From: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com

Introduce skeleton of the para-virtualized Xen sound frontend driver.

Initial handling for Xen bus states: implement Xen bus state machine for the frontend driver according to the state diagram and recovery flow from sound para-virtualized protocol: xen/interface/io/sndif.h.

Signed-off-by: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com Reviewed-by: Juergen Gross jgross@suse.com --- sound/Kconfig | 2 + sound/Makefile | 2 +- sound/xen/Kconfig | 10 ++ sound/xen/Makefile | 5 + sound/xen/xen_snd_front.c | 196 ++++++++++++++++++++++++++++++++++++++ sound/xen/xen_snd_front.h | 18 ++++ 6 files changed, 232 insertions(+), 1 deletion(-) create mode 100644 sound/xen/Kconfig create mode 100644 sound/xen/Makefile create mode 100644 sound/xen/xen_snd_front.c create mode 100644 sound/xen/xen_snd_front.h

diff --git a/sound/Kconfig b/sound/Kconfig index 6833db9002ec..1140e9988fc5 100644 --- a/sound/Kconfig +++ b/sound/Kconfig @@ -96,6 +96,8 @@ source "sound/x86/Kconfig"

source "sound/synth/Kconfig"

+source "sound/xen/Kconfig" + endif # SND

endif # !UML diff --git a/sound/Makefile b/sound/Makefile index 99d8c31262c8..797ecdcd35e2 100644 --- a/sound/Makefile +++ b/sound/Makefile @@ -5,7 +5,7 @@ obj-$(CONFIG_SOUND) += soundcore.o obj-$(CONFIG_DMASOUND) += oss/dmasound/ obj-$(CONFIG_SND) += core/ i2c/ drivers/ isa/ pci/ ppc/ arm/ sh/ synth/ usb/ \ - firewire/ sparc/ spi/ parisc/ pcmcia/ mips/ soc/ atmel/ hda/ x86/ + firewire/ sparc/ spi/ parisc/ pcmcia/ mips/ soc/ atmel/ hda/ x86/ xen/ obj-$(CONFIG_SND_AOA) += aoa/

# This one must be compilable even if sound is configured out diff --git a/sound/xen/Kconfig b/sound/xen/Kconfig new file mode 100644 index 000000000000..4f1fceea82d2 --- /dev/null +++ b/sound/xen/Kconfig @@ -0,0 +1,10 @@ +# ALSA Xen drivers + +config SND_XEN_FRONTEND + tristate "Xen para-virtualized sound frontend driver" + depends on XEN + select SND_PCM + select XEN_XENBUS_FRONTEND + help + Choose this option if you want to enable a para-virtualized + frontend sound driver for Xen guest OSes. diff --git a/sound/xen/Makefile b/sound/xen/Makefile new file mode 100644 index 000000000000..4507ef3c27fd --- /dev/null +++ b/sound/xen/Makefile @@ -0,0 +1,5 @@ +# SPDX-License-Identifier: GPL-2.0 OR MIT + +snd_xen_front-objs := xen_snd_front.o + +obj-$(CONFIG_SND_XEN_FRONTEND) += snd_xen_front.o diff --git a/sound/xen/xen_snd_front.c b/sound/xen/xen_snd_front.c new file mode 100644 index 000000000000..bbbe2767b565 --- /dev/null +++ b/sound/xen/xen_snd_front.c @@ -0,0 +1,196 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT + +/* + * Xen para-virtual sound device + * + * Copyright (C) 2016-2018 EPAM Systems Inc. + * + * Author: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com + */ + +#include <linux/delay.h> +#include <linux/module.h> + +#include <xen/platform_pci.h> +#include <xen/xen.h> +#include <xen/xenbus.h> + +#include <xen/interface/io/sndif.h> + +#include "xen_snd_front.h" + +static void xen_snd_drv_fini(struct xen_snd_front_info *front_info) +{ +} + +static int sndback_initwait(struct xen_snd_front_info *front_info) +{ + return 0; +} + +static int sndback_connect(struct xen_snd_front_info *front_info) +{ + return 0; +} + +static void sndback_disconnect(struct xen_snd_front_info *front_info) +{ + xen_snd_drv_fini(front_info); + xenbus_switch_state(front_info->xb_dev, XenbusStateInitialising); +} + +static void sndback_changed(struct xenbus_device *xb_dev, + enum xenbus_state backend_state) +{ + struct xen_snd_front_info *front_info = dev_get_drvdata(&xb_dev->dev); + int ret; + + dev_dbg(&xb_dev->dev, "Backend state is %s, front is %s\n", + xenbus_strstate(backend_state), + xenbus_strstate(xb_dev->state)); + + switch (backend_state) { + case XenbusStateReconfiguring: + /* fall through */ + case XenbusStateReconfigured: + /* fall through */ + case XenbusStateInitialised: + /* fall through */ + break; + + case XenbusStateInitialising: + /* Recovering after backend unexpected closure. */ + sndback_disconnect(front_info); + break; + + case XenbusStateInitWait: + /* Recovering after backend unexpected closure. */ + sndback_disconnect(front_info); + + ret = sndback_initwait(front_info); + if (ret < 0) + xenbus_dev_fatal(xb_dev, ret, "initializing frontend"); + else + xenbus_switch_state(xb_dev, XenbusStateInitialised); + break; + + case XenbusStateConnected: + if (xb_dev->state != XenbusStateInitialised) + break; + + ret = sndback_connect(front_info); + if (ret < 0) + xenbus_dev_fatal(xb_dev, ret, "initializing frontend"); + else + xenbus_switch_state(xb_dev, XenbusStateConnected); + break; + + case XenbusStateClosing: + /* + * In this state backend starts freeing resources, + * so let it go into closed state first, so we can also + * remove ours. + */ + break; + + case XenbusStateUnknown: + /* fall through */ + case XenbusStateClosed: + if (xb_dev->state == XenbusStateClosed) + break; + + sndback_disconnect(front_info); + break; + } +} + +static int xen_drv_probe(struct xenbus_device *xb_dev, + const struct xenbus_device_id *id) +{ + struct xen_snd_front_info *front_info; + + front_info = devm_kzalloc(&xb_dev->dev, + sizeof(*front_info), GFP_KERNEL); + if (!front_info) + return -ENOMEM; + + front_info->xb_dev = xb_dev; + dev_set_drvdata(&xb_dev->dev, front_info); + + return xenbus_switch_state(xb_dev, XenbusStateInitialising); +} + +static int xen_drv_remove(struct xenbus_device *dev) +{ + struct xen_snd_front_info *front_info = dev_get_drvdata(&dev->dev); + int to = 100; + + xenbus_switch_state(dev, XenbusStateClosing); + + /* + * On driver removal it is disconnected from XenBus, + * so no backend state change events come via .otherend_changed + * callback. This prevents us from exiting gracefully, e.g. + * signaling the backend to free event channels, waiting for its + * state to change to XenbusStateClosed and cleaning at our end. + * Normally when front driver removed backend will finally go into + * XenbusStateInitWait state. + * + * Workaround: read backend's state manually and wait with time-out. + */ + while ((xenbus_read_unsigned(front_info->xb_dev->otherend, "state", + XenbusStateUnknown) != XenbusStateInitWait) && + to--) + msleep(10); + + if (!to) { + unsigned int state; + + state = xenbus_read_unsigned(front_info->xb_dev->otherend, + "state", XenbusStateUnknown); + pr_err("Backend state is %s while removing driver\n", + xenbus_strstate(state)); + } + + xen_snd_drv_fini(front_info); + xenbus_frontend_closed(dev); + return 0; +} + +static const struct xenbus_device_id xen_drv_ids[] = { + { XENSND_DRIVER_NAME }, + { "" } +}; + +static struct xenbus_driver xen_driver = { + .ids = xen_drv_ids, + .probe = xen_drv_probe, + .remove = xen_drv_remove, + .otherend_changed = sndback_changed, +}; + +static int __init xen_drv_init(void) +{ + if (!xen_domain()) + return -ENODEV; + + if (!xen_has_pv_devices()) + return -ENODEV; + + pr_info("Initialising Xen " XENSND_DRIVER_NAME " frontend driver\n"); + return xenbus_register_frontend(&xen_driver); +} + +static void __exit xen_drv_fini(void) +{ + pr_info("Unregistering Xen " XENSND_DRIVER_NAME " frontend driver\n"); + xenbus_unregister_driver(&xen_driver); +} + +module_init(xen_drv_init); +module_exit(xen_drv_fini); + +MODULE_DESCRIPTION("Xen virtual sound device frontend"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("xen:" XENSND_DRIVER_NAME); +MODULE_SUPPORTED_DEVICE("{{ALSA,Virtual soundcard}}"); diff --git a/sound/xen/xen_snd_front.h b/sound/xen/xen_snd_front.h new file mode 100644 index 000000000000..4ae204b23d32 --- /dev/null +++ b/sound/xen/xen_snd_front.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 OR MIT */ + +/* + * Xen para-virtual sound device + * + * Copyright (C) 2016-2018 EPAM Systems Inc. + * + * Author: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com + */ + +#ifndef __XEN_SND_FRONT_H +#define __XEN_SND_FRONT_H + +struct xen_snd_front_info { + struct xenbus_device *xb_dev; +}; + +#endif /* __XEN_SND_FRONT_H */

