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(addr: x))
62 return false;
63 }
64
65 return pfn_valid(pfn: 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