virtio_mmio.c revision 1.3.2.1
1 /* $NetBSD: virtio_mmio.c,v 1.3.2.1 2021/04/03 22:28:51 thorpej Exp $ */ 2 /* $OpenBSD: virtio_mmio.c,v 1.2 2017/02/24 17:12:31 patrick Exp $ */ 3 4 /* 5 * Copyright (c) 2014 Patrick Wildt <patrick (at) blueri.se> 6 * Copyright (c) 2012 Stefan Fritsch. 7 * Copyright (c) 2010 Minoura Makoto. 8 * All rights reserved. 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 AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #include <sys/cdefs.h> 32 __KERNEL_RCSID(0, "$NetBSD: virtio_mmio.c,v 1.3.2.1 2021/04/03 22:28:51 thorpej Exp $"); 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/kernel.h> 37 #include <sys/device.h> 38 #include <sys/mutex.h> 39 40 #define VIRTIO_PRIVATE 41 #include <dev/virtio/virtio_mmiovar.h> 42 43 #define VIRTIO_MMIO_MAGIC ('v' | 'i' << 8 | 'r' << 16 | 't' << 24) 44 45 #define VIRTIO_MMIO_MAGIC_VALUE 0x000 46 #define VIRTIO_MMIO_VERSION 0x004 47 #define VIRTIO_MMIO_DEVICE_ID 0x008 48 #define VIRTIO_MMIO_VENDOR_ID 0x00c 49 #define VIRTIO_MMIO_HOST_FEATURES 0x010 50 #define VIRTIO_MMIO_HOST_FEATURES_SEL 0x014 51 #define VIRTIO_MMIO_GUEST_FEATURES 0x020 52 #define VIRTIO_MMIO_GUEST_FEATURES_SEL 0x024 53 #define VIRTIO_MMIO_GUEST_PAGE_SIZE 0x028 54 #define VIRTIO_MMIO_QUEUE_SEL 0x030 55 #define VIRTIO_MMIO_QUEUE_NUM_MAX 0x034 56 #define VIRTIO_MMIO_QUEUE_NUM 0x038 57 #define VIRTIO_MMIO_QUEUE_ALIGN 0x03c 58 #define VIRTIO_MMIO_QUEUE_PFN 0x040 59 #define VIRTIO_MMIO_QUEUE_NOTIFY 0x050 60 #define VIRTIO_MMIO_INTERRUPT_STATUS 0x060 61 #define VIRTIO_MMIO_INTERRUPT_ACK 0x064 62 #define VIRTIO_MMIO_STATUS 0x070 63 #define VIRTIO_MMIO_CONFIG 0x100 64 65 #define VIRTIO_MMIO_INT_VRING (1 << 0) 66 #define VIRTIO_MMIO_INT_CONFIG (1 << 1) 67 68 /* 69 * MMIO configuration space for virtio-mmio v1 is in guest byte order. 70 * 71 * XXX Note that aarch64eb pretends to be little endian. the MMIO registers 72 * are in little endian but the device config registers and data structures 73 * are in big endian; this is due to a bug in current Qemu. 74 */ 75 76 #if defined(__aarch64__) && BYTE_ORDER == BIG_ENDIAN 77 # define READ_ENDIAN LITTLE_ENDIAN 78 # define STRUCT_ENDIAN BIG_ENDIAN 79 #elif BYTE_ORDER == BIG_ENDIAN 80 # define READ_ENDIAN BIG_ENDIAN 81 # define STRUCT_ENDIAN BIG_ENDIAN 82 #else 83 # define READ_ENDIAN LITTLE_ENDIAN 84 # define STRUCT_ENDIAN LITTLE_ENDIAN 85 #endif 86 87 88 static void virtio_mmio_kick(struct virtio_softc *, uint16_t); 89 static uint16_t virtio_mmio_read_queue_size(struct virtio_softc *, uint16_t); 90 static void virtio_mmio_setup_queue(struct virtio_softc *, uint16_t, uint64_t); 91 static void virtio_mmio_set_status(struct virtio_softc *, int); 92 static void virtio_mmio_negotiate_features(struct virtio_softc *, uint64_t); 93 static int virtio_mmio_setup_interrupts(struct virtio_softc *); 94 static void virtio_mmio_free_interrupts(struct virtio_softc *); 95 96 static const struct virtio_ops virtio_mmio_ops = { 97 .kick = virtio_mmio_kick, 98 .read_queue_size = virtio_mmio_read_queue_size, 99 .setup_queue = virtio_mmio_setup_queue, 100 .set_status = virtio_mmio_set_status, 101 .neg_features = virtio_mmio_negotiate_features, 102 .setup_interrupts = virtio_mmio_setup_interrupts, 103 .free_interrupts = virtio_mmio_free_interrupts, 104 }; 105 106 static uint16_t 107 virtio_mmio_read_queue_size(struct virtio_softc *vsc, uint16_t idx) 108 { 109 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 110 bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_SEL, idx); 111 return bus_space_read_4(sc->sc_iot, sc->sc_ioh, 112 VIRTIO_MMIO_QUEUE_NUM_MAX); 113 } 114 115 static void 116 virtio_mmio_setup_queue(struct virtio_softc *vsc, uint16_t idx, uint64_t addr) 117 { 118 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 119 120 bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_SEL, idx); 121 bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_NUM, 122 bus_space_read_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_NUM_MAX)); 123 bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_ALIGN, 124 VIRTIO_PAGE_SIZE); 125 bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_PFN, 126 addr / VIRTIO_PAGE_SIZE); 127 } 128 129 static void 130 virtio_mmio_set_status(struct virtio_softc *vsc, int status) 131 { 132 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 133 int old = 0; 134 135 if (status != 0) 136 old = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 137 VIRTIO_MMIO_STATUS); 138 bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_STATUS, 139 status|old); 140 } 141 142 bool 143 virtio_mmio_common_probe_present(struct virtio_mmio_softc *sc) 144 { 145 uint32_t magic; 146 147 magic = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 148 VIRTIO_MMIO_MAGIC_VALUE); 149 return (magic == VIRTIO_MMIO_MAGIC); 150 } 151 152 void 153 virtio_mmio_common_attach(struct virtio_mmio_softc *sc) 154 { 155 struct virtio_softc *vsc = &sc->sc_sc; 156 device_t self = vsc->sc_dev; 157 uint32_t id, magic, ver; 158 159 magic = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 160 VIRTIO_MMIO_MAGIC_VALUE); 161 if (magic != VIRTIO_MMIO_MAGIC) { 162 aprint_error_dev(vsc->sc_dev, 163 "wrong magic value 0x%08x; giving up\n", magic); 164 return; 165 } 166 167 ver = bus_space_read_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_VERSION); 168 if (ver != 1) { 169 aprint_error_dev(vsc->sc_dev, 170 "unknown version 0x%02x; giving up\n", ver); 171 return; 172 } 173 174 id = bus_space_read_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_DEVICE_ID); 175 176 /* we could use PAGE_SIZE, but virtio(4) assumes 4KiB for now */ 177 bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_GUEST_PAGE_SIZE, 178 VIRTIO_PAGE_SIZE); 179 180 /* no device connected. */ 181 if (id == 0) 182 return; 183 184 virtio_print_device_type(self, id, ver); 185 vsc->sc_ops = &virtio_mmio_ops; 186 vsc->sc_bus_endian = READ_ENDIAN; 187 vsc->sc_struct_endian = STRUCT_ENDIAN; 188 189 /* set up our device config tag */ 190 vsc->sc_devcfg_iosize = sc->sc_iosize - VIRTIO_MMIO_CONFIG; 191 vsc->sc_devcfg_iot = sc->sc_iot; 192 if (bus_space_subregion(sc->sc_iot, sc->sc_ioh, 193 