highmem.h 1.7 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. * Used in CONFIG_HIGHMEM systems for memory pages which
  6. * are not addressable by direct kernel virtual addresses.
  7. *
  8. * Copyright (C) 1999 Gerhard Wichert, Siemens AG
  9. * [email protected]
  10. *
  11. *
  12. * Redesigned the x86 32-bit VM architecture to deal with
  13. * up to 16 Terabyte physical memory. With current x86 CPUs
  14. * we now support up to 64 Gigabytes physical RAM.
  15. *
  16. * Copyright (C) 1999 Ingo Molnar <[email protected]>
  17. */
  18. #ifndef _ASM_HIGHMEM_H
  19. #define _ASM_HIGHMEM_H
  20. #ifdef __KERNEL__
  21. #include <linux/bug.h>
  22. #include <linux/interrupt.h>
  23. #include <linux/uaccess.h>
  24. #include <asm/cpu-features.h>
  25. #include <asm/kmap_size.h>
  26. /* declarations for highmem.c */
  27. extern unsigned long highstart_pfn, highend_pfn;
  28. extern pte_t *pkmap_page_table;
  29. /*
  30. * Right now we initialize only a single pte table. It can be extended
  31. * easily, subsequent pte tables have to be allocated in one physical
  32. * chunk of RAM.
  33. */
  34. #if defined(CONFIG_PHYS_ADDR_T_64BIT) || defined(CONFIG_MIPS_HUGE_TLB_SUPPORT)
  35. #define LAST_PKMAP 512
  36. #else
  37. #define LAST_PKMAP 1024
  38. #endif
  39. #define LAST_PKMAP_MASK (LAST_PKMAP-1)
  40. #define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT)
  41. #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))
  42. #define ARCH_HAS_KMAP_FLUSH_TLB
  43. extern void kmap_flush_tlb(unsigned long addr);
  44. #define flush_cache_kmaps() BUG_ON(cpu_has_dc_aliases)
  45. #define arch_kmap_local_set_pte(mm, vaddr, ptep, ptev) set_pte(ptep, ptev)
  46. #define arch_kmap_local_post_map(vaddr, pteval) local_flush_tlb_one(vaddr)
  47. #define arch_kmap_local_post_unmap(vaddr) local_flush_tlb_one(vaddr)
  48. #endif /* __KERNEL__ */
  49. #endif /* _ASM_HIGHMEM_H */