Linux kernel mirror (for testing)
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linux
1/*
2 * Based on arch/arm/include/asm/memory.h
3 *
4 * Copyright (C) 2000-2002 Russell King
5 * Copyright (C) 2012 ARM Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 *
19 * Note: this file should not be included by non-asm/.h files
20 */
21#ifndef __ASM_MEMORY_H
22#define __ASM_MEMORY_H
23
24#include <linux/compiler.h>
25#include <linux/const.h>
26#include <linux/types.h>
27#include <asm/sizes.h>
28
29/*
30 * Allow for constants defined here to be used from assembly code
31 * by prepending the UL suffix only with actual C code compilation.
32 */
33#define UL(x) _AC(x, UL)
34
35/*
36 * PAGE_OFFSET - the virtual address of the start of the kernel image.
37 * VA_BITS - the maximum number of bits for virtual addresses.
38 * TASK_SIZE - the maximum size of a user space task.
39 * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
40 * The module space lives between the addresses given by TASK_SIZE
41 * and PAGE_OFFSET - it must be within 128MB of the kernel text.
42 */
43#define PAGE_OFFSET UL(0xffffffc000000000)
44#define MODULES_END (PAGE_OFFSET)
45#define MODULES_VADDR (MODULES_END - SZ_64M)
46#define EARLYCON_IOBASE (MODULES_VADDR - SZ_4M)
47#define VA_BITS (39)
48#define TASK_SIZE_64 (UL(1) << VA_BITS)
49
50#ifdef CONFIG_COMPAT
51#define TASK_SIZE_32 UL(0x100000000)
52#define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \
53 TASK_SIZE_32 : TASK_SIZE_64)
54#else
55#define TASK_SIZE TASK_SIZE_64
56#endif /* CONFIG_COMPAT */
57
58#define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE / 4))
59
60#if TASK_SIZE_64 > MODULES_VADDR
61#error Top of 64-bit user space clashes with start of module space
62#endif
63
64/*
65 * Physical vs virtual RAM address space conversion. These are
66 * private definitions which should NOT be used outside memory.h
67 * files. Use virt_to_phys/phys_to_virt/__pa/__va instead.
68 */
69#define __virt_to_phys(x) (((phys_addr_t)(x) - PAGE_OFFSET + PHYS_OFFSET))
70#define __phys_to_virt(x) ((unsigned long)((x) - PHYS_OFFSET + PAGE_OFFSET))
71
72/*
73 * Convert a physical address to a Page Frame Number and back
74 */
75#define __phys_to_pfn(paddr) ((unsigned long)((paddr) >> PAGE_SHIFT))
76#define __pfn_to_phys(pfn) ((phys_addr_t)(pfn) << PAGE_SHIFT)
77
78/*
79 * Convert a page to/from a physical address
80 */
81#define page_to_phys(page) (__pfn_to_phys(page_to_pfn(page)))
82#define phys_to_page(phys) (pfn_to_page(__phys_to_pfn(phys)))
83
84/*
85 * Memory types available.
86 */
87#define MT_DEVICE_nGnRnE 0
88#define MT_DEVICE_nGnRE 1
89#define MT_DEVICE_GRE 2
90#define MT_NORMAL_NC 3
91#define MT_NORMAL 4
92
93#ifndef __ASSEMBLY__
94
95extern phys_addr_t memstart_addr;
96/* PHYS_OFFSET - the physical address of the start of memory. */
97#define PHYS_OFFSET ({ memstart_addr; })
98
99/*
100 * PFNs are used to describe any physical page; this means
101 * PFN 0 == physical address 0.
102 *
103 * This is the PFN of the first RAM page in the kernel
104 * direct-mapped view. We assume this is the first page
105 * of RAM in the mem_map as well.
106 */
107#define PHYS_PFN_OFFSET (PHYS_OFFSET >> PAGE_SHIFT)
108
109/*
110 * Note: Drivers should NOT use these. They are the wrong
111 * translation for translating DMA addresses. Use the driver
112 * DMA support - see dma-mapping.h.
113 */
114static inline phys_addr_t virt_to_phys(const volatile void *x)
115{
116 return __virt_to_phys((unsigned long)(x));
117}
118
119static inline void *phys_to_virt(phys_addr_t x)
120{
121 return (void *)(__phys_to_virt(x));
122}
123
124/*
125 * Drivers should NOT use these either.
126 */
127#define __pa(x) __virt_to_phys((unsigned long)(x))
128#define __va(x) ((void *)__phys_to_virt((phys_addr_t)(x)))
129#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
130
131/*
132 * virt_to_page(k) convert a _valid_ virtual address to struct page *
133 * virt_addr_valid(k) indicates whether a virtual address is valid
134 */
135#define ARCH_PFN_OFFSET PHYS_PFN_OFFSET
136
137#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
138#define virt_addr_valid(kaddr) (((void *)(kaddr) >= (void *)PAGE_OFFSET) && \
139 ((void *)(kaddr) < (void *)high_memory))
140
141#endif
142
143#include <asm-generic/memory_model.h>
144
145#endif