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 */