomain.h> 14 #include <linux/kernel.h> 15 #include <linux/platform_device.h> 16 17 #include <clocksource/arm_arch_timer.h> 18 19 #undef pr_fmt 20 #define pr_fmt(fmt) "ACPI GTDT: " fmt 21 22 /** 23 * struct acpi_gtdt_descriptor - Store the key info of GTDT for all functions 24 * @gtdt: The pointer to the struct acpi_table_gtdt of GTDT table. 25 * @gtdt_end: The pointer to the end of GTDT table. 26 * @platform_timer: The pointer to the start of Platform Timer Structure 27 * 28 * The struct store the key info of GTDT table, it should be initialized by 29 * acpi_gtdt_init. 30 */ 31 struct acpi_gtdt_descriptor { 32 struct acpi_table_gtdt *gtdt; 33 void *gtdt_end; 34 void *platform_timer; 35 }; 36 37 static struct acpi_gtdt_descriptor acpi_gtdt_desc __initdata; 38 39 static __init bool platform_timer_valid(void *platform_timer) 40 { 41 struct acpi_gtdt_header *gh = platform_timer; 42 43 return (platform_timer >= (void *)(acpi_gtdt_desc.gtdt + 1) && 44 platform_timer < acpi_gtdt_desc.gtdt_end && 45 gh->length != 0 && 46 platform_timer + gh->length <= acpi_gtdt_desc.gtdt_end); 47 } 48 49 static __init void *next_platform_timer(void *platform_timer) 50 { 51 struct acpi_gtdt_header *gh = platform_timer; 52 53 return platform_timer + gh->length; 54 } 55 56 #define for_each_platform_timer(_g) \ 57 for (_g = acpi_gtdt_desc.platform_timer; platform_timer_valid(_g);\ 58 _g = next_platform_timer(_g)) 59 60 static inline bool is_timer_block(void *platform_timer) 61 { 62 struct acpi_gtdt_header *gh = platform_timer; 63 64 return gh->type == ACPI_GTDT_TYPE_TIMER_BLOCK; 65 } 66 67 static inline bool is_non_secure_watchdog(void *platform_timer) 68 { 69 struct acpi_gtdt_header *gh = platform_timer; 70 struct acpi_gtdt_watchdog *wd = platform_timer; 71 72 if (gh->type != ACPI_GTDT_TYPE_WATCHDOG) 73 return false; 74 75 return !(wd->timer_flags & ACPI_GTDT_WATCHDOG_SECURE); 76 } 77 78 static int __init map_gt_gsi(u32 interrupt, u32 flags) 79 { 80 int trigger, polarity; 81 82 trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE 83 : ACPI_LEVEL_SENSITIVE; 84 85 polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW 86 : ACPI_ACTIVE_HIGH; 87 88 return acpi_register_gsi(NULL, interrupt, trigger, polarity); 89 } 90 91 /** 92 * acpi_gtdt_map_ppi() - Map the PPIs of per-cpu arch_timer. 93 * @type: the type of PPI. 94 * 95 * Note: Secure state is not managed by the kernel on ARM64 systems. 96 * So we only handle the non-secure timer PPIs, 97 * ARCH_TIMER_PHYS_SECURE_PPI is treated as invalid type. 98 * 99 * Return: the mapped PPI value, 0 if error. 100 */ 101 int __init acpi_gtdt_map_ppi(int type) 102 { 103 struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt; 104 105 switch (type) { 106 case ARCH_TIMER_PHYS_NONSECURE_PPI: 107 return map_gt_gsi(gtdt->non_secure_el1_interrupt, 108 gtdt->non_secure_el1_flags); 109 case ARCH_TIMER_VIRT_PPI: 110 return map_gt_gsi(gtdt->virtual_timer_interrupt, 111 gtdt->virtual_timer_flags); 112 113 case ARCH_TIMER_HYP_PPI: 114 return map_gt_gsi(gtdt->non_secure_el2_interrupt, 115 gtdt->non_secure_el2_flags); 116 default: 117 pr_err("Failed to map timer interrupt: invalid type.