From: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com

Handle Xen event channels: - create for all configured streams and publish corresponding ring references and event channels in Xen store, so backend can connect - implement event channels interrupt handlers - create and destroy event channels with respect to Xen bus state

Signed-off-by: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com --- sound/xen/Makefile | 3 +- sound/xen/xen_snd_front.c | 9 +- sound/xen/xen_snd_front.h | 5 + sound/xen/xen_snd_front_evtchnl.c | 494 ++++++++++++++++++++++++++++++ sound/xen/xen_snd_front_evtchnl.h | 95 ++++++ 5 files changed, 604 insertions(+), 2 deletions(-) create mode 100644 sound/xen/xen_snd_front_evtchnl.c create mode 100644 sound/xen/xen_snd_front_evtchnl.h

diff --git a/sound/xen/Makefile b/sound/xen/Makefile index 06705bef61fa..03c669984000 100644 --- a/sound/xen/Makefile +++ b/sound/xen/Makefile @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 OR MIT

snd_xen_front-objs := xen_snd_front.o \ - xen_snd_front_cfg.o + xen_snd_front_cfg.o \ + xen_snd_front_evtchnl.o

obj-$(CONFIG_SND_XEN_FRONTEND) += snd_xen_front.o diff --git a/sound/xen/xen_snd_front.c b/sound/xen/xen_snd_front.c index 70fa91683c71..277214d4fd0a 100644 --- a/sound/xen/xen_snd_front.c +++ b/sound/xen/xen_snd_front.c @@ -18,9 +18,11 @@ #include <xen/interface/io/sndif.h>

#include "xen_snd_front.h" +#include "xen_snd_front_evtchnl.h"

static void xen_snd_drv_fini(struct xen_snd_front_info *front_info) { + xen_snd_front_evtchnl_free_all(front_info); }

static int sndback_initwait(struct xen_snd_front_info *front_info) @@ -32,7 +34,12 @@ static int sndback_initwait(struct xen_snd_front_info *front_info) if (ret < 0) return ret;

- return 0; + /* create event channels for all streams and publish */ + ret = xen_snd_front_evtchnl_create_all(front_info, num_streams); + if (ret < 0) + return ret; + + return xen_snd_front_evtchnl_publish_all(front_info); }

static int sndback_connect(struct xen_snd_front_info *front_info) diff --git a/sound/xen/xen_snd_front.h b/sound/xen/xen_snd_front.h index b52226cb30bc..9d0c92100c7b 100644 --- a/sound/xen/xen_snd_front.h +++ b/sound/xen/xen_snd_front.h @@ -13,9 +13,14 @@

#include "xen_snd_front_cfg.h"

+struct xen_snd_front_evtchnl_pair; + struct xen_snd_front_info { struct xenbus_device *xb_dev;

+ int num_evt_pairs; + struct xen_snd_front_evtchnl_pair *evt_pairs; + struct xen_front_cfg_card cfg; };

