sbi_ecall.c 3.7 KB

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  1. /*
  2. * SPDX-License-Identifier: BSD-2-Clause
  3. *
  4. * Copyright (c) 2019 Western Digital Corporation or its affiliates.
  5. *
  6. * Authors:
  7. * Anup Patel <anup.patel@wdc.com>
  8. */
  9. #include <sbi/sbi_console.h>
  10. #include <sbi/sbi_ecall.h>
  11. #include <sbi/sbi_ecall_interface.h>
  12. #include <sbi/sbi_error.h>
  13. #include <sbi/sbi_trap.h>
  14. u16 sbi_ecall_version_major(void)
  15. {
  16. return SBI_ECALL_VERSION_MAJOR;
  17. }
  18. u16 sbi_ecall_version_minor(void)
  19. {
  20. return SBI_ECALL_VERSION_MINOR;
  21. }
  22. static unsigned long ecall_impid = SBI_OPENSBI_IMPID;
  23. unsigned long sbi_ecall_get_impid(void)
  24. {
  25. return ecall_impid;
  26. }
  27. void sbi_ecall_set_impid(unsigned long impid)
  28. {
  29. ecall_impid = impid;
  30. }
  31. static SBI_LIST_HEAD(ecall_exts_list);
  32. struct sbi_ecall_extension *sbi_ecall_find_extension(unsigned long extid)
  33. {
  34. struct sbi_ecall_extension *t, *ret = NULL;
  35. sbi_list_for_each_entry(t, &ecall_exts_list, head) {
  36. if (t->extid_start <= extid && extid <= t->extid_end) {
  37. ret = t;
  38. break;
  39. }
  40. }
  41. return ret;
  42. }
  43. int sbi_ecall_register_extension(struct sbi_ecall_extension *ext)
  44. {
  45. struct sbi_ecall_extension *t;
  46. if (!ext || (ext->extid_end < ext->extid_start) || !ext->handle)
  47. return SBI_EINVAL;
  48. sbi_list_for_each_entry(t, &ecall_exts_list, head) {
  49. unsigned long start = t->extid_start;
  50. unsigned long end = t->extid_end;
  51. if (end < ext->extid_start || ext->extid_end < start)
  52. /* no overlap */;
  53. else
  54. return SBI_EINVAL;
  55. }
  56. SBI_INIT_LIST_HEAD(&ext->head);
  57. sbi_list_add_tail(&ext->head, &ecall_exts_list);
  58. return 0;
  59. }
  60. void sbi_ecall_unregister_extension(struct sbi_ecall_extension *ext)
  61. {
  62. bool found = FALSE;
  63. struct sbi_ecall_extension *t;
  64. if (!ext)
  65. return;
  66. sbi_list_for_each_entry(t, &ecall_exts_list, head) {
  67. if (t == ext) {
  68. found = TRUE;
  69. break;
  70. }
  71. }
  72. if (found)
  73. sbi_list_del_init(&ext->head);
  74. }
  75. int sbi_ecall_handler(struct sbi_trap_regs *regs)
  76. {
  77. int ret = 0;
  78. struct sbi_ecall_extension *ext;
  79. unsigned long extension_id = regs->a7;
  80. unsigned long func_id = regs->a6;
  81. struct sbi_trap_info trap = {0};
  82. unsigned long out_val = 0;
  83. bool is_0_1_spec = 0;
  84. ext = sbi_ecall_find_extension(extension_id);
  85. if (ext && ext->handle) {
  86. ret = ext->handle(extension_id, func_id,
  87. regs, &out_val, &trap);
  88. if (extension_id >= SBI_EXT_0_1_SET_TIMER &&
  89. extension_id <= SBI_EXT_0_1_SHUTDOWN)
  90. is_0_1_spec = 1;
  91. } else {
  92. ret = SBI_ENOTSUPP;
  93. }
  94. if (ret == SBI_ETRAP) {
  95. trap.epc = regs->mepc;
  96. sbi_trap_redirect(regs, &trap);
  97. } else {
  98. if (ret < SBI_LAST_ERR) {
  99. sbi_printf("%s: Invalid error %d for ext=0x%lx "
  100. "func=0x%lx\n", __func__, ret,
  101. extension_id, func_id);
  102. ret = SBI_ERR_FAILED;
  103. }
  104. /*
  105. * This function should return non-zero value only in case of
  106. * fatal error. However, there is no good way to distinguish
  107. * between a fatal and non-fatal errors yet. That's why we treat
  108. * every return value except ETRAP as non-fatal and just return
  109. * accordingly for now. Once fatal errors are defined, that
  110. * case should be handled differently.
  111. */
  112. regs->mepc += 4;
  113. regs->a0 = ret;
  114. if (!is_0_1_spec)
  115. regs->a1 = out_val;
  116. }
  117. return 0;
  118. }
  119. int sbi_ecall_init(void)
  120. {
  121. int ret;
  122. /* The order of below registrations is performance optimized */
  123. ret = sbi_ecall_register_extension(&ecall_time);
  124. if (ret)
  125. return ret;
  126. ret = sbi_ecall_register_extension(&ecall_rfence);
  127. if (ret)
  128. return ret;
  129. ret = sbi_ecall_register_extension(&ecall_ipi);
  130. if (ret)
  131. return ret;
  132. ret = sbi_ecall_register_extension(&ecall_base);
  133. if (ret)
  134. return ret;
  135. ret = sbi_ecall_register_extension(&ecall_hsm);
  136. if (ret)
  137. return ret;
  138. ret = sbi_ecall_register_extension(&ecall_srst);
  139. if (ret)
  140. return ret;
  141. ret = sbi_ecall_register_extension(&ecall_legacy);
  142. if (ret)
  143. return ret;
  144. ret = sbi_ecall_register_extension(&ecall_vendor);
  145. if (ret)
  146. return ret;
  147. return 0;
  148. }