Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
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 (top
37 * (VA_BITS - 1))
38 * VA_BITS - the maximum number of bits for virtual addresses.
39 * TASK_SIZE - the maximum size of a user space task.
40 * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
41 * The module space lives between the addresses given by TASK_SIZE
42 * and PAGE_OFFSET - it must be within 128MB of the kernel text.
43 */
44#ifdef CONFIG_ARM64_64K_PAGES
45#define VA_BITS (42)
46#else
47#define VA_BITS (39)
48#endif
49#define PAGE_OFFSET (UL(0xffffffffffffffff) << (VA_BITS - 1))
50#define MODULES_END (PAGE_OFFSET)
51#define MODULES_VADDR (MODULES_END - SZ_64M)
52#define EARLYCON_IOBASE (MODULES_VADDR - SZ_4M)
53#define TASK_SIZE_64 (UL(1) << VA_BITS)
54
55#ifdef CONFIG_COMPAT
56#define TASK_SIZE_32 UL(0x100000000)
57#define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \
58 TASK_SIZE_32 : TASK_SIZE_64)
59#else
60#define TASK_SIZE TASK_SIZE_64
61#endif /* CONFIG_COMPAT */
62
63#define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE / 4))
64
65#if TASK_SIZE_64 > MODULES_VADDR
66#error Top of 64-bit user space clashes with start of module space
67#endif
68
69/*
70 * Physical vs virtual RAM address space conversion. These are
71 * private definitions which should NOT be used outside memory.h
72 * files. Use virt_to_phys/phys_to_virt/__pa/__va instead.
73 */
74#define __virt_to_phys(x) (((phys_addr_t)(x) - PAGE_OFFSET + PHYS_OFFSET))
75#define __phys_to_virt(x) ((unsigned long)((x) - PHYS_OFFSET + PAGE_OFFSET))
76
77/*
78 * Convert a physical address to a Page Frame Number and back
79 */
80#define __phys_to_pfn(paddr) ((unsigned long)((paddr) >> PAGE_SHIFT))
81#define __pfn_to_phys(pfn) ((phys_addr_t)(pfn) << PAGE_SHIFT)
82
83/*
84 * Convert a page to/from a physical address
85 */
86#define page_to_phys(page) (__pfn_to_phys(page_to_pfn(page)))
87#define phys_to_page(phys) (pfn_to_page(__phys_to_pfn(phys)))
88
89/*
90 * Memory types available.
91 */
92#define MT_DEVICE_nGnRnE 0
93#define MT_DEVICE_nGnRE 1
94#define MT_DEVICE_GRE 2
95#define MT_NORMAL_NC 3
96#define MT_NORMAL 4
97
98/*
99 * Memory types for Stage-2 translation
100 */
101#define MT_S2_NORMAL 0xf
102#define MT_S2_DEVICE_nGnRE 0x1
103
104#ifndef __ASSEMBLY__
105
106extern phys_addr_t memstart_addr;
107/* PHYS_OFFSET - the physical address of the start of memory. */
108#define PHYS_OFFSET ({ memstart_addr; })
109
110/*
111 * PFNs are used to describe any physical page; this means
112 * PFN 0 == physical address 0.
113 *
114 * This is the PFN of the first RAM page in the kernel
115 * direct-mapped view. We assume this is the first page
116 * of RAM in the mem_map as well.
117 */
118#define PHYS_PFN_OFFSET (PHYS_OFFSET >> PAGE_SHIFT)
119
120/*
121 * Note: Drivers should NOT use these. They are the wrong
122 * translation for translating DMA addresses. Use the driver
123 * DMA support - see dma-mapping.h.
124 */
125static inline phys_addr_t virt_to_phys(const volatile void *x)
126{
127 return __virt_to_phys((unsigned long)(x));
128}
129
130static inline void *phys_to_virt(phys_addr_t x)
131{
132 return (void *)(__phys_to_virt(x));
133}
134
135/*
136 * Drivers should NOT use these either.
137 */
138#define __pa(x) __virt_to_phys((unsigned long)(x))
139#define __va(x) ((void *)__phys_to_virt((phys_addr_t)(x)))
140#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
141
142/*
143 * virt_to_page(k) convert a _valid_ virtual address to struct page *
144 * virt_addr_valid(k) indicates whether a virtual address is valid
145 */
146#define ARCH_PFN_OFFSET PHYS_PFN_OFFSET
147
148#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
149#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
150
151#endif
152
153#include <asm-generic/memory_model.h>
154
155#endif