\n"); 118 } 119 120 return 0; 121 } 122 123 /** 124 * acpi_gtdt_c3stop() - Got c3stop info from GTDT according to the type of PPI. 125 * @type: the type of PPI. 126 * 127 * Return: true if the timer HW state is lost when a CPU enters an idle state, 128 * false otherwise 129 */ 130 bool __init acpi_gtdt_c3stop(int type) 131 { 132 struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt; 133 134 switch (type) { 135 case ARCH_TIMER_PHYS_NONSECURE_PPI: 136 return !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON); 137 138 case ARCH_TIMER_VIRT_PPI: 139 return !(gtdt->virtual_timer_flags & ACPI_GTDT_ALWAYS_ON); 140 141 case ARCH_TIMER_HYP_PPI: 142 return !(gtdt->non_secure_el2_flags & ACPI_GTDT_ALWAYS_ON); 143 144 default: 145 pr_err("Failed to get c3stop info: invalid type.\n"); 146 } 147 148 return false; 149 } 150 151 /** 152 * acpi_gtdt_init() - Get the info of GTDT table to prepare for further init. 153 * @table: The pointer to GTDT table. 154 * @platform_timer_count: It points to a integer variable which is used 155 * for storing the number of platform timers. 156 * This pointer could be NULL, if the caller 157 * doesn't need this info. 158 * 159 * Return: 0 if success, -EINVAL if error. 160 */ 161 int __init acpi_gtdt_init(struct acpi_table_header *table, 162 int *platform_timer_count) 163 { 164 void *platform_timer; 165 struct acpi_table_gtdt *gtdt; 166 int cnt = 0; 167 168 gtdt = container_of(table, struct acpi_table_gtdt, header); 169 acpi_gtdt_desc.gtdt = gtdt; 170 acpi_gtdt_desc.gtdt_end = (void *)table + table->length; 171 acpi_gtdt_desc.platform_timer = NULL; 172 if (platform_timer_count) 173 *platform_timer_count = 0; 174 175 if (table->revision < 2) { 176 pr_warn("Revision:%d doesn't support Platform Timers.\n", 177 table->revision); 178 return 0; 179 } 180 181 if (!gtdt->platform_timer_count) { 182 pr_debug("No Platform Timer.\n"); 183 return 0; 184 } 185 186 acpi_gtdt_desc.platform_timer = (void *)gtdt + gtdt->platform_timer_offset; 187 for_each_platform_timer(platform_timer) 188 cnt++; 189 190 if (cnt != gtdt->platform_timer_count) { 191 acpi_gtdt_desc.platform_timer = NULL; 192 pr_err(FW_BUG "invalid timer data.\n"); 193 return -EINVAL; 194 } 195 196 if (platform_timer_count) 197 *platform_timer_count = gtdt->platform_timer_count; 198 199 return 0; 200 } 201 202 static int __init gtdt_parse_timer_block(struct acpi_gtdt_timer_block *block, 203 struct arch_timer_mem *timer_mem) 204 { 205 int i; 206 struct arch_timer_mem_frame *frame; 207 struct acpi_gtdt_timer_entry *gtdt_frame; 208 209 if (!block->timer_count) { 210 pr_err(FW_BUG "GT block present, but frame count is zero.\n"); 211 return -ENODEV; 212 } 213 214 if (block->timer_count > ARCH_TIMER_MEM_MAX_FRAMES) { 215 pr_err(FW_BUG "GT block lists %d frames, ACPI spec only allows 8\n", 216 block->timer_count); 217 return -EINVAL; 218 } 219 220 timer_mem->cntctlbase = (phys_addr_t)block->block_address; 221 /* 222 * The CNTCTLBase frame is 4KB (register offsets 0x000 - 0xFFC). 