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>
15 #include <linux/kernel.h>
17 #include <asm/types.h>
19 #include <asm/asm-const.h>
22 * On regular PPC32 page size is 4K (but we support 4K/16K/64K/256K pages
23 * on PPC44x and 4K/16K on 8xx). 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 #define PAGE_SHIFT CONFIG_PPC_PAGE_SHIFT
28 #define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT)
31 #ifdef CONFIG_HUGETLB_PAGE
32 extern bool hugetlb_disabled;
33 extern unsigned int HPAGE_SHIFT;
35 #define HPAGE_SHIFT PAGE_SHIFT
37 #define HPAGE_SIZE ((1UL) << HPAGE_SHIFT)
38 #define HPAGE_MASK (~(HPAGE_SIZE - 1))
39 #define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
40 #define HUGE_MAX_HSTATE (MMU_PAGE_COUNT-1)
44 * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we
45 * assign PAGE_MASK to a larger type it gets extended the way we want
46 * (i.e. with 1s in the high bits)
48 #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1))
51 * KERNELBASE is the virtual address of the start of the kernel, it's often
52 * the same as PAGE_OFFSET, but _might not be_.
54 * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET.
56 * PAGE_OFFSET is the virtual address of the start of lowmem.
58 * PHYSICAL_START is the physical address of the start of the kernel.
60 * MEMORY_START is the physical address of the start of lowmem.
62 * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on
63 * ppc32 and based on how they are set we determine MEMORY_START.
65 * For the linear mapping the following equation should be true:
66 * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START
68 * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START
70 * There are two ways to determine a physical address from a virtual one:
71 * va = pa + PAGE_OFFSET - MEMORY_START
72 * va = pa + KERNELBASE - PHYSICAL_START
74 * If you want to know something's offset from the start of the kernel you
75 * should subtract KERNELBASE.
77 * If you want to test if something's a kernel address, use is_kernel_addr().
80 #define KERNELBASE ASM_CONST(CONFIG_KERNEL_START)
81 #define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET)
82 #define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
84 #if defined(CONFIG_NONSTATIC_KERNEL)
87 extern phys_addr_t memstart_addr;
88 extern phys_addr_t kernstart_addr;
90 #if defined(CONFIG_RELOCATABLE) && defined(CONFIG_PPC32)
91 extern long long virt_phys_offset;
94 #endif /* __ASSEMBLY__ */
95 #define PHYSICAL_START kernstart_addr
97 #else /* !CONFIG_NONSTATIC_KERNEL */
98 #define PHYSICAL_START ASM_CONST(CONFIG_PHYSICAL_START)
101 /* See Description below for VIRT_PHYS_OFFSET */
102 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE)
103 #ifdef CONFIG_RELOCATABLE
104 #define VIRT_PHYS_OFFSET virt_phys_offset
106 #define VIRT_PHYS_OFFSET (KERNELBASE - PHYSICAL_START)
111 #define MEMORY_START 0UL
112 #elif defined(CONFIG_NONSTATIC_KERNEL)
113 #define MEMORY_START memstart_addr
115 #define MEMORY_START (PHYSICAL_START + PAGE_OFFSET - KERNELBASE)
118 #ifdef CONFIG_FLATMEM
119 #define ARCH_PFN_OFFSET ((unsigned long)(MEMORY_START >> PAGE_SHIFT))
121 extern unsigned long max_mapnr;
122 static inline bool pfn_valid(unsigned long pfn)
124 unsigned long min_pfn = ARCH_PFN_OFFSET;
126 return pfn >= min_pfn && pfn < max_mapnr;
131 #define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT)
132 #define virt_to_page(kaddr) pfn_to_page(virt_to_pfn(kaddr))
133 #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
135 #ifdef CONFIG_PPC_BOOK3S_64
137 * On hash the vmalloc and other regions alias to the kernel region when passed
138 * through __pa(), which virt_to_pfn() uses. That means virt_addr_valid() can
139 * return true for some vmalloc addresses, which is incorrect. So explicitly
140 * check that the address is in the kernel region.
142 #define virt_addr_valid(kaddr) (REGION_ID(kaddr) == KERNEL_REGION_ID && \
143 pfn_valid(virt_to_pfn(kaddr)))
145 #define virt_addr_valid(kaddr) pfn_valid(virt_to_pfn(kaddr))
149 * On Book-E parts we need __va to parse the device tree and we can't
150 * determine MEMORY_START until then. However we can determine PHYSICAL_START
151 * from information at hand (program counter, TLB lookup).
153 * On BookE with RELOCATABLE && PPC32
155 * With RELOCATABLE && PPC32, we support loading the kernel at any physical
156 * address without any restriction on the page alignment.
158 * We find the runtime address of _stext and relocate ourselves based on
159 * the following calculation:
161 * virtual_base = ALIGN_DOWN(KERNELBASE,256M) +
162 * MODULO(_stext.run,256M)
163 * and create the following mapping:
165 * ALIGN_DOWN(_stext.run,256M) => ALIGN_DOWN(KERNELBASE,256M)
167 * When we process relocations, we cannot depend on the
168 * existing equation for the __va()/__pa() translations:
170 * __va(x) = (x) - PHYSICAL_START + KERNELBASE
173 * PHYSICAL_START = kernstart_addr = Physical address of _stext
174 * KERNELBASE = Compiled virtual address of _stext.
