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