1 /*
2  * Memory layout definitions for the Hexagon architecture
3  *
4  * Copyright (c) 2010-2013, 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  * Compiling for a platform that needs a crazy physical offset
36  * (like if the memory starts at 1GB and up) means we need
37  * an actual PHYS_OFFSET.  Should be set up in head.S.
38  */
39 
40 #ifdef CONFIG_HEXAGON_PHYS_OFFSET
41 #ifndef __ASSEMBLY__
42 extern unsigned long	__phys_offset;
43 #endif
44 #define PHYS_OFFSET	__phys_offset
45 #endif
46 
47 #ifndef PHYS_OFFSET
48 #define PHYS_OFFSET	0
49 #endif
50 
51 #define PHYS_PFN_OFFSET	(PHYS_OFFSET >> PAGE_SHIFT)
52 #define ARCH_PFN_OFFSET	PHYS_PFN_OFFSET
53 
54 #define TASK_SIZE			(PAGE_OFFSET)
55 
56 /*  not sure how these are used yet  */
57 #define STACK_TOP			TASK_SIZE
58 #define STACK_TOP_MAX			TASK_SIZE
59 
60 #ifndef __ASSEMBLY__
61 enum fixed_addresses {
62 	FIX_KMAP_BEGIN,
63 	FIX_KMAP_END,  /*  check for per-cpuism  */
64 	__end_of_fixed_addresses
65 };
66 
67 #define MIN_KERNEL_SEG (PAGE_OFFSET >> PGDIR_SHIFT)   /* L1 shift is 22 bits */
68 extern int max_kernel_seg;
69 
70 /*
71  * Start of vmalloc virtual address space for kernel;
72  * supposed to be based on the amount of physical memory available
73  */
74 
75 #define VMALLOC_START ((unsigned long) __va(high_memory + VMALLOC_OFFSET))
76 
77 /* Gap between physical ram and vmalloc space for guard purposes. */
78 #define VMALLOC_OFFSET PAGE_SIZE
79 
80 /*
81  * Create the space between VMALLOC_START and FIXADDR_TOP backwards
82  * from the ... "top".
83  *
84  * Permanent IO mappings will live at 0xfexx_xxxx
85  * Hypervisor occupies the last 16MB page at 0xffxxxxxx
86  */
87 
88 #define FIXADDR_TOP     0xfe000000
89 #define FIXADDR_SIZE    (__end_of_fixed_addresses << PAGE_SHIFT)
90 #define FIXADDR_START   (FIXADDR_TOP - FIXADDR_SIZE)
91 
92 /*
93  * "permanent kernel mappings", defined as long-lasting mappings of
94  * high-memory page frames into the kernel address space.
95  */
96 
97 #define LAST_PKMAP	PTRS_PER_PTE
98 #define LAST_PKMAP_MASK	(LAST_PKMAP - 1)
99 #define PKMAP_NR(virt)	((virt - PKMAP_BASE) >> PAGE_SHIFT)
100 #define PKMAP_ADDR(nr)	(PKMAP_BASE + ((nr) << PAGE_SHIFT))
101 
102 /*
103  * To the "left" of the fixed map space is the kmap space
104  *
105  * "Permanent Kernel Mappings"; fancy (or less fancy) PTE table
106  * that looks like it's actually walked.
107  * Need to check the alignment/shift usage; some archs use
108  * PMD_MASK on this value
109  */
110 #define PKMAP_BASE (FIXADDR_START-PAGE_SIZE*LAST_PKMAP)
111 
112 /*
113  * 2 pages of guard gap between where vmalloc area ends
114  * and pkmap_base begins.
115  */
116 #define VMALLOC_END (PKMAP_BASE-PAGE_SIZE*2)
117 #endif /*  !__ASSEMBLY__  */
118 
119 
120 #endif /* _ASM_HEXAGON_MEM_LAYOUT_H */
121