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