Introduce skeleton of the virtio sound driver. The driver implements the virtio sound device specification, which has become part of the virtio standard.

Initial initialization of the device, virtqueues and creation of an empty ALSA sound device. Also, handling DEVICE_NEEDS_RESET device status.

Signed-off-by: Anton Yakovlev anton.yakovlev@opensynergy.com --- MAINTAINERS | 9 + include/uapi/linux/virtio_snd.h | 361 +++++++++++++++++++++++++++ sound/Kconfig | 2 + sound/Makefile | 3 +- sound/virtio/Kconfig | 10 + sound/virtio/Makefile | 7 + sound/virtio/virtio_card.c | 415 ++++++++++++++++++++++++++++++++ sound/virtio/virtio_card.h | 76 ++++++ 8 files changed, 882 insertions(+), 1 deletion(-) create mode 100644 include/uapi/linux/virtio_snd.h create mode 100644 sound/virtio/Kconfig create mode 100644 sound/virtio/Makefile create mode 100644 sound/virtio/virtio_card.c create mode 100644 sound/virtio/virtio_card.h

diff --git a/MAINTAINERS b/MAINTAINERS index 00836f6452f0..3f509d54a457 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -18936,6 +18936,15 @@ W: https://virtio-mem.gitlab.io/ F: drivers/virtio/virtio_mem.c F: include/uapi/linux/virtio_mem.h

