LXR linux/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
  15unsigned 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}
  33EXPORT_SYMBOL(__phys_addr);
  34
  35unsigned 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}
  44EXPORT_SYMBOL(__phys_addr_symbol);
  45#endif
  46
  47bool __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}
  67EXPORT_SYMBOL(__virt_addr_valid);
  68
  69#else
  70
  71#ifdef CONFIG_DEBUG_VIRTUAL
  72unsigned 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}
  85EXPORT_SYMBOL(__phys_addr);
  86#endif
  87
  88bool __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}
  98EXPORT_SYMBOL(__virt_addr_valid);
  99
 100#endif  /* CONFIG_X86_64 */
 101