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      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
     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
     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
    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
    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