xref: /openbmc/linux/arch/nios2/include/asm/page.h (revision a44e4f3a)
1 /*
2  * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
3  * Copyright (C) 2004 Microtronix Datacom Ltd.
4  *
5  * MMU support based on asm/page.h from mips which is:
6  *
7  * Copyright (C) 1994 - 1999, 2000, 03 Ralf Baechle
8  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
9  *
10  * This file is subject to the terms and conditions of the GNU General Public
11  * License.  See the file "COPYING" in the main directory of this archive
12  * for more details.
13  */
14 
15 #ifndef _ASM_NIOS2_PAGE_H
16 #define _ASM_NIOS2_PAGE_H
17 
18 #include <linux/pfn.h>
19 #include <linux/const.h>
20 
21 /*
22  * PAGE_SHIFT determines the page size
23  */
24 #define PAGE_SHIFT	12
25 #define PAGE_SIZE	(_AC(1, UL) << PAGE_SHIFT)
26 #define PAGE_MASK	(~(PAGE_SIZE - 1))
27 
28 /*
29  * PAGE_OFFSET -- the first address of the first page of memory.
30  */
31 #define PAGE_OFFSET	\
32 	(CONFIG_NIOS2_MEM_BASE + CONFIG_NIOS2_KERNEL_REGION_BASE)
33 
34 #ifndef __ASSEMBLY__
35 
36 /*
37  * This gives the physical RAM offset.
38  */
39 #define PHYS_OFFSET		CONFIG_NIOS2_MEM_BASE
40 
41 /*
42  * It's normally defined only for FLATMEM config but it's
43  * used in our early mem init code for all memory models.
44  * So always define it.
45  */
46 #define ARCH_PFN_OFFSET		PFN_UP(PHYS_OFFSET)
47 
48 #define clear_page(page)	memset((page), 0, PAGE_SIZE)
49 #define copy_page(to, from)	memcpy((to), (from), PAGE_SIZE)
50 
51 struct page;
52 
53 extern void clear_user_page(void *addr, unsigned long vaddr, struct page *page);
54 extern void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
55 				struct page *to);
56 
57 /*
58  * These are used to make use of C type-checking.
59  */
60 typedef struct page *pgtable_t;
61 typedef struct { unsigned long pte; } pte_t;
62 typedef struct { unsigned long pgd; } pgd_t;
63 typedef struct { unsigned long pgprot; } pgprot_t;
64 
65 #define pte_val(x)	((x).pte)
66 #define pgd_val(x)	((x).pgd)
67 #define pgprot_val(x)	((x).pgprot)
68 
69 #define __pte(x)	((pte_t) { (x) })
70 #define __pgd(x)	((pgd_t) { (x) })
71 #define __pgprot(x)	((pgprot_t) { (x) })
72 
73 extern unsigned long memory_start;
74 extern unsigned long memory_end;
75 extern unsigned long memory_size;
76 
77 extern struct page *mem_map;
78 
79 # define __pa(x)		\
80 	((unsigned long)(x) - PAGE_OFFSET + PHYS_OFFSET)
81 # define __va(x)		\
82 	((void *)((unsigned long)(x) + PAGE_OFFSET - PHYS_OFFSET))
83 
84 #define page_to_virt(page)	\
85 	((void *)(((page) - mem_map) << PAGE_SHIFT) + PAGE_OFFSET)
86 
87 # define pfn_to_kaddr(pfn)	__va((pfn) << PAGE_SHIFT)
88 
89 static inline bool pfn_valid(unsigned long pfn)
90 {
91 	/* avoid <linux/mm.h> include hell */
92 	extern unsigned long max_mapnr;
93 	unsigned long pfn_offset = ARCH_PFN_OFFSET;
94 
95 	return pfn >= pfn_offset && pfn < max_mapnr;
96 }
97 
98 # define virt_to_page(vaddr)	pfn_to_page(PFN_DOWN(virt_to_phys(vaddr)))
99 # define virt_addr_valid(vaddr)	pfn_valid(PFN_DOWN(virt_to_phys(vaddr)))
100 
101 # define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | \
102 				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
103 
104 #include <asm-generic/memory_model.h>
105 
106 #include <asm-generic/getorder.h>
107 
108 #endif /* !__ASSEMBLY__ */
109 
110 #endif /* _ASM_NIOS2_PAGE_H */
111