1 /* $NetBSD: bus_dma_hacks.h,v 1.3 2014/04/03 19:18:29 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 2013 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Taylor R. Campbell. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #ifndef _DRM_BUS_DMA_HACKS_H_ 33 #define _DRM_BUS_DMA_HACKS_H_ 34 35 #include <sys/cdefs.h> 36 #include <sys/bus.h> 37 38 #include <uvm/uvm.h> 39 #include <uvm/uvm_extern.h> 40 41 /* XXX This is x86-specific bollocks. */ 42 43 static inline int 44 bus_dmamem_wire_uvm_object(bus_dma_tag_t tag, struct uvm_object *uobj, 45 off_t start, bus_size_t size, struct pglist *pages, bus_size_t alignment, 46 bus_size_t boundary, bus_dma_segment_t *segs, int nsegs, int *rsegs, 47 int flags) 48 { 49 struct pglist pageq; 50 struct vm_page *page; 51 bus_addr_t prev_addr, addr; 52 unsigned int i; 53 int error; 54 55 /* 56 * XXX `#ifdef __x86_64__' is a horrible way to work around a 57 * completely stupid GCC warning that encourages unsafe, 58 * nonportable code and has no obvious way to be selectively 59 * suppressed. 60 */ 61 #if __x86_64__ 62 KASSERT(size <= __type_max(off_t)); 63 #endif 64 65 KASSERT(start <= (__type_max(off_t) - size)); 66 KASSERT(alignment == PAGE_SIZE); /* XXX */ 67 KASSERT(0 < nsegs); 68 69 if (pages == NULL) { 70 TAILQ_INIT(&pageq); 71 pages = &pageq; 72 } 73 74 error = uvm_obj_wirepages(uobj, start, (start + size), pages); 75 if (error) 76 goto fail0; 77 78 page = TAILQ_FIRST(pages); 79 KASSERT(page != NULL); 80 81 addr = VM_PAGE_TO_PHYS(page); 82 segs[0].ds_addr = addr; 83 segs[0].ds_len = PAGE_SIZE; 84 85 i = 0; 86 while ((page = TAILQ_NEXT(page, pageq.queue)) != NULL) { 87 prev_addr = addr; 88 addr = VM_PAGE_TO_PHYS(page); 89 if ((addr == (prev_addr + PAGE_SIZE)) && 90 ((addr & boundary) == (prev_addr & boundary))) { 91 segs[i].ds_len += PAGE_SIZE; 92 } else { 93 i += 1; 94 if (i >= nsegs) { 95 error = EFBIG; 96 goto fail1; 97 } 98 segs[i].ds_addr = addr; 99 segs[i].ds_len = PAGE_SIZE; 100 } 101 } 102 103 /* Success! */ 104 *rsegs = (i + 1); 105 return 0; 106 107 fail1: uvm_obj_unwirepages(uobj, start, (start + size)); 108 fail0: return error; 109 } 110 111 static inline void 112 bus_dmamem_unwire_uvm_object(bus_dma_tag_t tag __unused, 113 struct uvm_object *uobj, off_t start, bus_size_t size, 114 bus_dma_segment_t *segs __unused, int nsegs __unused) 115 { 116 uvm_obj_unwirepages(uobj, start, (start + size)); 117 } 118 119 #endif /* _DRM_BUS_DMA_HACKS_H_ */ 120