Oleksandr Andrushchenko | cc3196ae1 | 2018-05-14 09:27:37 +0300 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 OR MIT |
| 2 | |
| 3 | /* |
| 4 | * Xen para-virtual sound device |
| 5 | * |
| 6 | * Copyright (C) 2016-2018 EPAM Systems Inc. |
| 7 | * |
| 8 | * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> |
| 9 | */ |
| 10 | |
| 11 | #include <linux/delay.h> |
| 12 | #include <linux/module.h> |
| 13 | |
Oleksandr Andrushchenko | d6e0fbb | 2018-05-14 09:27:40 +0300 | [diff] [blame] | 14 | #include <xen/page.h> |
Oleksandr Andrushchenko | cc3196ae1 | 2018-05-14 09:27:37 +0300 | [diff] [blame] | 15 | #include <xen/platform_pci.h> |
| 16 | #include <xen/xen.h> |
| 17 | #include <xen/xenbus.h> |
| 18 | |
Oleksandr Andrushchenko | 58f9d80 | 2018-11-30 09:42:05 +0200 | [diff] [blame] | 19 | #include <xen/xen-front-pgdir-shbuf.h> |
Oleksandr Andrushchenko | cc3196ae1 | 2018-05-14 09:27:37 +0300 | [diff] [blame] | 20 | #include <xen/interface/io/sndif.h> |
| 21 | |
| 22 | #include "xen_snd_front.h" |
Oleksandr Andrushchenko | 1cee559 | 2018-05-14 09:27:41 +0300 | [diff] [blame] | 23 | #include "xen_snd_front_alsa.h" |
Oleksandr Andrushchenko | 788ef64 | 2018-05-14 09:27:39 +0300 | [diff] [blame] | 24 | #include "xen_snd_front_evtchnl.h" |
Oleksandr Andrushchenko | 1cee559 | 2018-05-14 09:27:41 +0300 | [diff] [blame] | 25 | |
| 26 | static struct xensnd_req * |
| 27 | be_stream_prepare_req(struct xen_snd_front_evtchnl *evtchnl, u8 operation) |
| 28 | { |
| 29 | struct xensnd_req *req; |
| 30 | |
| 31 | req = RING_GET_REQUEST(&evtchnl->u.req.ring, |
| 32 | evtchnl->u.req.ring.req_prod_pvt); |
| 33 | req->operation = operation; |
| 34 | req->id = evtchnl->evt_next_id++; |
| 35 | evtchnl->evt_id = req->id; |
| 36 | return req; |
| 37 | } |
| 38 | |
| 39 | static int be_stream_do_io(struct xen_snd_front_evtchnl *evtchnl) |
| 40 | { |
| 41 | if (unlikely(evtchnl->state != EVTCHNL_STATE_CONNECTED)) |
| 42 | return -EIO; |
| 43 | |
| 44 | reinit_completion(&evtchnl->u.req.completion); |
| 45 | xen_snd_front_evtchnl_flush(evtchnl); |
| 46 | return 0; |
| 47 | } |
| 48 | |
| 49 | static int be_stream_wait_io(struct xen_snd_front_evtchnl *evtchnl) |
| 50 | { |
| 51 | if (wait_for_completion_timeout(&evtchnl->u.req.completion, |
| 52 | msecs_to_jiffies(VSND_WAIT_BACK_MS)) <= 0) |
| 53 | return -ETIMEDOUT; |
| 54 | |
| 55 | return evtchnl->u.req.resp_status; |
| 56 | } |
| 57 | |
| 58 | int xen_snd_front_stream_query_hw_param(struct xen_snd_front_evtchnl *evtchnl, |
| 59 | struct xensnd_query_hw_param *hw_param_req, |
| 60 | struct xensnd_query_hw_param *hw_param_resp) |
| 61 | { |
| 62 | struct xensnd_req *req; |
| 63 | int ret; |
| 64 | |
| 65 | mutex_lock(&evtchnl->u.req.req_io_lock); |
| 66 | |
| 67 | mutex_lock(&evtchnl->ring_io_lock); |
| 68 | req = be_stream_prepare_req(evtchnl, XENSND_OP_HW_PARAM_QUERY); |
| 69 | req->op.hw_param = *hw_param_req; |
| 70 | mutex_unlock(&evtchnl->ring_io_lock); |
| 71 | |
| 72 | ret = be_stream_do_io(evtchnl); |
| 73 | |
| 74 | if (ret == 0) |
| 75 | ret = be_stream_wait_io(evtchnl); |
| 76 | |
| 77 | if (ret == 0) |
