1 /*
2 * include/asm-xtensa/page.h
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version2 as
6 * published by the Free Software Foundation.
7 *
8 * Copyright (C) 2001 - 2007 Tensilica Inc.
9 */
10
11 #ifndef _XTENSA_PAGE_H
12 #define _XTENSA_PAGE_H
13
14 #include <asm/processor.h>
15 #include <asm/types.h>
16 #include <asm/cache.h>
17 #include <asm/kmem_layout.h>
18
19 /*
20 * PAGE_SHIFT determines the page size
21 */
22
23 #define PAGE_SHIFT 12
24 #define PAGE_SIZE (__XTENSA_UL_CONST(1) << PAGE_SHIFT)
25 #define PAGE_MASK (~(PAGE_SIZE-1))
26
27 #ifdef CONFIG_MMU
28 #define PAGE_OFFSET XCHAL_KSEG_CACHED_VADDR
29 #define PHYS_OFFSET XCHAL_KSEG_PADDR
30 #define MAX_LOW_PFN (PHYS_PFN(XCHAL_KSEG_PADDR) + \
31 PHYS_PFN(XCHAL_KSEG_SIZE))
32 #else
33 #define PAGE_OFFSET _AC(CONFIG_DEFAULT_MEM_START, UL)
34 #define PHYS_OFFSET _AC(CONFIG_DEFAULT_MEM_START, UL)
35 #define MAX_LOW_PFN PHYS_PFN(0xfffffffful)
36 #endif
37
38 /*
39 * Cache aliasing:
40 *
41 * If the cache size for one way is greater than the page size, we have to
42 * deal with cache aliasing. The cache index is wider than the page size:
43 *
44 * | |cache| cache index
45 * | pfn |off| virtual address
46 * |xxxx:X|zzz|
47 * | : | |
48 * | \ / | |
49 * |trans.| |
50 * | / \ | |
51 * |yyyy:Y|zzz| physical address
52 *
53 * When the page number is translated to the physical page address, the lowest
54 * bit(s) (X) that are part of the cache index are also translated (Y).
55 * If this translation changes bit(s) (X), the cache index is also afected,
56 * thus resulting in a different cache line than before.
57 * The kernel does not provide a mechanism to ensure that the page color
58 * (represented by this bit) remains the same when allocated or when pages
59 * are remapped. When user pages are mapped into kernel space, the color of
60 * the page might also change.
61 *
62 * We use the address space VMALLOC_END ... VMALLOC_END + DCACHE_WAY_SIZE * 2
63 * to temporarily map a patch so we can match the color.
64 */
65
66 #if DCACHE_WAY_SIZE > PAGE_SIZE
67 # define DCACHE_ALIAS_ORDER (DCACHE_WAY_SHIFT - PAGE_SHIFT)
68 # define DCACHE_ALIAS_MASK (PAGE_MASK & (DCACHE_WAY_SIZE - 1))
69 # define DCACHE_ALIAS(a) (((a) & DCACHE_ALIAS_MASK) >> PAGE_SHIFT)
70 # define DCACHE_ALIAS_EQ(a,b) ((((a) ^ (b)) & DCACHE_ALIAS_MASK) == 0)
71 #else
72 # define DCACHE_ALIAS_ORDER 0
73 # define DCACHE_ALIAS(a) ((void)(a), 0)
74 #endif
75 #define DCACHE_N_COLORS (1 << DCACHE_ALIAS_ORDER)
76
77 #if ICACHE_WAY_SIZE > PAGE_SIZE
78 # define ICACHE_ALIAS_ORDER (ICACHE_WAY_SHIFT - PAGE_SHIFT)
79 # define ICACHE_ALIAS_MASK (PAGE_MASK & (ICACHE_WAY_SIZE - 1))
80 # define ICACHE_ALIAS(a) (((a) & ICACHE_ALIAS_MASK) >> PAGE_SHIFT)
81 # define ICACHE_ALIAS_EQ(a,b) ((((a) ^ (b)) & ICACHE_ALIAS_MASK) == 0)
82 #else
83 # define ICACHE_ALIAS_ORDER 0
84 #endif
85
86
87 #ifdef __ASSEMBLY__
88
89 #define __pgprot(x) (x)
90
91 #else
92
93 /*
94 * These are used to make use of C type-checking..
