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 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.
27 #if defined(CONFIG_PPC_256K_PAGES)
29 #elif defined(CONFIG_PPC_64K_PAGES)
31 #elif defined(CONFIG_PPC_16K_PAGES)
37 #define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT)
40 #ifdef CONFIG_HUGETLB_PAGE
41 extern unsigned int HPAGE_SHIFT;
43 #define HPAGE_SHIFT PAGE_SHIFT
45 #define HPAGE_SIZE ((1UL) << HPAGE_SHIFT)
46 #define HPAGE_MASK (~(HPAGE_SIZE - 1))
47 #define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
48 #define HUGE_MAX_HSTATE (MMU_PAGE_COUNT-1)
52 * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we
53 * assign PAGE_MASK to a larger type it gets extended the way we want
54 * (i.e. with 1s in the high bits)
56 #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1))
59 * KERNELBASE is the virtual address of the start of the kernel, it's often
60 * the same as PAGE_OFFSET, but _might not be_.
62 * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET.
64 * PAGE_OFFSET is the virtual address of the start of lowmem.
66 * PHYSICAL_START is the physical address of the start of the kernel.
68 * MEMORY_START is the physical address of the start of lowmem.
70 * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on
71 * ppc32 and based on how they are set we determine MEMORY_START.
73 * For the linear mapping the following equation should be true:
74 * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START
76 * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START
78 * There are two ways to determine a physical address from a virtual one:
79 * va = pa + PAGE_OFFSET - MEMORY_START
80 * va = pa + KERNELBASE - PHYSICAL_START
82 * If you want to know something's offset from the start of the kernel you
83 * should subtract KERNELBASE.
85 * If you want to test if something's a kernel address, use is_kernel_addr().
88 #define KERNELBASE ASM_CONST(CONFIG_KERNEL_START)
89 #define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET)
90 #define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
92 #if defined(CONFIG_NONSTATIC_KERNEL)
95 extern phys_addr_t memstart_addr;
96 extern phys_addr_t kernstart_addr;
98 #ifdef CONFIG_RELOCATABLE_PPC32
99 extern long long virt_phys_offset;
102 #endif /* __ASSEMBLY__ */
103 #define PHYSICAL_START kernstart_addr
105 #else /* !CONFIG_NONSTATIC_KERNEL */
106 #define PHYSICAL_START ASM_CONST(CONFIG_PHYSICAL_START)
109 /* See Description below for VIRT_PHYS_OFFSET */
110 #ifdef CONFIG_RELOCATABLE_PPC32
111 #define VIRT_PHYS_OFFSET virt_phys_offset
113 #define VIRT_PHYS_OFFSET (KERNELBASE - PHYSICAL_START)
118 #define MEMORY_START 0UL
119 #elif defined(CONFIG_NONSTATIC_KERNEL)
120 #define MEMORY_START memstart_addr
122 #define MEMORY_START (PHYSICAL_START + PAGE_OFFSET - KERNELBASE)
125 #ifdef CONFIG_FLATMEM
126 #define ARCH_PFN_OFFSET ((unsigned long)(MEMORY_START >> PAGE_SHIFT))
127 #define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < max_mapnr)
130 #define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT)
131 #define virt_to_page(kaddr) pfn_to_page(virt_to_pfn(kaddr))
132 #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
133 #define virt_addr_valid(kaddr) pfn_valid(virt_to_pfn(kaddr))
136 * On Book-E parts we need __va to parse the device tree and we can't
137 * determine MEMORY_START until then. However we can determine PHYSICAL_START
138 * from information at hand (program counter, TLB lookup).
140 * On BookE with RELOCATABLE (RELOCATABLE_PPC32)
142 * With RELOCATABLE_PPC32, we support loading the kernel at any physical
143 * address without any restriction on the page alignment.