+VIRTIO SOUND DRIVER +M: Anton Yakovlev anton.yakovlev@opensynergy.com +M: "Michael S. Tsirkin" mst@redhat.com +L: virtualization@lists.linux-foundation.org +L: alsa-devel@alsa-project.org (moderated for non-subscribers) +S: Maintained +F: include/uapi/linux/virtio_snd.h +F: sound/virtio/* + VIRTUAL BOX GUEST DEVICE DRIVER M: Hans de Goede hdegoede@redhat.com M: Arnd Bergmann arnd@arndb.de diff --git a/include/uapi/linux/virtio_snd.h b/include/uapi/linux/virtio_snd.h new file mode 100644 index 000000000000..1ff6310e54d6 --- /dev/null +++ b/include/uapi/linux/virtio_snd.h @@ -0,0 +1,361 @@ +/* SPDX-License-Identifier: BSD-3-Clause */ +/* + * Copyright (C) 2020 OpenSynergy GmbH + * + * This header is BSD licensed so anyone can use the definitions to + * implement compatible drivers/servers. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of OpenSynergy GmbH nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL IBM OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ +#ifndef VIRTIO_SND_IF_H +#define VIRTIO_SND_IF_H + +#include <linux/virtio_types.h> + +/******************************************************************************* + * CONFIGURATION SPACE + */ +struct virtio_snd_config { + /* # of available physical jacks */ + __le32 jacks; + /* # of available PCM streams */ + __le32 streams; + /* # of available channel maps */ + __le32 chmaps; +}; + +enum { + /* device virtqueue indexes */ + VIRTIO_SND_VQ_CONTROL = 0, + VIRTIO_SND_VQ_EVENT, + VIRTIO_SND_VQ_TX, + VIRTIO_SND_VQ_RX, + /* # of device virtqueues */ + VIRTIO_SND_VQ_MAX +}; + +/******************************************************************************* + * COMMON DEFINITIONS + */ + +/* supported dataflow directions */ +enum { + VIRTIO_SND_D_OUTPUT = 0, + VIRTIO_SND_D_INPUT +}; + +enum { + /* jack control request types */ + VIRTIO_SND_R_JACK_INFO = 1, + VIRTIO_SND_R_JACK_REMAP, + + /* PCM control request types */ + VIRTIO_SND_R_PCM_INFO = 0x0100, + VIRTIO_SND_R_PCM_SET_PARAMS, + VIRTIO_SND_R_PCM_PREPARE, + VIRTIO_SND_R_PCM_RELEASE, + VIRTIO_SND_R_PCM_START, + VIRTIO_SND_R_PCM_STOP, + + /* channel map control request types */ + VIRTIO_SND_R_CHMAP_INFO = 0x0200, + + /* jack event types */ + VIRTIO_SND_EVT_JACK_CONNECTED = 0x1000, + VIRTIO_SND_EVT_JACK_DISCONNECTED, + + /* PCM event types */ + VIRTIO_SND_EVT_PCM_PERIOD_ELAPSED = 0x1100, + VIRTIO_SND_EVT_PCM_XRUN, + + /* common status codes */ + VIRTIO_SND_S_OK = 0x8000, + VIRTIO_SND_S_BAD_MSG, + VIRTIO_SND_S_NOT_SUPP, + VIRTIO_SND_S_IO_ERR +}; + +/* common header */ +struct virtio_snd_hdr { + __le32 code; +}; + +/* event notification */ +struct virtio_snd_event { + /* VIRTIO_SND_EVT_XXX */ + struct virtio_snd_hdr hdr; + /* optional event data */ + __le32 data; +}; + +/* common control request to query an item information */ +struct virtio_snd_query_info { + /* VIRTIO_SND_R_XXX_INFO */ + struct virtio_snd_hdr hdr; + /* item start identifier */ + __le32 start_id; + /* item count to query */ + __le32 count; + /* item information size in bytes */ + __le32 size; +}; + +/* common item information header */ +struct virtio_snd_info { + /* function group node id (High Definition Audio Specification 7.1.2) */ + __le32 hda_fn_nid; +}; + +/******************************************************************************* + * JACK CONTROL MESSAGES + */ +struct virtio_snd_jack_hdr { + /* VIRTIO_SND_R_JACK_XXX */ + struct virtio_snd_hdr hdr; + /* 0 ... virtio_snd_config::jacks - 1 */ + __le32 jack_id; +}; + +/* supported jack features */ +enum { + VIRTIO_SND_JACK_F_REMAP = 0 +}; + +struct virtio_snd_jack_info { + /* common header */ + struct virtio_snd_info hdr; + /* supported feature bit map (1 << VIRTIO_SND_JACK_F_XXX) */ + __le32 features; + /* pin configuration (High Definition Audio Specification 7.3.3.31) */ + __le32 hda_reg_defconf; + /* pin capabilities (High Definition Audio Specification 7.3.4.9) */ + __le32 hda_reg_caps; + /* current jack connection status (0: disconnected, 1: connected) */ + __u8 connected; + + __u8 padding[7]; +}; + +/* jack remapping control request */ +struct virtio_snd_jack_remap { + /* .code = VIRTIO_SND_R_JACK_REMAP */ + struct virtio_snd_jack_hdr hdr; + /* selected association number */ + __le32 association; + /* selected sequence number */ + __le32 sequence; +}; + +/******************************************************************************* + * PCM CONTROL MESSAGES + */ +struct virtio_snd_pcm_hdr { + /* VIRTIO_SND_R_PCM_XXX */ + struct virtio_snd_hdr hdr; + /* 0 ... virtio_snd_config::streams - 1 */ + __le32 stream_id; +}; + +/* supported PCM stream features */ +enum { + VIRTIO_SND_PCM_F_SHMEM_HOST = 0, + VIRTIO_SND_PCM_F_SHMEM_GUEST, + VIRTIO_SND_PCM_F_MSG_POLLING, + VIRTIO_SND_PCM_F_EVT_SHMEM_PERIODS, + VIRTIO_SND_PCM_F_EVT_XRUNS +}; + +/* supported PCM sample formats */ +enum { + /* analog formats (width / physical width) */ + VIRTIO_SND_PCM_FMT_IMA_ADPCM = 0, /* 4 / 4 bits */ + VIRTIO_SND_PCM_FMT_MU_LAW, /* 8 / 8 bits */ + VIRTIO_SND_PCM_FMT_A_LAW, /* 8 / 8 bits */ + VIRTIO_SND_PCM_FMT_S8, /* 8 / 8 bits */ + VIRTIO_SND_PCM_FMT_U8, /* 8 / 8 bits */ + VIRTIO_SND_PCM_FMT_S16, /* 16 / 16 bits */ + VIRTIO_SND_PCM_FMT_U16, /* 16 / 16 bits */ + VIRTIO_SND_PCM_FMT_S18_3, /* 18 / 24 bits */ + VIRTIO_SND_PCM_FMT_U18_3, /* 18 / 24 bits */ + VIRTIO_SND_PCM_FMT_S20_3, /* 20 / 24 bits */ + VIRTIO_SND_PCM_FMT_U20_3, /* 20 / 24 bits */ + VIRTIO_SND_PCM_FMT_S24_3, /* 24 / 24 bits */ + VIRTIO_SND_PCM_FMT_U24_3, /* 24 / 24 bits */ + VIRTIO_SND_PCM_FMT_S20, /* 20 / 32 bits */ + VIRTIO_SND_PCM_FMT_U20, /* 20 / 32 bits */ + VIRTIO_SND_PCM_FMT_S24, /* 24 / 32 bits */ + VIRTIO_SND_PCM_FMT_U24, /* 24 / 32 bits */ + VIRTIO_SND_PCM_FMT_S32, /* 32 / 32 bits */ + VIRTIO_SND_PCM_FMT_U32, /* 32 / 32 bits */ + VIRTIO_SND_PCM_FMT_FLOAT, /* 32 / 32 bits */ + VIRTIO_SND_PCM_FMT_FLOAT64, /* 64 / 64 bits */ + /* digital formats (width / physical width) */ + VIRTIO_SND_PCM_FMT_DSD_U8, /* 8 / 8 bits */ + VIRTIO_SND_PCM_FMT_DSD_U16, /* 16 / 16 bits */ + VIRTIO_SND_PCM_FMT_DSD_U32, /* 32 / 32 bits */ + VIRTIO_SND_PCM_FMT_IEC958_SUBFRAME /* 32 / 32 bits */ +}; + +/* supported PCM frame rates */ +enum { + VIRTIO_SND_PCM_RATE_5512 = 0, + VIRTIO_SND_PCM_RATE_8000, + VIRTIO_SND_PCM_RATE_11025, + VIRTIO_SND_PCM_RATE_16000, + VIRTIO_SND_PCM_RATE_22050, + VIRTIO_SND_PCM_RATE_32000, + VIRTIO_SND_PCM_RATE_44100, + VIRTIO_SND_PCM_RATE_48000, + VIRTIO_SND_PCM_RATE_64000, + VIRTIO_SND_PCM_RATE_88200, + VIRTIO_SND_PCM_RATE_96000, + VIRTIO_SND_PCM_RATE_176400, + VIRTIO_SND_PCM_RATE_192000, + VIRTIO_SND_PCM_RATE_384000 +}; + +struct virtio_snd_pcm_info { + /* common header */ + struct virtio_snd_info hdr; + /* supported feature bit map (1 << VIRTIO_SND_PCM_F_XXX) */ + __le32 features; + /* supported sample format bit map (1 << VIRTIO_SND_PCM_FMT_XXX) */ + __le64 formats; + /* supported frame rate bit map (1 << VIRTIO_SND_PCM_RATE_XXX) */ + __le64 rates; + /* dataflow direction (VIRTIO_SND_D_XXX) */ + __u8 direction; + /* minimum # of supported channels */ + __u8 channels_min; + /* maximum # of supported channels */ + __u8 channels_max; + + __u8 padding[5]; +}; + +/* set PCM stream format */ +struct virtio_snd_pcm_set_params { + /* .code = VIRTIO_SND_R_PCM_SET_PARAMS */ + struct virtio_snd_pcm_hdr hdr; + /* size of the hardware buffer */ + __le32 buffer_bytes; + /* size of the hardware period */ + __le32 period_bytes; + /* selected feature bit map (1 << VIRTIO_SND_PCM_F_XXX) */ + __le32 features; + /* selected # of channels */ + __u8 channels; + /* selected sample format (VIRTIO_SND_PCM_FMT_XXX) */ + __u8 format; + /* selected frame rate (VIRTIO_SND_PCM_RATE_XXX) */ + __u8 rate; + + __u8 padding; +}; + +/******************************************************************************* + * PCM I/O MESSAGES + */ + +/* I/O request header */ +struct virtio_snd_pcm_xfer { + /* 0 ... virtio_snd_config::streams - 1 */ + __le32 stream_id; +}; + +/* I/O request status */ +struct virtio_snd_pcm_status { + /* VIRTIO_SND_S_XXX */ + __le32 status; + /* current device latency */ + __le32 latency_bytes; +}; + +/******************************************************************************* + * CHANNEL MAP CONTROL MESSAGES + */ +struct virtio_snd_chmap_hdr { + /* VIRTIO_SND_R_CHMAP_XXX */ + struct virtio_snd_hdr hdr; + /* 0 ... virtio_snd_config::chmaps - 1 */ + __le32 chmap_id; +}; + +/* standard channel position definition */ +enum { + VIRTIO_SND_CHMAP_NONE = 0, /* undefined */ + VIRTIO_SND_CHMAP_NA, /* silent */ + VIRTIO_SND_CHMAP_MONO, /* mono stream */ + VIRTIO_SND_CHMAP_FL, /* front left */ + VIRTIO_SND_CHMAP_FR, /* front right */ + VIRTIO_SND_CHMAP_RL, /* rear left */ + VIRTIO_SND_CHMAP_RR, /* rear right */ + VIRTIO_SND_CHMAP_FC, /* front center */ + VIRTIO_SND_CHMAP_LFE, /* low frequency (LFE) */ + VIRTIO_SND_CHMAP_SL, /* side left */ + VIRTIO_SND_CHMAP_SR, /* side right */ + VIRTIO_SND_CHMAP_RC, /* rear center */ + VIRTIO_SND_CHMAP_FLC, /* front left center */ + VIRTIO_SND_CHMAP_FRC, /* front right center */ + VIRTIO_SND_CHMAP_RLC, /* rear left center */ + VIRTIO_SND_CHMAP_RRC, /* rear right center */ + VIRTIO_SND_CHMAP_FLW, /* front left wide */ + VIRTIO_SND_CHMAP_FRW, /* front right wide */ + VIRTIO_SND_CHMAP_FLH, /* front left high */ + VIRTIO_SND_CHMAP_FCH, /* front center high */ + VIRTIO_SND_CHMAP_FRH, /* front right high */ + VIRTIO_SND_CHMAP_TC, /* top center */ + VIRTIO_SND_CHMAP_TFL, /* top front left */ + VIRTIO_SND_CHMAP_TFR, /* top front right */ + VIRTIO_SND_CHMAP_TFC, /* top front center */ + VIRTIO_SND_CHMAP_TRL, /* top rear left */ + VIRTIO_SND_CHMAP_TRR, /* top rear right */ + VIRTIO_SND_CHMAP_TRC, /* top rear center */ + VIRTIO_SND_CHMAP_TFLC, /* top front left center */ + VIRTIO_SND_CHMAP_TFRC, /* top front right center */ + VIRTIO_SND_CHMAP_TSL, /* top side left */ + VIRTIO_SND_CHMAP_TSR, /* top side right */ + VIRTIO_SND_CHMAP_LLFE, /* left LFE */ + VIRTIO_SND_CHMAP_RLFE, /* right LFE */ + VIRTIO_SND_CHMAP_BC, /* bottom center */ + VIRTIO_SND_CHMAP_BLC, /* bottom left center */ + VIRTIO_SND_CHMAP_BRC /* bottom right center */ +}; + +/* maximum possible number of channels */ +#define VIRTIO_SND_CHMAP_MAX_SIZE 18 + +struct virtio_snd_chmap_info { + /* common header */ + struct virtio_snd_info hdr; + /* dataflow direction (VIRTIO_SND_D_XXX) */ + __u8 direction; + /* # of valid channel position values */ + __u8 channels; + /* channel position values (VIRTIO_SND_CHMAP_XXX) */ + __u8 positions[VIRTIO_SND_CHMAP_MAX_SIZE]; +}; + +#endif /* VIRTIO_SND_IF_H */ diff --git a/sound/Kconfig b/sound/Kconfig index 36785410fbe1..e56d96d2b11c 100644 --- a/sound/Kconfig +++ b/sound/Kconfig @@ -99,6 +99,8 @@ source "sound/synth/Kconfig"

source "sound/xen/Kconfig"

