xref: /linux/arch/x86/mm/physaddr.c (revision 74ce1896c6c65b2f8cccbf59162d542988835835)
1 #include <linux/bootmem.h>
2 #include <linux/mmdebug.h>
3 #include <linux/export.h>
4 #include <linux/mm.h>
5 
6 #include <asm/page.h>
7 
8 #include "physaddr.h"
9 
10 #ifdef CONFIG_X86_64
11 
12 #ifdef CONFIG_DEBUG_VIRTUAL
13 unsigned long __phys_addr(unsigned long x)
14 {
15 	unsigned long y = x - __START_KERNEL_map;
16 
17 	/* use the carry flag to determine if x was < __START_KERNEL_map */
18 	if (unlikely(x > y)) {
19 		x = y + phys_base;
20 
21 		VIRTUAL_BUG_ON(y >= KERNEL_IMAGE_SIZE);
22 	} else {
23 		x = y + (__START_KERNEL_map - PAGE_OFFSET);
24 
25 		/* carry flag will be set if starting x was >= PAGE_OFFSET */
26 		VIRTUAL_BUG_ON((x > y) || !phys_addr_valid(x));
27 	}
28 
29 	return x;
30 }
31 EXPORT_SYMBOL(__phys_addr);
32 
33 unsigned long __phys_addr_symbol(unsigned long x)
34 {
35 	unsigned long y = x - __START_KERNEL_map;
36 
37 	/* only check upper bounds since lower bounds will trigger carry */
38 	VIRTUAL_BUG_ON(y >= KERNEL_IMAGE_SIZE);
39 
40 	return y + phys_base;
41 }
42 EXPORT_SYMBOL(__phys_addr_symbol);
43 #endif
44 
45 bool __virt_addr_valid(unsigned long x)
46 {
47 	unsigned long y = x - __START_KERNEL_map;
48 
49 	/* use the carry flag to determine if x was < __START_KERNEL_map */
50 	if (unlikely(x > y)) {
51 		x = y + phys_base;
52 
53 		if (y >= KERNEL_IMAGE_SIZE)
54 			return false;
55 	} else {
56 		x = y + (__START_KERNEL_map - PAGE_OFFSET);
57 
58 		/* carry flag will be set if starting x was >= PAGE_OFFSET */
59 		if ((x > y) || !phys_addr_valid(x))
60 			return false;
61 	}
62 
63 	return pfn_valid(x >> PAGE_SHIFT);
64 }
65 EXPORT_SYMBOL(__virt_addr_valid);
66 
67 #else
68 
69 #ifdef CONFIG_DEBUG_VIRTUAL
70 unsigned long __phys_addr(unsigned long x)
71 {
72 	unsigned long phys_addr = x - PAGE_OFFSET;
73 	/* VMALLOC_* aren't constants  */
74 	VIRTUAL_BUG_ON(x < PAGE_OFFSET);
75 	VIRTUAL_BUG_ON(__vmalloc_start_set && is_vmalloc_addr((void *) x));
76 	/* max_low_pfn is set early, but not _that_ early */
77 	if (max_low_pfn) {
78 		VIRTUAL_BUG_ON((phys_addr >> PAGE_SHIFT) > max_low_pfn);
79 		BUG_ON(slow_virt_to_phys((void *)x) != phys_addr);
80 	}
81 	return phys_addr;
82 }
83 EXPORT_SYMBOL(__phys_addr);
84 #endif
85 
86 bool __virt_addr_valid(unsigned long x)
87 {
88 	if (x < PAGE_OFFSET)
89 		return false;
90 	if (__vmalloc_start_set && is_vmalloc_addr((void *) x))
91 		return false;
92 	if (x >= FIXADDR_START)
93 		return false;
94 	return pfn_valid((x - PAGE_OFFSET) >> PAGE_SHIFT);
95 }
96 EXPORT_SYMBOL(__virt_addr_valid);
97 
98 #endif	/* CONFIG_X86_64 */
99