xref: /openbmc/linux/arch/arm64/include/asm/memory.h (revision afb46f79)
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 FIXADDR_TOP		(MODULES_VADDR - SZ_2M - PAGE_SIZE)
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 
106 extern 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  */
125 static inline phys_addr_t virt_to_phys(const volatile void *x)
126 {
127 	return __virt_to_phys((unsigned long)(x));
128 }
129 
130 static 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
156