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

endif # !UML diff --git a/sound/Makefile b/sound/Makefile index 797ecdcd35e2..04ef04b1168f 100644 --- a/sound/Makefile +++ b/sound/Makefile @@ -5,7 +5,8 @@ obj-$(CONFIG_SOUND) += soundcore.o obj-$(CONFIG_DMASOUND) += oss/dmasound/ obj-$(CONFIG_SND) += core/ i2c/ drivers/ isa/ pci/ ppc/ arm/ sh/ synth/ usb/ \ - firewire/ sparc/ spi/ parisc/ pcmcia/ mips/ soc/ atmel/ hda/ x86/ xen/ + firewire/ sparc/ spi/ parisc/ pcmcia/ mips/ soc/ atmel/ hda/ x86/ xen/ \ + virtio/ obj-$(CONFIG_SND_AOA) += aoa/

# This one must be compilable even if sound is configured out diff --git a/sound/virtio/Kconfig b/sound/virtio/Kconfig new file mode 100644 index 000000000000..094cba24ee5b --- /dev/null +++ b/sound/virtio/Kconfig @@ -0,0 +1,10 @@ +# SPDX-License-Identifier: GPL-2.0+ +# Sound card driver for virtio + +config SND_VIRTIO + tristate "Virtio sound driver" + depends on VIRTIO + select SND_PCM + select SND_JACK + help + This is the virtual sound driver for virtio. Say Y or M. diff --git a/sound/virtio/Makefile b/sound/virtio/Makefile new file mode 100644 index 000000000000..8c87ebb9982b --- /dev/null +++ b/sound/virtio/Makefile @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0+ + +obj-$(CONFIG_SND_VIRTIO) += virtio_snd.o + +virtio_snd-objs := \ + virtio_card.o + diff --git a/sound/virtio/virtio_card.c b/sound/virtio/virtio_card.c new file mode 100644 index 000000000000..532d823fdf6f --- /dev/null +++ b/sound/virtio/virtio_card.c @@ -0,0 +1,415 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Sound card driver for virtio + * Copyright (C) 2020 OpenSynergy GmbH + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see http://www.gnu.org/licenses/. + */ +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/virtio_config.h> +#include <sound/initval.h> +#include <uapi/linux/virtio_ids.h> + +#include "virtio_card.h" + +static void virtsnd_remove(struct virtio_device *vdev); + +/** + * virtsnd_event_send() - Add an event to the event queue. + * @vqueue: Underlying event virtqueue. + * @event: Event. + * @notify: Indicates whether or not to send a notification to the device. + * @gfp: Kernel flags for memory allocation. + * + * Context: Any context. + * Return: 0 on success, -errno on failure. + */ +static int virtsnd_event_send(struct virtqueue *vqueue, + struct virtio_snd_event *event, bool notify, + gfp_t gfp) +{ + struct scatterlist sg; + struct scatterlist *psgs[1] = { &sg }; + int rc; + + /* reset event content */ + memset(event, 0, sizeof(*event)); + + sg_init_one(&sg, event, sizeof(*event)); + + rc = virtqueue_add_sgs(vqueue, psgs, 0, 1, event, gfp); + if (rc) + return rc; + + if (notify) + if (virtqueue_kick_prepare(vqueue)) + if (!virtqueue_notify(vqueue)) + return -EIO; + + return 0; +} + +/** + * virtsnd_event_notify_cb() - Dispatch all reported events from the event queue. + * @vqueue: Underlying event virtqueue. + * + * This callback function is called upon a vring interrupt request from the + * device. + * + * Context: Interrupt context. + */ +static void virtsnd_event_notify_cb(struct virtqueue *vqueue) +{ + struct virtio_snd *snd = vqueue->vdev->priv; + struct virtio_snd_queue *queue = virtsnd_event_queue(snd); + unsigned long flags; + + spin_lock_irqsave(&queue->lock, flags); + while (queue->vqueue) { + virtqueue_disable_cb(queue->vqueue); + + for (;;) { + struct virtio_snd_event *event; + u32 length; + + event = virtqueue_get_buf(queue->vqueue, &length); + if (!event) + break; + + virtsnd_event_send(queue->vqueue, event, true, + GFP_ATOMIC); + } + + if (unlikely(virtqueue_is_broken(queue->vqueue))) + break; + + if (virtqueue_enable_cb(queue->vqueue)) + break; + } + spin_unlock_irqrestore(&queue->lock, flags); +} + +/** + * virtsnd_find_vqs() - Enumerate and initialize all virtqueues. + * @snd: VirtIO sound device. + * + * After calling this function, the event queue is disabled. + * + * Context: Any context. + * Return: 0 on success, -errno on failure. + */ +static int virtsnd_find_vqs(struct virtio_snd *snd) +{ + struct virtio_device *vdev = snd->vdev; + vq_callback_t *callbacks[VIRTIO_SND_VQ_MAX] = { 0 }; + const char *names[VIRTIO_SND_VQ_MAX] = { + [VIRTIO_SND_VQ_CONTROL] = "virtsnd-ctl", + [VIRTIO_SND_VQ_EVENT] = "virtsnd-event", + [VIRTIO_SND_VQ_TX] = "virtsnd-tx", + [VIRTIO_SND_VQ_RX] = "virtsnd-rx" + }; + struct virtqueue *vqs[VIRTIO_SND_VQ_MAX] = { 0 }; + unsigned int i; + unsigned int n = 0; + int rc; + + callbacks[VIRTIO_SND_VQ_EVENT] = virtsnd_event_notify_cb; + + rc = virtio_find_vqs(vdev, VIRTIO_SND_VQ_MAX, vqs, callbacks, names, + NULL); + if (rc) { + dev_err(&vdev->dev, "failed to initialize virtqueues\n"); + return rc; + } + + for (i = 0; i < VIRTIO_SND_VQ_MAX; ++i) + snd->queues[i].vqueue = vqs[i]; + + /* Allocate events and populate the event queue */ + virtqueue_disable_cb(vqs[VIRTIO_SND_VQ_EVENT]); + + n = virtqueue_get_vring_size(vqs[VIRTIO_SND_VQ_EVENT]); + + snd->event_msgs = devm_kcalloc(&vdev->dev, n, sizeof(*snd->event_msgs), + GFP_KERNEL); + if (!snd->event_msgs) + return -ENOMEM; + + for (i = 0; i < n; ++i) { + rc = virtsnd_event_send(vqs[VIRTIO_SND_VQ_EVENT], + &snd->event_msgs[i], false, GFP_KERNEL); + if (rc) + return rc; + } + + return 0; +} + +/** + * virtsnd_enable_event_vq() - Enable the event virtqueue. + * @snd: VirtIO sound device. + * + * Context: Any context. + */ +static void virtsnd_enable_event_vq(struct virtio_snd *snd) +{ + struct virtio_snd_queue *queue = virtsnd_event_queue(snd); + + if (!virtqueue_enable_cb(queue->vqueue)) + virtsnd_event_notify_cb(queue->vqueue); +} + +/** + * virtsnd_disable_vqs() - Disable all virtqueues. + * @snd: VirtIO sound device. + * + * Also free all allocated events and control messages. + * + * Context: Any context. + */ +static void virtsnd_disable_vqs(struct virtio_snd *snd) +{ + struct virtio_device *vdev = snd->vdev; + unsigned int i; + unsigned long flags; + + for (i = 0; i < VIRTIO_SND_VQ_MAX; ++i) { + struct virtio_snd_queue *queue = &snd->queues[i]; + + spin_lock_irqsave(&queue->lock, flags); + /* Prohibit the use of the queue */ + if (queue->vqueue) + virtqueue_disable_cb(queue->vqueue); + queue->vqueue = NULL; + spin_unlock_irqrestore(&queue->lock, flags); + } + + if (snd->event_msgs) + devm_kfree(&vdev->dev, snd->event_msgs); + + snd->event_msgs = NULL; +} + +/** + * virtsnd_reset_fn() - Kernel worker's function to reset the device. + * @work: Reset device work. + * + * Context: Process context. + */ +static void virtsnd_reset_fn(struct work_struct *work) +{ + struct virtio_snd *snd = + container_of(work, struct virtio_snd, reset_work); + struct virtio_device *vdev = snd->vdev; + struct device *dev = &vdev->dev; + int rc; + + dev_info(dev, "sound device needs reset\n"); + + /* + * It