1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_FIXMAP_H
3#define _ASM_FIXMAP_H
4
5/*
6 * This file defines the locations of the fixed mappings on parisc.
7 *
8 * All of the values in this file are machine virtual addresses.
9 *
10 * All of the values in this file must be <4GB (because of assembly
11 * loading restrictions).  If you place this region anywhere above
12 * __PAGE_OFFSET, you must adjust the memory map accordingly
13 */
14
15/*
16 * The tmpalias region is used in kernel space to copy/clear/flush data
17 * from pages congruently mapped with user space. It is comprised of
18 * a pair regions. The size of these regions is determined by the largest
19 * cache aliasing boundary for machines that support equivalent aliasing.
20 *
21 * The c3750 with PA8700 processor returns an alias value of 11. This
22 * indicates that it has an alias boundary of 4 MB. It also supports
23 * non-equivalent aliasing without a performance penalty.
24 *
25 * Machines with PA8800/PA8900 processors return an alias value of 0.
26 * This indicates the alias boundary is unknown and may be larger than
27 * 16 MB. Non-equivalent aliasing is not supported.
28 *
29 * Here we assume the maximum alias boundary is 4 MB.
30 */
31#define TMPALIAS_SIZE_BITS	22	/* 4 MB */
32#define TMPALIAS_MAP_START	((__PAGE_OFFSET) - (2 << TMPALIAS_SIZE_BITS))
33
34#define FIXMAP_SIZE		(FIX_BITMAP_COUNT << PAGE_SHIFT)
35#define FIXMAP_START		(TMPALIAS_MAP_START - FIXMAP_SIZE)
36/* This is the kernel area for all maps (vmalloc, dma etc.)  most
37 * usually, it extends up to TMPALIAS_MAP_START.  Virtual addresses
38 * 0..GATEWAY_PAGE_SIZE are reserved for the gateway page */
39#define KERNEL_MAP_START	(GATEWAY_PAGE_SIZE)
40#define KERNEL_MAP_END		(FIXMAP_START)
41
42#ifndef __ASSEMBLY__
43
44
45enum fixed_addresses {
46	/* Support writing RO kernel text via kprobes, jump labels, etc. */
47	FIX_TEXT_POKE0,
48	FIX_TEXT_KEXEC,
49	FIX_BITMAP_COUNT
50};
51
52extern void *parisc_vmalloc_start;
53#define PCXL_DMA_MAP_SIZE	(8*1024*1024)
54#define VMALLOC_START		((unsigned long)parisc_vmalloc_start)
55#define VMALLOC_END		(KERNEL_MAP_END)
56
57#define __fix_to_virt(_x) (FIXMAP_START + ((_x) << PAGE_SHIFT))
58
59void set_fixmap(enum fixed_addresses idx, phys_addr_t phys);
60void clear_fixmap(enum fixed_addresses idx);
61
62#endif /*__ASSEMBLY__*/
63
64#endif /*_ASM_FIXMAP_H*/
65