223 * See ARM DDI 0487A.k_iss10775, page I1-5129, Table I1-3 224 * "CNTCTLBase memory map". 225 */ 226 timer_mem->size = SZ_4K; 227 228 gtdt_frame = (void *)block + block->timer_offset; 229 if (gtdt_frame + block->timer_count != (void *)block + block->header.length) 230 return -EINVAL; 231 232 /* 233 * Get the GT timer Frame data for every GT Block Timer 234 */ 235 for (i = 0; i < block->timer_count; i++, gtdt_frame++) { 236 if (gtdt_frame->common_flags & ACPI_GTDT_GT_IS_SECURE_TIMER) 237 continue; 238 if (gtdt_frame->frame_number >= ARCH_TIMER_MEM_MAX_FRAMES || 239 !gtdt_frame->base_address || !gtdt_frame->timer_interrupt) 240 goto error; 241 242 frame = &timer_mem->frame[gtdt_frame->frame_number]; 243 244 /* duplicate frame */ 245 if (frame->valid) 246 goto error; 247 248 frame->phys_irq = map_gt_gsi(gtdt_frame->timer_interrupt, 249 gtdt_frame->timer_flags); 250 if (frame->phys_irq <= 0) { 251 pr_warn("failed to map physical timer irq in frame %d.\n", 252 gtdt_frame->frame_number); 253 goto error; 254 } 255 256 if (gtdt_frame->virtual_timer_interrupt) { 257 frame->virt_irq = 258 map_gt_gsi(gtdt_frame->virtual_timer_interrupt, 259 gtdt_frame->virtual_timer_flags); 260 if (frame->virt_irq <= 0) { 261 pr_warn("failed to map virtual timer irq in frame %d.\n", 262 gtdt_frame->frame_number); 263 goto error; 264 } 265 } else { 266 pr_debug("virtual timer in frame %d not implemented.\n", 267 gtdt_frame->frame_number); 268 } 269 270 frame->cntbase = gtdt_frame->base_address; 271 /* 272 * The CNTBaseN frame is 4KB (register offsets 0x000 - 0xFFC). 273 * See ARM DDI 0487A.k_iss10775, page I1-5130, Table I1-4 274 * "CNTBaseN memory map". 275 */ 276 frame->size = SZ_4K; 277 frame->valid = true; 278 } 279 280 return 0; 281 282 error: 283 do { 284 if (gtdt_frame->common_flags & ACPI_GTDT_GT_IS_SECURE_TIMER || 285 gtdt_frame->frame_number >= ARCH_TIMER_MEM_MAX_FRAMES) 286 continue; 287 288 frame = &timer_mem->frame[gtdt_frame->frame_number]; 289 290 if (frame->phys_irq > 0) 291 acpi_unregister_gsi(gtdt_frame->timer_interrupt); 292 frame->phys_irq = 0; 293 294 if (frame->virt_irq > 0) 295 acpi_unregister_gsi(gtdt_frame->virtual_timer_interrupt); 296 frame->virt_irq = 0; 297 } while (i-- > 0 && gtdt_frame--); 298 299 return -EINVAL; 300 } 301 302 /** 303 * acpi_arch_timer_mem_init() - Get the info of all GT blocks in GTDT table. 304 * @timer_mem: The pointer to the array of struct arch_timer_mem for returning 305 * the result of parsing. The element number of this array should 306 * be platform_timer_count(the total number of platform timers). 307 * @timer_count: It points to a integer variable which is used for storing the 308 * number of GT blocks we have parsed. 309 * 310 * Return: 0 if success, -EINVAL/-ENODEV if error. 311 */ 312 int __init acpi_arch_timer_mem_init(struct arch_timer_mem *timer_mem, 313 int *timer_count) 314 { 315 int ret; 316 void *platform_timer; 317 318 *timer_count = 0; 319 for_each_platform_timer(platform_timer) { 320 if (is_timer_block(platform_timer)) { 321 ret = gtdt_parse_timer_block(platform_timer, timer_mem); 322 if (ret) 323 return ret; 324 timer_mem++; 325 (*timer_count)++; 326 } 327 } 328 329 if (*timer_count) 330 pr_info("found %d memory-mapped timer block(s).