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#endif
35
36bool __virt_addr_valid(unsigned long x)
37{
38	unsigned long y = x - __START_KERNEL_map;
39
40	/* use the carry flag to determine if x was < __START_KERNEL_map */
41	if (unlikely(x > y)) {
42		x = y + phys_base;
43
44		if (y >= KERNEL_IMAGE_SIZE)
45			return false;
46	} else {
47		x = y + (__START_KERNEL_map - PAGE_OFFSET);
48
49		/* carry flag will be set if starting x was >= PAGE_OFFSET */
50		if ((x > y) || !phys_addr_valid(x))
51			return false;
52	}
53
54	return pfn_valid(x >> PAGE_SHIFT);
55}
56EXPORT_SYMBOL(__virt_addr_valid);
57
58#else
59
60#ifdef CONFIG_DEBUG_VIRTUAL
61unsigned long __phys_addr(unsigned long x)
62{
63	unsigned long phys_addr = x - PAGE_OFFSET;
64	/* VMALLOC_* aren't constants  */
65	VIRTUAL_BUG_ON(x < PAGE_OFFSET);
66	VIRTUAL_BUG_ON(__vmalloc_start_set && is_vmalloc_addr((void *) x));
67	/* max_low_pfn is set early, but not _that_ early */
68	if (max_low_pfn) {
69		VIRTUAL_BUG_ON((phys_addr >> PAGE_SHIFT) > max_low_pfn);
70		BUG_ON(slow_virt_to_phys((void *)x) != phys_addr);
71	}
72	return phys_addr;
73}
74EXPORT_SYMBOL(__phys_addr);
75#endif
76
77bool __virt_addr_valid(unsigned long x)
78{
79	if (x < PAGE_OFFSET)
80		return false;
81	if (__vmalloc_start_set && is_vmalloc_addr((void *) x))
82		return false;
83	if (x >= FIXADDR_START)
84		return false;
85	return pfn_valid((x - PAGE_OFFSET) >> PAGE_SHIFT);
86}
87EXPORT_SYMBOL(__virt_addr_valid);
88
89#endif	/* CONFIG_X86_64 */