1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Memory layout definitions for the Hexagon architecture
4  *
5  * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved.
6  */
7 
8 #ifndef _ASM_HEXAGON_MEM_LAYOUT_H
9 #define _ASM_HEXAGON_MEM_LAYOUT_H
10 
11 #include <linux/const.h>
12 
13 /*
14  * Have to do this for ginormous numbers, else they get printed as
15  * negative numbers, which the linker no likey when you try to
16  * assign it to the location counter.
17  */
18 
19 #define PAGE_OFFSET			_AC(0xc0000000, UL)
20 
21 /*
22  * Compiling for a platform that needs a crazy physical offset
23  * (like if the memory starts at 1GB and up) means we need
24  * an actual PHYS_OFFSET.  Should be set up in head.S.
25  */
26 
27 #ifdef CONFIG_HEXAGON_PHYS_OFFSET
28 #ifndef __ASSEMBLY__
29 extern unsigned long	__phys_offset;
30 #endif
31 #define PHYS_OFFSET	__phys_offset
32 #endif
33 
34 #ifndef PHYS_OFFSET
35 #define PHYS_OFFSET	0
36 #endif
37 
38 #define PHYS_PFN_OFFSET	(PHYS_OFFSET >> PAGE_SHIFT)
39 #define ARCH_PFN_OFFSET	PHYS_PFN_OFFSET
40 
41 #define TASK_SIZE			(PAGE_OFFSET)
42 
43 /*  not sure how these are used yet  */
44 #define STACK_TOP			TASK_SIZE
45 #define STACK_TOP_MAX			TASK_SIZE
46 
47 #ifndef __ASSEMBLY__
48 enum fixed_addresses {
49 	FIX_KMAP_BEGIN,
50 	FIX_KMAP_END,  /*  check for per-cpuism  */
51 	__end_of_fixed_addresses
52 };
53 
54 #define MIN_KERNEL_SEG (PAGE_OFFSET >> PGDIR_SHIFT)   /* L1 shift is 22 bits */
55 extern int max_kernel_seg;
56 
57 /*
58  * Start of vmalloc virtual address space for kernel;
59  * supposed to be based on the amount of physical memory available
60  */
61 
62 #define VMALLOC_START ((unsigned long) __va(high_memory + VMALLOC_OFFSET))
63 
64 /* Gap between physical ram and vmalloc space for guard purposes. */
65 #define VMALLOC_OFFSET PAGE_SIZE
66 
67 /*
68  * Create the space between VMALLOC_START and FIXADDR_TOP backwards
69  * from the ... "top".
70  *
71  * Permanent IO mappings will live at 0xfexx_xxxx
72  * Hypervisor occupies the last 16MB page at 0xffxxxxxx
73  */
74 
75 #define FIXADDR_TOP     0xfe000000
76 #define FIXADDR_SIZE    (__end_of_fixed_addresses << PAGE_SHIFT)
77 #define FIXADDR_START   (FIXADDR_TOP - FIXADDR_SIZE)
78 
79 /*
80  * "permanent kernel mappings", defined as long-lasting mappings of
81  * high-memory page frames into the kernel address space.
82  */
83 
84 #define LAST_PKMAP	PTRS_PER_PTE
85 #define LAST_PKMAP_MASK	(LAST_PKMAP - 1)
86 #define PKMAP_NR(virt)	((virt - PKMAP_BASE) >> PAGE_SHIFT)
87 #define PKMAP_ADDR(nr)	(PKMAP_BASE + ((nr) << PAGE_SHIFT))
88 
89 /*
90  * To the "left" of the fixed map space is the kmap space
91  *
92  * "Permanent Kernel Mappings"; fancy (or less fancy) PTE table
93  * that looks like it's actually walked.
94  * Need to check the alignment/shift usage; some archs use
95  * PMD_MASK on this value
96  */
97 #define PKMAP_BASE (FIXADDR_START-PAGE_SIZE*LAST_PKMAP)
98 
99 /*
100  * 2 pages of guard gap between where vmalloc area ends
101  * and pkmap_base begins.
102  */
103 #define VMALLOC_END (PKMAP_BASE-PAGE_SIZE*2)
104 #endif /*  !__ASSEMBLY__  */
105 
106 
107 #endif /* _ASM_HEXAGON_MEM_LAYOUT_H */
108