| 78 | *hw_param_resp = evtchnl->u.req.resp.hw_param; |
| 79 | |
| 80 | mutex_unlock(&evtchnl->u.req.req_io_lock); |
| 81 | return ret; |
| 82 | } |
| 83 | |
| 84 | int xen_snd_front_stream_prepare(struct xen_snd_front_evtchnl *evtchnl, |
Oleksandr Andrushchenko | 58f9d80 | 2018-11-30 09:42:05 +0200 | [diff] [blame] | 85 | struct xen_front_pgdir_shbuf *shbuf, |
Oleksandr Andrushchenko | 1cee559 | 2018-05-14 09:27:41 +0300 | [diff] [blame] | 86 | u8 format, unsigned int channels, |
| 87 | unsigned int rate, u32 buffer_sz, |
| 88 | u32 period_sz) |
| 89 | { |
| 90 | struct xensnd_req *req; |
| 91 | int ret; |
| 92 | |
| 93 | mutex_lock(&evtchnl->u.req.req_io_lock); |
| 94 | |
| 95 | mutex_lock(&evtchnl->ring_io_lock); |
| 96 | req = be_stream_prepare_req(evtchnl, XENSND_OP_OPEN); |
| 97 | req->op.open.pcm_format = format; |
| 98 | req->op.open.pcm_channels = channels; |
| 99 | req->op.open.pcm_rate = rate; |
| 100 | req->op.open.buffer_sz = buffer_sz; |
| 101 | req->op.open.period_sz = period_sz; |
Oleksandr Andrushchenko | 58f9d80 | 2018-11-30 09:42:05 +0200 | [diff] [blame] | 102 | req->op.open.gref_directory = |
| 103 | xen_front_pgdir_shbuf_get_dir_start(shbuf); |
Oleksandr Andrushchenko | 1cee559 | 2018-05-14 09:27:41 +0300 | [diff] [blame] | 104 | mutex_unlock(&evtchnl->ring_io_lock); |
| 105 | |
| 106 | ret = be_stream_do_io(evtchnl); |
| 107 | |
| 108 | if (ret == 0) |
| 109 | ret = be_stream_wait_io(evtchnl); |
| 110 | |
| 111 | mutex_unlock(&evtchnl->u.req.req_io_lock); |
| 112 | return ret; |
| 113 | } |
| 114 | |
| 115 | int xen_snd_front_stream_close(struct xen_snd_front_evtchnl *evtchnl) |
| 116 | { |
Pierre-Louis Bossart | 04b3c79 | 2020-07-02 14:35:58 -0500 | [diff] [blame] | 117 | __always_unused struct xensnd_req *req; |
Oleksandr Andrushchenko | 1cee559 | 2018-05-14 09:27:41 +0300 | [diff] [blame] | 118 | int ret; |
| 119 | |
| 120 | mutex_lock(&evtchnl->u.req.req_io_lock); |
| 121 | |
| 122 | mutex_lock(&evtchnl->ring_io_lock); |
| 123 | req = be_stream_prepare_req(evtchnl, XENSND_OP_CLOSE); |
| 124 | mutex_unlock(&evtchnl->ring_io_lock); |
| 125 | |
| 126 | ret = be_stream_do_io(evtchnl); |
| 127 | |
| 128 | if (ret == 0) |
| 129 | ret = be_stream_wait_io(evtchnl); |
| 130 | |
| 131 | mutex_unlock(&evtchnl->u.req.req_io_lock); |
| 132 | return ret; |
| 133 | } |
| 134 | |
| 135 | int xen_snd_front_stream_write(struct xen_snd_front_evtchnl *evtchnl, |
| 136 | unsigned long pos, unsigned long count) |
| 137 | { |
| 138 | struct xensnd_req *req; |
| 139 | int ret; |
| 140 | |
| 141 | mutex_lock(&evtchnl->u.req.req_io_lock); |
| 142 | |
| 143 | mutex_lock(&evtchnl->ring_io_lock); |
| 144 | req = be_stream_prepare_req(evtchnl, XENSND_OP_WRITE); |
| 145 | req->op.rw.length = count; |
| 146 | req->op.rw.offset = pos; |
| 147 | mutex_unlock(&evtchnl->ring_io_lock); |
| 148 | |
| 149 | ret = be_stream_do_io(evtchnl); |
| 150 | |
| 151 | if (ret == 0) |
| 152 | ret = be_stream_wait_io(evtchnl); |
| 153 | |
| 154 | mutex_unlock(&evtchnl->u.req.req_io_lock); |
| 155 | return ret; |
| 156 | } |
| 157 | |
| 158 | int xen_snd_front_stream_read(struct xen_snd_front_evtchnl *evtchnl, |
