xref: /netbsd-src/sys/arch/arc/arc/bus_space_large.c (revision 8ff6f65dafc58186614d149001c905dec4c934a2)
1 /*	$NetBSD: bus_space_large.c,v 1.9 2023/12/20 06:36:02 thorpej Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996, 1997, 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Charles M. Hannum and by Jason R. Thorpe of the Numerical Aerospace
9  * Simulation Facility, NASA Ames Research Center.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * For large sparse bus space
35  * (e.g. NEC RISCstation 2250 PCI memory space: 432MB)
36  *
37  * This bus_space uses either wired TLB or normal KSEG2 mapping
38  * for each bus space region.
39  *
40  * Wired TLB will be used on the following cases:
41  * - If requested region is already mapped by wired TLBs.
42  *	This is needed for some critical resources which are used
43  *	on kernel early stage (e.g. console device resources)
44  * - If requested region size >= ARC_THRESHOLD_TO_USE_WIRED_TLB,
45  *   and enough wired TLBs are still free.
46  *	In this case, the size of wired TLBs becomes always
47  *	MIPS3_WIRED_SIZE (i.e. 16MB). (See wired_map_machdep.c for detail.)
48  */
49 
50 #include <sys/cdefs.h>
51 __KERNEL_RCSID(0, "$NetBSD: bus_space_large.c,v 1.9 2023/12/20 06:36:02 thorpej Exp $");
52 
53 #include <sys/param.h>
54 #include <sys/systm.h>
55 
56 #include <uvm/uvm_extern.h>
57 
58 #include <sys/bus.h>
59 #include <machine/wired_map.h>
60 
61 static int arc_large_bus_space_compose_handle(bus_space_tag_t, bus_addr_t,
62     bus_size_t, int, bus_space_handle_t *);
63 static int arc_large_bus_space_dispose_handle(bus_space_tag_t,
64     bus_space_handle_t, bus_size_t);
65 static int arc_large_bus_space_paddr(bus_space_tag_t, bus_space_handle_t,
66     paddr_t *);
67 
68 void
arc_large_bus_space_init(bus_space_tag_t bst,const char * name,paddr_t paddr,bus_addr_t start,bus_size_t size)69 arc_large_bus_space_init(bus_space_tag_t bst, const char *name, paddr_t paddr,
70     bus_addr_t start, bus_size_t size)
71 {
72 
73 	arc_sparse_bus_space_init(bst, name, paddr, start, size);
74 	bst->bs_compose_handle = arc_large_bus_space_compose_handle;
75 	bst->bs_dispose_handle = arc_large_bus_space_dispose_handle;
76 	bst->bs_paddr = arc_large_bus_space_paddr;
77 }
78 
79 static int
arc_large_bus_space_compose_handle(bus_space_tag_t bst,bus_addr_t addr,bus_size_t size,int flags,bus_space_handle_t * bshp)80 arc_large_bus_space_compose_handle(bus_space_tag_t bst, bus_addr_t addr,
81     bus_size_t size, int flags, bus_space_handle_t *bshp)
82 {
83 	paddr_t pa;
84 	vaddr_t va;
85 
86 	pa = bst->bs_pbase + (addr - bst->bs_start);
87 	/*
88 	 * Check whether the physical address is already wired mapped
89 	 * or not.  If not mapped but requested region is large enough,
90 	 * try to use wired TLB.
91 	 */
92 	if ((va = arc_contiguously_wired_mapped(pa, size)) != 0 ||
93 	    (/* requested region is large enough? */
94 	     size >= ARC_THRESHOLD_TO_USE_WIRED_TLB &&
95 	     /* enough wired TLBs are still available? */
96 	     (va = arc_map_wired(pa, size)) != 0)) {
97 #ifdef DIAGNOSTIC
98 		/*
99 		 * If wired TLB is used,
100 		 * we will not make this bus_space region cacheable,
101 		 * since other bus_space might share this wired TLB.
102 		 */
103 		if (flags & BUS_SPACE_MAP_CACHEABLE)
104 			printf("arc_large_bus_space_compose_handle: "
105 			    "ignore cacheable 0x%llx..0x%llx\n",
106 			    pa, pa + size - 1);
107 #endif
108 		*bshp = va;
109 		return 0;
110 	}
111 	return arc_sparse_bus_space_compose_handle(bst, addr, size, flags,
112 	    bshp);
113 }
114 
115 static int
arc_large_bus_space_dispose_handle(bus_space_tag_t bst,bus_space_handle_t bsh,bus_size_t size)116 arc_large_bus_space_dispose_handle(bus_space_tag_t bst, bus_space_handle_t bsh,
117     bus_size_t size)
118 {
119 	paddr_t pa;
120 
121 	/*
122 	 * We never free already wired TLB entries,
123 	 * since the TLBs might be used for other bus_space region.
124 	 */
125 	if (arc_wired_map_extract(bsh, &pa))
126 		return 0;
127 	return arc_sparse_bus_space_dispose_handle(bst, bsh, size);
128 }
129 
130 static int
arc_large_bus_space_paddr(bus_space_tag_t bst,bus_space_handle_t bsh,paddr_t * pap)131 arc_large_bus_space_paddr(bus_space_tag_t bst, bus_space_handle_t bsh,
132     paddr_t *pap)
133 {
134 
135 	if (arc_wired_map_extract(bsh, pap))
136 		return 0;
137 	return arc_sparse_bus_space_paddr(bst, bsh, pap);
138 }
139