diff --git a/sound/xen/xen_snd_front_evtchnl.c b/sound/xen/xen_snd_front_evtchnl.c new file mode 100644 index 000000000000..1faafff08807 --- /dev/null +++ b/sound/xen/xen_snd_front_evtchnl.c @@ -0,0 +1,494 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT + +/* + * Xen para-virtual sound device + * + * Copyright (C) 2016-2018 EPAM Systems Inc. + * + * Author: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com + */ + +#include <xen/events.h> +#include <xen/grant_table.h> +#include <xen/xen.h> +#include <xen/xenbus.h> + +#include "xen_snd_front.h" +#include "xen_snd_front_cfg.h" +#include "xen_snd_front_evtchnl.h" + +static irqreturn_t evtchnl_interrupt_req(int irq, void *dev_id) +{ + struct xen_snd_front_evtchnl *channel = dev_id; + struct xen_snd_front_info *front_info = channel->front_info; + struct xensnd_resp *resp; + RING_IDX i, rp; + + if (unlikely(channel->state != EVTCHNL_STATE_CONNECTED)) + return IRQ_HANDLED; + + mutex_lock(&channel->ring_io_lock); + +again: + rp = channel->u.req.ring.sring->rsp_prod; + /* Ensure we see queued responses up to rp. */ + rmb(); + + /* + * Assume that the backend is trusted to always write sane values + * to the ring counters, so no overflow checks on frontend side + * are required. + */ + for (i = channel->u.req.ring.rsp_cons; i != rp; i++) { + resp = RING_GET_RESPONSE(&channel->u.req.ring, i); + if (resp->id != channel->evt_id) + continue; + switch (resp->operation) { + case XENSND_OP_OPEN: + /* fall through */ + case XENSND_OP_CLOSE: + /* fall through */ + case XENSND_OP_READ: + /* fall through */ + case XENSND_OP_WRITE: + /* fall through */ + case XENSND_OP_TRIGGER: + channel->u.req.resp_status = resp->status; + complete(&channel->u.req.completion); + break; + case XENSND_OP_HW_PARAM_QUERY: + channel->u.req.resp_status = resp->status; + channel->u.req.resp.hw_param = + resp->resp.hw_param; + complete(&channel->u.req.completion); + break; + + default: + dev_err(&front_info->xb_dev->dev, + "Operation %d is not supported\n", + resp->operation); + break; + } + } + + channel->u.req.ring.rsp_cons = i; + if (i != channel->u.req.ring.req_prod_pvt) { + int more_to_do; + + RING_FINAL_CHECK_FOR_RESPONSES(&channel->u.req.ring, + more_to_do); + if (more_to_do) + goto again; + } else { + channel->u.req.ring.sring->rsp_event = i + 1; + } + + mutex_unlock(&channel->ring_io_lock); + return IRQ_HANDLED; +} + +static irqreturn_t evtchnl_interrupt_evt(int irq, void *dev_id) +{ + struct xen_snd_front_evtchnl *channel = dev_id; + struct xensnd_event_page *page = channel->u.evt.page; + u32 cons, prod; + + if (unlikely(channel->state != EVTCHNL_STATE_CONNECTED)) + return IRQ_HANDLED; + + mutex_lock(&channel->ring_io_lock); + + prod = page->in_prod; + /* Ensure we see ring contents up to prod. */ + virt_rmb(); + if (prod == page->in_cons) + goto out; + + /* + * Assume that the backend is trusted to always write sane values + * to the ring counters, so no overflow checks on frontend side + * are required. + */ + for (cons = page->in_cons; cons != prod; cons++) { + struct xensnd_evt *event; + + event = &XENSND_IN_RING_REF(page, cons); + if (unlikely(event->id != channel->evt_id++)) + continue; + + switch (event->type) { + case XENSND_EVT_CUR_POS: + /* Do nothing at the moment. */ + break; + } + } + + page->in_cons = cons; + /* Ensure ring contents. */ + virt_wmb(); + +out: + mutex_unlock(&channel->ring_io_lock); + return IRQ_HANDLED; +} + +void xen_snd_front_evtchnl_flush(struct xen_snd_front_evtchnl *channel) +{ + int notify; + + channel->u.req.ring.req_prod_pvt++; + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&channel->u.req.ring, notify); + if (notify) + notify_remote_via_irq(channel->irq); +} + +static void evtchnl_free(struct xen_snd_front_info *front_info, + struct xen_snd_front_evtchnl *channel) +{ + unsigned long page = 0; + + if (channel->type == EVTCHNL_TYPE_REQ) + page = (unsigned long)channel->u.req.ring.sring; + else if (channel->type == EVTCHNL_TYPE_EVT) + page = (unsigned long)channel->u.evt.page; + + if (!page) + return; + + channel->state = EVTCHNL_STATE_DISCONNECTED; + if (channel->type == EVTCHNL_TYPE_REQ) { + /* Release all who still waits for response if any. */ + channel->u.req.resp_status = -EIO; + complete_all(&channel->u.req.completion); + } + + if (channel->irq) + unbind_from_irqhandler(channel->irq, channel); + + if (channel->port) + xenbus_free_evtchn(front_info->xb_dev, channel->port); + + /* End access and free the page. */ + if (channel->gref != GRANT_INVALID_REF) + gnttab_end_foreign_access(channel->gref, 0, page); + else + free_page(page); + + memset(channel, 0, sizeof(*channel)); +} + +void xen_snd_front_evtchnl_free_all(struct xen_snd_front_info *front_info) +{ + int i; + + if (!front_info->evt_pairs) + return; + + for (i = 0; i < front_info->num_evt_pairs; i++) { + evtchnl_free(front_info, &front_info->evt_pairs[i].req); + evtchnl_free(front_info, &front_info->evt_pairs[i].evt); + } + + kfree(front_info->evt_pairs); + front_info->evt_pairs = NULL; +} + +static int evtchnl_alloc(struct xen_snd_front_info *front_info, int index, + struct xen_snd_front_evtchnl *channel, + enum xen_snd_front_evtchnl_type type) +{ + struct xenbus_device *xb_dev = front_info->xb_dev; + unsigned long page; + grant_ref_t gref; + irq_handler_t handler; + char *handler_name = NULL; + int ret; + + memset(channel, 0, sizeof(*channel)); + channel->type = type; + channel->index = index; + channel->front_info = front_info; + channel->state = EVTCHNL_STATE_DISCONNECTED; + channel->gref = GRANT_INVALID_REF; + page = get_zeroed_page(GFP_KERNEL); + if (!page) { + ret = -ENOMEM; + goto fail; + } + + handler_name = kasprintf(GFP_KERNEL, "%s-%s", XENSND_DRIVER_NAME, + type == EVTCHNL_TYPE_REQ ? + XENSND_FIELD_RING_REF : + XENSND_FIELD_EVT_RING_REF); + if (!handler_name) { + ret = -ENOMEM; + goto fail; + } + + mutex_init(&channel->ring_io_lock); + + if (type == EVTCHNL_TYPE_REQ) { + struct xen_sndif_sring *sring = (struct xen_sndif_sring *)page; + + init_completion(&channel->u.req.completion); + mutex_init(&channel->u.req.req_io_lock); + SHARED_RING_INIT(sring); + FRONT_RING_INIT(&channel->u.req.ring, sring, XEN_PAGE_SIZE); + + ret = xenbus_grant_ring(xb_dev, sring, 1, &gref); + if (ret < 0) { + channel->u.req.ring.sring = NULL; + goto fail; + } + + handler = evtchnl_interrupt_req; + } else { + ret = gnttab_grant_foreign_access(xb_dev->otherend_id, + virt_to_gfn((void *)page), 0); + if (ret < 0) + goto fail; + + channel->u.evt.page = (struct xensnd_event_page *)page; + gref = ret; + handler = evtchnl_interrupt_evt; + } + + channel->gref = gref; + + ret = xenbus_alloc_evtchn(xb_dev, &channel->port); + if (ret < 0) + goto fail; + + ret = bind_evtchn_to_irq(channel->port); + if (ret < 0) { + dev_err(&xb_dev->dev, + "Failed to bind IRQ for domid %d port %d: %d\n", + front_info->xb_dev->otherend_id, channel->port, ret); + goto fail; + } + + channel->irq = ret; + + ret = request_threaded_irq(channel->irq, NULL, handler, + IRQF_ONESHOT, handler_name, channel); + if (ret < 0) { + dev_err(&xb_dev->dev, "Failed to request IRQ %d: %d\n", + channel->irq, ret); + goto fail; + } + + kfree(handler_name); + return 0; + +fail: + if (page) + free_page(page); + kfree(handler_name); + dev_err(&xb_dev->dev, "Failed to allocate ring: %d\n", ret); + return ret; +} + +int xen_snd_front_evtchnl_create_all(struct xen_snd_front_info *front_info, + int num_streams) +{ + struct xen_front_cfg_card *cfg = &front_info->cfg; + struct device *dev = &front_info->xb_dev->dev; + int d, ret = 0; + + front_info->evt_pairs = + kcalloc(num_streams, + sizeof(struct xen_snd_front_evtchnl_pair), + GFP_KERNEL); + if (!front_info->evt_pairs) + return -ENOMEM; + + /* Iterate over devices and their streams and create event channels. */ + for (d = 0; d < cfg->num_pcm_instances; d++) { + struct xen_front_cfg_pcm_instance *pcm_instance; + int s, index; + + pcm_instance = &cfg->pcm_instances[d]; + + for (s = 0; s < pcm_instance->num_streams_pb; s++) { + index = pcm_instance->streams_pb[s].index; + + ret = evtchnl_alloc(front_info, index, + &front_info->evt_pairs[index].req, + EVTCHNL_TYPE_REQ); + if (ret < 0) { + dev_err(dev, "Error allocating control channel\n"); + goto fail; + } + + ret = evtchnl_alloc(front_info, index, + &front_info->evt_pairs[index].evt, + EVTCHNL_TYPE_EVT); + if (ret < 0) { + dev_err(dev, "Error allocating in-event channel\n"); + goto fail; + } + } + + for (s = 0; s < pcm_instance->num_streams_cap; s++) { + index = pcm_instance->streams_cap[s].index; + + ret = evtchnl_alloc(front_info, index, + &front_info->evt_pairs[index].req, + EVTCHNL_TYPE_REQ); + if (ret < 0) { + dev_err(dev, "Error allocating control channel\n"); + goto fail; + } + + ret = evtchnl_alloc(front_info, index, + &front_info->evt_pairs[index].evt, + EVTCHNL_TYPE_EVT); + if (ret < 0) { + dev_err(dev, "Error allocating in-event channel\n"); + goto fail; + } + } + } + if (ret < 0) + goto fail; + + front_info->num_evt_pairs = num_streams; + return 0; + +fail: + xen_snd_front_evtchnl_free_all(front_info); + return ret; +} + +static int evtchnl_publish(struct xenbus_transaction xbt, + struct xen_snd_front_evtchnl *channel, + const char *path, const char *node_ring, + const char *node_chnl) +{ + struct xenbus_device *xb_dev = channel->front_info->xb_dev; + int ret; + + /* Write control channel ring reference. */ + ret = xenbus_printf(xbt, path, node_ring, "%u", channel->gref); + if (ret < 0) { + dev_err(&xb_dev->dev, "Error writing ring-ref: %d\n", ret); + return ret; + } + + /* Write event channel ring reference. */ + ret = xenbus_printf(xbt, path, node_chnl, "%u", channel->port); + if (ret < 0) { + dev_err(&xb_dev->dev, "Error writing event channel: %d\n", ret); + return ret; + } + + return 0; +} + +int xen_snd_front_evtchnl_publish_all(struct xen_snd_front_info *front_info) +{ + struct xen_front_cfg_card *cfg = &front_info->cfg; + struct xenbus_transaction xbt; + int ret, d; + +again: + ret = xenbus_transaction_start(&xbt); + if (ret < 0) { + xenbus_dev_fatal(front_info->xb_dev, ret, + "starting transaction"); + return ret; + } + + for (d = 0; d < cfg->num_pcm_instances; d++) { + struct xen_front_cfg_pcm_instance *pcm_instance; + int s, index; + + pcm_instance = &cfg->pcm_instances[d]; + + for (s = 0; s < pcm_instance->num_streams_pb; s++) { + index = pcm_instance->streams_pb[s].index; + + ret = evtchnl_publish(xbt, + &front_info->evt_pairs[index].req, + pcm_instance->streams_pb[s].xenstore_path, + XENSND_FIELD_RING_REF, + XENSND_FIELD_EVT_CHNL); + if (ret < 0) + goto fail; + + ret = evtchnl_publish(xbt, + &front_info->evt_pairs[index].evt, + pcm_instance->streams_pb[s].xenstore_path, + XENSND_FIELD_EVT_RING_REF, + XENSND_FIELD_EVT_EVT_CHNL); + if (ret < 0) + goto fail; + } + + for (s = 0; s < pcm_instance->num_streams_cap; s++) { + index = pcm_instance->streams_cap[s].index; + + ret = evtchnl_publish(xbt, + &front_info->evt_pairs[index].req, + pcm_instance->streams_cap[s].xenstore_path, + XENSND_FIELD_RING_REF, + XENSND_FIELD_EVT_CHNL); + if (ret < 0) + goto fail; + + ret = evtchnl_publish(xbt, + &front_info->evt_pairs[index].evt, + pcm_instance->streams_cap[s].xenstore_path, + XENSND_FIELD_EVT_RING_REF, + XENSND_FIELD_EVT_EVT_CHNL); + if (ret < 0) + goto fail; + } + } + ret = xenbus_transaction_end(xbt, 0); + if (ret < 0) { + if (ret == -EAGAIN) + goto again; + + xenbus_dev_fatal(front_info->xb_dev, ret, + "completing transaction"); + goto fail_to_end; + } + return 0; +fail: + xenbus_transaction_end(xbt, 1); +fail_to_end: + xenbus_dev_fatal(front_info->xb_dev, ret, "writing XenStore"); + return ret; +} + +void xen_snd_front_evtchnl_pair_set_connected(struct xen_snd_front_evtchnl_pair *evt_pair, + bool is_connected) +{ + enum xen_snd_front_evtchnl_state state; + + if (is_connected) + state = EVTCHNL_STATE_CONNECTED; + else + state = EVTCHNL_STATE_DISCONNECTED; + + mutex_lock(&evt_pair->req.ring_io_lock); + evt_pair->req.state = state; + mutex_unlock(&evt_pair->req.ring_io_lock); + + mutex_lock(&evt_pair->evt.ring_io_lock); + evt_pair->evt.state = state; + mutex_unlock(&evt_pair->evt.ring_io_lock); +} + +void xen_snd_front_evtchnl_pair_clear(struct xen_snd_front_evtchnl_pair *evt_pair) +{ + mutex_lock(&evt_pair->req.ring_io_lock); + evt_pair->req.evt_next_id = 0; + mutex_unlock(&evt_pair->req.ring_io_lock); + + mutex_lock(&evt_pair->evt.ring_io_lock); + evt_pair->evt.evt_next_id = 0; + mutex_unlock(&evt_pair->evt.ring_io_lock); +} + diff --git a/sound/xen/xen_snd_front_evtchnl.h b/sound/xen/xen_snd_front_evtchnl.h new file mode 100644 index 000000000000..cbe51fd1ec15 --- /dev/null +++ b/sound/xen/xen_snd_front_evtchnl.h @@ -0,0 +1,95 @@ +/* SPDX-License-Identifier: GPL-2.0 OR MIT */ + +/* + * Xen para-virtual sound device + * + * Copyright (C) 2016-2018 EPAM Systems Inc. + * + * Author: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com + */ + +#ifndef __XEN_SND_FRONT_EVTCHNL_H +#define __XEN_SND_FRONT_EVTCHNL_H + +#include <xen/interface/io/sndif.h> + +struct xen_snd_front_info; + +#ifndef GRANT_INVALID_REF +/* + * FIXME: usage of grant reference 0 as invalid grant reference: + * grant reference 0 is valid, but never exposed to a PV driver, + * because of the fact it is already in use/reserved by the PV console. + */ +#define GRANT_INVALID_REF 0 +#endif + +/* Timeout in ms to wait for backend to respond. */ +#define VSND_WAIT_BACK_MS 3000 + +enum xen_snd_front_evtchnl_state { + EVTCHNL_STATE_DISCONNECTED, + EVTCHNL_STATE_CONNECTED, +}; + +enum xen_snd_front_evtchnl_type { + EVTCHNL_TYPE_REQ, + EVTCHNL_TYPE_EVT, +}; + +struct xen_snd_front_evtchnl { + struct xen_snd_front_info *front_info; + int gref; + int port; + int irq; + int index; + /* State of the event channel. */ + enum xen_snd_front_evtchnl_state state; + enum xen_snd_front_evtchnl_type type; + /* Either response id or incoming event id. */ + u16 evt_id; + /* Next request id or next expected event id. */ + u16 evt_next_id; + /* Shared ring access lock. */ + struct mutex ring_io_lock; + union { + struct { + struct xen_sndif_front_ring ring; + struct completion completion; + /* Serializer for backend IO: request/response. */ + struct mutex req_io_lock; + + /* Latest response status. */ + int resp_status; + union { + struct xensnd_query_hw_param hw_param; + } resp; + } req; + struct { + struct xensnd_event_page *page; + /* This is needed to handle XENSND_EVT_CUR_POS event. */ + struct snd_pcm_substream *substream; + } evt; + } u; +}; + +struct xen_snd_front_evtchnl_pair { + struct xen_snd_front_evtchnl req; + struct xen_snd_front_evtchnl evt; +}; + +int xen_snd_front_evtchnl_create_all(struct xen_snd_front_info *front_info, + int num_streams); + +void xen_snd_front_evtchnl_free_all(struct xen_snd_front_info *front_info); + +int xen_snd_front_evtchnl_publish_all(struct xen_snd_front_info *front_info); + +void xen_snd_front_evtchnl_flush(struct xen_snd_front_evtchnl *evtchnl); + +void xen_snd_front_evtchnl_pair_set_connected(struct xen_snd_front_evtchnl_pair *evt_pair, + bool is_connected); + +void xen_snd_front_evtchnl_pair_clear(struct xen_snd_front_evtchnl_pair *evt_pair); + +#endif /* __XEN_SND_FRONT_EVTCHNL_H */