95 */
96
97 typedef struct { unsigned long pte; } pte_t; /* page table entry */
98 typedef struct { unsigned long pgd; } pgd_t; /* PGD table entry */
99 typedef struct { unsigned long pgprot; } pgprot_t;
100 typedef struct page *pgtable_t;
101
102 #define pte_val(x) ((x).pte)
103 #define pgd_val(x) ((x).pgd)
104 #define pgprot_val(x) ((x).pgprot)
105
106 #define __pte(x) ((pte_t) { (x) } )
107 #define __pgd(x) ((pgd_t) { (x) } )
108 #define __pgprot(x) ((pgprot_t) { (x) } )
109
110 /*
111 * Pure 2^n version of get_order
112 * Use 'nsau' instructions if supported by the processor or the generic version.
113 */
114
115 #if XCHAL_HAVE_NSA
116
get_order(unsigned long size)117 static inline __attribute_const__ int get_order(unsigned long size)
118 {
119 int lz;
120 asm ("nsau %0, %1" : "=r" (lz) : "r" ((size - 1) >> PAGE_SHIFT));
121 return 32 - lz;
122 }
123
124 #else
125
126 # include <asm-generic/getorder.h>
127
128 #endif
129
130 struct page;
131 struct vm_area_struct;
132 extern void clear_page(void *page);
133 extern void copy_page(void *to, void *from);
134
135 /*
136 * If we have cache aliasing and writeback caches, we might have to do
137 * some extra work
138 */
139
140 #if defined(CONFIG_MMU) && DCACHE_WAY_SIZE > PAGE_SIZE
141 extern void clear_page_alias(void *vaddr, unsigned long paddr);
142 extern void copy_page_alias(void *to, void *from,
143 unsigned long to_paddr, unsigned long from_paddr);
144
145 #define clear_user_highpage clear_user_highpage
146 void clear_user_highpage(struct page *page, unsigned long vaddr);
147 #define __HAVE_ARCH_COPY_USER_HIGHPAGE
148 void copy_user_highpage(struct page *to, struct page *from,
149 unsigned long vaddr, struct vm_area_struct *vma);
150 #else
151 # define clear_user_page(page, vaddr, pg) clear_page(page)
152 # define copy_user_page(to, from, vaddr, pg) copy_page(to, from)
153 #endif
154
155 /*
156 * This handles the memory map. We handle pages at
157 * XCHAL_KSEG_CACHED_VADDR for kernels with 32 bit address space.
158 * These macros are for conversion of kernel address, not user
159 * addresses.
160 */
161
162 #define ARCH_PFN_OFFSET (PHYS_OFFSET >> PAGE_SHIFT)
163
164 #ifdef CONFIG_MMU
___pa(unsigned long va)165 static inline unsigned long ___pa(unsigned long va)
166 {
167 unsigned long off = va - PAGE_OFFSET;
168
169 if (off >= XCHAL_KSEG_SIZE)
170 off -= XCHAL_KSEG_SIZE;
171
172 return off + PHYS_OFFSET;
173 }
174 #define __pa(x) ___pa((unsigned long)(x))
175 #else
176 #define __pa(x) \
177 ((unsigned long) (x) - PAGE_OFFSET + PHYS_OFFSET)
178 #endif
179 #define __va(x) \
180 ((void *)((unsigned long) (x) - PHYS_OFFSET + PAGE_OFFSET))
181 #define pfn_valid(pfn) \
182 ((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr)
183
184 #ifdef CONFIG_DISCONTIGMEM
185 # error CONFIG_DISCONTIGMEM not supported
186 #endif
187
188 #define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
189 #define page_to_virt(page) __va(page_to_pfn(page) << PAGE_SHIFT)
190 #define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
191 #define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT)
192
193 #endif /* __ASSEMBLY__ */
194
195 #define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_EXEC | \
196 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
197
198 #include <asm-generic/memory_model.h>
199 #endif /* _XTENSA_PAGE_H */
200