176 * This formula holds true iff, kernel load address is TLB page aligned.
178 * In our case, we need to also account for the shift in the kernel Virtual
183 * Let the kernel be loaded at 64MB and KERNELBASE be 0xc0000000 (same as PAGE_OFFSET).
184 * In this case, we would be mapping 0 to 0xc0000000, and kernstart_addr = 64M
186 * Now __va(1MB) = (0x100000) - (0x4000000) + 0xc0000000
187 * = 0xbc100000 , which is wrong.
189 * Rather, it should be : 0xc0000000 + 0x100000 = 0xc0100000
190 * according to our mapping.
192 * Hence we use the following formula to get the translations right:
194 * __va(x) = (x) - [ PHYSICAL_START - Effective KERNELBASE ]
197 * PHYSICAL_START = dynamic load address.(kernstart_addr variable)
198 * Effective KERNELBASE = virtual_base =
199 * = ALIGN_DOWN(KERNELBASE,256M) +
200 * MODULO(PHYSICAL_START,256M)
202 * To make the cost of __va() / __pa() more light weight, we introduce
203 * a new variable virt_phys_offset, which will hold :
205 * virt_phys_offset = Effective KERNELBASE - PHYSICAL_START
206 * = ALIGN_DOWN(KERNELBASE,256M) -
207 * ALIGN_DOWN(PHYSICALSTART,256M)
211 * __va(x) = x - PHYSICAL_START + Effective KERNELBASE
212 * = x + virt_phys_offset
215 * __pa(x) = x + PHYSICAL_START - Effective KERNELBASE
216 * = x - virt_phys_offset
218 * On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use
219 * the other definitions for __va & __pa.
221 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE)
222 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET))
223 #define __pa(x) ((unsigned long)(x) - VIRT_PHYS_OFFSET)
227 * gcc miscompiles (unsigned long)(&static_var) - PAGE_OFFSET
228 * with -mcmodel=medium, so we use & and | instead of - and + on 64-bit.
230 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET))
231 #define __pa(x) ((unsigned long)(x) & 0x0fffffffffffffffUL)
233 #else /* 32-bit, non book E */
234 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + PAGE_OFFSET - MEMORY_START))
235 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START)
240 * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
241 * and needs to be executable. This means the whole heap ends
242 * up being executable.
244 #define VM_DATA_DEFAULT_FLAGS32 \
245 (((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \
246 VM_READ | VM_WRITE | \
247 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
249 #define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \
250 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
253 #include <asm/page_64.h>
255 #include <asm/page_32.h>
258 /* align addr on a size boundary - adjust address up/down if needed */
259 #define _ALIGN_UP(addr, size) __ALIGN_KERNEL(addr, size)
260 #define _ALIGN_DOWN(addr, size) ((addr)&(~((typeof(addr))(size)-1)))
262 /* align addr on a size boundary - adjust address up if needed */
263 #define _ALIGN(addr,size) _ALIGN_UP(addr,size)
266 * Don't compare things with KERNELBASE or PAGE_OFFSET to test for
267 * "kernelness", use is_kernel_addr() - it should do what you want.
269 #ifdef CONFIG_PPC_BOOK3E_64
270 #define is_kernel_addr(x) ((x) >= 0x8000000000000000ul)
272 #define is_kernel_addr(x) ((x) >= PAGE_OFFSET)
275 #ifndef CONFIG_PPC_BOOK3S_64
277 * Use the top bit of the higher-level page table entries to indicate whether
278 * the entries we point to contain hugepages. This works because we know that
279 * the page tables live in kernel space. If we ever decide to support having
280 * page tables at arbitrary addresses, this breaks and will have to change.
283 #define PD_HUGE 0x8000000000000000UL
285 #define PD_HUGE 0x80000000
288 #else /* CONFIG_PPC_BOOK3S_64 */
290 * Book3S 64 stores real addresses in the hugepd entries to
291 * avoid overlaps with _PAGE_PRESENT and _PAGE_PTE.
293 #define HUGEPD_ADDR_MASK (0x0ffffffffffffffful & ~HUGEPD_SHIFT_MASK)
294 #endif /* CONFIG_PPC_BOOK3S_64 */
297 * Some number of bits at the level of the page table that points to
298 * a hugepte are used to encode the size. This masks those bits.
300 #define HUGEPD_SHIFT_MASK 0x3f
304 #ifdef CONFIG_PPC_BOOK3S_64
305 #include <asm/pgtable-be-types.h>
307 #include <asm/pgtable-types.h>
311 #ifndef CONFIG_HUGETLB_PAGE
312 #define is_hugepd(pdep) (0)
313 #define pgd_huge(pgd) (0)
314 #endif /* CONFIG_HUGETLB_PAGE */
317 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
318 extern void copy_user_page(void *to, void *from, unsigned long vaddr,
320 extern int devmem_is_allowed(unsigned long pfn);
322 #ifdef CONFIG_PPC_SMLPAR
323 void arch_free_page(struct page *page, int order);
324 #define HAVE_ARCH_FREE_PAGE
327 struct vm_area_struct;
329 #include <asm-generic/memory_model.h>
330 #endif /* __ASSEMBLY__ */
331 #include <asm/slice.h>
333 #define ARCH_ZONE_DMA_BITS 31
335 #endif /* _ASM_POWERPC_PAGE_H */