seems that the only way to properly reset the device is to remove + * and re-create the ALSA sound card device. + * + * Also resetting the device involves a number of steps with setting the + * status bits described in the virtio specification. And the easiest + * way to get everything right is to use the virtio bus interface. + */ + rc = dev->bus->remove(dev); + if (rc) + dev_warn(dev, "bus->remove() failed: %d", rc); + + rc = dev->bus->probe(dev); + if (rc) + dev_err(dev, "bus->probe() failed: %d", rc); +} + +/** + * virtsnd_build_devs() - Read configuration and build ALSA devices. + * @snd: VirtIO sound device. + * + * Context: Any context that permits to sleep. + * Return: 0 on success, -errno on failure. + */ +static int virtsnd_build_devs(struct virtio_snd *snd) +{ + struct virtio_device *vdev = snd->vdev; + int rc; + + rc = snd_card_new(&vdev->dev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1, + THIS_MODULE, 0, &snd->card); + if (rc < 0) + return rc; + + snd->card->private_data = snd; + + strscpy(snd->card->id, "viosnd", sizeof(snd->card->id)); + strscpy(snd->card->driver, "virtio_snd", sizeof(snd->card->driver)); + strscpy(snd->card->shortname, "VIOSND", sizeof(snd->card->shortname)); + strscpy(snd->card->longname, "VirtIO Sound Card", + sizeof(snd->card->longname)); + + return snd_card_register(snd->card); +} + +/** + * virtsnd_validate() - Validate if the device can be started. + * @vdev: VirtIO parent device. + * + * Context: Any context. + * Return: 0 on success, -EINVAL on failure. + */ +static int virtsnd_validate(struct virtio_device *vdev) +{ + if (!vdev->config->get) { + dev_err(&vdev->dev, "configuration access disabled\n"); + return -EINVAL; + } + + if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) { + dev_err(&vdev->dev, + "device does not comply with spec version 1.x\n"); + return -EINVAL; + } + + return 0; +} + +/** + * virtsnd_probe() - Create and initialize the device. + * @vdev: VirtIO parent device. + * + * Context: Any context that permits to sleep. + * Return: 0 on success, -errno on failure. + */ +static int virtsnd_probe(struct virtio_device *vdev) +{ + struct virtio_snd *snd; + unsigned int i; + int rc; + + snd = devm_kzalloc(&vdev->dev, sizeof(*snd), GFP_KERNEL); + if (!snd) + return -ENOMEM; + + snd->vdev = vdev; + INIT_WORK(&snd->reset_work, virtsnd_reset_fn); + + vdev->priv = snd; + + for (i = 0; i < VIRTIO_SND_VQ_MAX; ++i) + spin_lock_init(&snd->queues[i].lock); + + rc = virtsnd_find_vqs(snd); + if (rc) + goto on_failure; + + virtio_device_ready(vdev); + + rc = virtsnd_build_devs(snd); + if (rc) + goto on_failure; + + virtsnd_enable_event_vq(snd); + +on_failure: + if (rc) + virtsnd_remove(vdev); + + return rc; +} + +/** + * virtsnd_remove() - Remove VirtIO and ALSA devices. + * @vdev: VirtIO parent device. + * + * Context: Any context that permits to sleep. + */ +static void virtsnd_remove(struct virtio_device *vdev) +{ + struct virtio_snd *snd = vdev->priv; + + if (!snd) + return; + + /* + * Make sure no one is accessing the virtqueues and sending synchronous + * requests to the device. This can happen if we got here because the + * device needs to be reset. + */ + virtsnd_disable_vqs(snd); + + if (snd->card) + snd_card_free(snd->card); + + vdev->config->reset(vdev); + vdev->config->del_vqs(vdev); + + devm_kfree(&vdev->dev, snd); + + vdev->priv = NULL; +} + +/** + * virtsnd_config_changed() - Handle configuration change notification. + * @vdev: VirtIO parent device. + * + * This callback function is called upon a configuration change interrupt + * request from the device. Currently only used to handle NEEDS_RESET device + * status. + * + * Context: Interrupt context. + */ +static void virtsnd_config_changed(struct virtio_device *vdev) +{ + struct virtio_snd *snd = vdev->priv; + unsigned int status = vdev->config->get_status(vdev); + + if (status & VIRTIO_CONFIG_S_NEEDS_RESET) + schedule_work(&snd->reset_work); + else + dev_warn(&vdev->dev, + "sound device configuration was changed\n"); +} + +static const struct virtio_device_id id_table[] = { + { VIRTIO_ID_SOUND, VIRTIO_DEV_ANY_ID }, + { 0 }, +}; + +static struct virtio_driver virtsnd_driver = { + .driver.name = KBUILD_MODNAME, + .driver.owner = THIS_MODULE, + .id_table = id_table, + .validate = virtsnd_validate, + .probe = virtsnd_probe, + .remove = virtsnd_remove, + .config_changed = virtsnd_config_changed, +}; + +static int __init init(void) +{ + return register_virtio_driver(&virtsnd_driver); +} +module_init(init); + +static void __exit fini(void) +{ + unregister_virtio_driver(&virtsnd_driver); +} +module_exit(fini); + +MODULE_DEVICE_TABLE(virtio, id_table); +MODULE_DESCRIPTION("Virtio sound card driver"); +MODULE_LICENSE("GPL"); diff --git a/sound/virtio/virtio_card.h b/sound/virtio/virtio_card.h new file mode 100644 index 000000000000..10084abaaf18 --- /dev/null +++ b/sound/virtio/virtio_card.h @@ -0,0 +1,76 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Sound card driver for virtio + * Copyright (C) 2020 OpenSynergy GmbH + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see http://www.gnu.org/licenses/. + */ +#ifndef VIRTIO_SND_CARD_H +#define VIRTIO_SND_CARD_H + +#include <linux/virtio.h> +#include <sound/core.h> +#include <uapi/linux/virtio_snd.h> + +/** + * struct virtio_snd_queue - Virtqueue wrapper structure. + * @lock: Used to synchronize access to a virtqueue. + * @vqueue: Underlying virtqueue. + */ +struct virtio_snd_queue { + spinlock_t lock; + struct virtqueue *vqueue; +}; + +/** + * struct virtio_snd - VirtIO sound card device. + * @vdev: Underlying virtio device. + * @queues: Virtqueue wrappers. + * @reset_work: Reset device work. + * @card: ALSA sound card. + * @event_msgs: Device events. + */ +struct virtio_snd { + struct virtio_device *vdev; + struct virtio_snd_queue queues[VIRTIO_SND_VQ_MAX]; + struct work_struct reset_work; + struct snd_card *card; + struct virtio_snd_event *event_msgs; +}; + +static inline struct virtio_snd_queue * +virtsnd_control_queue(struct virtio_snd *snd) +{ + return &snd->queues[VIRTIO_SND_VQ_CONTROL]; +} + +static inline struct virtio_snd_queue * +virtsnd_event_queue(struct virtio_snd *snd) +{ + return &snd->queues[VIRTIO_SND_VQ_EVENT]; +} + +static inline struct virtio_snd_queue * +virtsnd_tx_queue(struct virtio_snd *snd) +{ + return &snd->queues[VIRTIO_SND_VQ_TX]; +} + +static inline struct virtio_snd_queue * +virtsnd_rx_queue(struct virtio_snd *snd) +{ + return &snd->queues[VIRTIO_SND_VQ_RX]; +} + +#endif /* VIRTIO_SND_CARD_H */

The control queue can be used by different parts of the driver to send commands to the device. Control messages can be either synchronous or asynchronous. The lifetime of a message is controlled by a reference count.