From: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com

Implement essential initialization of the sound driver: - introduce required data structures - handle driver registration - handle sound card registration - register sound driver on backend connection - remove sound driver on backend disconnect

Initialize virtual sound card with streams according to the Xen store configuration.

Implement ALSA driver operations including: - manage frontend/backend shared buffers - manage Xen bus event channel states

Implement requests from front to back for ALSA PCM operations. - report ALSA period elapsed event: handle XENSND_EVT_CUR_POS notifications from the backend when stream position advances during playback/capture. The event carries a value of how many octets were played/captured at the time of the event. - implement explicit stream parameter negotiation between backend and frontend: handle XENSND_OP_HW_PARAM_QUERY request to read/update configuration space for the parameter given: request passes desired parameter interval and the response to this request returns min/max interval for the parameter to be used.

Signed-off-by: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com --- sound/xen/Makefile | 3 +- sound/xen/xen_snd_front.c | 181 ++++++- sound/xen/xen_snd_front.h | 27 + sound/xen/xen_snd_front_alsa.c | 821 ++++++++++++++++++++++++++++++ sound/xen/xen_snd_front_alsa.h | 23 + sound/xen/xen_snd_front_evtchnl.c | 4 +- 6 files changed, 1056 insertions(+), 3 deletions(-) create mode 100644 sound/xen/xen_snd_front_alsa.c create mode 100644 sound/xen/xen_snd_front_alsa.h

diff --git a/sound/xen/Makefile b/sound/xen/Makefile index f028bc30af5d..1e6470ecc2f2 100644 --- a/sound/xen/Makefile +++ b/sound/xen/Makefile @@ -3,6 +3,7 @@ snd_xen_front-objs := xen_snd_front.o \ xen_snd_front_cfg.o \ xen_snd_front_evtchnl.o \ - xen_snd_front_shbuf.o + xen_snd_front_shbuf.o \ + xen_snd_front_alsa.o

obj-$(CONFIG_SND_XEN_FRONTEND) += snd_xen_front.o diff --git a/sound/xen/xen_snd_front.c b/sound/xen/xen_snd_front.c index cdf66ea516c4..c18973a9bc9b 100644 --- a/sound/xen/xen_snd_front.c +++ b/sound/xen/xen_snd_front.c @@ -19,10 +19,189 @@ #include <xen/interface/io/sndif.h>

