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mem-layout.h
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1 /*
2  * Memory layout definitions for the Hexagon architecture
3  *
4  * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 and
8  * only version 2 as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18  * 02110-1301, USA.
19  */
20 
21 #ifndef _ASM_HEXAGON_MEM_LAYOUT_H
22 #define _ASM_HEXAGON_MEM_LAYOUT_H
23 
24 #include <linux/const.h>
25 
26 /*
27  * Have to do this for ginormous numbers, else they get printed as
28  * negative numbers, which the linker no likey when you try to
29  * assign it to the location counter.
30  */
31 
32 #define PAGE_OFFSET _AC(0xc0000000, UL)
33 
34 /*
35  * LOAD_ADDRESS is the physical/linear address of where in memory
36  * the kernel gets loaded. The 12 least significant bits must be zero (0)
37  * due to limitations on setting the EVB
38  *
39  */
40 
41 #ifndef LOAD_ADDRESS
42 #define LOAD_ADDRESS 0x00000000
43 #endif
44 
45 #define TASK_SIZE (PAGE_OFFSET)
46 
47 /* not sure how these are used yet */
48 #define STACK_TOP TASK_SIZE
49 #define STACK_TOP_MAX TASK_SIZE
50 
51 #ifndef __ASSEMBLY__
54  FIX_KMAP_END, /* check for per-cpuism */
56 };
57 
58 #define MIN_KERNEL_SEG 0x300 /* From 0xc0000000 */
59 extern int max_kernel_seg;
60 
61 /*
62  * Start of vmalloc virtual address space for kernel;
63  * supposed to be based on the amount of physical memory available
64  */
65 
66 #define VMALLOC_START (PAGE_OFFSET + VMALLOC_OFFSET + \
67  (unsigned long)high_memory)
68 
69 /* Gap between physical ram and vmalloc space for guard purposes. */
70 #define VMALLOC_OFFSET PAGE_SIZE
71 
72 /*
73  * Create the space between VMALLOC_START and FIXADDR_TOP backwards
74  * from the ... "top".
75  *
76  * Permanent IO mappings will live at 0xfexx_xxxx
77  * Hypervisor occupies the last 16MB page at 0xffxxxxxx
78  */
79 
80 #define FIXADDR_TOP 0xfe000000
81 #define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
82 #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
83 
84 /*
85  * "permanent kernel mappings", defined as long-lasting mappings of
86  * high-memory page frames into the kernel address space.
87  */
88 
89 #define LAST_PKMAP PTRS_PER_PTE
90 #define LAST_PKMAP_MASK (LAST_PKMAP - 1)
91 #define PKMAP_NR(virt) ((virt - PKMAP_BASE) >> PAGE_SHIFT)
92 #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))
93 
94 /*
95  * To the "left" of the fixed map space is the kmap space
96  *
97  * "Permanent Kernel Mappings"; fancy (or less fancy) PTE table
98  * that looks like it's actually walked.
99  * Need to check the alignment/shift usage; some archs use
100  * PMD_MASK on this value
101  */
102 #define PKMAP_BASE (FIXADDR_START-PAGE_SIZE*LAST_PKMAP)
103 
104 /*
105  * 2 pages of guard gap between where vmalloc area ends
106  * and pkmap_base begins.
107  */
108 #define VMALLOC_END (PKMAP_BASE-PAGE_SIZE*2)
109 #endif /* !__ASSEMBLY__ */
110 
111 
112 #endif /* _ASM_HEXAGON_MEM_LAYOUT_H */