arch/x86/mm/physaddr.c

   1 #include <linux/bootmem.h>
   2 #include <linux/mmdebug.h>
   3 #include <linux/export.h>
   4 #include <linux/mm.h>
   5
   6 #include <asm/page.h>
   7
   8 #include "physaddr.h"
   9
  10 #ifdef CONFIG_X86_64
  11
  12 #ifdef CONFIG_DEBUG_VIRTUAL
  13 unsigned long __phys_addr(unsigned long x)
  14 {
  15         unsigned long y = x - __START_KERNEL_map;
  16
  17         /* use the carry flag to determine if x was < __START_KERNEL_map */
  18         if (unlikely(x > y)) {
  19                 x = y + phys_base;
  20
  21                 VIRTUAL_BUG_ON(y >= KERNEL_IMAGE_SIZE);
  22         } else {
  23                 x = y + (__START_KERNEL_map - PAGE_OFFSET);
  24
  25                 /* carry flag will be set if starting x was >= PAGE_OFFSET */
  26                 VIRTUAL_BUG_ON((x > y) || !phys_addr_valid(x));
  27         }
  28
  29         return x;
  30 }
  31 EXPORT_SYMBOL(__phys_addr);
  32
  33 unsigned long __phys_addr_symbol(unsigned long x)
  34 {
  35         unsigned long y = x - __START_KERNEL_map;
  36
  37         /* only check upper bounds since lower bounds will trigger carry */
  38         VIRTUAL_BUG_ON(y >= KERNEL_IMAGE_SIZE);
  39
  40         return y + phys_base;
  41 }
  42 EXPORT_SYMBOL(__phys_addr_symbol);
  43 #endif
  44
  45 bool __virt_addr_valid(unsigned long x)
  46 {
  47         unsigned long y = x - __START_KERNEL_map;
  48
  49         /* use the carry flag to determine if x was < __START_KERNEL_map */
  50         if (unlikely(x > y)) {
  51                 x = y + phys_base;
  52
  53                 if (y >= KERNEL_IMAGE_SIZE)
  54                         return false;
  55         } else {
  56                 x = y + (__START_KERNEL_map - PAGE_OFFSET);
  57
  58                 /* carry flag will be set if starting x was >= PAGE_OFFSET */
  59                 if ((x > y) || !phys_addr_valid(x))
  60                         return false;
  61         }
  62
  63         return pfn_valid(x >> PAGE_SHIFT);
  64 }
  65 EXPORT_SYMBOL(__virt_addr_valid);
  66
  67 #else
  68
  69 #ifdef CONFIG_DEBUG_VIRTUAL
  70 unsigned long __phys_addr(unsigned long x)
  71 {
  72         unsigned long phys_addr = x - PAGE_OFFSET;
  73         /* VMALLOC_* aren't constants  */
  74         VIRTUAL_BUG_ON(x < PAGE_OFFSET);
  75         VIRTUAL_BUG_ON(__vmalloc_start_set && is_vmalloc_addr((void *) x));
  76         /* max_low_pfn is set early, but not _that_ early */
  77         if (max_low_pfn) {
  78                 VIRTUAL_BUG_ON((phys_addr >> PAGE_SHIFT) > max_low_pfn);
  79                 BUG_ON(slow_virt_to_phys((void *)x) != phys_addr);
  80         }
  81         return phys_addr;
  82 }
  83 EXPORT_SYMBOL(__phys_addr);
  84 #endif
  85
  86 bool __virt_addr_valid(unsigned long x)
  87 {
  88         if (x < PAGE_OFFSET)
  89                 return false;
  90         if (__vmalloc_start_set && is_vmalloc_addr((void *) x))
  91                 return false;
  92         if (x >= FIXADDR_START)
  93                 return false;
  94         return pfn_valid((x - PAGE_OFFSET) >> PAGE_SHIFT);
  95 }
  96 EXPORT_SYMBOL(__virt_addr_valid);
  97
  98 #endif  /* CONFIG_X86_64 */