| 159 | unsigned long pos, unsigned long count) |
| 160 | { |
| 161 | struct xensnd_req *req; |
| 162 | int ret; |
| 163 | |
| 164 | mutex_lock(&evtchnl->u.req.req_io_lock); |
| 165 | |
| 166 | mutex_lock(&evtchnl->ring_io_lock); |
| 167 | req = be_stream_prepare_req(evtchnl, XENSND_OP_READ); |
| 168 | req->op.rw.length = count; |
| 169 | req->op.rw.offset = pos; |
| 170 | mutex_unlock(&evtchnl->ring_io_lock); |
| 171 | |
| 172 | ret = be_stream_do_io(evtchnl); |
| 173 | |
| 174 | if (ret == 0) |
| 175 | ret = be_stream_wait_io(evtchnl); |
| 176 | |
| 177 | mutex_unlock(&evtchnl->u.req.req_io_lock); |
| 178 | return ret; |
| 179 | } |
| 180 | |
| 181 | int xen_snd_front_stream_trigger(struct xen_snd_front_evtchnl *evtchnl, |
| 182 | int type) |
| 183 | { |
| 184 | struct xensnd_req *req; |
| 185 | int ret; |
| 186 | |
| 187 | mutex_lock(&evtchnl->u.req.req_io_lock); |
| 188 | |
| 189 | mutex_lock(&evtchnl->ring_io_lock); |
| 190 | req = be_stream_prepare_req(evtchnl, XENSND_OP_TRIGGER); |
| 191 | req->op.trigger.type = type; |
| 192 | mutex_unlock(&evtchnl->ring_io_lock); |
| 193 | |
| 194 | ret = be_stream_do_io(evtchnl); |
| 195 | |
| 196 | if (ret == 0) |
| 197 | ret = be_stream_wait_io(evtchnl); |
| 198 | |
| 199 | mutex_unlock(&evtchnl->u.req.req_io_lock); |
| 200 | return ret; |
| 201 | } |
Oleksandr Andrushchenko | cc3196ae1 | 2018-05-14 09:27:37 +0300 | [diff] [blame] | 202 | |
| 203 | static void xen_snd_drv_fini(struct xen_snd_front_info *front_info) |
| 204 | { |
Oleksandr Andrushchenko | 1cee559 | 2018-05-14 09:27:41 +0300 | [diff] [blame] | 205 | xen_snd_front_alsa_fini(front_info); |
Oleksandr Andrushchenko | 788ef64 | 2018-05-14 09:27:39 +0300 | [diff] [blame] | 206 | xen_snd_front_evtchnl_free_all(front_info); |
Oleksandr Andrushchenko | cc3196ae1 | 2018-05-14 09:27:37 +0300 | [diff] [blame] | 207 | } |
| 208 | |
| 209 | static int sndback_initwait(struct xen_snd_front_info *front_info) |
| 210 | { |
Oleksandr Andrushchenko | fd3b360 | 2018-05-14 09:27:38 +0300 | [diff] [blame] | 211 | int num_streams; |
| 212 | int ret; |
| 213 | |
| 214 | ret = xen_snd_front_cfg_card(front_info, &num_streams); |
| 215 | if (ret < 0) |
| 216 | return ret; |
| 217 | |
Oleksandr Andrushchenko | 788ef64 | 2018-05-14 09:27:39 +0300 | [diff] [blame] | 218 | /* create event channels for all streams and publish */ |
| 219 | ret = xen_snd_front_evtchnl_create_all(front_info, num_streams); |
| 220 | if (ret < 0) |
| 221 | return ret; |
| 222 | |
| 223 | return xen_snd_front_evtchnl_publish_all(front_info); |
Oleksandr Andrushchenko | cc3196ae1 | 2018-05-14 09:27:37 +0300 | [diff] [blame] | 224 | } |
| 225 | |
| 226 | static int sndback_connect(struct xen_snd_front_info *front_info) |
| 227 | { |
Oleksandr Andrushchenko | 1cee559 | 2018-05-14 09:27:41 +0300 | [diff] [blame] | 228 | return xen_snd_front_alsa_init(front_info); |
Oleksandr Andrushchenko | cc3196ae1 | 2018-05-14 09:27:37 +0300 | [diff] [blame] | 229 | } |
| 230 | |
| 231 | static void sndback_disconnect(struct xen_snd_front_info *front_info) |
| 232 | { |
| 233 | xen_snd_drv_fini(front_info); |