#include "xen_snd_front.h" +#include "xen_snd_front_alsa.h" #include "xen_snd_front_evtchnl.h" +#include "xen_snd_front_shbuf.h" + +static struct xensnd_req * +be_stream_prepare_req(struct xen_snd_front_evtchnl *evtchnl, u8 operation) +{ + struct xensnd_req *req; + + req = RING_GET_REQUEST(&evtchnl->u.req.ring, + evtchnl->u.req.ring.req_prod_pvt); + req->operation = operation; + req->id = evtchnl->evt_next_id++; + evtchnl->evt_id = req->id; + return req; +} + +static int be_stream_do_io(struct xen_snd_front_evtchnl *evtchnl) +{ + if (unlikely(evtchnl->state != EVTCHNL_STATE_CONNECTED)) + return -EIO; + + reinit_completion(&evtchnl->u.req.completion); + xen_snd_front_evtchnl_flush(evtchnl); + return 0; +} + +static int be_stream_wait_io(struct xen_snd_front_evtchnl *evtchnl) +{ + if (wait_for_completion_timeout(&evtchnl->u.req.completion, + msecs_to_jiffies(VSND_WAIT_BACK_MS)) <= 0) + return -ETIMEDOUT; + + return evtchnl->u.req.resp_status; +} + +int xen_snd_front_stream_query_hw_param(struct xen_snd_front_evtchnl *evtchnl, + struct xensnd_query_hw_param *hw_param_req, + struct xensnd_query_hw_param *hw_param_resp) +{ + struct xensnd_req *req; + int ret; + + mutex_lock(&evtchnl->u.req.req_io_lock); + + mutex_lock(&evtchnl->ring_io_lock); + req = be_stream_prepare_req(evtchnl, XENSND_OP_HW_PARAM_QUERY); + req->op.hw_param = *hw_param_req; + mutex_unlock(&evtchnl->ring_io_lock); + + ret = be_stream_do_io(evtchnl); + + if (ret == 0) + ret = be_stream_wait_io(evtchnl); + + if (ret == 0) + *hw_param_resp = evtchnl->u.req.resp.hw_param; + + mutex_unlock(&evtchnl->u.req.req_io_lock); + return ret; +} + +int xen_snd_front_stream_prepare(struct xen_snd_front_evtchnl *evtchnl, + struct xen_snd_front_shbuf *sh_buf, + u8 format, unsigned int channels, + unsigned int rate, u32 buffer_sz, + u32 period_sz) +{ + struct xensnd_req *req; + int ret; + + mutex_lock(&evtchnl->u.req.req_io_lock); + + mutex_lock(&evtchnl->ring_io_lock); + req = be_stream_prepare_req(evtchnl, XENSND_OP_OPEN); + req->op.open.pcm_format = format; + req->op.open.pcm_channels = channels; + req->op.open.pcm_rate = rate; + req->op.open.buffer_sz = buffer_sz; + req->op.open.period_sz = period_sz; + req->op.open.gref_directory = xen_snd_front_shbuf_get_dir_start(sh_buf); + mutex_unlock(&evtchnl->ring_io_lock); + + ret = be_stream_do_io(evtchnl); + + if (ret == 0) + ret = be_stream_wait_io(evtchnl); + + mutex_unlock(&evtchnl->u.req.req_io_lock); + return ret; +} + +int xen_snd_front_stream_close(struct xen_snd_front_evtchnl *evtchnl) +{ + struct xensnd_req *req; + int ret; + + mutex_lock(&evtchnl->u.req.req_io_lock); + + mutex_lock(&evtchnl->ring_io_lock); + req = be_stream_prepare_req(evtchnl, XENSND_OP_CLOSE); + mutex_unlock(&evtchnl->ring_io_lock); + + ret = be_stream_do_io(evtchnl); + + if (ret == 0) + ret = be_stream_wait_io(evtchnl); + + mutex_unlock(&evtchnl->u.req.req_io_lock); + return ret; +} + +int xen_snd_front_stream_write(struct xen_snd_front_evtchnl *evtchnl, + unsigned long pos, unsigned long count) +{ + struct xensnd_req *req; + int ret; + + mutex_lock(&evtchnl->u.req.req_io_lock); + + mutex_lock(&evtchnl->ring_io_lock); + req = be_stream_prepare_req(evtchnl, XENSND_OP_WRITE); + req->op.rw.length = count; + req->op.rw.offset = pos; + mutex_unlock(&evtchnl->ring_io_lock); + + ret = be_stream_do_io(evtchnl); + + if (ret == 0) + ret = be_stream_wait_io(evtchnl); + + mutex_unlock(&evtchnl->u.req.req_io_lock); + return ret; +} + +int xen_snd_front_stream_read(struct xen_snd_front_evtchnl *evtchnl, + unsigned long pos, unsigned long count) +{ + struct xensnd_req *req; + int ret; + + mutex_lock(&evtchnl->u.req.req_io_lock); + + mutex_lock(&evtchnl->ring_io_lock); + req = be_stream_prepare_req(evtchnl, XENSND_OP_READ); + req->op.rw.length = count; + req->op.rw.offset = pos; + mutex_unlock(&evtchnl->ring_io_lock); + + ret = be_stream_do_io(evtchnl); + + if (ret == 0) + ret = be_stream_wait_io(evtchnl); + + mutex_unlock(&evtchnl->u.req.req_io_lock); + return ret; +} + +int xen_snd_front_stream_trigger(struct xen_snd_front_evtchnl *evtchnl, + int type) +{ + struct xensnd_req *req; + int ret; + + mutex_lock(&evtchnl->u.req.req_io_lock); + + mutex_lock(&evtchnl->ring_io_lock); + req = be_stream_prepare_req(evtchnl, XENSND_OP_TRIGGER); + req->op.trigger.type = type; + mutex_unlock(&evtchnl->ring_io_lock); + + ret = be_stream_do_io(evtchnl); + + if (ret == 0) + ret = be_stream_wait_io(evtchnl); + + mutex_unlock(&evtchnl->u.req.req_io_lock); + return ret; +}

static void xen_snd_drv_fini(struct xen_snd_front_info *front_info) { + xen_snd_front_alsa_fini(front_info); xen_snd_front_evtchnl_free_all(front_info); }

@@ -45,7 +224,7 @@ static int sndback_initwait(struct xen_snd_front_info *front_info)

static int sndback_connect(struct xen_snd_front_info *front_info) { - return 0; + return xen_snd_front_alsa_init(front_info); }

static void sndback_disconnect(struct xen_snd_front_info *front_info) diff --git a/sound/xen/xen_snd_front.h b/sound/xen/xen_snd_front.h index 9d0c92100c7b..a2ea2463bcc5 100644 --- a/sound/xen/xen_snd_front.h +++ b/sound/xen/xen_snd_front.h @@ -13,15 +13,42 @@

#include "xen_snd_front_cfg.h"

+struct xen_snd_front_card_info; +struct xen_snd_front_evtchnl; struct xen_snd_front_evtchnl_pair; +struct xen_snd_front_shbuf; +struct xensnd_query_hw_param;

struct xen_snd_front_info { struct xenbus_device *xb_dev;

+ struct xen_snd_front_card_info *card_info; + int num_evt_pairs; struct xen_snd_front_evtchnl_pair *evt_pairs;

struct xen_front_cfg_card cfg; };

