arch/riscv/kernel/sbi.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * SBI initialilization and all extension implementation.
   4  *
   5  * Copyright (c) 2020 Western Digital Corporation or its affiliates.
   6  */
   7
   8 #include <linux/init.h>
   9 #include <linux/pm.h>
  10 #include <asm/sbi.h>
  11 #include <asm/smp.h>
  12
  13 /* default SBI version is 0.1 */
  14 unsigned long sbi_spec_version = SBI_SPEC_VERSION_DEFAULT;
  15 EXPORT_SYMBOL(sbi_spec_version);
  16
  17 static void (*__sbi_set_timer)(uint64_t stime);
  18 static int (*__sbi_send_ipi)(const unsigned long *hart_mask);
  19 static int (*__sbi_rfence)(int fid, const unsigned long *hart_mask,
  20                            unsigned long start, unsigned long size,
  21                            unsigned long arg4, unsigned long arg5);
  22
  23 struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
  24                         unsigned long arg1, unsigned long arg2,
  25                         unsigned long arg3, unsigned long arg4,
  26                         unsigned long arg5)
  27 {
  28         struct sbiret ret;
  29
  30         register uintptr_t a0 asm ("a0") = (uintptr_t)(arg0);
  31         register uintptr_t a1 asm ("a1") = (uintptr_t)(arg1);
  32         register uintptr_t a2 asm ("a2") = (uintptr_t)(arg2);
  33         register uintptr_t a3 asm ("a3") = (uintptr_t)(arg3);
  34         register uintptr_t a4 asm ("a4") = (uintptr_t)(arg4);
  35         register uintptr_t a5 asm ("a5") = (uintptr_t)(arg5);
  36         register uintptr_t a6 asm ("a6") = (uintptr_t)(fid);
  37         register uintptr_t a7 asm ("a7") = (uintptr_t)(ext);
  38         asm volatile ("ecall"
  39                       : "+r" (a0), "+r" (a1)
  40                       : "r" (a2), "r" (a3), "r" (a4), "r" (a5), "r" (a6), "r" (a7)
  41                       : "memory");
  42         ret.error = a0;
  43         ret.value = a1;
  44
  45         return ret;
  46 }
  47 EXPORT_SYMBOL(sbi_ecall);
  48
  49 int sbi_err_map_linux_errno(int err)
  50 {
  51         switch (err) {
  52         case SBI_SUCCESS:
  53                 return 0;
  54         case SBI_ERR_DENIED:
  55                 return -EPERM;
  56         case SBI_ERR_INVALID_PARAM:
  57                 return -EINVAL;
  58         case SBI_ERR_INVALID_ADDRESS:
  59                 return -EFAULT;
  60         case SBI_ERR_NOT_SUPPORTED:
  61         case SBI_ERR_FAILURE:
  62         default:
  63                 return -ENOTSUPP;
  64         };
  65 }
  66 EXPORT_SYMBOL(sbi_err_map_linux_errno);
  67
  68 #ifdef CONFIG_RISCV_SBI_V01
  69 /**
  70  * sbi_console_putchar() - Writes given character to the console device.
  71  * @ch: The data to be written to the console.
  72  *
  73  * Return: None
  74  */
  75 void sbi_console_putchar(int ch)
  76 {
  77         sbi_ecall(SBI_EXT_0_1_CONSOLE_PUTCHAR, 0, ch, 0, 0, 0, 0, 0);
  78 }
  79 EXPORT_SYMBOL(sbi_console_putchar);
  80
  81 /**
  82  * sbi_console_getchar() - Reads a byte from console device.
  83  *
  84  * Returns the value read from console.
  85  */
  86 int sbi_console_getchar(void)
  87 {
  88         struct sbiret ret;
  89
  90         ret = sbi_ecall(SBI_EXT_0_1_CONSOLE_GETCHAR, 0, 0, 0, 0, 0, 0, 0);
  91
  92         return ret.error;
  93 }
  94 EXPORT_SYMBOL(sbi_console_getchar);
  95
  96 /**
  97  * sbi_shutdown() - Remove all the harts from executing supervisor code.
