xref: /openbmc/linux/arch/sparc/include/asm/io-unit.h (revision f21e49be)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* io-unit.h: Definitions for the sun4d IO-UNIT.
3  *
4  * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
5  */
6 #ifndef _SPARC_IO_UNIT_H
7 #define _SPARC_IO_UNIT_H
8 
9 #include <linux/spinlock.h>
10 #include <linux/pgtable.h>
11 #include <asm/page.h>
12 
13 /* The io-unit handles all virtual to physical address translations
14  * that occur between the SBUS and physical memory.  Access by
15  * the cpu to IO registers and similar go over the xdbus so are
16  * translated by the on chip SRMMU.  The io-unit and the srmmu do
17  * not need to have the same translations at all, in fact most
18  * of the time the translations they handle are a disjunct set.
19  * Basically the io-unit handles all dvma sbus activity.
20  */
21 
22 /* AIEEE, unlike the nice sun4m, these monsters have
23    fixed DMA range 64M */
24 
25 #define IOUNIT_DMA_BASE	    0xfc000000 /* TOP - 64M */
26 #define IOUNIT_DMA_SIZE	    0x04000000 /* 64M */
27 /* We use last 1M for sparc_dvma_malloc */
28 #define IOUNIT_DVMA_SIZE    0x00100000 /* 1M */
29 
30 /* The format of an iopte in the external page tables */
31 #define IOUPTE_PAGE          0xffffff00 /* Physical page number (PA[35:12])	*/
32 #define IOUPTE_CACHE         0x00000080 /* Cached (in Viking/MXCC)		*/
33 /* XXX Jakub, find out how to program SBUS streaming cache on XDBUS/sun4d.
34  * XXX Actually, all you should need to do is find out where the registers
35  * XXX are and copy over the sparc64 implementation I wrote.  There may be
36  * XXX some horrible hwbugs though, so be careful.  -DaveM
37  */
38 #define IOUPTE_STREAM        0x00000040 /* Translation can use streaming cache	*/
39 #define IOUPTE_INTRA	     0x00000008 /* SBUS direct slot->slot transfer	*/
40 #define IOUPTE_WRITE         0x00000004 /* Writeable				*/
41 #define IOUPTE_VALID         0x00000002 /* IOPTE is valid			*/
42 #define IOUPTE_PARITY        0x00000001 /* Parity is checked during DVMA	*/
43 
44 struct iounit_struct {
45 	unsigned long		bmap[(IOUNIT_DMA_SIZE >> (PAGE_SHIFT + 3)) / sizeof(unsigned long)];
46 	spinlock_t		lock;
47 	iopte_t __iomem		*page_table;
48 	unsigned long		rotor[3];
49 	unsigned long		limit[4];
50 };
51 
52 #define IOUNIT_BMAP1_START	0x00000000
53 #define IOUNIT_BMAP1_END	(IOUNIT_DMA_SIZE >> (PAGE_SHIFT + 1))
54 #define IOUNIT_BMAP2_START	IOUNIT_BMAP1_END
55 #define IOUNIT_BMAP2_END	IOUNIT_BMAP2_START + (IOUNIT_DMA_SIZE >> (PAGE_SHIFT + 2))
56 #define IOUNIT_BMAPM_START	IOUNIT_BMAP2_END
57 #define IOUNIT_BMAPM_END	((IOUNIT_DMA_SIZE - IOUNIT_DVMA_SIZE) >> PAGE_SHIFT)
58 
59 #endif /* !(_SPARC_IO_UNIT_H) */
60