Introduce a module parameter to set the message completion timeout: msg_timeout_ms [=1000]

Signed-off-by: Anton Yakovlev anton.yakovlev@opensynergy.com --- sound/virtio/Makefile | 3 +- sound/virtio/virtio_card.c | 20 +++ sound/virtio/virtio_card.h | 7 + sound/virtio/virtio_ctl_msg.c | 293 ++++++++++++++++++++++++++++++++++ sound/virtio/virtio_ctl_msg.h | 122 ++++++++++++++ 5 files changed, 444 insertions(+), 1 deletion(-) create mode 100644 sound/virtio/virtio_ctl_msg.c create mode 100644 sound/virtio/virtio_ctl_msg.h

diff --git a/sound/virtio/Makefile b/sound/virtio/Makefile index 8c87ebb9982b..dc551e637441 100644 --- a/sound/virtio/Makefile +++ b/sound/virtio/Makefile @@ -3,5 +3,6 @@ obj-$(CONFIG_SND_VIRTIO) += virtio_snd.o

virtio_snd-objs := \ - virtio_card.o + virtio_card.o \ + virtio_ctl_msg.o

diff --git a/sound/virtio/virtio_card.c b/sound/virtio/virtio_card.c index 532d823fdf6f..955eadc2d858 100644 --- a/sound/virtio/virtio_card.c +++ b/sound/virtio/virtio_card.c @@ -24,6 +24,10 @@

#include "virtio_card.h"

+int msg_timeout_ms = MSEC_PER_SEC; +module_param(msg_timeout_ms, int, 0644); +MODULE_PARM_DESC(msg_timeout_ms, "Message completion timeout in milliseconds"); + static void virtsnd_remove(struct virtio_device *vdev);

/** @@ -125,6 +129,7 @@ static int virtsnd_find_vqs(struct virtio_snd *snd) unsigned int n = 0; int rc;

+ callbacks[VIRTIO_SND_VQ_CONTROL] = virtsnd_ctl_notify_cb; callbacks[VIRTIO_SND_VQ_EVENT] = virtsnd_event_notify_cb;

rc = virtio_find_vqs(vdev, VIRTIO_SND_VQ_MAX, vqs, callbacks, names, @@ -193,6 +198,15 @@ static void virtsnd_disable_vqs(struct virtio_snd *snd) if (queue->vqueue) virtqueue_disable_cb(queue->vqueue); queue->vqueue = NULL; + /* Cancel all pending requests for the control queue */ + if (i == VIRTIO_SND_VQ_CONTROL) { + struct virtio_snd_msg *msg; + struct virtio_snd_msg *next; + + list_for_each_entry_safe(msg, next, &snd->ctl_msgs, + list) + virtsnd_ctl_msg_complete(snd, msg); + } spin_unlock_irqrestore(&queue->lock, flags); }

@@ -283,6 +297,11 @@ static int virtsnd_validate(struct virtio_device *vdev) return -EINVAL; }

+ if (!msg_timeout_ms) { + dev_err(&vdev->dev, "msg_timeout_ms value cannot be zero\n"); + return -EINVAL; + } + return 0; }

@@ -305,6 +324,7 @@ static int virtsnd_probe(struct virtio_device *vdev)

snd->vdev = vdev; INIT_WORK(&snd->reset_work, virtsnd_reset_fn); + INIT_LIST_HEAD(&snd->ctl_msgs);

vdev->priv = snd;

diff --git a/sound/virtio/virtio_card.h b/sound/virtio/virtio_card.h index 10084abaaf18..37b734a92134 100644 --- a/sound/virtio/virtio_card.h +++ b/sound/virtio/virtio_card.h @@ -23,6 +23,8 @@ #include <sound/core.h> #include <uapi/linux/virtio_snd.h>

+#include "virtio_ctl_msg.h" + /** * struct virtio_snd_queue - Virtqueue wrapper structure. * @lock: Used to synchronize access to a virtqueue. @@ -39,6 +41,7 @@ struct virtio_snd_queue { * @queues: Virtqueue wrappers. * @reset_work: Reset device work. * @card: ALSA sound card. + * @ctl_msgs: Pending control request list. * @event_msgs: Device events. */ struct virtio_snd { @@ -46,9 +49,13 @@ struct virtio_snd { struct virtio_snd_queue queues[VIRTIO_SND_VQ_MAX]; struct work_struct reset_work; struct snd_card *card; + struct list_head ctl_msgs; struct virtio_snd_event *event_msgs; };