VIRTIO_MMIO_CONFIG, vsc->sc_devcfg_iosize, 194 &vsc->sc_devcfg_ioh)) { 195 aprint_error_dev(self, "can't map config i/o space\n"); 196 return; 197 } 198 199 virtio_device_reset(vsc); 200 virtio_mmio_set_status(vsc, VIRTIO_CONFIG_DEVICE_STATUS_ACK); 201 virtio_mmio_set_status(vsc, VIRTIO_CONFIG_DEVICE_STATUS_DRIVER); 202 203 /* XXX: use softc as aux... */ 204 vsc->sc_childdevid = id; 205 vsc->sc_child = NULL; 206 } 207 208 int 209 virtio_mmio_common_detach(struct virtio_mmio_softc *sc, int flags) 210 { 211 struct virtio_softc *vsc = &sc->sc_sc; 212 int r; 213 214 if (vsc->sc_child != NULL && vsc->sc_child != VIRTIO_CHILD_FAILED) { 215 r = config_detach(vsc->sc_child, flags); 216 if (r) 217 return r; 218 } 219 KASSERT(vsc->sc_child == NULL || vsc->sc_child == VIRTIO_CHILD_FAILED); 220 KASSERT(vsc->sc_vqs == NULL); 221 KASSERT(sc->sc_ih == NULL); 222 223 if (sc->sc_iosize) { 224 bus_space_unmap(sc->sc_iot, sc->sc_ioh, sc->sc_iosize); 225 sc->sc_iosize = 0; 226 } 227 228 return 0; 229 } 230 231 /* 232 * Feature negotiation. 233 */ 234 static void 235 virtio_mmio_negotiate_features(struct virtio_softc *vsc, uint64_t 236 guest_features) 237 { 238 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 239 uint32_t r; 240 241 bus_space_write_4(sc->sc_iot, sc->sc_ioh, 242 VIRTIO_MMIO_HOST_FEATURES_SEL, 0); 243 r = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 244 VIRTIO_MMIO_HOST_FEATURES); 245 r &= guest_features; 246 bus_space_write_4(sc->sc_iot, sc->sc_ioh, 247 VIRTIO_MMIO_GUEST_FEATURES_SEL, 0); 248 bus_space_write_4(sc->sc_iot, sc->sc_ioh, 249 VIRTIO_MMIO_GUEST_FEATURES, r); 250 251 vsc->sc_active_features = r; 252 } 253 254 /* 255 * Interrupt handler. 256 */ 257 int 258 virtio_mmio_intr(void *arg) 259 { 260 struct virtio_mmio_softc *sc = arg; 261 struct virtio_softc *vsc = &sc->sc_sc; 262 int isr, r = 0; 263 264 /* check and ack the interrupt */ 265 isr = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 266 VIRTIO_MMIO_INTERRUPT_STATUS); 267 bus_space_write_4(sc->sc_iot, sc->sc_ioh, 268 VIRTIO_MMIO_INTERRUPT_ACK, isr); 269 if ((isr & VIRTIO_MMIO_INT_CONFIG) && 270 (vsc->sc_config_change != NULL)) 271 r = (vsc->sc_config_change)(vsc); 272 if ((isr & VIRTIO_MMIO_INT_VRING) && 273 (vsc->sc_intrhand != NULL)) { 274 if (vsc->sc_soft_ih != NULL) 275 softint_schedule(vsc->sc_soft_ih); 276 else 277 r |= (vsc->sc_intrhand)(vsc); 278 } 279 280 return r; 281 } 282 283 static void 284 virtio_mmio_kick(struct virtio_softc *vsc, uint16_t idx) 285 { 286 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 287 bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_NOTIFY, 288 idx); 289 } 290 291 static int 292 virtio_mmio_setup_interrupts(struct virtio_softc *vsc) 293 { 294 struct virtio_mmio_softc * const sc = (struct virtio_mmio_softc *)vsc; 295 296 return sc->sc_setup_interrupts(sc); 297 } 298 299 static void 300 virtio_mmio_free_interrupts(struct virtio_softc *vsc) 301 { 302 struct virtio_mmio_softc * const sc = (struct virtio_mmio_softc *)vsc; 303 304 sc->sc_free_interrupts(sc); 305 } 306
Indexes created Wed Oct 15 16:09:53 GMT 2025