1 /*
2  *  linux/include/asm-arm/memory.h
3  *
4  *  Copyright (C) 2000-2002 Russell King
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  *  Note: this file should not be included by non-asm/.h files
11  */
12 #ifndef __ASM_ARM_MEMORY_H
13 #define __ASM_ARM_MEMORY_H
14 
15 #include <linux/config.h>
16 #include <asm/arch/memory.h>
17 
18 /*
19  * PFNs are used to describe any physical page; this means
20  * PFN 0 == physical address 0.
21  *
22  * This is the PFN of the first RAM page in the kernel
23  * direct-mapped view.  We assume this is the first page
24  * of RAM in the mem_map as well.
25  */
26 #define PHYS_PFN_OFFSET	(PHYS_OFFSET >> PAGE_SHIFT)
27 
28 /*
29  * These are *only* valid on the kernel direct mapped RAM memory.
30  */
virt_to_phys(void * x)31 static inline unsigned long virt_to_phys(void *x)
32 {
33 	return __virt_to_phys((unsigned long)(x));
34 }
35 
phys_to_virt(unsigned long x)36 static inline void *phys_to_virt(unsigned long x)
37 {
38 	return (void *)(__phys_to_virt((unsigned long)(x)));
39 }
40 
41 #define __pa(x)			__virt_to_phys((unsigned long)(x))
42 #define __va(x)			((void *)__phys_to_virt((unsigned long)(x)))
43 
44 /*
45  * Virtual <-> DMA view memory address translations
46  * Again, these are *only* valid on the kernel direct mapped RAM
47  * memory.  Use of these is *depreciated*.
48  */
49 #define virt_to_bus(x)		(__virt_to_bus((unsigned long)(x)))
50 #define bus_to_virt(x)		((void *)(__bus_to_virt((unsigned long)(x))))
51 
52 /*
53  * Conversion between a struct page and a physical address.
54  *
55  * Note: when converting an unknown physical address to a
56  * struct page, the resulting pointer must be validated
57  * using VALID_PAGE().  It must return an invalid struct page
58  * for any physical address not corresponding to a system
59  * RAM address.
60  *
61  *  page_to_pfn(page)	convert a struct page * to a PFN number
62  *  pfn_to_page(pfn)	convert a _valid_ PFN number to struct page *
63  *  pfn_valid(pfn)	indicates whether a PFN number is valid
64  *
65  *  virt_to_page(k)	convert a _valid_ virtual address to struct page *
66  *  virt_addr_valid(k)	indicates whether a virtual address is valid
67  */
68 #ifndef CONFIG_DISCONTIGMEM
69 
70 #define page_to_pfn(page)	(((page) - mem_map) + PHYS_PFN_OFFSET)
71 #define pfn_to_page(pfn)	((mem_map + (pfn)) - PHYS_PFN_OFFSET)
72 #define pfn_valid(pfn)		((pfn) >= PHYS_PFN_OFFSET && (pfn) < (PHYS_PFN_OFFSET + max_mapnr))
73 
74 #define virt_to_page(kaddr)	(pfn_to_page(__pa(kaddr) >> PAGE_SHIFT))
75 #define virt_addr_valid(kaddr)	((kaddr) >= PAGE_OFFSET && (kaddr) < (unsigned long)high_memory)
76 
77 #define PHYS_TO_NID(addr)	(0)
78 
79 #define VALID_PAGE(page)	((page - mem_map) < max_mapnr)
80 
81 #else
82 
83 /*
84  * This is more complex.  We have a set of mem_map arrays spread
85  * around in memory.
86  */
87 #define page_to_pfn(page)					\
88 	(((page) - page_zone(page)->zone_mem_map)		\
89 	  + (page_zone(page)->zone_start_paddr >> PAGE_SHIFT))
90 
91 #define pfn_to_page(pfn)					\
92 	(PFN_TO_MAPBASE(pfn) + LOCAL_MAP_NR((pfn) << PAGE_SHIFT))
93 
94 #define pfn_valid(pfn)						\
95   ({								\
96 	unsigned int node = PFN_TO_NID(pfn);			\
97 	struct pglist_data *nd = NODE_DATA(node);		\
98 	((node < NR_NODES) &&					\
99 	 ((pfn - (nd->node_start_paddr >> PAGE_SHIFT)) < nd->node_size));\
100    })
101 
102 #define virt_to_page(kaddr)					\
103 	(ADDR_TO_MAPBASE(kaddr) + LOCAL_MAP_NR(kaddr))
104 
105 #define virt_addr_valid(kaddr)	(KVADDR_TO_NID(kaddr) < NR_NODES)
106 
107 /*
108  * Common discontigmem stuff.
109  *  PHYS_TO_NID is used by the ARM kernel/setup.c
110  */
111 #define PHYS_TO_NID(addr)	PFN_TO_NID((addr) >> PAGE_SHIFT)
112 
113 /*
114  * 2.4 compatibility
115  *
116  * VALID_PAGE returns a non-zero value if given page pointer is valid.
117  * This assumes all node's mem_maps are stored within the node they
118  * refer to.  This is actually inherently buggy.
119  */
120 #define VALID_PAGE(page) \
121 ({ unsigned int node = KVADDR_TO_NID(page); \
122    ((node < NR_NODES) && \
123      ((unsigned)((page) - NODE_MEM_MAP(node)) < NODE_DATA(node)->node_size)); \
124 })
125 
126 #endif
127 
128 /*
129  * For BIO.  "will die".  Kill me when bio_to_phys() and bvec_to_phys() die.
130  */
131 #define page_to_phys(page)	(page_to_pfn(page) << PAGE_SHIFT)
132 
133 /*
134  * We should really eliminate virt_to_bus() here - it's depreciated.
135  */
136 #define page_to_bus(page)	(virt_to_bus(page_address(page)))
137 
138 #endif
139