145 * We find the runtime address of _stext and relocate ourselves based on
146 * the following calculation:
148 * virtual_base = ALIGN_DOWN(KERNELBASE,256M) +
149 * MODULO(_stext.run,256M)
150 * and create the following mapping:
152 * ALIGN_DOWN(_stext.run,256M) => ALIGN_DOWN(KERNELBASE,256M)
154 * When we process relocations, we cannot depend on the
155 * existing equation for the __va()/__pa() translations:
157 * __va(x) = (x) - PHYSICAL_START + KERNELBASE
160 * PHYSICAL_START = kernstart_addr = Physical address of _stext
161 * KERNELBASE = Compiled virtual address of _stext.
163 * This formula holds true iff, kernel load address is TLB page aligned.
165 * In our case, we need to also account for the shift in the kernel Virtual
170 * Let the kernel be loaded at 64MB and KERNELBASE be 0xc0000000 (same as PAGE_OFFSET).
171 * In this case, we would be mapping 0 to 0xc0000000, and kernstart_addr = 64M
173 * Now __va(1MB) = (0x100000) - (0x4000000) + 0xc0000000
174 * = 0xbc100000 , which is wrong.
176 * Rather, it should be : 0xc0000000 + 0x100000 = 0xc0100000
177 * according to our mapping.
179 * Hence we use the following formula to get the translations right:
181 * __va(x) = (x) - [ PHYSICAL_START - Effective KERNELBASE ]
184 * PHYSICAL_START = dynamic load address.(kernstart_addr variable)
185 * Effective KERNELBASE = virtual_base =
186 * = ALIGN_DOWN(KERNELBASE,256M) +
187 * MODULO(PHYSICAL_START,256M)
189 * To make the cost of __va() / __pa() more light weight, we introduce
190 * a new variable virt_phys_offset, which will hold :
192 * virt_phys_offset = Effective KERNELBASE - PHYSICAL_START
193 * = ALIGN_DOWN(KERNELBASE,256M) -
194 * ALIGN_DOWN(PHYSICALSTART,256M)
198 * __va(x) = x - PHYSICAL_START + Effective KERNELBASE
199 * = x + virt_phys_offset
202 * __pa(x) = x + PHYSICAL_START - Effective KERNELBASE
203 * = x - virt_phys_offset
205 * On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use
206 * the other definitions for __va & __pa.
209 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET))
210 #define __pa(x) ((unsigned long)(x) - VIRT_PHYS_OFFSET)
214 * gcc miscompiles (unsigned long)(&static_var) - PAGE_OFFSET
215 * with -mcmodel=medium, so we use & and | instead of - and + on 64-bit.
217 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET))
218 #define __pa(x) ((unsigned long)(x) & 0x0fffffffffffffffUL)
220 #else /* 32-bit, non book E */
221 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + PAGE_OFFSET - MEMORY_START))
222 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START)
227 * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
228 * and needs to be executable. This means the whole heap ends
229 * up being executable.
231 #define VM_DATA_DEFAULT_FLAGS32 (VM_READ | VM_WRITE | VM_EXEC | \
232 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
234 #define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \
235 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
238 #include <asm/page_64.h>
240 #include <asm/page_32.h>
243 /* align addr on a size boundary - adjust address up/down if needed */
244 #define _ALIGN_UP(addr,size) (((addr)+((size)-1))&(~((size)-1)))
245 #define _ALIGN_DOWN(addr,size) ((addr)&(~((size)-1)))
247 /* align addr on a size boundary - adjust address up if needed */
248 #define _ALIGN(addr,size) _ALIGN_UP(addr,size)
251 * Don't compare things with KERNELBASE or PAGE_OFFSET to test for
252 * "kernelness", use is_kernel_addr() - it should do what you want.
254 #ifdef CONFIG_PPC_BOOK3E_64
255 #define is_kernel_addr(x) ((x) >= 0x8000000000000000ul)
257 #define is_kernel_addr(x) ((x) >= PAGE_OFFSET)
260 #ifndef CONFIG_PPC_BOOK3S_64
262 * Use the top bit of the higher-level page table entries to indicate whether
263 * the entries we point to contain hugepages. This works because we know that
264 * the page tables live in kernel space. If we ever decide to support having
265 * page tables at arbitrary addresses, this breaks and will have to change.