+/* Message completion timeout in milliseconds (module parameter). */ +extern int msg_timeout_ms; + static inline struct virtio_snd_queue * virtsnd_control_queue(struct virtio_snd *snd) { diff --git a/sound/virtio/virtio_ctl_msg.c b/sound/virtio/virtio_ctl_msg.c new file mode 100644 index 000000000000..c1701756bc32 --- /dev/null +++ b/sound/virtio/virtio_ctl_msg.c @@ -0,0 +1,293 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Sound card driver for virtio + * Copyright (C) 2020 OpenSynergy GmbH + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see http://www.gnu.org/licenses/. + */ +#include <linux/moduleparam.h> +#include <linux/virtio_config.h> + +#include "virtio_card.h" +#include "virtio_ctl_msg.h" + +/** + * virtsnd_ctl_msg_alloc_ext() - Allocate and initialize a control message. + * @vdev: VirtIO parent device. + * @request_size: Size of request header (pointed to by sg_request field). + * @response_size: Size of response header (pointed to by sg_response field). + * @sgs: Additional data to attach to the message (may be NULL). + * @out_sgs: Number of scattergather elements to attach to the request header. + * @in_sgs: Number of scattergather elements to attach to the response header. + * @gfp: Kernel flags for memory allocation. + * + * The message will be automatically freed when the ref_count value is 0. + * + * Context: Any context. May sleep if @gfp flags permit. + * Return: Allocated message on success, ERR_PTR(-errno) on failure. + */ +struct virtio_snd_msg *virtsnd_ctl_msg_alloc_ext(struct virtio_device *vdev, + size_t request_size, + size_t response_size, + struct scatterlist *sgs, + unsigned int out_sgs, + unsigned int in_sgs, gfp_t gfp) +{ + struct virtio_snd_msg *msg; + size_t msg_size = + sizeof(*msg) + (1 + out_sgs + 1 + in_sgs) * sizeof(*msg->sgs); + unsigned int i; + + msg = devm_kzalloc(&vdev->dev, msg_size + request_size + response_size, + gfp); + if (!msg) + return ERR_PTR(-ENOMEM); + + sg_init_one(&msg->sg_request, (u8 *)msg + msg_size, request_size); + sg_init_one(&msg->sg_response, (u8 *)msg + msg_size + request_size, + response_size); + + INIT_LIST_HEAD(&msg->list); + init_completion(&msg->notify); + atomic_set(&msg->ref_count, 1); + + msg->sgs[msg->out_sgs++] = &msg->sg_request; + if (sgs) + for (i = 0; i < out_sgs; ++i) + msg->sgs[msg->out_sgs++] = &sgs[i]; + + msg->sgs[msg->out_sgs + msg->in_sgs++] = &msg->sg_response; + if (sgs) + for (i = out_sgs; i < out_sgs + in_sgs; ++i) + msg->sgs[msg->out_sgs + msg->in_sgs++] = &sgs[i]; + + return msg; +} + +/** + * virtsnd_ctl_msg_send() - Send an (asynchronous) control message. + * @snd: VirtIO sound device. + * @msg: Control message. + * + * If a message is failed to be enqueued, it will be deleted. If message content + * is still needed, the caller must additionally to virtsnd_ctl_msg_ref/unref() + * it. + * + * Context: Any context. Takes and releases the control queue spinlock. + * Return: 0 on success, -errno on failure. + */ +int virtsnd_ctl_msg_send(struct virtio_snd *snd, struct virtio_snd_msg *msg) +{ + struct virtio_device *vdev = snd->vdev; + struct virtio_snd_queue *queue = virtsnd_control_queue(snd); + struct virtio_snd_hdr *response = sg_virt(&msg->sg_response); + bool notify = false; + unsigned long flags; + int rc = -EIO; + + /* Set the default status in case the message was not sent or was + * canceled. + */ + response->code = cpu_to_virtio32(vdev, VIRTIO_SND_S_IO_ERR); + + spin_lock_irqsave(&queue->lock, flags); + if (queue->vqueue) { + rc = virtqueue_add_sgs(queue->vqueue, msg->sgs, msg->out_sgs, + msg->in_sgs, msg, GFP_ATOMIC); + if (!rc) { + notify = virtqueue_kick_prepare(queue->vqueue); + list_add_tail(&msg->list, &snd->ctl_msgs); + } + } + spin_unlock_irqrestore(&queue->lock, flags); + + if (!rc) { + if (!notify || virtqueue_notify(queue->vqueue)) + return 0; + + spin_lock_irqsave(&queue->lock, flags); + list_del(&msg->list); + spin_unlock_irqrestore(&queue->lock, flags); + } + + virtsnd_ctl_msg_unref(snd->vdev, msg); + + return -EIO; +} + +/** + * virtsnd_ctl_msg_send_sync() - Send a (synchronous) control message. + * @snd: VirtIO sound device. + * @msg: Control message. + * + * After returning from this function, the message will be deleted. If message + * content is still needed, the caller must additionally to + * virtsnd_ctl_msg_ref/unref() it. + * + * The msg_timeout_ms module parameter defines the message completion timeout. + * If the message is not completed within this time, the function will return an + * error. + * + * Context: Any context. Takes and releases the control queue spinlock. + * Return: 0 on success, -errno on failure. + * + * The return value is a message status code (VIRTIO_SND_S_XXX) converted to an + * appropriate -errno value. + */ +int virtsnd_ctl_msg_send_sync(struct virtio_snd *snd, + struct virtio_snd_msg *msg) +{ + struct virtio_device *vdev = snd->vdev; + unsigned int js = msecs_to_jiffies(msg_timeout_ms); + struct virtio_snd_hdr *response; + int rc; + + virtsnd_ctl_msg_ref(vdev, msg); + + rc = virtsnd_ctl_msg_send(snd, msg); + if (rc) + goto on_failure; + + rc = wait_for_completion_interruptible_timeout(&msg->notify, js); + if (rc <= 0) { + if (!rc) { + struct virtio_snd_hdr *request = + sg_virt(&msg->sg_request); + + dev_err(&vdev->dev, + "control message (0x%08x) timeout\n", + le32_to_cpu(request->code)); + rc = -EIO; + } + + goto on_failure; + } + + response = sg_virt(&msg->sg_response); + + switch (le32_to_cpu(response->code)) { + case VIRTIO_SND_S_OK: + rc = 0; + break; + case VIRTIO_SND_S_BAD_MSG: + rc = -EINVAL; + break; + case VIRTIO_SND_S_NOT_SUPP: + rc = -EOPNOTSUPP; + break; + case VIRTIO_SND_S_IO_ERR: + rc = -EIO; + break; + default: + rc = -EPERM; + break; + } + +on_failure: + virtsnd_ctl_msg_unref(vdev, msg); + + return rc; +} + +/** + * virtsnd_ctl_msg_complete() - Complete a control message. + * @snd: VirtIO sound device. + * @msg: Control message. + * + * Context: Any context. + */ +void virtsnd_ctl_msg_complete(struct virtio_snd *snd, + struct virtio_snd_msg *msg) +{ + list_del(&msg->list); + complete(&msg->notify); + + virtsnd_ctl_msg_unref(snd->vdev, msg); +} + +/** + * virtsnd_ctl_query_info() - Query the item configuration from the device. + * @snd: VirtIO sound device. + * @command: Control request code (VIRTIO_SND_R_XXX_INFO). + * @start_id: Item start identifier. + * @count: Item count to query. + * @size: Item information size in bytes. + * @info: Buffer for storing item information. + * + * Context: Any context that permits to sleep. + * Return: 0 on success, -errno on failure. + */ +int virtsnd_ctl_query_info(struct virtio_snd *snd, int command, int start_id, + int count, size_t size, void *info) +{ + struct virtio_device *vdev = snd->vdev; + struct virtio_snd_msg *msg; + struct virtio_snd_query_info *query; + struct scatterlist sg; + + sg_init_one(&sg, info, count * size); + + msg = virtsnd_ctl_msg_alloc_ext(vdev, sizeof(*query), + sizeof(struct virtio_snd_hdr), &sg, 0, + 1, GFP_KERNEL); + if (IS_ERR(msg)) + return PTR_ERR(msg); + + query = sg_virt(&msg->sg_request); + query->hdr.code = cpu_to_virtio32(vdev, command); + query->start_id = cpu_to_virtio32(vdev, start_id); + query->count = cpu_to_virtio32(vdev, count); + query->size = cpu_to_virtio32(vdev, size); + + return virtsnd_ctl_msg_send_sync(snd, msg); +} + +/** + * virtsnd_ctl_notify_cb() - Process all completed control messages. + * @vqueue: Underlying control virtqueue. + * + * This callback function is called upon a vring interrupt request from the + * device. + * + * Context: Interrupt context. Takes and releases the control queue spinlock. + */ +void virtsnd_ctl_notify_cb(struct virtqueue *vqueue) +{ + struct virtio_snd *snd = vqueue->vdev->priv; + struct virtio_snd_queue *queue = virtsnd_control_queue(snd); + unsigned long flags; + + spin_lock_irqsave(&queue->lock, flags); + while (queue->vqueue) { + virtqueue_disable_cb(queue->vqueue); + + for (;;) { + struct virtio_snd_msg *msg; + u32 length; + + msg = virtqueue_get_buf(queue->vqueue, &length); + if (!msg) + break; + + virtsnd_ctl_msg_complete(snd, msg); + } + + if (unlikely(virtqueue_is_broken(queue->vqueue))) + break; + + if (virtqueue_enable_cb(queue->vqueue)) + break; + } + spin_unlock_irqrestore(&queue->lock, flags); +} diff --git a/sound/virtio/virtio_ctl_msg.h b/sound/virtio/virtio_ctl_msg.h new file mode 100644 index 000000000000..0f8de8f2fd2d --- /dev/null +++ b/sound/virtio/virtio_ctl_msg.h @@ -0,0 +1,122 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Sound card driver for virtio + * Copyright (C) 2020 OpenSynergy GmbH + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see http://www.gnu.org/licenses/. + */ +#ifndef VIRTIO_SND_MSG_H +#define VIRTIO_SND_MSG_H + +#include <linux/atomic.h> +#include <linux/virtio.h> + +struct virtio_snd; + +/** + * struct virtio_snd_msg - Control message. + * @sg_request: Scattergather element containing a device request (header). + * @sg_response: Scattergather element containing a device response (status). + * @list: Pending message list entry. + * @notify: Request completed notification. + * @ref_count: Reference count used to manage a message lifetime. + * @out_sgs: Number of read-only sg elements in the sgs array. + * @in_sgs: Number of write-only sg elements in the sgs array. + * @sgs: Array of sg elements to add to the control virtqueue. + */ +struct virtio_snd_msg { +/* public: */ + struct scatterlist sg_request; + struct scatterlist sg_response; +/* private: internal use only */ + struct list_head list; + struct completion notify; + atomic_t ref_count; + unsigned int out_sgs; + unsigned int in_sgs; + struct scatterlist *sgs[0]; +}; + +/** + * virtsnd_ctl_msg_ref() - Increment reference counter for the message. + * @vdev: VirtIO parent device. + * @msg: Control message. + * + * Context: Any context. + */ +static inline void virtsnd_ctl_msg_ref(struct virtio_device *vdev, + struct virtio_snd_msg *msg) +{ + atomic_inc(&msg->ref_count); +} + +/** + * virtsnd_ctl_msg_unref() - Decrement reference counter for the message. + * @vdev: VirtIO parent device. + * @msg: Control message. + * + * The message will be freed when the ref_count value is 0. + * + * Context: Any context. + */ +static inline void virtsnd_ctl_msg_unref(struct virtio_device *vdev, + struct virtio_snd_msg *msg) +{ + if (!atomic_dec_return(&msg->ref_count)) + devm_kfree(&vdev->dev, msg); +} + +struct virtio_snd_msg *virtsnd_ctl_msg_alloc_ext(struct virtio_device *vdev, + size_t request_size, + size_t response_size, + struct scatterlist *sgs, + unsigned int out_sgs, + unsigned int in_sgs, + gfp_t gfp); + +/** + * virtsnd_ctl_msg_alloc() - Simplified control message allocation. + * @vdev: VirtIO parent device. + * @request_size: Size of request header (pointed to by sg_request field). + * @response_size: Size of response header (pointed to by sg_response field). + * @gfp: Kernel flags for memory allocation. + * + * The message will be automatically freed when the ref_count value is 0. + * + * Context: Any context. May sleep if @gfp flags permit. + * Return: Allocated message on success, ERR_PTR(-errno) on failure. + */ +static inline +struct virtio_snd_msg *virtsnd_ctl_msg_alloc(struct virtio_device *vdev, + size_t request_size, + size_t response_size, gfp_t gfp) +{ + return virtsnd_ctl_msg_alloc_ext(vdev, request_size, response_size, + NULL, 0, 0, gfp); +} + +int virtsnd_ctl_msg_send(struct virtio_snd *snd, struct virtio_snd_msg *msg); + +int virtsnd_ctl_msg_send_sync(struct virtio_snd *snd, + struct virtio_snd_msg *msg); + +void virtsnd_ctl_msg_complete(struct virtio_snd *snd, + struct virtio_snd_msg *msg); + +int virtsnd_ctl_query_info(struct virtio_snd *snd, int command, int start_id, + int count, size_t size, void *info); + +void virtsnd_ctl_notify_cb(struct virtqueue *vqueue); + +#endif /* VIRTIO_SND_MSG_H */

