arch/score/include/asm/fixmap.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_SCORE_FIXMAP_H
   3 #define _ASM_SCORE_FIXMAP_H
   4
   5 #include <asm/page.h>
   6
   7 #define PHY_RAM_BASE            0x00000000
   8 #define PHY_IO_BASE             0x10000000
   9
  10 #define VIRTUAL_RAM_BASE        0xa0000000
  11 #define VIRTUAL_IO_BASE         0xb0000000
  12
  13 #define RAM_SPACE_SIZE          0x10000000
  14 #define IO_SPACE_SIZE           0x10000000
  15
  16 /* Kernel unmapped, cached 512MB */
  17 #define KSEG1                   0xa0000000
  18
  19 /*
  20  * Here we define all the compile-time 'special' virtual
  21  * addresses. The point is to have a constant address at
  22  * compile time, but to set the physical address only
  23  * in the boot process. We allocate these special addresses
  24  * from the end of virtual memory (0xfffff000) backwards.
  25  * Also this lets us do fail-safe vmalloc(), we
  26  * can guarantee that these special addresses and
  27  * vmalloc()-ed addresses never overlap.
  28  *
  29  * these 'compile-time allocated' memory buffers are
  30  * fixed-size 4k pages. (or larger if used with an increment
  31  * highger than 1) use fixmap_set(idx,phys) to associate
  32  * physical memory with fixmap indices.
  33  *
  34  * TLB entries of such buffers will not be flushed across
  35  * task switches.
  36  */
  37
  38 /*
  39  * on UP currently we will have no trace of the fixmap mechanizm,
  40  * no page table allocations, etc. This might change in the
  41  * future, say framebuffers for the console driver(s) could be
  42  * fix-mapped?
  43  */
  44 enum fixed_addresses {
  45 #define FIX_N_COLOURS 8
  46         FIX_CMAP_BEGIN,
  47         FIX_CMAP_END = FIX_CMAP_BEGIN + FIX_N_COLOURS,
  48         __end_of_fixed_addresses
  49 };
  50
  51 /*
  52  * used by vmalloc.c.
  53  *
  54  * Leave one empty page between vmalloc'ed areas and
  55  * the start of the fixmap, and leave one page empty
  56  * at the top of mem..
  57  */
  58 #define FIXADDR_TOP     ((unsigned long)(long)(int)0xfefe0000)
  59 #define FIXADDR_SIZE    (__end_of_fixed_addresses << PAGE_SHIFT)
  60 #define FIXADDR_START   (FIXADDR_TOP - FIXADDR_SIZE)
  61
  62 #define __fix_to_virt(x)        (FIXADDR_TOP - ((x) << PAGE_SHIFT))
  63 #define __virt_to_fix(x)        \
  64         ((FIXADDR_TOP - ((x) & PAGE_MASK)) >> PAGE_SHIFT)
  65
  66 extern void __this_fixmap_does_not_exist(void);
  67
  68 /*
  69  * 'index to address' translation. If anyone tries to use the idx
  70  * directly without tranlation, we catch the bug with a NULL-deference
  71  * kernel oops. Illegal ranges of incoming indices are caught too.
  72  */
  73 static inline unsigned long fix_to_virt(const unsigned int idx)
  74 {
  75         return __fix_to_virt(idx);
  76 }
  77
  78 static inline unsigned long virt_to_fix(const unsigned long vaddr)
  79 {
  80         return __virt_to_fix(vaddr);
  81 }
  82
  83 #endif /* _ASM_SCORE_FIXMAP_H */