highmem.h 2.0 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. /*
  3. * highmem.h: virtual kernel memory mappings for high memory
  4. *
  5. * PowerPC version, stolen from the i386 version.
  6. *
  7. * Used in CONFIG_HIGHMEM systems for memory pages which
  8. * are not addressable by direct kernel virtual addresses.
  9. *
  10. * Copyright (C) 1999 Gerhard Wichert, Siemens AG
  11. * [email protected]
  12. *
  13. *
  14. * Redesigned the x86 32-bit VM architecture to deal with
  15. * up to 16 Terrabyte physical memory. With current x86 CPUs
  16. * we now support up to 64 Gigabytes physical RAM.
  17. *
  18. * Copyright (C) 1999 Ingo Molnar <[email protected]>
  19. */
  20. #ifndef _ASM_HIGHMEM_H
  21. #define _ASM_HIGHMEM_H
  22. #ifdef __KERNEL__
  23. #include <linux/interrupt.h>
  24. #include <asm/cacheflush.h>
  25. #include <asm/page.h>
  26. #include <asm/fixmap.h>
  27. extern pte_t *pkmap_page_table;
  28. /*
  29. * Right now we initialize only a single pte table. It can be extended
  30. * easily, subsequent pte tables have to be allocated in one physical
  31. * chunk of RAM.
  32. */
  33. /*
  34. * We use one full pte table with 4K pages. And with 16K/64K/256K pages pte
  35. * table covers enough memory (32MB/512MB/2GB resp.), so that both FIXMAP
  36. * and PKMAP can be placed in a single pte table. We use 512 pages for PKMAP
  37. * in case of 16K/64K/256K page sizes.
  38. */
  39. #ifdef CONFIG_PPC_4K_PAGES
  40. #define PKMAP_ORDER PTE_SHIFT
  41. #else
  42. #define PKMAP_ORDER 9
  43. #endif
  44. #define LAST_PKMAP (1 << PKMAP_ORDER)
  45. #ifndef CONFIG_PPC_4K_PAGES
  46. #define PKMAP_BASE (FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1))
  47. #else
  48. #define PKMAP_BASE ((FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) & PMD_MASK)
  49. #endif
  50. #define LAST_PKMAP_MASK (LAST_PKMAP-1)
  51. #define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT)
  52. #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))
  53. #define flush_cache_kmaps() flush_cache_all()
  54. #define arch_kmap_local_set_pte(mm, vaddr, ptep, ptev) \
  55. __set_pte_at(mm, vaddr, ptep, ptev, 1)
  56. #define arch_kmap_local_post_map(vaddr, pteval) \
  57. local_flush_tlb_page(NULL, vaddr)
  58. #define arch_kmap_local_post_unmap(vaddr) \
  59. local_flush_tlb_page(NULL, vaddr)
  60. #endif /* __KERNEL__ */
  61. #endif /* _ASM_HIGHMEM_H */