+int xen_snd_front_stream_query_hw_param(struct xen_snd_front_evtchnl *evtchnl, + struct xensnd_query_hw_param *hw_param_req, + struct xensnd_query_hw_param *hw_param_resp); + +int xen_snd_front_stream_prepare(struct xen_snd_front_evtchnl *evtchnl, + struct xen_snd_front_shbuf *sh_buf, + u8 format, unsigned int channels, + unsigned int rate, u32 buffer_sz, + u32 period_sz); + +int xen_snd_front_stream_close(struct xen_snd_front_evtchnl *evtchnl); + +int xen_snd_front_stream_write(struct xen_snd_front_evtchnl *evtchnl, + unsigned long pos, unsigned long count); + +int xen_snd_front_stream_read(struct xen_snd_front_evtchnl *evtchnl, + unsigned long pos, unsigned long count); + +int xen_snd_front_stream_trigger(struct xen_snd_front_evtchnl *evtchnl, + int type); + #endif /* __XEN_SND_FRONT_H */ diff --git a/sound/xen/xen_snd_front_alsa.c b/sound/xen/xen_snd_front_alsa.c new file mode 100644 index 000000000000..5041f83e98d2 --- /dev/null +++ b/sound/xen/xen_snd_front_alsa.c @@ -0,0 +1,821 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT + +/* + * Xen para-virtual sound device + * + * Copyright (C) 2016-2018 EPAM Systems Inc. + * + * Author: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com + */ + +#include <linux/platform_device.h> + +#include <sound/core.h> +#include <sound/pcm.h> +#include <sound/pcm_params.h> + +#include <xen/xenbus.h> + +#include "xen_snd_front.h" +#include "xen_snd_front_alsa.h" +#include "xen_snd_front_cfg.h" +#include "xen_snd_front_evtchnl.h" +#include "xen_snd_front_shbuf.h" + +struct xen_snd_front_pcm_stream_info { + struct xen_snd_front_info *front_info; + struct xen_snd_front_evtchnl_pair *evt_pair; + struct xen_snd_front_shbuf sh_buf; + int index; + + bool is_open; + struct snd_pcm_hardware pcm_hw; + + /* Number of processed frames as reported by the backend. */ + snd_pcm_uframes_t be_cur_frame; + /* Current HW pointer to be reported via .period callback. */ + atomic_t hw_ptr; + /* Modulo of the number of processed frames - for period detection. */ + u32 out_frames; +}; + +struct xen_snd_front_pcm_instance_info { + struct xen_snd_front_card_info *card_info; + struct snd_pcm *pcm; + struct snd_pcm_hardware pcm_hw; + int num_pcm_streams_pb; + struct xen_snd_front_pcm_stream_info *streams_pb; + int num_pcm_streams_cap; + struct xen_snd_front_pcm_stream_info *streams_cap; +}; + +struct xen_snd_front_card_info { + struct xen_snd_front_info *front_info; + struct snd_card *card; + struct snd_pcm_hardware pcm_hw; + int num_pcm_instances; + struct xen_snd_front_pcm_instance_info *pcm_instances; +}; + +struct alsa_sndif_sample_format { + u8 sndif; + snd_pcm_format_t alsa; +}; + +struct alsa_sndif_hw_param { + u8 sndif; + snd_pcm_hw_param_t alsa; +}; + +static const struct alsa_sndif_sample_format ALSA_SNDIF_FORMATS[] = { + { + .sndif = XENSND_PCM_FORMAT_U8, + .alsa = SNDRV_PCM_FORMAT_U8 + }, + { + .sndif = XENSND_PCM_FORMAT_S8, + .alsa = SNDRV_PCM_FORMAT_S8 + }, + { + .sndif = XENSND_PCM_FORMAT_U16_LE, + .alsa = SNDRV_PCM_FORMAT_U16_LE + }, + { + .sndif = XENSND_PCM_FORMAT_U16_BE, + .alsa = SNDRV_PCM_FORMAT_U16_BE + }, + { + .sndif = XENSND_PCM_FORMAT_S16_LE, + .alsa = SNDRV_PCM_FORMAT_S16_LE + }, + { + .sndif = XENSND_PCM_FORMAT_S16_BE, + .alsa = SNDRV_PCM_FORMAT_S16_BE + }, + { + .sndif = XENSND_PCM_FORMAT_U24_LE, + .alsa = SNDRV_PCM_FORMAT_U24_LE + }, + { + .sndif = XENSND_PCM_FORMAT_U24_BE, + .alsa = SNDRV_PCM_FORMAT_U24_BE + }, + { + .sndif = XENSND_PCM_FORMAT_S24_LE, + .alsa = SNDRV_PCM_FORMAT_S24_LE + }, + { + .sndif = XENSND_PCM_FORMAT_S24_BE, + .alsa = SNDRV_PCM_FORMAT_S24_BE + }, + { + .sndif = XENSND_PCM_FORMAT_U32_LE, + .alsa = SNDRV_PCM_FORMAT_U32_LE + }, + { + .sndif = XENSND_PCM_FORMAT_U32_BE, + .alsa = SNDRV_PCM_FORMAT_U32_BE + }, + { + .sndif = XENSND_PCM_FORMAT_S32_LE, + .alsa = SNDRV_PCM_FORMAT_S32_LE + }, + { + .sndif = XENSND_PCM_FORMAT_S32_BE, + .alsa = SNDRV_PCM_FORMAT_S32_BE + }, + { + .sndif = XENSND_PCM_FORMAT_A_LAW, + .alsa = SNDRV_PCM_FORMAT_A_LAW + }, + { + .sndif = XENSND_PCM_FORMAT_MU_LAW, + .alsa = SNDRV_PCM_FORMAT_MU_LAW + }, + { + .sndif = XENSND_PCM_FORMAT_F32_LE, + .alsa = SNDRV_PCM_FORMAT_FLOAT_LE + }, + { + .sndif = XENSND_PCM_FORMAT_F32_BE, + .alsa = SNDRV_PCM_FORMAT_FLOAT_BE + }, + { + .sndif = XENSND_PCM_FORMAT_F64_LE, + .alsa = SNDRV_PCM_FORMAT_FLOAT64_LE + }, + { + .sndif = XENSND_PCM_FORMAT_F64_BE, + .alsa = SNDRV_PCM_FORMAT_FLOAT64_BE + }, + { + .sndif = XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE, + .alsa = SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE + }, + { + .sndif = XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE, + .alsa = SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE + }, + { + .sndif = XENSND_PCM_FORMAT_IMA_ADPCM, + .alsa = SNDRV_PCM_FORMAT_IMA_ADPCM + }, + { + .sndif = XENSND_PCM_FORMAT_MPEG, + .alsa = SNDRV_PCM_FORMAT_MPEG + }, + { + .sndif = XENSND_PCM_FORMAT_GSM, + .alsa = SNDRV_PCM_FORMAT_GSM + }, +}; + +static int to_sndif_format(snd_pcm_format_t format) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(ALSA_SNDIF_FORMATS); i++) + if (ALSA_SNDIF_FORMATS[i].alsa == format) + return ALSA_SNDIF_FORMATS[i].sndif; + + return -EINVAL; +} + +static u64 to_sndif_formats_mask(u64 alsa_formats) +{ + u64 mask; + int i; + + mask = 0; + for (i = 0; i < ARRAY_SIZE(ALSA_SNDIF_FORMATS); i++) + if (1 << ALSA_SNDIF_FORMATS[i].alsa & alsa_formats) + mask |= 1 << ALSA_SNDIF_FORMATS[i].sndif; + + return mask; +} + +static u64 to_alsa_formats_mask(u64 sndif_formats) +{ + u64 mask; + int i; + + mask = 0; + for (i = 0; i < ARRAY_SIZE(ALSA_SNDIF_FORMATS); i++) + if (1 << ALSA_SNDIF_FORMATS[i].sndif & sndif_formats) + mask |= 1 << ALSA_SNDIF_FORMATS[i].alsa; + + return mask; +} + +static void stream_clear(struct xen_snd_front_pcm_stream_info *stream) +{ + stream->is_open = false; + stream->be_cur_frame = 0; + stream->out_frames = 0; + atomic_set(&stream->hw_ptr, 0); + xen_snd_front_evtchnl_pair_clear(stream->evt_pair); + xen_snd_front_shbuf_clear(&stream->sh_buf); +} + +static void stream_free(struct xen_snd_front_pcm_stream_info *stream) +{ + xen_snd_front_shbuf_free(&stream->sh_buf); + stream_clear(stream); +} + +static struct xen_snd_front_pcm_stream_info * +stream_get(struct snd_pcm_substream *substream) +{ + struct xen_snd_front_pcm_instance_info *pcm_instance = + snd_pcm_substream_chip(substream); + struct xen_snd_front_pcm_stream_info *stream; + + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) + stream = &pcm_instance->streams_pb[substream->number]; + else + stream = &pcm_instance->streams_cap[substream->number]; + + return stream; +} + +static int alsa_hw_rule(struct snd_pcm_hw_params *params, + struct snd_pcm_hw_rule *rule) +{ + struct xen_snd_front_pcm_stream_info *stream = rule->private; + struct device *dev = &stream->front_info->xb_dev->dev; + struct snd_mask *formats = + hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT); + struct snd_interval *rates = + hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE); + struct snd_interval *channels = + hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS); + struct snd_interval *period = + hw_param_interval(params, + SNDRV_PCM_HW_PARAM_PERIOD_SIZE); + struct snd_interval *buffer = + hw_param_interval(params, + SNDRV_PCM_HW_PARAM_BUFFER_SIZE); + struct xensnd_query_hw_param req; + struct xensnd_query_hw_param resp; + struct snd_interval interval; + struct snd_mask mask; + u64 sndif_formats; + int changed, ret; + + /* Collect all the values we need for the query. */ + + req.formats = to_sndif_formats_mask((u64)formats->bits[0] | + (u64)(formats->bits[1]) << 32); + + req.rates.min = rates->min; + req.rates.max = rates->max; + + req.channels.min = channels->min; + req.channels.max = channels->max; + + req.buffer.min = buffer->min; + req.buffer.max = buffer->max; + + req.period.min = period->min; + req.period.max = period->max; + + ret = xen_snd_front_stream_query_hw_param(&stream->evt_pair->req, + &req, &resp); + if (ret < 0) { + /* Check if this