1 /* $NetBSD: virtio_mmio.c,v 1.3 2020/10/03 13:51:34 jmcneill 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@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 2020/10/03 13:51:34 jmcneill 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 is in guest byte order. AArch64 BE is special, 70 * as the guest starts in LE and we switch to BE after the kernel starts. 71 * For this case, we need to byte swap all config space accesses. 72 */ 73 #if defined(__aarch64__) && BYTE_ORDER == BIG_ENDIAN 74 #define VIO16TOH(x) le16toh(x) 75 #define VIO32TOH(x) le32toh(x) 76 #define VIO64TOH(x) le64toh(x) 77 #define HTOVIO16(x) htole16(x) 78 #define HTOVIO32(x) htole32(x) 79 #define HTOVIO64(x) htole64(x) 80 #else 81 #define VIO16TOH(x) (x) 82 #define VIO32TOH(x) (x) 83 #define VIO64TOH(x) (x) 84 #define HTOVIO16(x) (x) 85 #define HTOVIO32(x) (x) 86 #define HTOVIO64(x) (x) 87 #endif 88 89 /* 90 * XXX: Before being used on big endian arches, the access to config registers 91 * XXX: needs to be reviewed/fixed. The non-device specific registers are 92 * XXX: PCI-endian while the device specific registers are native endian. 93 */ 94 95 static void virtio_mmio_kick(struct virtio_softc *, uint16_t); 96 static uint8_t virtio_mmio_read_device_config_1(struct virtio_softc *, int); 97 static uint16_t virtio_mmio_read_device_config_2(struct virtio_softc *, int); 98 static uint32_t virtio_mmio_read_device_config_4(struct virtio_softc *, int); 99 static uint64_t virtio_mmio_read_device_config_8(struct virtio_softc *, int); 100 static void virtio_mmio_write_device_config_1(struct virtio_softc *, int, uint8_t); 101 static void virtio_mmio_write_device_config_2(struct virtio_softc *, int, uint16_t); 102 static void virtio_mmio_write_device_config_4(struct virtio_softc *, int, uint32_t); 103 static void virtio_mmio_write_device_config_8(struct virtio_softc *, int, uint64_t); 104 static uint16_t virtio_mmio_read_queue_size(struct virtio_softc *, uint16_t); 105 static void virtio_mmio_setup_queue(struct virtio_softc *, uint16_t, uint32_t); 106 static void virtio_mmio_set_status(struct virtio_softc *, int); 107 static uint32_t virtio_mmio_negotiate_features(struct virtio_softc *, uint32_t); 108 static int virtio_mmio_setup_interrupts(struct virtio_softc *); 109 static void virtio_mmio_free_interrupts(struct virtio_softc *); 110 111 static const struct virtio_ops virtio_mmio_ops = { 112 .kick = virtio_mmio_kick, 113 .read_dev_cfg_1 = virtio_mmio_read_device_config_1, 114 .read_dev_cfg_2 = virtio_mmio_read_device_config_2, 115 .read_dev_cfg_4 = virtio_mmio_read_device_config_4, 116 .read_dev_cfg_8 = virtio_mmio_read_device_config_8, 117 .write_dev_cfg_1 = virtio_mmio_write_device_config_1, 118 .write_dev_cfg_2 = virtio_mmio_write_device_config_2, 119 .write_dev_cfg_4 = virtio_mmio_write_device_config_4, 120 .write_dev_cfg_8 = virtio_mmio_write_device_config_8, 121 .read_queue_size = virtio_mmio_read_queue_size, 122 .setup_queue = virtio_mmio_setup_queue, 123 .set_status = virtio_mmio_set_status, 124 .neg_features = virtio_mmio_negotiate_features, 125 .setup_interrupts = virtio_mmio_setup_interrupts, 126 .free_interrupts = virtio_mmio_free_interrupts, 127 }; 128 129 static uint16_t 130 virtio_mmio_read_queue_size(struct virtio_softc *vsc, uint16_t idx) 131 { 132 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 133 bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_SEL, idx); 134 return bus_space_read_4(sc->sc_iot, sc->sc_ioh, 135 VIRTIO_MMIO_QUEUE_NUM_MAX); 136 } 137 138 static void 139 virtio_mmio_setup_queue(struct virtio_softc *vsc, uint16_t