xref: /linux/arch/sparc/include/asm/io-unit.h (revision 93df8a1ed6231727c5db94a80b1a6bd5ee67cec3)
1 /* io-unit.h: Definitions for the sun4d IO-UNIT.
2  *
3  * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
4  */
5 #ifndef _SPARC_IO_UNIT_H
6 #define _SPARC_IO_UNIT_H
7 
8 #include <linux/spinlock.h>
9 #include <asm/page.h>
10 #include <asm/pgtable.h>
11 
12 /* The io-unit handles all virtual to physical address translations
13  * that occur between the SBUS and physical memory.  Access by
14  * the cpu to IO registers and similar go over the xdbus so are
15  * translated by the on chip SRMMU.  The io-unit and the srmmu do
16  * not need to have the same translations at all, in fact most
17  * of the time the translations they handle are a disjunct set.
18  * Basically the io-unit handles all dvma sbus activity.
19  */
20 
21 /* AIEEE, unlike the nice sun4m, these monsters have
22    fixed DMA range 64M */
23 
24 #define IOUNIT_DMA_BASE	    0xfc000000 /* TOP - 64M */
25 #define IOUNIT_DMA_SIZE	    0x04000000 /* 64M */
26 /* We use last 1M for sparc_dvma_malloc */
27 #define IOUNIT_DVMA_SIZE    0x00100000 /* 1M */
28 
29 /* The format of an iopte in the external page tables */
30 #define IOUPTE_PAGE          0xffffff00 /* Physical page number (PA[35:12])	*/
31 #define IOUPTE_CACHE         0x00000080 /* Cached (in Viking/MXCC)		*/
32 /* XXX Jakub, find out how to program SBUS streaming cache on XDBUS/sun4d.
33  * XXX Actually, all you should need to do is find out where the registers
34  * XXX are and copy over the sparc64 implementation I wrote.  There may be
35  * XXX some horrible hwbugs though, so be careful.  -DaveM
36  */
37 #define IOUPTE_STREAM        0x00000040 /* Translation can use streaming cache	*/
38 #define IOUPTE_INTRA	     0x00000008 /* SBUS direct slot->slot transfer	*/
39 #define IOUPTE_WRITE         0x00000004 /* Writeable				*/
40 #define IOUPTE_VALID         0x00000002 /* IOPTE is valid			*/
41 #define IOUPTE_PARITY        0x00000001 /* Parity is checked during DVMA	*/
42 
43 struct iounit_struct {
44 	unsigned long		bmap[(IOUNIT_DMA_SIZE >> (PAGE_SHIFT + 3)) / sizeof(unsigned long)];
45 	spinlock_t		lock;
46 	iopte_t __iomem		*page_table;
47 	unsigned long		rotor[3];
48 	unsigned long		limit[4];
49 };
50 
51 #define IOUNIT_BMAP1_START	0x00000000
52 #define IOUNIT_BMAP1_END	(IOUNIT_DMA_SIZE >> (PAGE_SHIFT + 1))
53 #define IOUNIT_BMAP2_START	IOUNIT_BMAP1_END
54 #define IOUNIT_BMAP2_END	IOUNIT_BMAP2_START + (IOUNIT_DMA_SIZE >> (PAGE_SHIFT + 2))
55 #define IOUNIT_BMAPM_START	IOUNIT_BMAP2_END
56 #define IOUNIT_BMAPM_END	((IOUNIT_DMA_SIZE - IOUNIT_DVMA_SIZE) >> PAGE_SHIFT)
57 
58 #endif /* !(_SPARC_IO_UNIT_H) */
59