  98  *
  99  * Return: None
 100  */
 101 void sbi_shutdown(void)
 102 {
 103         sbi_ecall(SBI_EXT_0_1_SHUTDOWN, 0, 0, 0, 0, 0, 0, 0);
 104 }
 105 EXPORT_SYMBOL(sbi_set_timer);
 106
 107 /**
 108  * sbi_clear_ipi() - Clear any pending IPIs for the calling hart.
 109  *
 110  * Return: None
 111  */
 112 void sbi_clear_ipi(void)
 113 {
 114         sbi_ecall(SBI_EXT_0_1_CLEAR_IPI, 0, 0, 0, 0, 0, 0, 0);
 115 }
 116 EXPORT_SYMBOL(sbi_shutdown);
 117
 118 /**
 119  * sbi_set_timer_v01() - Program the timer for next timer event.
 120  * @stime_value: The value after which next timer event should fire.
 121  *
 122  * Return: None
 123  */
 124 static void __sbi_set_timer_v01(uint64_t stime_value)
 125 {
 126 #if __riscv_xlen == 32
 127         sbi_ecall(SBI_EXT_0_1_SET_TIMER, 0, stime_value,
 128                   stime_value >> 32, 0, 0, 0, 0);
 129 #else
 130         sbi_ecall(SBI_EXT_0_1_SET_TIMER, 0, stime_value, 0, 0, 0, 0, 0);
 131 #endif
 132 }
 133
 134 static int __sbi_send_ipi_v01(const unsigned long *hart_mask)
 135 {
 136         sbi_ecall(SBI_EXT_0_1_SEND_IPI, 0, (unsigned long)hart_mask,
 137                   0, 0, 0, 0, 0);
 138         return 0;
 139 }
 140
 141 static int __sbi_rfence_v01(int fid, const unsigned long *hart_mask,
 142                             unsigned long start, unsigned long size,
 143                             unsigned long arg4, unsigned long arg5)
 144 {
 145         int result = 0;
 146
 147         /* v0.2 function IDs are equivalent to v0.1 extension IDs */
 148         switch (fid) {
 149         case SBI_EXT_RFENCE_REMOTE_FENCE_I:
 150                 sbi_ecall(SBI_EXT_0_1_REMOTE_FENCE_I, 0,
 151                           (unsigned long)hart_mask, 0, 0, 0, 0, 0);
 152                 break;
 153         case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA:
 154                 sbi_ecall(SBI_EXT_0_1_REMOTE_SFENCE_VMA, 0,
 155                           (unsigned long)hart_mask, start, size,
 156                           0, 0, 0);
 157                 break;
 158         case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID:
 159                 sbi_ecall(SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID, 0,
 160                           (unsigned long)hart_mask, start, size,
 161                           arg4, 0, 0);
 162                 break;
 163         default:
 164                 pr_err("SBI call [%d]not supported in SBI v0.1\n", fid);
 165                 result = -EINVAL;
 166         }
 167
 168         return result;
 169 }
 170 #else
 171 static void __sbi_set_timer_v01(uint64_t stime_value)
 172 {
 173         pr_warn("Timer extension is not available in SBI v%lu.%lu\n",
 174                 sbi_major_version(), sbi_minor_version());
 175 }
 176
 177 static int __sbi_send_ipi_v01(const unsigned long *hart_mask)
 178 {
 179         pr_warn("IPI extension is not available in SBI v%lu.%lu\n",
 180                 sbi_major_version(), sbi_minor_version());
 181
 182         return 0;
 183 }
 184
 185 static int __sbi_rfence_v01(int fid, const unsigned long *hart_mask,
 186                             unsigned long start, unsigned long size,
 187                             unsigned long arg4, unsigned long arg5)
 188 {
 189         pr_warn("remote fence extension is not available in SBI v%lu.%lu\n",
 190                 sbi_major_version(), sbi_minor_version());
 191
 192         return 0;
 193 }
 194 #endif /* CONFIG_RISCV_SBI_V01 */
 195
 196 static void __sbi_set_timer_v02(uint64_t stime_value)
 197 {
 198 #if __riscv_xlen == 32
 199         sbi_ecall(SBI_EXT_TIME, SBI_EXT_TIME_SET_TIMER, stime_value,
