/arch/unicore32/mm/pgd.c

http://github.com/mirrors/linux · C · 102 lines · 66 code · 17 blank · 19 comment · 7 complexity · aeb5de05843c894129e26dabafef188f MD5 · raw file

  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * linux/arch/unicore32/mm/pgd.c
  4. *
  5. * Code specific to PKUnity SoC and UniCore ISA
  6. *
  7. * Copyright (C) 2001-2010 GUAN Xue-tao
  8. */
  9. #include <linux/mm.h>
  10. #include <linux/gfp.h>
  11. #include <linux/highmem.h>
  12. #include <asm/pgalloc.h>
  13. #include <asm/page.h>
  14. #include <asm/tlbflush.h>
  15. #include "mm.h"
  16. #define FIRST_KERNEL_PGD_NR (FIRST_USER_PGD_NR + USER_PTRS_PER_PGD)
  17. /*
  18. * need to get a 4k page for level 1
  19. */
  20. pgd_t *get_pgd_slow(struct mm_struct *mm)
  21. {
  22. pgd_t *new_pgd, *init_pgd;
  23. pmd_t *new_pmd, *init_pmd;
  24. pte_t *new_pte, *init_pte;
  25. new_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, 0);
  26. if (!new_pgd)
  27. goto no_pgd;
  28. memset(new_pgd, 0, FIRST_KERNEL_PGD_NR * sizeof(pgd_t));
  29. /*
  30. * Copy over the kernel and IO PGD entries
  31. */
  32. init_pgd = pgd_offset_k(0);
  33. memcpy(new_pgd + FIRST_KERNEL_PGD_NR, init_pgd + FIRST_KERNEL_PGD_NR,
  34. (PTRS_PER_PGD - FIRST_KERNEL_PGD_NR) * sizeof(pgd_t));
  35. clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
  36. if (!vectors_high()) {
  37. /*
  38. * On UniCore, first page must always be allocated since it
  39. * contains the machine vectors.
  40. */
  41. new_pmd = pmd_alloc(mm, (pud_t *)new_pgd, 0);
  42. if (!new_pmd)
  43. goto no_pmd;
  44. new_pte = pte_alloc_map(mm, new_pmd, 0);
  45. if (!new_pte)
  46. goto no_pte;
  47. init_pmd = pmd_offset((pud_t *)init_pgd, 0);
  48. init_pte = pte_offset_map(init_pmd, 0);
  49. set_pte(new_pte, *init_pte);
  50. pte_unmap(init_pte);
  51. pte_unmap(new_pte);
  52. }
  53. return new_pgd;
  54. no_pte:
  55. pmd_free(mm, new_pmd);
  56. mm_dec_nr_pmds(mm);
  57. no_pmd:
  58. free_pages((unsigned long)new_pgd, 0);
  59. no_pgd:
  60. return NULL;
  61. }
  62. void free_pgd_slow(struct mm_struct *mm, pgd_t *pgd)
  63. {
  64. pmd_t *pmd;
  65. pgtable_t pte;
  66. if (!pgd)
  67. return;
  68. /* pgd is always present and good */
  69. pmd = pmd_off(pgd, 0);
  70. if (pmd_none(*pmd))
  71. goto free;
  72. if (pmd_bad(*pmd)) {
  73. pmd_ERROR(*pmd);
  74. pmd_clear(pmd);
  75. goto free;
  76. }
  77. pte = pmd_pgtable(*pmd);
  78. pmd_clear(pmd);
  79. pte_free(mm, pte);
  80. mm_dec_nr_ptes(mm);
  81. pmd_free(mm, pmd);
  82. mm_dec_nr_pmds(mm);
  83. free:
  84. free_pages((unsigned long) pgd, 0);
  85. }