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      1 /*	$NetBSD: bus_space_sparse.c,v 1.21 2023/12/20 06:36:02 thorpej Exp $	*/
      2 /*	NetBSD: bus_machdep.c,v 1.1 2000/01/26 18:48:00 drochner Exp 	*/
      3 
      4 /*-
      5  * Copyright (c) 1996, 1997, 1998 The NetBSD Foundation, Inc.
      6  * All rights reserved.
      7  *
      8  * This code is derived from software contributed to The NetBSD Foundation
      9  * by Charles M. Hannum and by Jason R. Thorpe of the Numerical Aerospace
     10  * Simulation Facility, NASA Ames Research Center.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notice, this list of conditions and the following disclaimer.
     17  * 2. Redistributions in binary form must reproduce the above copyright
     18  *    notice, this list of conditions and the following disclaimer in the
     19  *    documentation and/or other materials provided with the distribution.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     31  * POSSIBILITY OF SUCH DAMAGE.
     32  */
     33 
     34 /*
     35  * For sparse bus space
     36  *
     37  * This bus_space uses KSEG2 mapping, if the physical address is not
     38  * accessible via KSEG0/KSEG1.
     39  */
     40 
     41 #include <sys/cdefs.h>
     42 __KERNEL_RCSID(0, "$NetBSD: bus_space_sparse.c,v 1.21 2023/12/20 06:36:02 thorpej Exp $");
     43 
     44 #include <sys/param.h>
     45 #include <sys/bus.h>
     46 #include <sys/systm.h>
     47 
     48 #include <uvm/uvm_extern.h>
     49 
     50 #include <mips/locore.h>
     51 #include <mips/pte.h>
     52 
     53 extern paddr_t kvtophys(vaddr_t);	/* XXX */
     54 
     55 void
     56 arc_sparse_bus_space_init(bus_space_tag_t bst, const char *name, paddr_t paddr,
     57     bus_addr_t start, bus_size_t size)
     58 {
     59 
     60 	arc_bus_space_init(bst, name, paddr, ARC_BUS_SPACE_UNMAPPED,
     61 	    start, size);
     62 	bst->bs_compose_handle = arc_sparse_bus_space_compose_handle;
     63 	bst->bs_dispose_handle = arc_sparse_bus_space_dispose_handle;
     64 	bst->bs_paddr = arc_sparse_bus_space_paddr;
     65 }
     66 
     67 int
     68 arc_sparse_bus_space_compose_handle(bus_space_tag_t bst, bus_addr_t addr,
     69     bus_size_t size, int flags, bus_space_handle_t *bshp)
     70 {
     71 	bus_size_t offset = addr - bst->bs_start;
     72 	/*
     73 	 * Since all buses can be linearly mappable, we don't have to check
     74 	 * BUS_SPACE_MAP_LINEAR and BUS_SPACE_MAP_PREFETCHABLE.
     75 	 */
     76 	const bool cacheable = (flags & BUS_SPACE_MAP_CACHEABLE) != 0;
     77 	const u_int pmap_flags = cacheable ? PMAP_WRITE_BACK : 0;
     78 
     79 	/*
     80 	 * XXX - `bst->bs_pbase' must be page aligned,
     81 	 * mips_trunc/round_page() cannot treat paddr_t due to overflow.
     82 	 */
     83 	paddr_t start = bst->bs_pbase + mips_trunc_page(offset);
     84 	paddr_t end = bst->bs_pbase + mips_round_page(offset + size);
     85 
     86 	if (end <= MIPS_KSEG1_START - MIPS_KSEG0_START) {
     87 		/* mappable on KSEG0 or KSEG1 */
     88 		*bshp = (cacheable ?
     89 		    MIPS_PHYS_TO_KSEG0(start) :
     90 		    MIPS_PHYS_TO_KSEG1(start));
     91 	} else {
     92 		vaddr_t vaddr = uvm_km_alloc(kernel_map, (vsize_t)(end - start),
     93 		    0, UVM_KMF_VAONLY | UVM_KMF_NOWAIT);
     94 
     95 		if (vaddr == 0)
     96 			panic("arc_sparse_bus_space_compose_handle: "
     97 			      "cannot allocate KVA 0x%llx..0x%llx",
     98 			      start, end);
     99 		for (vaddr_t va = vaddr; start < end;
    100 		     start += PAGE_SIZE, va += PAGE_SIZE) {
    101 			pmap_kenter_pa(va, start, VM_PROT_READ|VM_PROT_WRITE,
    102 			    pmap_flags);
    103 		}
    104 		pmap_update(pmap_kernel());
    105 		vaddr += (offset & PGOFSET);
    106 		*bshp = vaddr;
    107 	}
    108 	return 0;
    109 }
    110 
    111 int
    112 arc_sparse_bus_space_dispose_handle(bus_space_tag_t bst, bus_space_handle_t bsh,
    113     bus_size_t size)
    114 {
    115 	vaddr_t start = mips_trunc_page(bsh);
    116 	vaddr_t end = mips_round_page(bsh + size);
    117 
    118 	if (start < MIPS_KSEG2_START) /* KSEG0/KSEG1 */
    119 		return 0;
    120 
    121 	pmap_kremove(start, end - start);
    122 	pmap_update(pmap_kernel());
    123 	uvm_km_free(kernel_map, start, end - start, UVM_KMF_VAONLY);
    124 	return 0;
    125 }
    126 
    127 int
    128 arc_sparse_bus_space_paddr(bus_space_tag_t bst, bus_space_handle_t bsh,
    129     paddr_t *pap)
    130 {
    131 
    132 	*pap = kvtophys(bsh);
    133 	return 0;
    134 }
    135