 200                   stime_value >> 32, 0, 0, 0, 0);
 201 #else
 202         sbi_ecall(SBI_EXT_TIME, SBI_EXT_TIME_SET_TIMER, stime_value, 0,
 203                   0, 0, 0, 0);
 204 #endif
 205 }
 206
 207 static int __sbi_send_ipi_v02(const unsigned long *hart_mask)
 208 {
 209         unsigned long hartid, hmask_val, hbase;
 210         struct cpumask tmask;
 211         struct sbiret ret = {0};
 212         int result;
 213
 214         if (!hart_mask || !(*hart_mask)) {
 215                 riscv_cpuid_to_hartid_mask(cpu_online_mask, &tmask);
 216                 hart_mask = cpumask_bits(&tmask);
 217         }
 218
 219         hmask_val = 0;
 220         hbase = 0;
 221         for_each_set_bit(hartid, hart_mask, NR_CPUS) {
 222                 if (hmask_val && ((hbase + BITS_PER_LONG) <= hartid)) {
 223                         ret = sbi_ecall(SBI_EXT_IPI, SBI_EXT_IPI_SEND_IPI,
 224                                         hmask_val, hbase, 0, 0, 0, 0);
 225                         if (ret.error)
 226                                 goto ecall_failed;
 227                         hmask_val = 0;
 228                         hbase = 0;
 229                 }
 230                 if (!hmask_val)
 231                         hbase = hartid;
 232                 hmask_val |= 1UL << (hartid - hbase);
 233         }
 234
 235         if (hmask_val) {
 236                 ret = sbi_ecall(SBI_EXT_IPI, SBI_EXT_IPI_SEND_IPI,
 237                                 hmask_val, hbase, 0, 0, 0, 0);
 238                 if (ret.error)
 239                         goto ecall_failed;
 240         }
 241
 242         return 0;
 243
 244 ecall_failed:
 245         result = sbi_err_map_linux_errno(ret.error);
 246         pr_err("%s: hbase = [%lu] hmask = [0x%lx] failed (error [%d])\n",
 247                __func__, hbase, hmask_val, result);
 248         return result;
 249 }
 250
 251 static int __sbi_rfence_v02_call(unsigned long fid, unsigned long hmask_val,
 252                                  unsigned long hbase, unsigned long start,
 253                                  unsigned long size, unsigned long arg4,
 254                                  unsigned long arg5)
 255 {
 256         struct sbiret ret = {0};
 257         int ext = SBI_EXT_RFENCE;
 258         int result = 0;
 259
 260         switch (fid) {
 261         case SBI_EXT_RFENCE_REMOTE_FENCE_I:
 262                 ret = sbi_ecall(ext, fid, hmask_val, hbase, 0, 0, 0, 0);
 263                 break;
 264         case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA:
 265                 ret = sbi_ecall(ext, fid, hmask_val, hbase, start,
 266                                 size, 0, 0);
 267                 break;
 268         case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID:
 269                 ret = sbi_ecall(ext, fid, hmask_val, hbase, start,
 270                                 size, arg4, 0);
 271                 break;
 272
 273         case SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA:
 274                 ret = sbi_ecall(ext, fid, hmask_val, hbase, start,
 275                                 size, 0, 0);
 276                 break;
 277         case SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA_VMID:
 278                 ret = sbi_ecall(ext, fid, hmask_val, hbase, start,
 279                                 size, arg4, 0);
 280                 break;
 281         case SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA:
 282                 ret = sbi_ecall(ext, fid, hmask_val, hbase, start,
 283                                 size, 0, 0);
 284                 break;
