xref: /openbmc/linux/arch/powerpc/include/asm/page.h (revision fd589a8f)
1 #ifndef _ASM_POWERPC_PAGE_H
2 #define _ASM_POWERPC_PAGE_H
3 
4 /*
5  * Copyright (C) 2001,2005 IBM Corporation.
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * as published by the Free Software Foundation; either version
10  * 2 of the License, or (at your option) any later version.
11  */
12 
13 #ifndef __ASSEMBLY__
14 #include <linux/types.h>
15 #else
16 #include <asm/types.h>
17 #endif
18 #include <asm/asm-compat.h>
19 #include <asm/kdump.h>
20 
21 /*
22  * On regular PPC32 page size is 4K (but we support 4K/16K/64K/256K pages
23  * on PPC44x). For PPC64 we support either 4K or 64K software
24  * page size. When using 64K pages however, whether we are really supporting
25  * 64K pages in HW or not is irrelevant to those definitions.
26  */
27 #if defined(CONFIG_PPC_256K_PAGES)
28 #define PAGE_SHIFT		18
29 #elif defined(CONFIG_PPC_64K_PAGES)
30 #define PAGE_SHIFT		16
31 #elif defined(CONFIG_PPC_16K_PAGES)
32 #define PAGE_SHIFT		14
33 #else
34 #define PAGE_SHIFT		12
35 #endif
36 
37 #define PAGE_SIZE		(ASM_CONST(1) << PAGE_SHIFT)
38 
39 /* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
40 #define __HAVE_ARCH_GATE_AREA		1
41 
42 /*
43  * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we
44  * assign PAGE_MASK to a larger type it gets extended the way we want
45  * (i.e. with 1s in the high bits)
46  */
47 #define PAGE_MASK      (~((1 << PAGE_SHIFT) - 1))
48 
49 /*
50  * KERNELBASE is the virtual address of the start of the kernel, it's often
51  * the same as PAGE_OFFSET, but _might not be_.
52  *
53  * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET.
54  *
55  * PAGE_OFFSET is the virtual address of the start of lowmem.
56  *
57  * PHYSICAL_START is the physical address of the start of the kernel.
58  *
59  * MEMORY_START is the physical address of the start of lowmem.
60  *
61  * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on
62  * ppc32 and based on how they are set we determine MEMORY_START.
63  *
64  * For the linear mapping the following equation should be true:
65  * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START
66  *
67  * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START
68  *
69  * There are two was to determine a physical address from a virtual one:
70  * va = pa + PAGE_OFFSET - MEMORY_START
71  * va = pa + KERNELBASE - PHYSICAL_START
72  *
73  * If you want to know something's offset from the start of the kernel you
74  * should subtract KERNELBASE.
75  *
76  * If you want to test if something's a kernel address, use is_kernel_addr().
77  */
78 
79 #define KERNELBASE      ASM_CONST(CONFIG_KERNEL_START)
80 #define PAGE_OFFSET	ASM_CONST(CONFIG_PAGE_OFFSET)
81 #define LOAD_OFFSET	ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
82 
83 #if defined(CONFIG_RELOCATABLE)
84 #ifndef __ASSEMBLY__
85 
86 extern phys_addr_t memstart_addr;
87 extern phys_addr_t kernstart_addr;
88 #endif
89 #define PHYSICAL_START	kernstart_addr
90 #else
91 #define PHYSICAL_START	ASM_CONST(CONFIG_PHYSICAL_START)
92 #endif
93 
94 #ifdef CONFIG_PPC64
95 #define MEMORY_START	0UL
96 #elif defined(CONFIG_RELOCATABLE)
97 #define MEMORY_START	memstart_addr
98 #else
99 #define MEMORY_START	(PHYSICAL_START + PAGE_OFFSET - KERNELBASE)
100 #endif
101 
102 #ifdef CONFIG_FLATMEM
103 #define ARCH_PFN_OFFSET		(MEMORY_START >> PAGE_SHIFT)
104 #define pfn_valid(pfn)		((pfn) >= ARCH_PFN_OFFSET && (pfn) < (ARCH_PFN_OFFSET + max_mapnr))
105 #endif
106 
107 #define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
108 #define pfn_to_kaddr(pfn)	__va((pfn) << PAGE_SHIFT)
109 #define virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
110 
111 #define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET - MEMORY_START))
112 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START)
113 
114 /*
115  * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
116  * and needs to be executable.  This means the whole heap ends
117  * up being executable.