\n", 331 *timer_count); 332 333 return 0; 334 } 335 336 /* 337 * Initialize a SBSA generic Watchdog platform device info from GTDT 338 */ 339 static int __init gtdt_import_sbsa_gwdt(struct acpi_gtdt_watchdog *wd, 340 int index) 341 { 342 struct platform_device *pdev; 343 int irq; 344 345 /* 346 * According to SBSA specification the size of refresh and control 347 * frames of SBSA Generic Watchdog is SZ_4K(Offset 0x000 – 0xFFF). 348 */ 349 struct resource res[] = { 350 DEFINE_RES_MEM(wd->control_frame_address, SZ_4K), 351 DEFINE_RES_MEM(wd->refresh_frame_address, SZ_4K), 352 {}, 353 }; 354 int nr_res = ARRAY_SIZE(res); 355 356 pr_debug("found a Watchdog (0x%llx/0x%llx gsi:%u flags:0x%x).\n", 357 wd->refresh_frame_address, wd->control_frame_address, 358 wd->timer_interrupt, wd->timer_flags); 359 360 if (!(wd->refresh_frame_address && wd->control_frame_address)) { 361 pr_err(FW_BUG "failed to get the Watchdog base address.\n"); 362 return -EINVAL; 363 } 364 365 irq = map_gt_gsi(wd->timer_interrupt, wd->timer_flags); 366 res[2] = DEFINE_RES_IRQ(irq); 367 if (irq <= 0) { 368 pr_warn("failed to map the Watchdog interrupt.\n"); 369 nr_res--; 370 } 371 372 /* 373 * Add a platform device named "sbsa-gwdt" to match the platform driver. 374 * "sbsa-gwdt": SBSA(Server Base System Architecture) Generic Watchdog 375 * The platform driver can get device info below by matching this name. 376 */ 377 pdev = platform_device_register_simple("sbsa-gwdt", index, res, nr_res); 378 if (IS_ERR(pdev)) { 379 if (irq > 0) 380 acpi_unregister_gsi(wd->timer_interrupt); 381 return PTR_ERR(pdev); 382 } 383 384 return 0; 385 } 386 387 static int __init gtdt_sbsa_gwdt_init(void) 388 { 389 void *platform_timer; 390 struct acpi_table_header *table; 391 int ret, timer_count, gwdt_count = 0; 392 393 if (acpi_disabled) 394 return 0; 395 396 if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_GTDT, 0, &table))) 397 return -EINVAL; 398 399 /* 400 * Note: Even though the global variable acpi_gtdt_desc has been 401 * initialized by acpi_gtdt_init() while initializing the arch timers, 402 * when we call this function to get SBSA watchdogs info from GTDT, the 403 * pointers stashed in it are stale (since they are early temporary 404 * mappings carried out before acpi_permanent_mmap is set) and we need 405 * to re-initialize them with permanent mapped pointer values to let the 406 * GTDT parsing possible. 407 */ 408 ret = acpi_gtdt_init(table, &timer_count); 409 if (ret || !timer_count) 410 goto out_put_gtdt; 411 412 for_each_platform_timer(platform_timer) { 413 if (is_non_secure_watchdog(platform_timer)) { 414 ret = gtdt_import_sbsa_gwdt(platform_timer, gwdt_count); 415 if (ret) 416 break; 417 gwdt_count++; 418 } 419 } 420 421 if (gwdt_count) 422 pr_info("found %d SBSA generic Watchdog(s).\n", gwdt_count); 423 424 out_put_gtdt: 425 acpi_put_table(table); 426 return ret; 427 } 428 429 device_initcall(gtdt_sbsa_gwdt_init); 430