1 /* $NetBSD: pmap_pvt.c,v 1.3 2016/02/07 18:41:25 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 2014 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 #include <sys/cdefs.h> 33 __RCSID("$NetBSD: pmap_pvt.c,v 1.3 2016/02/07 18:41:25 riastradh Exp $"); 34 35 #include <sys/kmem.h> 36 #include <sys/pserialize.h> 37 38 #include <uvm/uvm.h> 39 #include <uvm/pmap/pmap_pvt.h> 40 41 /* 42 * unmanaged pv-tracked ranges 43 * 44 * This is a linear list for now because the only user are the DRM 45 * graphics drivers, with a single tracked range per device, for the 46 * graphics aperture, so there are expected to be few of them. 47 * 48 * This is used only after the VM system is initialized well enough 49 * that we can use kmem_alloc. 50 */ 51 52 struct pv_track { 53 paddr_t pvt_start; 54 psize_t pvt_size; 55 struct pv_track *pvt_next; 56 struct pmap_page pvt_pages[]; 57 }; 58 59 static struct { 60 kmutex_t lock; 61 pserialize_t psz; 62 struct pv_track *list; 63 } pv_unmanaged __cacheline_aligned; 64 65 void 66 pmap_pv_init(void) 67 { 68 69 mutex_init(&pv_unmanaged.lock, MUTEX_DEFAULT, IPL_NONE); 70 pv_unmanaged.psz = pserialize_create(); 71 pv_unmanaged.list = NULL; 72 } 73 74 void 75 pmap_pv_track(paddr_t start, psize_t size) 76 { 77 struct pv_track *pvt; 78 size_t npages; 79 80 KASSERT(start == trunc_page(start)); 81 KASSERT(size == trunc_page(size)); 82 83 /* We may sleep for allocation. */ 84 ASSERT_SLEEPABLE(); 85 86 npages = size >> PAGE_SHIFT; 87 pvt = kmem_zalloc(offsetof(struct pv_track, pvt_pages[npages]), 88 KM_SLEEP); 89 pvt->pvt_start = start; 90 pvt->pvt_size = size; 91 92 mutex_enter(&pv_unmanaged.lock); 93 pvt->pvt_next = pv_unmanaged.list; 94 membar_producer(); 95 pv_unmanaged.list = pvt; 96 mutex_exit(&pv_unmanaged.lock); 97 } 98 99 void 100 pmap_pv_untrack(paddr_t start, psize_t size) 101 { 102 struct pv_track **pvtp, *pvt; 103 size_t npages; 104 105 KASSERT(start == trunc_page(start)); 106 KASSERT(size == trunc_page(size)); 107 108 /* We may sleep for pserialize_perform. */ 109 ASSERT_SLEEPABLE(); 110 111 mutex_enter(&pv_unmanaged.lock); 112 for (pvtp = &pv_unmanaged.list; 113 (pvt = *pvtp) != NULL; 114 pvtp = &pvt->pvt_next) { 115 if (pvt->pvt_start != start) 116 continue; 117 if (pvt->pvt_size != size) 118 panic("pmap_pv_untrack: pv-tracking at 0x%"PRIxPADDR 119 ": 0x%"PRIxPSIZE" bytes, not 0x%"PRIxPSIZE" bytes", 120 pvt->pvt_start, pvt->pvt_size, size); 121 *pvtp = pvt->pvt_next; 122 pserialize_perform(pv_unmanaged.psz); 123 pvt->pvt_next = NULL; 124 goto out; 125 } 126 panic("pmap_pv_untrack: pages not pv-tracked at 0x%"PRIxPADDR 127 " (0x%"PRIxPSIZE" bytes)", 128 start, size); 129 out: mutex_exit(&pv_unmanaged.lock); 130 131 npages = size >> PAGE_SHIFT; 132 kmem_free(pvt, offsetof(struct pv_track, pvt_pages[npages])); 133 } 134 135 struct pmap_page * 136 pmap_pv_tracked(paddr_t pa) 137 { 138 struct pv_track *pvt; 139 size_t pgno; 140 int s; 141 142 KASSERT(pa == trunc_page(pa)); 143 144 s = pserialize_read_enter(); 145 for (pvt = pv_unmanaged.list; pvt != NULL; pvt = pvt->pvt_next) { 146 membar_datadep_consumer(); 147 if ((pvt->pvt_start <= pa) && 148 ((pa - pvt->pvt_start) < pvt->pvt_size)) 149 break; 150 } 151 pserialize_read_exit(s); 152 153 if (pvt == NULL) 154 return NULL; 155 KASSERT(pvt->pvt_start <= pa); 156 KASSERT((pa - pvt->pvt_start) < pvt->pvt_size); 157 pgno = (pa - pvt->pvt_start) >> PAGE_SHIFT; 158 return &pvt->pvt_pages[pgno]; 159 } 160 161