 285         case SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA_ASID:
 286                 ret = sbi_ecall(ext, fid, hmask_val, hbase, start,
 287                                 size, arg4, 0);
 288                 break;
 289         default:
 290                 pr_err("unknown function ID [%lu] for SBI extension [%d]\n",
 291                        fid, ext);
 292                 result = -EINVAL;
 293         }
 294
 295         if (ret.error) {
 296                 result = sbi_err_map_linux_errno(ret.error);
 297                 pr_err("%s: hbase = [%lu] hmask = [0x%lx] failed (error [%d])\n",
 298                        __func__, hbase, hmask_val, result);
 299         }
 300
 301         return result;
 302 }
 303
 304 static int __sbi_rfence_v02(int fid, const unsigned long *hart_mask,
 305                             unsigned long start, unsigned long size,
 306                             unsigned long arg4, unsigned long arg5)
 307 {
 308         unsigned long hmask_val, hartid, hbase;
 309         struct cpumask tmask;
 310         int result;
 311
 312         if (!hart_mask || !(*hart_mask)) {
 313                 riscv_cpuid_to_hartid_mask(cpu_online_mask, &tmask);
 314                 hart_mask = cpumask_bits(&tmask);
 315         }
 316
 317         hmask_val = 0;
 318         hbase = 0;
 319         for_each_set_bit(hartid, hart_mask, NR_CPUS) {
 320                 if (hmask_val && ((hbase + BITS_PER_LONG) <= hartid)) {
 321                         result = __sbi_rfence_v02_call(fid, hmask_val, hbase,
 322                                                        start, size, arg4, arg5);
 323                         if (result)
 324                                 return result;
 325                         hmask_val = 0;
 326                         hbase = 0;
 327                 }
 328                 if (!hmask_val)
 329                         hbase = hartid;
 330                 hmask_val |= 1UL << (hartid - hbase);
 331         }
 332
 333         if (hmask_val) {
 334                 result = __sbi_rfence_v02_call(fid, hmask_val, hbase,
 335                                                start, size, arg4, arg5);
 336                 if (result)
 337                         return result;
 338         }
 339
 340         return 0;
 341 }
 342
 343 /**
 344  * sbi_set_timer() - Program the timer for next timer event.
 345  * @stime_value: The value after which next timer event should fire.
 346  *
 347  * Return: None
 348  */
 349 void sbi_set_timer(uint64_t stime_value)
 350 {
 351         __sbi_set_timer(stime_value);
 352 }
 353
 354 /**
 355  * sbi_send_ipi() - Send an IPI to any hart.
 356  * @hart_mask: A cpu mask containing all the target harts.
 357  *
 358  * Return: None
 359  */
 360 void sbi_send_ipi(const unsigned long *hart_mask)
 361 {
 362         __sbi_send_ipi(hart_mask);
 363 }
 364 EXPORT_SYMBOL(sbi_send_ipi);
 365
 366 /**
 367  * sbi_remote_fence_i() - Execute FENCE.I instruction on given remote harts.
 368  * @hart_mask: A cpu mask containing all the target harts.
 369  *
 370  * Return: None
 371  */
 372 void sbi_remote_fence_i(const unsigned long *hart_mask)
 373 {
 374         __sbi_rfence(SBI_EXT_RFENCE_REMOTE_FENCE_I,
 375                      hart_mask, 0, 0, 0, 0);
 376 }
 377 EXPORT_SYMBOL(sbi_remote_fence_i);
 378
 379 /**
 380  * sbi_remote_sfence_vma() - Execute SFENCE.VMA instructions on given remote
 381  *                           harts for the specified virtual address range.
 382  * @hart_mask: A cpu mask containing all the target harts.
 383  * @start: Start of the virtual address
 384  * @size: Total size of the virtual address range.