idx, uint32_t addr) 140 { 141 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 142 143 bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_SEL, idx); 144 bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_NUM, 145 bus_space_read_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_NUM_MAX)); 146 bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_ALIGN, 147 VIRTIO_PAGE_SIZE); 148 bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_PFN, addr); 149 } 150 151 static void 152 virtio_mmio_set_status(struct virtio_softc *vsc, int status) 153 { 154 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 155 int old = 0; 156 157 if (status != 0) 158 old = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 159 VIRTIO_MMIO_STATUS); 160 bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_STATUS, 161 status|old); 162 } 163 164 void 165 virtio_mmio_common_attach(struct virtio_mmio_softc *sc) 166 { 167 struct virtio_softc *vsc = &sc->sc_sc; 168 uint32_t id, magic, ver; 169 170 magic = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 171 VIRTIO_MMIO_MAGIC_VALUE); 172 if (magic != VIRTIO_MMIO_MAGIC) { 173 aprint_error_dev(vsc->sc_dev, 174 "wrong magic value 0x%08x; giving up\n", magic); 175 return; 176 } 177 178 ver = bus_space_read_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_VERSION); 179 if (ver != 1) { 180 aprint_error_dev(vsc->sc_dev, 181 "unknown version 0x%02x; giving up\n", ver); 182 return; 183 } 184 185 id = bus_space_read_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_DEVICE_ID); 186 187 /* we could use PAGE_SIZE, but virtio(4) assumes 4KiB for now */ 188 bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_GUEST_PAGE_SIZE, 189 VIRTIO_PAGE_SIZE); 190 191 /* No device connected. */ 192 if (id == 0) 193 return; 194 195 vsc->sc_ops = &virtio_mmio_ops; 196 197 virtio_device_reset(vsc); 198 virtio_mmio_set_status(vsc, VIRTIO_CONFIG_DEVICE_STATUS_ACK); 199 virtio_mmio_set_status(vsc, VIRTIO_CONFIG_DEVICE_STATUS_DRIVER); 200 201 /* XXX: use softc as aux... */ 202 vsc->sc_childdevid = id; 203 vsc->sc_child = NULL; 204 } 205 206 int 207 virtio_mmio_common_detach(struct virtio_mmio_softc *sc, int flags) 208 { 209 struct virtio_softc *vsc = &sc->sc_sc; 210 int r; 211 212 if (vsc->sc_child != NULL && vsc->sc_child != VIRTIO_CHILD_FAILED) { 213 r = config_detach(vsc->sc_child, flags); 214 if (r) 215 return r; 216 } 217 KASSERT(vsc->sc_child == NULL || vsc->sc_child == VIRTIO_CHILD_FAILED); 218 KASSERT(vsc->sc_vqs == NULL); 219 KASSERT(sc->sc_ih == NULL); 220 221 if (sc->sc_iosize) { 222 bus_space_unmap(sc->sc_iot, sc->sc_ioh, sc->sc_iosize); 223 sc->sc_iosize = 0; 224 } 225 226 return 0; 227 } 228 229 /* 230 * Feature negotiation. 231 */ 232 static uint32_t 233 virtio_mmio_negotiate_features(struct virtio_softc *vsc, uint32_t 234 guest_features) 235 { 236 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 237 uint32_t r; 238 239 bus_space_write_4(sc->sc_iot, sc->sc_ioh, 240 VIRTIO_MMIO_HOST_FEATURES_SEL, 0); 241 r = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 242 VIRTIO_MMIO_HOST_FEATURES); 243 r &= guest_features; 244 bus_space_write_4(sc->sc_iot, sc->sc_ioh, 245 VIRTIO_MMIO_GUEST_FEATURES_SEL, 0); 246 bus_space_write_4(sc->sc_iot, sc->sc_ioh, 247 VIRTIO_MMIO_GUEST_FEATURES, r); 248 return r; 249 } 250 251 /* 252 * Device configuration registers. 