The driver implements a message-based transport for I/O substream operations. Before the start of the substream, the hardware buffer is sliced into I/O messages, the number of which is equal to the current number of periods. The size of each message is equal to the current size of one period.

I/O messages are organized in an ordered queue. The completion of the I/O message indicates an elapsed period (the only exception is the end of the stream for the capture substream). Upon completion, the message is automatically re-added to the end of the queue.

Signed-off-by: Anton Yakovlev anton.yakovlev@opensynergy.com --- sound/virtio/Makefile | 3 +- sound/virtio/virtio_card.c | 10 ++ sound/virtio/virtio_card.h | 9 + sound/virtio/virtio_pcm.c | 3 + sound/virtio/virtio_pcm.h | 31 ++++ sound/virtio/virtio_pcm_msg.c | 325 ++++++++++++++++++++++++++++++++++ 6 files changed, 380 insertions(+), 1 deletion(-) create mode 100644 sound/virtio/virtio_pcm_msg.c

diff --git a/sound/virtio/Makefile b/sound/virtio/Makefile index 69162a545a41..626af3cc3ed7 100644 --- a/sound/virtio/Makefile +++ b/sound/virtio/Makefile @@ -5,5 +5,6 @@ obj-$(CONFIG_SND_VIRTIO) += virtio_snd.o virtio_snd-objs := \ virtio_card.o \ virtio_ctl_msg.o \ - virtio_pcm.o + virtio_pcm.o \ + virtio_pcm_msg.o

diff --git a/sound/virtio/virtio_card.c b/sound/virtio/virtio_card.c index 39fe13b43dd1..11d025ee77c2 100644 --- a/sound/virtio/virtio_card.c +++ b/sound/virtio/virtio_card.c @@ -143,6 +143,12 @@ static int virtsnd_find_vqs(struct virtio_snd *snd) callbacks[VIRTIO_SND_VQ_CONTROL] = virtsnd_ctl_notify_cb; callbacks[VIRTIO_SND_VQ_EVENT] = virtsnd_event_notify_cb;

+ virtio_cread(vdev, struct virtio_snd_config, streams, &n); + if (n) { + callbacks[VIRTIO_SND_VQ_TX] = virtsnd_pcm_tx_notify_cb; + callbacks[VIRTIO_SND_VQ_RX] = virtsnd_pcm_rx_notify_cb; + } + rc = virtio_find_vqs(vdev, VIRTIO_SND_VQ_MAX, vqs, callbacks, names, NULL); if (rc) { @@ -177,6 +183,10 @@ static int virtsnd_find_vqs(struct virtio_snd *snd) * virtsnd_enable_event_vq() - Enable the event virtqueue. * @snd: VirtIO sound device. * + * The tx queue is enabled only if the device supports playback stream(s). + * + * The rx queue is enabled only if the device supports capture stream(s). + * * Context: Any context. */ static void virtsnd_enable_event_vq(struct virtio_snd *snd) diff --git a/sound/virtio/virtio_card.h b/sound/virtio/virtio_card.h index be6651a6aaf8..b11c09984882 100644 --- a/sound/virtio/virtio_card.h +++ b/sound/virtio/virtio_card.h @@ -89,4 +89,13 @@ virtsnd_rx_queue(struct virtio_snd *snd) return &snd->queues[VIRTIO_SND_VQ_RX]; }

+static inline struct virtio_snd_queue * +virtsnd_pcm_queue(struct virtio_pcm_substream *substream) +{ + if (substream->direction == SNDRV_PCM_STREAM_PLAYBACK) + return virtsnd_tx_queue(substream->snd); + else + return virtsnd_rx_queue(substream->snd); +} + #endif /* VIRTIO_SND_CARD_H */ diff --git a/sound/virtio/virtio_pcm.c b/sound/virtio/virtio_pcm.c index 036990b7b78a..1ab50dcc88c8 100644 --- a/sound/virtio/virtio_pcm.c +++ b/sound/virtio/virtio_pcm.c @@ -376,6 +376,7 @@ int virtsnd_pcm_parse_cfg(struct virtio_snd *snd)

substream->snd = snd; substream->sid = i; + init_waitqueue_head(&substream->msg_empty);

rc = virtsnd_pcm_build_hw(substream, &info[i]); if (rc) @@ -530,6 +531,8 @@ void virtsnd_pcm_event(struct virtio_snd *snd, struct virtio_snd_event *event) break; } case VIRTIO_SND_EVT_PCM_XRUN: { + if (atomic_read(&substream->xfer_enabled)) + atomic_set(&substream->xfer_xrun, 1); break; } } diff --git a/sound/virtio/virtio_pcm.h b/sound/virtio/virtio_pcm.h index 73fb4d9dc524..d011b7e1d18d 100644 --- a/sound/virtio/virtio_pcm.h +++ b/sound/virtio/virtio_pcm.h @@ -24,6 +24,7 @@ #include <sound/pcm.h>

struct virtio_pcm; +struct virtio_pcm_msg;

/** * struct virtio_pcm_substream - VirtIO PCM substream. @@ -34,6 +35,16 @@ struct virtio_pcm; * @features: Stream VirtIO feature bit map (1 << VIRTIO_SND_PCM_F_XXX). * @substream: Kernel ALSA substream. * @hw: Kernel ALSA substream hardware descriptor. + * @frame_bytes: Current frame size in bytes. + * @period_size: Current period size in frames. + * @buffer_size: Current buffer size in frames. + * @hw_ptr: Substream hardware pointer value in frames [0 ... buffer_size). + * @xfer_enabled: Data transfer state (0 - off, 1 - on). + * @xfer_xrun: Data underflow/overflow state (0 - no xrun, 1 - xrun). + * @msgs: I/O messages. + * @msg_last_enqueued: Index of the last I/O message added to the virtqueue. + * @msg_count: Number of pending I/O messages in the virtqueue. + * @msg_empty: Notify when msg_count is zero. */ struct virtio_pcm_substream { struct virtio_snd *snd; @@ -43,6 +54,16 @@ struct virtio_pcm_substream { u32 features; struct snd_pcm_substream *substream; struct snd_pcm_hardware hw; + unsigned int frame_bytes; + snd_pcm_uframes_t period_size; + snd_pcm_uframes_t buffer_size; + atomic_t hw_ptr; + atomic_t xfer_enabled; + atomic_t xfer_xrun; + struct virtio_pcm_msg *msgs; + int msg_last_enqueued; + atomic_t msg_count; + wait_queue_head_t msg_empty; };