is due to backend communication error. */ + if (ret == -EIO || ret == -ETIMEDOUT) + dev_err(dev, "Failed to query ALSA HW parameters\n"); + return ret; + } + + /* Refine HW parameters after the query. */ + changed = 0; + + sndif_formats = to_alsa_formats_mask(resp.formats); + snd_mask_none(&mask); + mask.bits[0] = (u32)sndif_formats; + mask.bits[1] = (u32)(sndif_formats >> 32); + ret = snd_mask_refine(formats, &mask); + if (ret < 0) + return ret; + changed |= ret; + + interval.openmin = 0; + interval.openmax = 0; + interval.integer = 1; + + interval.min = resp.rates.min; + interval.max = resp.rates.max; + ret = snd_interval_refine(rates, &interval); + if (ret < 0) + return ret; + changed |= ret; + + interval.min = resp.channels.min; + interval.max = resp.channels.max; + ret = snd_interval_refine(channels, &interval); + if (ret < 0) + return ret; + changed |= ret; + + interval.min = resp.buffer.min; + interval.max = resp.buffer.max; + ret = snd_interval_refine(buffer, &interval); + if (ret < 0) + return ret; + changed |= ret; + + interval.min = resp.period.min; + interval.max = resp.period.max; + ret = snd_interval_refine(period, &interval); + if (ret < 0) + return ret; + changed |= ret; + + return changed; +} + +static int alsa_open(struct snd_pcm_substream *substream) +{ + struct xen_snd_front_pcm_instance_info *pcm_instance = + snd_pcm_substream_chip(substream); + struct xen_snd_front_pcm_stream_info *stream = stream_get(substream); + struct snd_pcm_runtime *runtime = substream->runtime; + struct xen_snd_front_info *front_info = + pcm_instance->card_info->front_info; + struct device *dev = &front_info->xb_dev->dev; + int ret; + + /* + * Return our HW properties: override defaults with those configured + * via XenStore. + */ + runtime->hw = stream->pcm_hw; + runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP | + SNDRV_PCM_INFO_MMAP_VALID | + SNDRV_PCM_INFO_DOUBLE | + SNDRV_PCM_INFO_BATCH | + SNDRV_PCM_INFO_NONINTERLEAVED | + SNDRV_PCM_INFO_RESUME | + SNDRV_PCM_INFO_PAUSE); + runtime->hw.info |= SNDRV_PCM_INFO_INTERLEAVED; + + stream->evt_pair = &front_info->evt_pairs[stream->index]; + + stream->front_info = front_info; + + stream->evt_pair->evt.u.evt.substream = substream; + + stream_clear(stream); + + xen_snd_front_evtchnl_pair_set_connected(stream->evt_pair, true); + + ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT, + alsa_hw_rule, stream, + SNDRV_PCM_HW_PARAM_FORMAT, -1); + if (ret) { + dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_FORMAT\n"); + return ret; + } + + ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE, + alsa_hw_rule, stream, + SNDRV_PCM_HW_PARAM_RATE, -1); + if (ret) { + dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_RATE\n"); + return ret; + } + + ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS, + alsa_hw_rule, stream, + SNDRV_PCM_HW_PARAM_CHANNELS, -1); + if (ret) { + dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_CHANNELS\n"); + return ret; + } + + ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, + alsa_hw_rule, stream, + SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1); + if (ret) { + dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_PERIOD_SIZE\n"); + return ret; + } + + ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_SIZE, + alsa_hw_rule, stream, + SNDRV_PCM_HW_PARAM_BUFFER_SIZE, -1); + if (ret) { + dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_BUFFER_SIZE\n"); + return ret; + } + + return 0; +} + +static int alsa_close(struct snd_pcm_substream *substream) +{ + struct xen_snd_front_pcm_stream_info *stream = stream_get(substream); + + xen_snd_front_evtchnl_pair_set_connected(stream->evt_pair, false); + return 0; +} + +static int alsa_hw_params(struct snd_pcm_substream *substream, + struct snd_pcm_hw_params *params) +{ + struct xen_snd_front_pcm_stream_info *stream = stream_get(substream); + int ret; + + /* + * This callback may be called multiple times, + * so free the previously allocated shared buffer if any. + */ + stream_free(stream); + + ret = xen_snd_front_shbuf_alloc(stream->front_info->xb_dev, + &stream->sh_buf, + params_buffer_bytes(params)); + if (ret < 0) { + stream_free(stream); + dev_err(&stream->front_info->xb_dev->dev, + "Failed to allocate buffers for stream with index %d\n", + stream->index); + return ret; + } + + return 0; +} + +static int alsa_hw_free(struct snd_pcm_substream *substream) +{ + struct xen_snd_front_pcm_stream_info *stream = stream_get(substream); + int ret; + + ret = xen_snd_front_stream_close(&stream->evt_pair->req); + stream_free(stream); + return ret; +} + +static int alsa_prepare(struct snd_pcm_substream *substream) +{ + struct xen_snd_front_pcm_stream_info *stream = stream_get(substream); + + if (!stream->is_open) { + struct snd_pcm_runtime *runtime = substream->runtime; + u8 sndif_format; + int ret; + + sndif_format = to_sndif_format(runtime->format); + if (sndif_format < 0) { + dev_err(&stream->front_info->xb_dev->dev, + "Unsupported sample format: %d\n", + runtime->format); + return sndif_format; + } + + ret = xen_snd_front_stream_prepare(&stream->evt_pair->req, + &stream->sh_buf, + sndif_format, + runtime->channels, + runtime->rate, + snd_pcm_lib_buffer_bytes(substream), + snd_pcm_lib_period_bytes(substream)); + if (ret < 0) + return ret; + + stream->is_open = true; + } + + return 0; +} + +static int alsa_trigger(struct snd_pcm_substream *substream, int cmd) +{ + struct xen_snd_front_pcm_stream_info *stream = stream_get(substream); + int type; + + switch (cmd) { + case SNDRV_PCM_TRIGGER_START: + type = XENSND_OP_TRIGGER_START; + break; + + case SNDRV_PCM_TRIGGER_RESUME: + type = XENSND_OP_TRIGGER_RESUME; + break; + + case SNDRV_PCM_TRIGGER_STOP: + type = XENSND_OP_TRIGGER_STOP; + break; + + case SNDRV_PCM_TRIGGER_SUSPEND: + type = XENSND_OP_TRIGGER_PAUSE; + break; + + default: + return -EINVAL; + } + + return xen_snd_front_stream_trigger(&stream->evt_pair->req, type); +} + +void xen_snd_front_alsa_handle_cur_pos(struct xen_snd_front_evtchnl *evtchnl, + u64 pos_bytes) +{ + struct snd_pcm_substream *substream = evtchnl->u.evt.substream; + struct xen_snd_front_pcm_stream_info *stream = stream_get(substream); + snd_pcm_uframes_t delta, new_hw_ptr, cur_frame; + + cur_frame = bytes_to_frames(substream->runtime, pos_bytes); + + delta = cur_frame - stream->be_cur_frame; + stream->be_cur_frame = cur_frame; + + new_hw_ptr = (snd_pcm_uframes_t)atomic_read(&stream->hw_ptr); + new_hw_ptr = (new_hw_ptr + delta) % substream->runtime->buffer_size; + atomic_set(&stream->hw_ptr, (int)new_hw_ptr); + + stream->out_frames += delta; + if (stream->out_frames > substream->runtime->period_size) { + stream->out_frames %= substream->runtime->period_size; + snd_pcm_period_elapsed(substream); + } +} + +static snd_pcm_uframes_t alsa_pointer(struct snd_pcm_substream *substream) +{ + struct xen_snd_front_pcm_stream_info *stream = stream_get(substream); + + return (snd_pcm_uframes_t)atomic_read(&stream->hw_ptr); +} + +static int alsa_pb_copy_user(struct snd_pcm_substream *substream, + int channel, unsigned long pos, void __user *src, + unsigned long count) +{ + struct xen_snd_front_pcm_stream_info *stream = stream_get(substream); + + if (unlikely(pos + count > stream->sh_buf.buffer_sz)) + return -EINVAL; + + if (copy_from_user(stream->sh_buf.buffer + pos, src, count)) + return -EFAULT; + + return xen_snd_front_stream_write(&stream->evt_pair->req, pos, count); +} + +static int alsa_pb_copy_kernel(struct snd_pcm_substream *substream, + int channel, unsigned long pos, void *src, + unsigned long count) +{ + struct xen_snd_front_pcm_stream_info *stream = stream_get(substream); + + if (unlikely(pos + count > stream->sh_buf.buffer_sz)) + return -EINVAL; + + memcpy(stream->sh_buf.buffer + pos, src, count); + + return xen_snd_front_stream_write(&stream->evt_pair->req, pos, count); +} + +static int alsa_cap_copy_user(struct snd_pcm_substream *substream, + int channel, unsigned long pos, void __user *dst, + unsigned