arch/x86/mm/physaddr.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/memblock.h>
   3 #include <linux/mmdebug.h>
   4 #include <linux/export.h>
   5 #include <linux/mm.h>
   6
   7 #include <asm/page.h>
   8 #include <linux/vmalloc.h>
   9
  10 #include "physaddr.h"
  11
  12 #ifdef CONFIG_X86_64
  13
  14 #ifdef CONFIG_DEBUG_VIRTUAL
  15 unsigned long __phys_addr(unsigned long x)
  16 {
  17         unsigned long y = x - __START_KERNEL_map;
  18
  19         /* use the carry flag to determine if x was < __START_KERNEL_map */
  20         if (unlikely(x > y)) {
  21                 x = y + phys_base;
  22
  23                 VIRTUAL_BUG_ON(y >= KERNEL_IMAGE_SIZE);
  24         } else {
  25                 x = y + (__START_KERNEL_map - PAGE_OFFSET);
  26
  27                 /* carry flag will be set if starting x was >= PAGE_OFFSET */
  28                 VIRTUAL_BUG_ON((x > y) || !phys_addr_valid(x));
  29         }
  30
  31         return x;
  32 }
  33 EXPORT_SYMBOL(__phys_addr);
  34
  35 unsigned long __phys_addr_symbol(unsigned long x)
  36 {
  37         unsigned long y = x - __START_KERNEL_map;
  38
  39         /* only check upper bounds since lower bounds will trigger carry */
  40         VIRTUAL_BUG_ON(y >= KERNEL_IMAGE_SIZE);
  41
  42         return y + phys_base;
  43 }
  44 EXPORT_SYMBOL(__phys_addr_symbol);
  45 #endif
  46
  47 bool __virt_addr_valid(unsigned long x)
  48 {
  49         unsigned long y = x - __START_KERNEL_map;
  50
  51         /* use the carry flag to determine if x was < __START_KERNEL_map */
  52         if (unlikely(x > y)) {
  53                 x = y + phys_base;
  54
  55                 if (y >= KERNEL_IMAGE_SIZE)
  56                         return false;
  57         } else {
  58                 x = y + (__START_KERNEL_map - PAGE_OFFSET);
  59
  60                 /* carry flag will be set if starting x was >= PAGE_OFFSET */
  61                 if ((x > y) || !phys_addr_valid(x))
  62                         return false;
  63         }
  64
  65         return pfn_valid(x >> PAGE_SHIFT);
  66 }
  67 EXPORT_SYMBOL(__virt_addr_valid);
  68
  69 #else
  70
  71 #ifdef CONFIG_DEBUG_VIRTUAL
  72 unsigned long __phys_addr(unsigned long x)
  73 {
  74         unsigned long phys_addr = x - PAGE_OFFSET;
  75         /* VMALLOC_* aren't constants  */
  76         VIRTUAL_BUG_ON(x < PAGE_OFFSET);
  77         VIRTUAL_BUG_ON(__vmalloc_start_set && is_vmalloc_addr((void *) x));
  78         /* max_low_pfn is set early, but not _that_ early */
  79         if (max_low_pfn) {
  80                 VIRTUAL_BUG_ON((phys_addr >> PAGE_SHIFT) > max_low_pfn);
  81                 BUG_ON(slow_virt_to_phys((void *)x) != phys_addr);
  82         }
  83         return phys_addr;
  84 }
  85 EXPORT_SYMBOL(__phys_addr);
  86 #endif
  87
  88 bool __virt_addr_valid(unsigned long x)
  89 {
  90         if (x < PAGE_OFFSET)
  91                 return false;
  92         if (__vmalloc_start_set && is_vmalloc_addr((void *) x))
  93                 return false;
  94         if (x >= FIXADDR_START)
  95                 return false;
  96         return pfn_valid((x - PAGE_OFFSET) >> PAGE_SHIFT);
  97 }
  98 EXPORT_SYMBOL(__virt_addr_valid);
  99
 100 #endif  /* CONFIG_X86_64 */