xref: /openbmc/linux/include/asm-generic/page.h (revision 293d5b43)
1 #ifndef __ASM_GENERIC_PAGE_H
2 #define __ASM_GENERIC_PAGE_H
3 /*
4  * Generic page.h implementation, for NOMMU architectures.
5  * This provides the dummy definitions for the memory management.
6  */
7 
8 #ifdef CONFIG_MMU
9 #error need to prove a real asm/page.h
10 #endif
11 
12 
13 /* PAGE_SHIFT determines the page size */
14 
15 #define PAGE_SHIFT	12
16 #ifdef __ASSEMBLY__
17 #define PAGE_SIZE	(1 << PAGE_SHIFT)
18 #else
19 #define PAGE_SIZE	(1UL << PAGE_SHIFT)
20 #endif
21 #define PAGE_MASK	(~(PAGE_SIZE-1))
22 
23 #include <asm/setup.h>
24 
25 #ifndef __ASSEMBLY__
26 
27 #define clear_page(page)	memset((page), 0, PAGE_SIZE)
28 #define copy_page(to,from)	memcpy((to), (from), PAGE_SIZE)
29 
30 #define clear_user_page(page, vaddr, pg)	clear_page(page)
31 #define copy_user_page(to, from, vaddr, pg)	copy_page(to, from)
32 
33 /*
34  * These are used to make use of C type-checking..
35  */
36 typedef struct {
37 	unsigned long pte;
38 } pte_t;
39 typedef struct {
40 	unsigned long pmd[16];
41 } pmd_t;
42 typedef struct {
43 	unsigned long pgd;
44 } pgd_t;
45 typedef struct {
46 	unsigned long pgprot;
47 } pgprot_t;
48 typedef struct page *pgtable_t;
49 
50 #define pte_val(x)	((x).pte)
51 #define pmd_val(x)	((&x)->pmd[0])
52 #define pgd_val(x)	((x).pgd)
53 #define pgprot_val(x)	((x).pgprot)
54 
55 #define __pte(x)	((pte_t) { (x) } )
56 #define __pmd(x)	((pmd_t) { (x) } )
57 #define __pgd(x)	((pgd_t) { (x) } )
58 #define __pgprot(x)	((pgprot_t) { (x) } )
59 
60 extern unsigned long memory_start;
61 extern unsigned long memory_end;
62 
63 #endif /* !__ASSEMBLY__ */
64 
65 #ifdef CONFIG_KERNEL_RAM_BASE_ADDRESS
66 #define PAGE_OFFSET		(CONFIG_KERNEL_RAM_BASE_ADDRESS)
67 #else
68 #define PAGE_OFFSET		(0)
69 #endif
70 
71 #ifndef ARCH_PFN_OFFSET
72 #define ARCH_PFN_OFFSET		(PAGE_OFFSET >> PAGE_SHIFT)
73 #endif
74 
75 #ifndef __ASSEMBLY__
76 
77 #define __va(x) ((void *)((unsigned long) (x)))
78 #define __pa(x) ((unsigned long) (x))
79 
80 #define virt_to_pfn(kaddr)	(__pa(kaddr) >> PAGE_SHIFT)
81 #define pfn_to_virt(pfn)	__va((pfn) << PAGE_SHIFT)
82 
83 #define virt_to_page(addr)	pfn_to_page(virt_to_pfn(addr))
84 #define page_to_virt(page)	pfn_to_virt(page_to_pfn(page))
85 
86 #ifndef page_to_phys
87 #define page_to_phys(page)      ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
88 #endif
89 
90 #define pfn_valid(pfn)		((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr)
91 
92 #define	virt_addr_valid(kaddr)	(((void *)(kaddr) >= (void *)PAGE_OFFSET) && \
93 				((void *)(kaddr) < (void *)memory_end))
94 
95 #endif /* __ASSEMBLY__ */
96 
97 #include <asm-generic/memory_model.h>
98 #include <asm-generic/getorder.h>
99 
100 #endif /* __ASM_GENERIC_PAGE_H */
101