fixmap.h 1.8 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. /*
  3. * fixmap.h: compile-time virtual memory allocation
  4. *
  5. * Copyright (C) 1998 Ingo Molnar
  6. *
  7. * Copyright 2008 Freescale Semiconductor Inc.
  8. * Port to powerpc added by Kumar Gala
  9. *
  10. * Copyright 2011 Michal Simek <[email protected]>
  11. * Copyright 2011 PetaLogix Qld Pty Ltd
  12. * Port to Microblaze
  13. */
  14. #ifndef _ASM_FIXMAP_H
  15. #define _ASM_FIXMAP_H
  16. #ifndef __ASSEMBLY__
  17. #include <linux/kernel.h>
  18. #include <asm/page.h>
  19. #ifdef CONFIG_HIGHMEM
  20. #include <linux/threads.h>
  21. #include <asm/kmap_size.h>
  22. #endif
  23. #define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE))
  24. /*
  25. * Here we define all the compile-time 'special' virtual
  26. * addresses. The point is to have a constant address at
  27. * compile time, but to set the physical address only
  28. * in the boot process. We allocate these special addresses
  29. * from the end of virtual memory (0xfffff000) backwards.
  30. * Also this lets us do fail-safe vmalloc(), we
  31. * can guarantee that these special addresses and
  32. * vmalloc()-ed addresses never overlap.
  33. *
  34. * these 'compile-time allocated' memory buffers are
  35. * fixed-size 4k pages. (or larger if used with an increment
  36. * highger than 1) use fixmap_set(idx,phys) to associate
  37. * physical memory with fixmap indices.
  38. *
  39. * TLB entries of such buffers will not be flushed across
  40. * task switches.
  41. */
  42. enum fixed_addresses {
  43. FIX_HOLE,
  44. #ifdef CONFIG_HIGHMEM
  45. FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
  46. FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * num_possible_cpus()) - 1,
  47. #endif
  48. __end_of_fixed_addresses
  49. };
  50. extern void __set_fixmap(enum fixed_addresses idx,
  51. phys_addr_t phys, pgprot_t flags);
  52. #define __FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
  53. #define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE)
  54. #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_CI
  55. #include <asm-generic/fixmap.h>
  56. #endif /* !__ASSEMBLY__ */
  57. #endif