long count) +{ + struct xen_snd_front_pcm_stream_info *stream = stream_get(substream); + int ret; + + if (unlikely(pos + count > stream->sh_buf.buffer_sz)) + return -EINVAL; + + ret = xen_snd_front_stream_read(&stream->evt_pair->req, pos, count); + if (ret < 0) + return ret; + + return copy_to_user(dst, stream->sh_buf.buffer + pos, count) ? + -EFAULT : 0; +} + +static int alsa_cap_copy_kernel(struct snd_pcm_substream *substream, + int channel, unsigned long pos, void *dst, + unsigned long count) +{ + struct xen_snd_front_pcm_stream_info *stream = stream_get(substream); + int ret; + + if (unlikely(pos + count > stream->sh_buf.buffer_sz)) + return -EINVAL; + + ret = xen_snd_front_stream_read(&stream->evt_pair->req, pos, count); + if (ret < 0) + return ret; + + memcpy(dst, stream->sh_buf.buffer + pos, count); + + return 0; +} + +static int alsa_pb_fill_silence(struct snd_pcm_substream *substream, + int channel, unsigned long pos, + unsigned long count) +{ + struct xen_snd_front_pcm_stream_info *stream = stream_get(substream); + + if (unlikely(pos + count > stream->sh_buf.buffer_sz)) + return -EINVAL; + + memset(stream->sh_buf.buffer + pos, 0, count); + + return xen_snd_front_stream_write(&stream->evt_pair->req, pos, count); +} + +/* + * FIXME: The mmaped data transfer is asynchronous and there is no + * ack signal from user-space when it is done. This is the + * reason it is not implemented in the PV driver as we do need + * to know when the buffer can be transferred to the backend. + */ + +static struct snd_pcm_ops snd_drv_alsa_playback_ops = { + .open = alsa_open, + .close = alsa_close, + .ioctl = snd_pcm_lib_ioctl, + .hw_params = alsa_hw_params, + .hw_free = alsa_hw_free, + .prepare = alsa_prepare, + .trigger = alsa_trigger, + .pointer = alsa_pointer, + .copy_user = alsa_pb_copy_user, + .copy_kernel = alsa_pb_copy_kernel, + .fill_silence = alsa_pb_fill_silence, +}; + +static struct snd_pcm_ops snd_drv_alsa_capture_ops = { + .open = alsa_open, + .close = alsa_close, + .ioctl = snd_pcm_lib_ioctl, + .hw_params = alsa_hw_params, + .hw_free = alsa_hw_free, + .prepare = alsa_prepare, + .trigger = alsa_trigger, + .pointer = alsa_pointer, + .copy_user = alsa_cap_copy_user, + .copy_kernel = alsa_cap_copy_kernel, +}; + +static int new_pcm_instance(struct xen_snd_front_card_info *card_info, + struct xen_front_cfg_pcm_instance *instance_cfg, + struct xen_snd_front_pcm_instance_info *pcm_instance_info) +{ + struct snd_pcm *pcm; + int ret, i; + + dev_dbg(&card_info->front_info->xb_dev->dev, + "New PCM device "%s" with id %d playback %d capture %d", + instance_cfg->name, + instance_cfg->device_id, + instance_cfg->num_streams_pb, + instance_cfg->num_streams_cap); + + pcm_instance_info->card_info = card_info; + + pcm_instance_info->pcm_hw = instance_cfg->pcm_hw; + + if (instance_cfg->num_streams_pb) { + pcm_instance_info->streams_pb = + devm_kcalloc(&card_info->card->card_dev, + instance_cfg->num_streams_pb, + sizeof(struct xen_snd_front_pcm_stream_info), + GFP_KERNEL); + if (!pcm_instance_info->streams_pb) + return -ENOMEM; + } + + if (instance_cfg->num_streams_cap) { + pcm_instance_info->streams_cap = + devm_kcalloc(&card_info->card->card_dev, + instance_cfg->num_streams_cap, + sizeof(struct xen_snd_front_pcm_stream_info), + GFP_KERNEL); + if (!pcm_instance_info->streams_cap) + return -ENOMEM; + } + + pcm_instance_info->num_pcm_streams_pb = + instance_cfg->num_streams_pb; + pcm_instance_info->num_pcm_streams_cap = + instance_cfg->num_streams_cap; + + for (i = 0; i < pcm_instance_info->num_pcm_streams_pb; i++) { + pcm_instance_info->streams_pb[i].pcm_hw = + instance_cfg->streams_pb[i].pcm_hw; + pcm_instance_info->streams_pb[i].index = + instance_cfg->streams_pb[i].index; + } + + for (i = 0; i < pcm_instance_info->num_pcm_streams_cap; i++) { + pcm_instance_info->streams_cap[i].pcm_hw = + instance_cfg->streams_cap[i].pcm_hw; + pcm_instance_info->streams_cap[i].index = + instance_cfg->streams_cap[i].index; + } + + ret = snd_pcm_new(card_info->card, instance_cfg->name, + instance_cfg->device_id, + instance_cfg->num_streams_pb, + instance_cfg->num_streams_cap, + &pcm); + if (ret < 0) + return ret; + + pcm->private_data = pcm_instance_info; + pcm->info_flags = 0; + /* we want to handle all PCM operations in non-atomic context */ + pcm->nonatomic = true; + strncpy(pcm->name, "Virtual card PCM", sizeof(pcm->name)); + + if (instance_cfg->num_streams_pb) + snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, + &snd_drv_alsa_playback_ops); + + if (instance_cfg->num_streams_cap) + snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, + &snd_drv_alsa_capture_ops); + + pcm_instance_info->pcm = pcm; + return 0; +} + +int xen_snd_front_alsa_init(struct xen_snd_front_info *front_info) +{ + struct device *dev = &front_info->xb_dev->dev; + struct xen_front_cfg_card *cfg = &front_info->cfg; + struct xen_snd_front_card_info *card_info; + struct snd_card *card; + int ret, i; + + dev_dbg(dev, "Creating virtual sound card\n"); + + ret = snd_card_new(dev, 0, XENSND_DRIVER_NAME, THIS_MODULE, + sizeof(struct xen_snd_front_card_info), &card); + if (ret < 0) + return ret; + + card_info = card->private_data; + card_info->front_info = front_info; + front_info->card_info = card_info; + card_info->card = card; + card_info->pcm_instances = + devm_kcalloc(dev, cfg->num_pcm_instances, + sizeof(struct xen_snd_front_pcm_instance_info), + GFP_KERNEL); + if (!card_info->pcm_instances) { + ret = -ENOMEM; + goto fail; + } + + card_info->num_pcm_instances = cfg->num_pcm_instances; + card_info->pcm_hw = cfg->pcm_hw; + + for (i = 0; i < cfg->num_pcm_instances; i++) { + ret = new_pcm_instance(card_info, &cfg->pcm_instances[i], + &card_info->pcm_instances[i]); + if (ret < 0) + goto fail; + } + + strncpy(card->driver, XENSND_DRIVER_NAME, sizeof(card->driver)); + strncpy(card->shortname, cfg->name_short, sizeof(card->shortname)); + strncpy(card->longname, cfg->name_long, sizeof(card->longname)); + + ret = snd_card_register(card); + if (ret < 0) + goto fail; + + return 0; + +fail: + snd_card_free(card); + return ret; +} + +void xen_snd_front_alsa_fini(struct xen_snd_front_info *front_info) +{ + struct xen_snd_front_card_info *card_info; + struct snd_card *card; + + card_info = front_info->card_info; + if (!card_info) + return; + + card = card_info->card; + if (!card) + return; + + dev_dbg(&front_info->xb_dev->dev, "Removing virtual sound card %d\n", + card->number); + snd_card_free(card); + + /* Card_info will be freed when destroying front_info->xb_dev->dev. */ + card_info->card = NULL; +} diff --git a/sound/xen/xen_snd_front_alsa.h b/sound/xen/xen_snd_front_alsa.h new file mode 100644 index 000000000000..18abd9eec967 --- /dev/null +++ b/sound/xen/xen_snd_front_alsa.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0 OR MIT */ + +/* + * Xen para-virtual sound device + * + * Copyright (C) 2016-2018 EPAM Systems Inc. + * + * Author: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com + */ + +#ifndef __XEN_SND_FRONT_ALSA_H +#define __XEN_SND_FRONT_ALSA_H + +struct xen_snd_front_info; + +int xen_snd_front_alsa_init(struct xen_snd_front_info *front_info); + +void xen_snd_front_alsa_fini(struct xen_snd_front_info *front_info); + +void xen_snd_front_alsa_handle_cur_pos(struct xen_snd_front_evtchnl *evtchnl, + u64 pos_bytes); + +#endif /* __XEN_SND_FRONT_ALSA_H */ diff --git a/sound/xen/xen_snd_front_evtchnl.c b/sound/xen/xen_snd_front_evtchnl.c index 1faafff08807..d70a62e7f910 100644 --- a/sound/xen/xen_snd_front_evtchnl.c +++ b/sound/xen/xen_snd_front_evtchnl.c @@ -14,6 +14,7 @@ #include <xen/xenbus.h>

#include "xen_snd_front.h" +#include "xen_snd_front_alsa.h" #include "xen_snd_front_cfg.h" #include "xen_snd_front_evtchnl.h"

@@ -118,7 +119,8 @@ static irqreturn_t evtchnl_interrupt_evt(int irq, void *dev_id)

switch (event->type) { case XENSND_EVT_CUR_POS: - /* Do nothing at the moment. */ + xen_snd_front_alsa_handle_cur_pos(channel, + event->op.cur_pos.position); break; } }