| 234 | xenbus_switch_state(front_info->xb_dev, XenbusStateInitialising); |
| 235 | } |
| 236 | |
| 237 | static void sndback_changed(struct xenbus_device *xb_dev, |
| 238 | enum xenbus_state backend_state) |
| 239 | { |
| 240 | struct xen_snd_front_info *front_info = dev_get_drvdata(&xb_dev->dev); |
| 241 | int ret; |
| 242 | |
| 243 | dev_dbg(&xb_dev->dev, "Backend state is %s, front is %s\n", |
| 244 | xenbus_strstate(backend_state), |
| 245 | xenbus_strstate(xb_dev->state)); |
| 246 | |
| 247 | switch (backend_state) { |
| 248 | case XenbusStateReconfiguring: |
Oleksandr Andrushchenko | cc3196ae1 | 2018-05-14 09:27:37 +0300 | [diff] [blame] | 249 | case XenbusStateReconfigured: |
Oleksandr Andrushchenko | cc3196ae1 | 2018-05-14 09:27:37 +0300 | [diff] [blame] | 250 | case XenbusStateInitialised: |
Oleksandr Andrushchenko | cc3196ae1 | 2018-05-14 09:27:37 +0300 | [diff] [blame] | 251 | break; |
| 252 | |
| 253 | case XenbusStateInitialising: |
| 254 | /* Recovering after backend unexpected closure. */ |
| 255 | sndback_disconnect(front_info); |
| 256 | break; |
| 257 | |
| 258 | case XenbusStateInitWait: |
| 259 | /* Recovering after backend unexpected closure. */ |
| 260 | sndback_disconnect(front_info); |
| 261 | |
| 262 | ret = sndback_initwait(front_info); |
| 263 | if (ret < 0) |
| 264 | xenbus_dev_fatal(xb_dev, ret, "initializing frontend"); |
| 265 | else |
| 266 | xenbus_switch_state(xb_dev, XenbusStateInitialised); |
| 267 | break; |
| 268 | |
| 269 | case XenbusStateConnected: |
| 270 | if (xb_dev->state != XenbusStateInitialised) |
| 271 | break; |
| 272 | |
| 273 | ret = sndback_connect(front_info); |
| 274 | if (ret < 0) |
| 275 | xenbus_dev_fatal(xb_dev, ret, "initializing frontend"); |
| 276 | else |
| 277 | xenbus_switch_state(xb_dev, XenbusStateConnected); |
| 278 | break; |
| 279 | |
| 280 | case XenbusStateClosing: |
| 281 | /* |
| 282 | * In this state backend starts freeing resources, |
| 283 | * so let it go into closed state first, so we can also |
| 284 | * remove ours. |
| 285 | */ |
| 286 | break; |
| 287 | |
| 288 | case XenbusStateUnknown: |
Oleksandr Andrushchenko | cc3196ae1 | 2018-05-14 09:27:37 +0300 | [diff] [blame] | 289 | case XenbusStateClosed: |
| 290 | if (xb_dev->state == XenbusStateClosed) |
| 291 | break; |
| 292 | |
| 293 | sndback_disconnect(front_info); |
| 294 | break; |
| 295 | } |
| 296 | } |
| 297 | |
| 298 | static int xen_drv_probe(struct xenbus_device *xb_dev, |
| 299 | const struct xenbus_device_id *id) |
| 300 | { |
| 301 | struct xen_snd_front_info *front_info; |
| 302 | |
| 303 | front_info = devm_kzalloc(&xb_dev->dev, |
| 304 | sizeof(*front_info), GFP_KERNEL); |
| 305 | if (!front_info) |
| 306 | return -ENOMEM; |
| 307 | |
| 308 | front_info->xb_dev = xb_dev; |
| 309 | dev_set_drvdata(&xb_dev->dev, front_info); |
| 310 | |
| 311 | return xenbus_switch_state(xb_dev, XenbusStateInitialising); |
| 312 | } |
| 313 | |
| 314 | static int xen_drv_remove(struct xenbus_device *dev) |
| 315 | { |
| 316 | struct xen_snd_front_info *front_info = dev_get_drvdata(&dev->dev); |
| 317 | int to = 100; |
| 318 | |
