1 #ifndef _ASM_POWERPC_PAGE_H
2 #define _ASM_POWERPC_PAGE_H
5 * Copyright (C) 2001,2005 IBM Corporation.
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.
13 #include <asm/asm-compat.h>
14 #include <asm/kdump.h>
16 #include <linux/types.h>
20 * On PPC32 page size is 4K. For PPC64 we support either 4K or 64K software
21 * page size. When using 64K pages however, whether we are really supporting
22 * 64K pages in HW or not is irrelevant to those definitions.
24 #ifdef CONFIG_PPC_64K_PAGES
30 #define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT)
32 /* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
33 #define __HAVE_ARCH_GATE_AREA 1
36 * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we
37 * assign PAGE_MASK to a larger type it gets extended the way we want
38 * (i.e. with 1s in the high bits)
40 #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1))
43 * KERNELBASE is the virtual address of the start of the kernel, it's often
44 * the same as PAGE_OFFSET, but _might not be_.
46 * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET.
48 * PAGE_OFFSET is the virtual address of the start of lowmem.
50 * PHYSICAL_START is the physical address of the start of the kernel.
52 * MEMORY_START is the physical address of the start of lowmem.
54 * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on
55 * ppc32 and based on how they are set we determine MEMORY_START.
57 * For the linear mapping the following equation should be true:
58 * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START
60 * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START
62 * There are two was to determine a physical address from a virtual one:
63 * va = pa + PAGE_OFFSET - MEMORY_START
64 * va = pa + KERNELBASE - PHYSICAL_START
66 * If you want to know something's offset from the start of the kernel you
67 * should subtract KERNELBASE.
69 * If you want to test if something's a kernel address, use is_kernel_addr().
72 #define KERNELBASE ASM_CONST(CONFIG_KERNEL_START)
73 #define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET)
74 #define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
76 #if defined(CONFIG_RELOCATABLE)
79 extern phys_addr_t memstart_addr;
80 extern phys_addr_t kernstart_addr;
82 #define PHYSICAL_START kernstart_addr
84 #define PHYSICAL_START ASM_CONST(CONFIG_PHYSICAL_START)
88 #define MEMORY_START 0UL
89 #elif defined(CONFIG_RELOCATABLE)
90 #define MEMORY_START memstart_addr
92 #define MEMORY_START (PHYSICAL_START + PAGE_OFFSET - KERNELBASE)
96 #define ARCH_PFN_OFFSET (MEMORY_START >> PAGE_SHIFT)
97 #define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < (ARCH_PFN_OFFSET + max_mapnr))
100 #define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
101 #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
102 #define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
104 #define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET - MEMORY_START))
105 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START)
108 * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
109 * and needs to be executable. This means the whole heap ends
110 * up being executable.
112 #define VM_DATA_DEFAULT_FLAGS32 (VM_READ | VM_WRITE | VM_EXEC | \
113 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
115 #define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \
116 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
119 #include <asm/page_64.h>
121 #include <asm/page_32.h>
124 /* align addr on a size boundary - adjust address up/down if needed */
125 #define _ALIGN_UP(addr,size) (((addr)+((size)-1))&(~((size)-1)))
126 #define _ALIGN_DOWN(addr,size) ((addr)&(~((size)-1)))
128 /* align addr on a size boundary - adjust address up if needed */
129 #define _ALIGN(addr,size) _ALIGN_UP(addr,size)
132 * Don't compare things with KERNELBASE or PAGE_OFFSET to test for
133 * "kernelness", use is_kernel_addr() - it should do what you want.
135 #define is_kernel_addr(x) ((x) >= PAGE_OFFSET)
139 #undef STRICT_MM_TYPECHECKS
141 #ifdef STRICT_MM_TYPECHECKS
142 /* These are used to make use of C type-checking. */
145 typedef struct { pte_basic_t pte; } pte_t;
146 #define pte_val(x) ((x).pte)
147 #define __pte(x) ((pte_t) { (x) })
149 /* 64k pages additionally define a bigger "real PTE" type that gathers
150 * the "second half" part of the PTE for pseudo 64k pages
152 #ifdef CONFIG_PPC_64K_PAGES
153 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
155 typedef struct { pte_t pte; } real_pte_t;
160 typedef struct { unsigned long pmd; } pmd_t;
161 #define pmd_val(x) ((x).pmd)
162 #define __pmd(x) ((pmd_t) { (x) })
164 /* PUD level exusts only on 4k pages */
165 #ifndef CONFIG_PPC_64K_PAGES
166 typedef struct { unsigned long pud; } pud_t;
167 #define pud_val(x) ((x).pud)
168 #define __pud(x) ((pud_t) { (x) })
169 #endif /* !CONFIG_PPC_64K_PAGES */
170 #endif /* CONFIG_PPC64 */
173 typedef struct { unsigned long pgd; } pgd_t;
174 #define pgd_val(x) ((x).pgd)
175 #define __pgd(x) ((pgd_t) { (x) })
177 /* Page protection bits */
178 typedef struct { unsigned long pgprot; } pgprot_t;
179 #define pgprot_val(x) ((x).pgprot)
180 #define __pgprot(x) ((pgprot_t) { (x) })
185 * .. while these make it easier on the compiler
188 typedef pte_basic_t pte_t;
189 #define pte_val(x) (x)
192 #ifdef CONFIG_PPC_64K_PAGES
193 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
195 typedef unsigned long real_pte_t;
200 typedef unsigned long pmd_t;
201 #define pmd_val(x) (x)
204 #ifndef CONFIG_PPC_64K_PAGES
205 typedef unsigned long pud_t;
206 #define pud_val(x) (x)
208 #endif /* !CONFIG_PPC_64K_PAGES */
209 #endif /* CONFIG_PPC64 */
211 typedef unsigned long pgd_t;
212 #define pgd_val(x) (x)
213 #define pgprot_val(x) (x)
215 typedef unsigned long pgprot_t;
217 #define __pgprot(x) (x)
222 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
223 extern void copy_user_page(void *to, void *from, unsigned long vaddr,
225 extern int page_is_ram(unsigned long pfn);
227 struct vm_area_struct;
229 typedef struct page *pgtable_t;
231 #include <asm-generic/memory_model.h>
232 #endif /* __ASSEMBLY__ */
234 #endif /* _ASM_POWERPC_PAGE_H */