drivers/acpi/arm64/gtdt.c

   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 __init 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);