File: /usr/src/linux/include/asm-arm/arch-sa1100/memory.h
1 /*
2 * linux/include/asm-arm/arch-sa1100/memory.h
3 *
4 * Copyright (C) 1999-2000 Nicolas Pitre <nico@cam.org>
5 */
6
7 #ifndef __ASM_ARCH_MEMORY_H
8 #define __ASM_ARCH_MEMORY_H
9
10 #include <linux/config.h>
11
12 /*
13 * Task size: 3GB
14 */
15 #define TASK_SIZE (0xc0000000UL)
16 #define TASK_SIZE_26 (0x04000000UL)
17
18 /*
19 * This decides where the kernel will search for a free chunk of vm
20 * space during mmap's.
21 */
22 #define TASK_UNMAPPED_BASE (TASK_SIZE / 3)
23
24 /*
25 * Page offset: 3GB
26 */
27 #define PAGE_OFFSET (0xc0000000UL)
28
29 /*
30 * Physical DRAM offset is 0xc0000000 on the SA1100
31 */
32 #define PHYS_OFFSET (0xc0000000UL)
33
34 /*
35 * We take advantage of the fact that physical and virtual address can be the
36 * same. The NUMA code is handling the large holes that might exist between
37 * all memory banks.
38 */
39 #define __virt_to_phys__is_a_macro
40 #define __phys_to_virt__is_a_macro
41 #define __virt_to_phys(x) (x)
42 #define __phys_to_virt(x) (x)
43
44 /*
45 * Virtual view <-> DMA view memory address translations
46 * virt_to_bus: Used to translate the virtual address to an
47 * address suitable to be passed to set_dma_addr
48 * bus_to_virt: Used to convert an address for DMA operations
49 * to an address that the kernel can use.
50 *
51 * On the SA1100, bus addresses are equivalent to physical addresses.
52 */
53 #define __virt_to_bus__is_a_macro
54 #define __bus_to_virt__is_a_macro
55 #define __virt_to_bus(x) __virt_to_phys(x)
56 #define __bus_to_virt(x) __phys_to_virt(x)
57
58 #ifdef CONFIG_DISCONTIGMEM
59 /*
60 * Because of the wide memory address space between physical RAM banks on the
61 * SA1100, it's much convenient to use Linux's NUMA support to implement our
62 * memory map representation. Assuming all memory nodes have equal access
63 * characteristics, we then have generic discontigous memory support.
64 *
65 * Of course, all this isn't mandatory for SA1100 implementations with only
66 * one used memory bank. For those, simply undefine CONFIG_DISCONTIGMEM.
67 *
68 * The nodes are matched with the physical memory bank addresses which are
69 * incidentally the same as virtual addresses.
70 *
71 * node 0: 0xc0000000 - 0xc7ffffff
72 * node 1: 0xc8000000 - 0xcfffffff
73 * node 2: 0xd0000000 - 0xd7ffffff
74 * node 3: 0xd8000000 - 0xdfffffff
75 */
76
77 #define NR_NODES 4
78
79 /*
80 * Given a kernel address, find the home node of the underlying memory.
81 */
82 #define KVADDR_TO_NID(addr) \
83 (((unsigned long)(addr) - 0xc0000000) >> 27)
84
85 /*
86 * Given a physical address, convert it to a node id.
87 */
88 #define PHYS_TO_NID(addr) KVADDR_TO_NID(__phys_to_virt(addr))
89
90 /*
91 * Given a kaddr, ADDR_TO_MAPBASE finds the owning node of the memory
92 * and returns the mem_map of that node.
93 */
94 #define ADDR_TO_MAPBASE(kaddr) \
95 NODE_MEM_MAP(KVADDR_TO_NID((unsigned long)(kaddr)))
96
97 /*
98 * Given a kaddr, LOCAL_MEM_MAP finds the owning node of the memory
99 * and returns the index corresponding to the appropriate page in the
100 * node's mem_map.
101 */
102 #define LOCAL_MAP_NR(kvaddr) \
103 (((unsigned long)(kvaddr) & 0x07ffffff) >> PAGE_SHIFT)
104
105 /*
106 * Given a kaddr, virt_to_page returns a pointer to the corresponding
107 * mem_map entry.
108 */
109 #define virt_to_page(kaddr) \
110 (ADDR_TO_MAPBASE(kaddr) + LOCAL_MAP_NR(kaddr))
111
112 /*
113 * VALID_PAGE returns a non-zero value if given page pointer is valid.
114 * This assumes all node's mem_maps are stored within the node they refer to.
115 */
116 #define VALID_PAGE(page) \
117 ({ unsigned int node = KVADDR_TO_NID(page); \
118 ( (node < NR_NODES) && \
119 ((unsigned)((page) - NODE_MEM_MAP(node)) < NODE_DATA(node)->node_size) ); \
120 })
121
122 #else
123
124 #define PHYS_TO_NID(addr) (0)
125
126 #endif
127
128 #endif
129