| 319 | xenbus_switch_state(dev, XenbusStateClosing); |
| 320 | |
| 321 | /* |
| 322 | * On driver removal it is disconnected from XenBus, |
| 323 | * so no backend state change events come via .otherend_changed |
| 324 | * callback. This prevents us from exiting gracefully, e.g. |
| 325 | * signaling the backend to free event channels, waiting for its |
| 326 | * state to change to XenbusStateClosed and cleaning at our end. |
| 327 | * Normally when front driver removed backend will finally go into |
| 328 | * XenbusStateInitWait state. |
| 329 | * |
| 330 | * Workaround: read backend's state manually and wait with time-out. |
| 331 | */ |
| 332 | while ((xenbus_read_unsigned(front_info->xb_dev->otherend, "state", |
| 333 | XenbusStateUnknown) != XenbusStateInitWait) && |
Dan Carpenter | 0d5bcfc | 2018-05-31 09:25:07 +0300 | [diff] [blame] | 334 | --to) |
Oleksandr Andrushchenko | cc3196ae1 | 2018-05-14 09:27:37 +0300 | [diff] [blame] | 335 | msleep(10); |
| 336 | |
| 337 | if (!to) { |
| 338 | unsigned int state; |
| 339 | |
| 340 | state = xenbus_read_unsigned(front_info->xb_dev->otherend, |
| 341 | "state", XenbusStateUnknown); |
| 342 | pr_err("Backend state is %s while removing driver\n", |
| 343 | xenbus_strstate(state)); |
| 344 | } |
| 345 | |
| 346 | xen_snd_drv_fini(front_info); |
| 347 | xenbus_frontend_closed(dev); |
| 348 | return 0; |
| 349 | } |
| 350 | |
| 351 | static const struct xenbus_device_id xen_drv_ids[] = { |
| 352 | { XENSND_DRIVER_NAME }, |
| 353 | { "" } |
| 354 | }; |
| 355 | |
| 356 | static struct xenbus_driver xen_driver = { |
| 357 | .ids = xen_drv_ids, |
| 358 | .probe = xen_drv_probe, |
| 359 | .remove = xen_drv_remove, |
| 360 | .otherend_changed = sndback_changed, |
| 361 | }; |
| 362 | |
| 363 | static int __init xen_drv_init(void) |
| 364 | { |
| 365 | if (!xen_domain()) |
| 366 | return -ENODEV; |
| 367 | |
| 368 | if (!xen_has_pv_devices()) |
| 369 | return -ENODEV; |
| 370 | |
Oleksandr Andrushchenko | d6e0fbb | 2018-05-14 09:27:40 +0300 | [diff] [blame] | 371 | /* At the moment we only support case with XEN_PAGE_SIZE == PAGE_SIZE */ |
| 372 | if (XEN_PAGE_SIZE != PAGE_SIZE) { |
| 373 | pr_err(XENSND_DRIVER_NAME ": different kernel and Xen page sizes are not supported: XEN_PAGE_SIZE (%lu) != PAGE_SIZE (%lu)\n", |
| 374 | XEN_PAGE_SIZE, PAGE_SIZE); |
| 375 | return -ENODEV; |
| 376 | } |
| 377 | |
Oleksandr Andrushchenko | cc3196ae1 | 2018-05-14 09:27:37 +0300 | [diff] [blame] | 378 | pr_info("Initialising Xen " XENSND_DRIVER_NAME " frontend driver\n"); |
| 379 | return xenbus_register_frontend(&xen_driver); |
| 380 | } |
| 381 | |
| 382 | static void __exit xen_drv_fini(void) |
| 383 | { |
| 384 | pr_info("Unregistering Xen " XENSND_DRIVER_NAME " frontend driver\n"); |
| 385 | xenbus_unregister_driver(&xen_driver); |
| 386 | } |
| 387 | |
| 388 | module_init(xen_drv_init); |
| 389 | module_exit(xen_drv_fini); |
| 390 | |
| 391 | MODULE_DESCRIPTION("Xen virtual sound device frontend"); |
| 392 | MODULE_LICENSE("GPL"); |
| 393 | MODULE_ALIAS("xen:" XENSND_DRIVER_NAME); |
| 394 | MODULE_SUPPORTED_DEVICE("{{ALSA,Virtual soundcard}}"); |