 385  *
 386  * Return: None
 387  */
 388 void sbi_remote_sfence_vma(const unsigned long *hart_mask,
 389                            unsigned long start,
 390                            unsigned long size)
 391 {
 392         __sbi_rfence(SBI_EXT_RFENCE_REMOTE_SFENCE_VMA,
 393                      hart_mask, start, size, 0, 0);
 394 }
 395 EXPORT_SYMBOL(sbi_remote_sfence_vma);
 396
 397 /**
 398  * sbi_remote_sfence_vma_asid() - Execute SFENCE.VMA instructions on given
 399  * remote harts for a virtual address range belonging to a specific ASID.
 400  *
 401  * @hart_mask: A cpu mask containing all the target harts.
 402  * @start: Start of the virtual address
 403  * @size: Total size of the virtual address range.
 404  * @asid: The value of address space identifier (ASID).
 405  *
 406  * Return: None
 407  */
 408 void sbi_remote_sfence_vma_asid(const unsigned long *hart_mask,
 409                                 unsigned long start,
 410                                 unsigned long size,
 411                                 unsigned long asid)
 412 {
 413         __sbi_rfence(SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID,
 414                      hart_mask, start, size, asid, 0);
 415 }
 416 EXPORT_SYMBOL(sbi_remote_sfence_vma_asid);
 417
 418 /**
 419  * sbi_remote_hfence_gvma() - Execute HFENCE.GVMA instructions on given remote
 420  *                         harts for the specified guest physical address range.
 421  * @hart_mask: A cpu mask containing all the target harts.
 422  * @start: Start of the guest physical address
 423  * @size: Total size of the guest physical address range.
 424  *
 425  * Return: None
 426  */
 427 int sbi_remote_hfence_gvma(const unsigned long *hart_mask,
 428                            unsigned long start,
 429                            unsigned long size)
 430 {
 431         return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA,
 432                             hart_mask, start, size, 0, 0);
 433 }
 434 EXPORT_SYMBOL_GPL(sbi_remote_hfence_gvma);
 435
 436 /**
 437  * sbi_remote_hfence_gvma_vmid() - Execute HFENCE.GVMA instructions on given
 438  * remote harts for a guest physical address range belonging to a specific VMID.
 439  *
 440  * @hart_mask: A cpu mask containing all the target harts.
 441  * @start: Start of the guest physical address
 442  * @size: Total size of the guest physical address range.
 443  * @vmid: The value of guest ID (VMID).
 444  *
 445  * Return: 0 if success, Error otherwise.
 446  */
 447 int sbi_remote_hfence_gvma_vmid(const unsigned long *hart_mask,
 448                                 unsigned long start,
 449                                 unsigned long size,
 450                                 unsigned long vmid)
 451 {
 452         return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA_VMID,
 453                             hart_mask, start, size, vmid, 0);
 454 }
 455 EXPORT_SYMBOL(sbi_remote_hfence_gvma_vmid);
 456
 457 /**
 458  * sbi_remote_hfence_vvma() - Execute HFENCE.VVMA instructions on given remote
 459  *                           harts for the current guest virtual address range.
 460  * @hart_mask: A cpu mask containing all the target harts.
 461  * @start: Start of the current guest virtual address
 462  * @size: Total size of the current guest virtual address range.
 463  *
 464  * Return: None
 465  */
 466 int sbi_remote_hfence_vvma(const unsigned long *hart_mask,
 467                            unsigned long start,
 468                            unsigned long size)
 469 {
 470         return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA,
 471                             hart_mask, start, size, 0, 0);
 472 }
 473 EXPORT_SYMBOL(sbi_remote_hfence_vvma);
 474
 475 /**
 476  * sbi_remote_hfence_vvma_asid() - Execute HFENCE.VVMA instructions on given
 477  * remote harts for current guest virtual address range belonging to a specific
 478  * ASID.
 479  *
 480  * @hart_mask: A cpu mask containing all the target harts.
 481  * @start: Start of the current guest virtual address
 482  * @size: Total size of the current guest virtual address range.
 483  * @asid: The value of address space identifier (ASID).