118  */
119 #define VM_DATA_DEFAULT_FLAGS32	(VM_READ | VM_WRITE | VM_EXEC | \
120 				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
121 
122 #define VM_DATA_DEFAULT_FLAGS64	(VM_READ | VM_WRITE | \
123 				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
124 
125 #ifdef __powerpc64__
126 #include <asm/page_64.h>
127 #else
128 #include <asm/page_32.h>
129 #endif
130 
131 /* align addr on a size boundary - adjust address up/down if needed */
132 #define _ALIGN_UP(addr,size)	(((addr)+((size)-1))&(~((size)-1)))
133 #define _ALIGN_DOWN(addr,size)	((addr)&(~((size)-1)))
134 
135 /* align addr on a size boundary - adjust address up if needed */
136 #define _ALIGN(addr,size)     _ALIGN_UP(addr,size)
137 
138 /*
139  * Don't compare things with KERNELBASE or PAGE_OFFSET to test for
140  * "kernelness", use is_kernel_addr() - it should do what you want.
141  */
142 #ifdef CONFIG_PPC_BOOK3E_64
143 #define is_kernel_addr(x)	((x) >= 0x8000000000000000ul)
144 #else
145 #define is_kernel_addr(x)	((x) >= PAGE_OFFSET)
146 #endif
147 
148 #ifndef __ASSEMBLY__
149 
150 #undef STRICT_MM_TYPECHECKS
151 
152 #ifdef STRICT_MM_TYPECHECKS
153 /* These are used to make use of C type-checking. */
154 
155 /* PTE level */
156 typedef struct { pte_basic_t pte; } pte_t;
157 #define pte_val(x)	((x).pte)
158 #define __pte(x)	((pte_t) { (x) })
159 
160 /* 64k pages additionally define a bigger "real PTE" type that gathers
161  * the "second half" part of the PTE for pseudo 64k pages
162  */
163 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
164 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
165 #else
166 typedef struct { pte_t pte; } real_pte_t;
167 #endif
168 
169 /* PMD level */
170 #ifdef CONFIG_PPC64
171 typedef struct { unsigned long pmd; } pmd_t;
172 #define pmd_val(x)	((x).pmd)
173 #define __pmd(x)	((pmd_t) { (x) })
174 
175 /* PUD level exusts only on 4k pages */
176 #ifndef CONFIG_PPC_64K_PAGES
177 typedef struct { unsigned long pud; } pud_t;
178 #define pud_val(x)	((x).pud)
179 #define __pud(x)	((pud_t) { (x) })
180 #endif /* !CONFIG_PPC_64K_PAGES */
181 #endif /* CONFIG_PPC64 */
182 
183 /* PGD level */
184 typedef struct { unsigned long pgd; } pgd_t;
185 #define pgd_val(x)	((x).pgd)
186 #define __pgd(x)	((pgd_t) { (x) })
187 
188 /* Page protection bits */
189 typedef struct { unsigned long pgprot; } pgprot_t;
190 #define pgprot_val(x)	((x).pgprot)
191 #define __pgprot(x)	((pgprot_t) { (x) })
192 
193 #else
194 
195 /*
196  * .. while these make it easier on the compiler
197  */
198 
199 typedef pte_basic_t pte_t;
200 #define pte_val(x)	(x)
201 #define __pte(x)	(x)
202 
203 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
204 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
205 #else
206 typedef pte_t real_pte_t;
207 #endif
208 
209 
210 #ifdef CONFIG_PPC64
211 typedef unsigned long pmd_t;
212 #define pmd_val(x)	(x)
213 #define __pmd(x)	(x)
214 
215 #ifndef CONFIG_PPC_64K_PAGES
216 typedef unsigned long pud_t;
217 #define pud_val(x)	(x)
218 #define __pud(x)	(x)
219 #endif /* !CONFIG_PPC_64K_PAGES */
220 #endif /* CONFIG_PPC64 */
221 
222 typedef unsigned long pgd_t;
223 #define pgd_val(x)	(x)
224 #define pgprot_val(x)	(x)
225 
226 typedef unsigned long pgprot_t;
227 #define __pgd(x)	(x)
228 #define __pgprot(x)	(x)
229 
230 #endif
231 
232 struct page;
233 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
234 extern void copy_user_page(void *to, void *from, unsigned long vaddr,
235 		struct page *p);
236 extern int page_is_ram(unsigned long pfn);
237 
238 #ifdef CONFIG_PPC_SMLPAR
239 void arch_free_page(struct page *page, int order);
240 #define HAVE_ARCH_FREE_PAGE
241 #endif
242 
243 struct vm_area_struct;
244 
245 typedef struct page *pgtable_t;
246 
247 #include <asm-generic/memory_model.h>
248 #endif /* __ASSEMBLY__ */
249 
250 #endif /* _ASM_POWERPC_PAGE_H */
251