268 #define PD_HUGE 0x8000000000000000
270 #define PD_HUGE 0x80000000
272 #endif /* CONFIG_PPC_BOOK3S_64 */
275 * Some number of bits at the level of the page table that points to
276 * a hugepte are used to encode the size. This masks those bits.
278 #define HUGEPD_SHIFT_MASK 0x3f
282 #ifdef CONFIG_STRICT_MM_TYPECHECKS
283 /* These are used to make use of C type-checking. */
286 typedef struct { pte_basic_t pte; } pte_t;
287 #define pte_val(x) ((x).pte)
288 #define __pte(x) ((pte_t) { (x) })
290 /* 64k pages additionally define a bigger "real PTE" type that gathers
291 * the "second half" part of the PTE for pseudo 64k pages
293 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
294 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
296 typedef struct { pte_t pte; } real_pte_t;
301 typedef struct { unsigned long pmd; } pmd_t;
302 #define pmd_val(x) ((x).pmd)
303 #define __pmd(x) ((pmd_t) { (x) })
305 /* PUD level exusts only on 4k pages */
306 #ifndef CONFIG_PPC_64K_PAGES
307 typedef struct { unsigned long pud; } pud_t;
308 #define pud_val(x) ((x).pud)
309 #define __pud(x) ((pud_t) { (x) })
310 #endif /* !CONFIG_PPC_64K_PAGES */
311 #endif /* CONFIG_PPC64 */
314 typedef struct { unsigned long pgd; } pgd_t;
315 #define pgd_val(x) ((x).pgd)
316 #define __pgd(x) ((pgd_t) { (x) })
318 /* Page protection bits */
319 typedef struct { unsigned long pgprot; } pgprot_t;
320 #define pgprot_val(x) ((x).pgprot)
321 #define __pgprot(x) ((pgprot_t) { (x) })
326 * .. while these make it easier on the compiler
329 typedef pte_basic_t pte_t;
330 #define pte_val(x) (x)
333 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
334 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
336 typedef pte_t real_pte_t;
341 typedef unsigned long pmd_t;
342 #define pmd_val(x) (x)
345 #ifndef CONFIG_PPC_64K_PAGES
346 typedef unsigned long pud_t;
347 #define pud_val(x) (x)
349 #endif /* !CONFIG_PPC_64K_PAGES */
350 #endif /* CONFIG_PPC64 */
352 typedef unsigned long pgd_t;
353 #define pgd_val(x) (x)
354 #define pgprot_val(x) (x)
356 typedef unsigned long pgprot_t;
358 #define __pgprot(x) (x)
362 typedef struct { signed long pd; } hugepd_t;
364 #ifdef CONFIG_HUGETLB_PAGE
365 #ifdef CONFIG_PPC_BOOK3S_64
366 static inline int hugepd_ok(hugepd_t hpd)
369 * hugepd pointer, bottom two bits == 00 and next 4 bits
370 * indicate size of table
372 return (((hpd.pd & 0x3) == 0x0) && ((hpd.pd & HUGEPD_SHIFT_MASK) != 0));
375 static inline int hugepd_ok(hugepd_t hpd)
381 #define is_hugepd(hpd) (hugepd_ok(hpd))
382 #define pgd_huge pgd_huge
383 int pgd_huge(pgd_t pgd);
384 #else /* CONFIG_HUGETLB_PAGE */
385 #define is_hugepd(pdep) 0
386 #define pgd_huge(pgd) 0
387 #endif /* CONFIG_HUGETLB_PAGE */
388 #define __hugepd(x) ((hugepd_t) { (x) })
391 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
392 extern void copy_user_page(void *to, void *from, unsigned long vaddr,
394 extern int page_is_ram(unsigned long pfn);
395 extern int devmem_is_allowed(unsigned long pfn);
397 #ifdef CONFIG_PPC_SMLPAR
398 void arch_free_page(struct page *page, int order);
399 #define HAVE_ARCH_FREE_PAGE
402 struct vm_area_struct;
404 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC64)
405 typedef pte_t *pgtable_t;
407 typedef struct page *pgtable_t;
410 #include <asm-generic/memory_model.h>
411 #endif /* __ASSEMBLY__ */
413 #endif /* _ASM_POWERPC_PAGE_H */