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.
14 #include <linux/types.h>
16 #include <asm/types.h>
18 #include <asm/asm-compat.h>
19 #include <asm/kdump.h>
22 * On PPC32 page size is 4K. For PPC64 we support either 4K or 64K software
23 * page size. When using 64K pages however, whether we are really supporting
24 * 64K pages in HW or not is irrelevant to those definitions.
26 #ifdef CONFIG_PPC_64K_PAGES
32 #define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT)
34 /* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
35 #define __HAVE_ARCH_GATE_AREA 1
38 * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we
39 * assign PAGE_MASK to a larger type it gets extended the way we want
40 * (i.e. with 1s in the high bits)
42 #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1))
45 * KERNELBASE is the virtual address of the start of the kernel, it's often
46 * the same as PAGE_OFFSET, but _might not be_.
48 * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET.
50 * PAGE_OFFSET is the virtual address of the start of lowmem.
52 * PHYSICAL_START is the physical address of the start of the kernel.
54 * MEMORY_START is the physical address of the start of lowmem.
56 * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on
57 * ppc32 and based on how they are set we determine MEMORY_START.
59 * For the linear mapping the following equation should be true:
60 * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START
62 * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START
64 * There are two was to determine a physical address from a virtual one:
65 * va = pa + PAGE_OFFSET - MEMORY_START
66 * va = pa + KERNELBASE - PHYSICAL_START
68 * If you want to know something's offset from the start of the kernel you
69 * should subtract KERNELBASE.
71 * If you want to test if something's a kernel address, use is_kernel_addr().
74 #define KERNELBASE ASM_CONST(CONFIG_KERNEL_START)
75 #define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET)
76 #define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
78 #if defined(CONFIG_RELOCATABLE)
81 extern phys_addr_t memstart_addr;
82 extern phys_addr_t kernstart_addr;
84 #define PHYSICAL_START kernstart_addr
86 #define PHYSICAL_START ASM_CONST(CONFIG_PHYSICAL_START)
90 #define MEMORY_START 0UL
91 #elif defined(CONFIG_RELOCATABLE)
92 #define MEMORY_START memstart_addr
94 #define MEMORY_START (PHYSICAL_START + PAGE_OFFSET - KERNELBASE)
98 #define ARCH_PFN_OFFSET (MEMORY_START >> PAGE_SHIFT)
99 #define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < (ARCH_PFN_OFFSET + max_mapnr))
102 #define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
103 #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
104 #define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
106 #define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET - MEMORY_START))
107 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START)
110 * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
111 * and needs to be executable. This means the whole heap ends
112 * up being executable.
114 #define VM_DATA_DEFAULT_FLAGS32 (VM_READ | VM_WRITE | VM_EXEC | \
115 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
117 #define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \
118 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
121 #include <asm/page_64.h>
123 #include <asm/page_32.h>
126 /* align addr on a size boundary - adjust address up/down if needed */
127 #define _ALIGN_UP(addr,size) (((addr)+((size)-1))&(~((size)-1)))
128 #define _ALIGN_DOWN(addr,size) ((addr)&(~((size)-1)))
130 /* align addr on a size boundary - adjust address up if needed */
131 #define _ALIGN(addr,size) _ALIGN_UP(addr,size)
134 * Don't compare things with KERNELBASE or PAGE_OFFSET to test for
135 * "kernelness", use is_kernel_addr() - it should do what you want.
137 #define is_kernel_addr(x) ((x) >= PAGE_OFFSET)
141 #undef STRICT_MM_TYPECHECKS
143 #ifdef STRICT_MM_TYPECHECKS
144 /* These are used to make use of C type-checking. */
147 typedef struct { pte_basic_t pte; } pte_t;
148 #define pte_val(x) ((x).pte)
149 #define __pte(x) ((pte_t) { (x) })
151 /* 64k pages additionally define a bigger "real PTE" type that gathers
152 * the "second half" part of the PTE for pseudo 64k pages
154 #ifdef CONFIG_PPC_64K_PAGES
155 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
157 typedef struct { pte_t pte; } real_pte_t;
162 typedef struct { unsigned long pmd; } pmd_t;
163 #define pmd_val(x) ((x).pmd)
164 #define __pmd(x) ((pmd_t) { (x) })
166 /* PUD level exusts only on 4k pages */
167 #ifndef CONFIG_PPC_64K_PAGES
168 typedef struct { unsigned long pud; } pud_t;
169 #define pud_val(x) ((x).pud)
170 #define __pud(x) ((pud_t) { (x) })
171 #endif /* !CONFIG_PPC_64K_PAGES */
172 #endif /* CONFIG_PPC64 */
175 typedef struct { unsigned long pgd; } pgd_t;
176 #define pgd_val(x) ((x).pgd)
177 #define __pgd(x) ((pgd_t) { (x) })
179 /* Page protection bits */
180 typedef struct { unsigned long pgprot; } pgprot_t;
181 #define pgprot_val(x) ((x).pgprot)
182 #define __pgprot(x) ((pgprot_t) { (x) })
187 * .. while these make it easier on the compiler
190 typedef pte_basic_t pte_t;
191 #define pte_val(x) (x)
194 #ifdef CONFIG_PPC_64K_PAGES
195 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
197 typedef unsigned long real_pte_t;
202 typedef unsigned long pmd_t;
203 #define pmd_val(x) (x)
206 #ifndef CONFIG_PPC_64K_PAGES
207 typedef unsigned long pud_t;
208 #define pud_val(x) (x)
210 #endif /* !CONFIG_PPC_64K_PAGES */
211 #endif /* CONFIG_PPC64 */
213 typedef unsigned long pgd_t;
214 #define pgd_val(x) (x)
215 #define pgprot_val(x) (x)
217 typedef unsigned long pgprot_t;
219 #define __pgprot(x) (x)
224 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
225 extern void copy_user_page(void *to, void *from, unsigned long vaddr,
227 extern int page_is_ram(unsigned long pfn);
229 struct vm_area_struct;
231 typedef struct page *pgtable_t;
233 #include <asm-generic/memory_model.h>
234 #endif /* __ASSEMBLY__ */
236 #endif /* _ASM_POWERPC_PAGE_H */