253 */ 254 static uint8_t 255 virtio_mmio_read_device_config_1(struct virtio_softc *vsc, int index) 256 { 257 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 258 return bus_space_read_1(sc->sc_iot, sc->sc_ioh, 259 VIRTIO_MMIO_CONFIG + index); 260 } 261 262 static uint16_t 263 virtio_mmio_read_device_config_2(struct virtio_softc *vsc, int index) 264 { 265 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 266 return VIO16TOH(bus_space_read_2(sc->sc_iot, sc->sc_ioh, 267 VIRTIO_MMIO_CONFIG + index)); 268 } 269 270 static uint32_t 271 virtio_mmio_read_device_config_4(struct virtio_softc *vsc, int index) 272 { 273 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 274 return VIO32TOH(bus_space_read_4(sc->sc_iot, sc->sc_ioh, 275 VIRTIO_MMIO_CONFIG + index)); 276 } 277 278 static uint64_t 279 virtio_mmio_read_device_config_8(struct virtio_softc *vsc, int index) 280 { 281 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 282 uint64_t r; 283 284 r = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 285 VIRTIO_MMIO_CONFIG + index + sizeof(uint32_t)); 286 r <<= 32; 287 r += bus_space_read_4(sc->sc_iot, sc->sc_ioh, 288 VIRTIO_MMIO_CONFIG + index); 289 return VIO64TOH(r); 290 } 291 292 static void 293 virtio_mmio_write_device_config_1(struct virtio_softc *vsc, 294 int index, uint8_t value) 295 { 296 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 297 bus_space_write_1(sc->sc_iot, sc->sc_ioh, 298 VIRTIO_MMIO_CONFIG + index, value); 299 } 300 301 static void 302 virtio_mmio_write_device_config_2(struct virtio_softc *vsc, 303 int index, uint16_t value) 304 { 305 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 306 bus_space_write_2(sc->sc_iot, sc->sc_ioh, 307 VIRTIO_MMIO_CONFIG + index, HTOVIO16(value)); 308 } 309 310 static void 311 virtio_mmio_write_device_config_4(struct virtio_softc *vsc, 312 int index, uint32_t value) 313 { 314 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 315 bus_space_write_4(sc->sc_iot, sc->sc_ioh, 316 VIRTIO_MMIO_CONFIG + index, HTOVIO32(value)); 317 } 318 319 static void 320 virtio_mmio_write_device_config_8(struct virtio_softc *vsc, 321 int index, uint64_t value) 322 { 323 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 324 bus_space_write_4(sc->sc_iot, sc->sc_ioh, 325 VIRTIO_MMIO_CONFIG + index, 326 HTOVIO64(value) & 0xffffffff); 327 bus_space_write_4(sc->sc_iot, sc->sc_ioh, 328 VIRTIO_MMIO_CONFIG + index + sizeof(uint32_t), 329 HTOVIO64(value) >> 32); 330 } 331 332 /* 333 * Interrupt handler. 334 */ 335 int 336 virtio_mmio_intr(void *arg) 337 { 338 struct virtio_mmio_softc *sc = arg; 339 struct virtio_softc *vsc = &sc->sc_sc; 340 int isr, r = 0; 341 342 /* check and ack the interrupt */ 343 isr = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 344 VIRTIO_MMIO_INTERRUPT_STATUS); 345 bus_space_write_4(sc->sc_iot, sc->sc_ioh, 346 VIRTIO_MMIO_INTERRUPT_ACK, isr); 347 if ((isr & VIRTIO_MMIO_INT_CONFIG) && 348 (vsc->sc_config_change != NULL)) 349 r = (vsc->sc_config_change)(vsc); 350 if ((isr & VIRTIO_MMIO_INT_VRING) && 351 (vsc->sc_intrhand != NULL)) { 352 if (vsc->sc_soft_ih != NULL) 353 softint_schedule(vsc->sc_soft_ih); 354 else 355 r |= (vsc->sc_intrhand)(vsc); 356 } 357 358 return r; 359 } 360 361 static void 362 virtio_mmio_kick(struct virtio_softc *vsc, uint16_t idx) 363 { 364 struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc; 365 bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_NOTIFY, 366 idx); 367 } 368 369 static int 370 virtio_mmio_setup_interrupts(struct virtio_softc *vsc) 371 { 372 struct virtio_mmio_softc * const sc = (struct virtio_mmio_softc *)vsc; 373 374 return sc->sc_setup_interrupts(sc); 375 } 376 377 static void 378 virtio_mmio_free_interrupts(struct virtio_softc *vsc) 379 { 380 struct virtio_mmio_softc * const sc = (struct virtio_mmio_softc *)vsc; 381 382 sc->sc_free_interrupts(sc); 383 } 384