 484  *
 485  * Return: None
 486  */
 487 int sbi_remote_hfence_vvma_asid(const unsigned long *hart_mask,
 488                                 unsigned long start,
 489                                 unsigned long size,
 490                                 unsigned long asid)
 491 {
 492         return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA_ASID,
 493                             hart_mask, start, size, asid, 0);
 494 }
 495 EXPORT_SYMBOL(sbi_remote_hfence_vvma_asid);
 496
 497 /**
 498  * sbi_probe_extension() - Check if an SBI extension ID is supported or not.
 499  * @extid: The extension ID to be probed.
 500  *
 501  * Return: Extension specific nonzero value f yes, -ENOTSUPP otherwise.
 502  */
 503 int sbi_probe_extension(int extid)
 504 {
 505         struct sbiret ret;
 506
 507         ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_PROBE_EXT, extid,
 508                         0, 0, 0, 0, 0);
 509         if (!ret.error)
 510                 if (ret.value)
 511                         return ret.value;
 512
 513         return -ENOTSUPP;
 514 }
 515 EXPORT_SYMBOL(sbi_probe_extension);
 516
 517 static long __sbi_base_ecall(int fid)
 518 {
 519         struct sbiret ret;
 520
 521         ret = sbi_ecall(SBI_EXT_BASE, fid, 0, 0, 0, 0, 0, 0);
 522         if (!ret.error)
 523                 return ret.value;
 524         else
 525                 return sbi_err_map_linux_errno(ret.error);
 526 }
 527
 528 static inline long sbi_get_spec_version(void)
 529 {
 530         return __sbi_base_ecall(SBI_EXT_BASE_GET_SPEC_VERSION);
 531 }
 532
 533 static inline long sbi_get_firmware_id(void)
 534 {
 535         return __sbi_base_ecall(SBI_EXT_BASE_GET_IMP_ID);
 536 }
 537
 538 static inline long sbi_get_firmware_version(void)
 539 {
 540         return __sbi_base_ecall(SBI_EXT_BASE_GET_IMP_VERSION);
 541 }
 542
 543 static void sbi_power_off(void)
 544 {
 545         sbi_shutdown();
 546 }
 547
 548 int __init sbi_init(void)
 549 {
 550         int ret;
 551
 552         pm_power_off = sbi_power_off;
 553         ret = sbi_get_spec_version();
 554         if (ret > 0)
 555                 sbi_spec_version = ret;
 556
 557         pr_info("SBI specification v%lu.%lu detected\n",
 558                 sbi_major_version(), sbi_minor_version());
 559
 560         if (!sbi_spec_is_0_1()) {
 561                 pr_info("SBI implementation ID=0x%lx Version=0x%lx\n",
 562                         sbi_get_firmware_id(), sbi_get_firmware_version());
 563                 if (sbi_probe_extension(SBI_EXT_TIME) > 0) {
 564                         __sbi_set_timer = __sbi_set_timer_v02;
 565                         pr_info("SBI v0.2 TIME extension detected\n");
 566                 } else {
 567                         __sbi_set_timer = __sbi_set_timer_v01;
 568                 }
 569                 if (sbi_probe_extension(SBI_EXT_IPI) > 0) {
 570                         __sbi_send_ipi  = __sbi_send_ipi_v02;
 571                         pr_info("SBI v0.2 IPI extension detected\n");
 572                 } else {
 573                         __sbi_send_ipi  = __sbi_send_ipi_v01;
 574                 }
 575                 if (sbi_probe_extension(SBI_EXT_RFENCE) > 0) {
 576                         __sbi_rfence    = __sbi_rfence_v02;
 577                         pr_info("SBI v0.2 RFENCE extension detected\n");
 578                 } else {
 579                         __sbi_rfence    = __sbi_rfence_v01;
 580                 }
 581         } else {
 582                 __sbi_set_timer = __sbi_set_timer_v01;
 583                 __sbi_send_ipi  = __sbi_send_ipi_v01;
 584                 __sbi_rfence    = __sbi_rfence_v01;
 585         }
 586
 587         return 0;
 588 }