arch/x86/mm/physaddr.c

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