xref: /openbmc/linux/include/asm-generic/page.h (revision 132db935)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_GENERIC_PAGE_H
3 #define __ASM_GENERIC_PAGE_H
4 /*
5  * Generic page.h implementation, for NOMMU architectures.
6  * This provides the dummy definitions for the memory management.
7  */
8 
9 #ifdef CONFIG_MMU
10 #error need to provide a real asm/page.h
11 #endif
12 
13 
14 /* PAGE_SHIFT determines the page size */
15 
16 #define PAGE_SHIFT	12
17 #ifdef __ASSEMBLY__
18 #define PAGE_SIZE	(1 << PAGE_SHIFT)
19 #else
20 #define PAGE_SIZE	(1UL << PAGE_SHIFT)
21 #endif
22 #define PAGE_MASK	(~(PAGE_SIZE-1))
23 
24 #include <asm/setup.h>
25 
26 #ifndef __ASSEMBLY__
27 
28 #define clear_page(page)	memset((page), 0, PAGE_SIZE)
29 #define copy_page(to,from)	memcpy((to), (from), PAGE_SIZE)
30 
31 #define clear_user_page(page, vaddr, pg)	clear_page(page)
32 #define copy_user_page(to, from, vaddr, pg)	copy_page(to, from)
33 
34 /*
35  * These are used to make use of C type-checking..
36  */
37 typedef struct {
38 	unsigned long pte;
39 } pte_t;
40 typedef struct {
41 	unsigned long pmd[16];
42 } pmd_t;
43 typedef struct {
44 	unsigned long pgd;
45 } pgd_t;
46 typedef struct {
47 	unsigned long pgprot;
48 } pgprot_t;
49 typedef struct page *pgtable_t;
50 
51 #define pte_val(x)	((x).pte)
52 #define pmd_val(x)	((&x)->pmd[0])
53 #define pgd_val(x)	((x).pgd)
54 #define pgprot_val(x)	((x).pgprot)
55 
56 #define __pte(x)	((pte_t) { (x) } )
57 #define __pmd(x)	((pmd_t) { (x) } )
58 #define __pgd(x)	((pgd_t) { (x) } )
59 #define __pgprot(x)	((pgprot_t) { (x) } )
60 
61 extern unsigned long memory_start;
62 extern unsigned long memory_end;
63 
64 #endif /* !__ASSEMBLY__ */
65 
66 #ifdef CONFIG_KERNEL_RAM_BASE_ADDRESS
67 #define PAGE_OFFSET		(CONFIG_KERNEL_RAM_BASE_ADDRESS)
68 #else
69 #define PAGE_OFFSET		(0)
70 #endif
71 
72 #ifndef ARCH_PFN_OFFSET
73 #define ARCH_PFN_OFFSET		(PAGE_OFFSET >> PAGE_SHIFT)
74 #endif
75 
76 #ifndef __ASSEMBLY__
77 
78 #define __va(x) ((void *)((unsigned long) (x)))
79 #define __pa(x) ((unsigned long) (x))
80 
81 #define virt_to_pfn(kaddr)	(__pa(kaddr) >> PAGE_SHIFT)
82 #define pfn_to_virt(pfn)	__va((pfn) << PAGE_SHIFT)
83 
84 #define virt_to_page(addr)	pfn_to_page(virt_to_pfn(addr))
85 #define page_to_virt(page)	pfn_to_virt(page_to_pfn(page))
86 
87 #ifndef page_to_phys
88 #define page_to_phys(page)      ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
89 #endif
90 
91 #define pfn_valid(pfn)		((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr)
92 
93 #define	virt_addr_valid(kaddr)	(((void *)(kaddr) >= (void *)PAGE_OFFSET) && \
94 				((void *)(kaddr) < (void *)memory_end))
95 
96 #endif /* __ASSEMBLY__ */
97 
98 #include <asm-generic/memory_model.h>
99 #include <asm-generic/getorder.h>
100 
101 #endif /* __ASM_GENERIC_PAGE_H */
102