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 
45 enum 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 
52 extern 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 
59 void set_fixmap(enum fixed_addresses idx, phys_addr_t phys);
60 void clear_fixmap(enum fixed_addresses idx);
61 
62 #endif /*__ASSEMBLY__*/
63 
64 #endif /*_ASM_FIXMAP_H*/
65