| 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 | |