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