/** @@ -86,4 +107,14 @@ struct virtio_pcm *virtsnd_pcm_find(struct virtio_snd *snd, unsigned int nid); struct virtio_pcm *virtsnd_pcm_find_or_create(struct virtio_snd *snd, unsigned int nid);

+struct virtio_snd_msg * +virtsnd_pcm_ctl_msg_alloc(struct virtio_pcm_substream *substream, + unsigned int command, gfp_t gfp); + +int virtsnd_pcm_msg_alloc(struct virtio_pcm_substream *substream, + unsigned int nmsg, u8 *dma_area, + unsigned int period_bytes); + +int virtsnd_pcm_msg_send(struct virtio_pcm_substream *substream); + #endif /* VIRTIO_SND_PCM_H */ diff --git a/sound/virtio/virtio_pcm_msg.c b/sound/virtio/virtio_pcm_msg.c new file mode 100644 index 000000000000..d524e7cbe43f --- /dev/null +++ b/sound/virtio/virtio_pcm_msg.c @@ -0,0 +1,325 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Sound card driver for virtio + * Copyright (C) 2020 OpenSynergy GmbH + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see http://www.gnu.org/licenses/. + */ +#include <sound/pcm_params.h> + +#include "virtio_card.h" + +/** + * enum pcm_msg_sg_index - Scatter-gather element indexes for an I/O message. + * @PCM_MSG_SG_XFER: Element containing a virtio_snd_pcm_xfer structure. + * @PCM_MSG_SG_DATA: Element containing a data buffer. + * @PCM_MSG_SG_STATUS: Element containing a virtio_snd_pcm_status structure. + * @PCM_MSG_SG_MAX: The maximum number of elements in the scatter-gather table. + * + * These values are used as the index of the payload scatter-gather table. + */ +enum pcm_msg_sg_index { + PCM_MSG_SG_XFER = 0, + PCM_MSG_SG_DATA, + PCM_MSG_SG_STATUS, + PCM_MSG_SG_MAX +}; + +/** + * struct virtio_pcm_msg - VirtIO I/O message. + * @substream: VirtIO PCM substream. + * @xfer: Request header payload. + * @status: Response header payload. + * @sgs: Payload scatter-gather table. + */ +struct virtio_pcm_msg { + struct virtio_pcm_substream *substream; + struct virtio_snd_pcm_xfer xfer; + struct virtio_snd_pcm_status status; + struct scatterlist sgs[PCM_MSG_SG_MAX]; +}; + +/** + * virtsnd_pcm_msg_alloc() - Allocate I/O messages. + * @substream: VirtIO PCM substream. + * @nmsg: Number of messages (equal to the number of periods). + * @dma_area: Pointer to used audio buffer. + * @period_bytes: Period (message payload) size. + * + * The function slices the buffer into nmsg parts (each with the size of + * period_bytes), and creates nmsg corresponding I/O messages. + * + * Context: Any context that permits to sleep. + * Return: 0 on success, -ENOMEM on failure. + */ +int virtsnd_pcm_msg_alloc(struct virtio_pcm_substream *substream, + unsigned int nmsg, u8 *dma_area, + unsigned int period_bytes) +{ + struct virtio_device *vdev = substream->snd->vdev; + unsigned int i; + + if (substream->msgs) + devm_kfree(&vdev->dev, substream->msgs); + + substream->msgs = devm_kcalloc(&vdev->dev, nmsg, + sizeof(*substream->msgs), GFP_KERNEL); + if (!substream->msgs) + return -ENOMEM; + + for (i = 0; i < nmsg; ++i) { + struct virtio_pcm_msg *msg = &substream->msgs[i]; + + msg->substream = substream; + + sg_init_table(msg->sgs, PCM_MSG_SG_MAX); + sg_init_one(&msg->sgs[PCM_MSG_SG_XFER], &msg->xfer, + sizeof(msg->xfer)); + sg_init_one(&msg->sgs[PCM_MSG_SG_DATA], + dma_area + period_bytes * i, period_bytes); + sg_init_one(&msg->sgs[PCM_MSG_SG_STATUS], &msg->status, + sizeof(msg->status)); + } + + return 0; +} + +/** + * virtsnd_pcm_msg_send() - Send asynchronous I/O messages. + * @substream: VirtIO PCM substream. + * + * All messages are organized in an ordered circular list. Each time the + * function is called, all currently non-enqueued messages are added to the + * virtqueue. For this, the function keeps track of two values: + * + * msg_last_enqueued = index of the last enqueued message, + * msg_count = # of pending messages in the virtqueue. + * + * Context: Any context. + * Return: 0 on success, -EIO on failure. + */ +int virtsnd_pcm_msg_send(struct virtio_pcm_substream *substream) +{ + struct snd_pcm_runtime *runtime = substream->substream->runtime; + struct virtio_snd *snd = substream->snd; + struct virtio_device *vdev = snd->vdev; + struct virtqueue *vqueue = virtsnd_pcm_queue(substream)->vqueue; + int i; + int n; + bool notify = false; + + if (!vqueue) + return -EIO; + + i = (substream->msg_last_enqueued + 1) % runtime->periods; + n = runtime->periods - atomic_read(&substream->msg_count); + + for (; n; --n, i = (i + 1) % runtime->periods) { + struct virtio_pcm_msg *msg = &substream->msgs[i]; + struct scatterlist *psgs[PCM_MSG_SG_MAX] = { + [PCM_MSG_SG_XFER] = &msg->sgs[PCM_MSG_SG_XFER], + [PCM_MSG_SG_DATA] = &msg->sgs[PCM_MSG_SG_DATA], + [PCM_MSG_SG_STATUS] = &msg->sgs[PCM_MSG_SG_STATUS] + }; + int rc; + + msg->xfer.stream_id = cpu_to_virtio32(vdev, substream->sid); + memset(&msg->status, 0, sizeof(msg->status)); + + atomic_inc(&substream->msg_count); + + if (substream->direction == SNDRV_PCM_STREAM_PLAYBACK) + rc = virtqueue_add_sgs(vqueue, psgs, 2, 1, msg, + GFP_ATOMIC); + else + rc = virtqueue_add_sgs(vqueue, psgs, 1, 2, msg, + GFP_ATOMIC); + + if (rc) { + atomic_dec(&substream->msg_count); + return -EIO; + } + + substream->msg_last_enqueued = i; + } + + if (!(substream->features & (1U << VIRTIO_SND_PCM_F_MSG_POLLING))) + notify = virtqueue_kick_prepare(vqueue); + + if (notify) + if (!virtqueue_notify(vqueue)) + return -EIO; + + return 0; +} + +/** + * virtsnd_pcm_msg_complete() - Complete an I/O message. + * @msg: I/O message. + * @size: Number of bytes written. + * + * Completion of the message means the elapsed period. + * + * The interrupt handler modifies three fields of the substream structure + * (hw_ptr, xfer_xrun, msg_count) that are used in operator functions. These + * values are atomic to avoid frequent interlocks with the interrupt handler. + * This becomes especially important in the case of multiple running substreams + * that share both the virtqueue and interrupt handler. + * + * Context: Interrupt context. + */ +static void virtsnd_pcm_msg_complete(struct virtio_pcm_msg *msg, size_t size) +{ + struct virtio_pcm_substream *substream = msg->substream; + snd_pcm_uframes_t hw_ptr; + unsigned int msg_count; + + /* + * hw_ptr always indicates the buffer position of the first I/O message + * in the virtqueue. Therefore, on each completion of an I/O message, + * the hw_ptr value is unconditionally advanced. + */ + hw_ptr = (snd_pcm_uframes_t)atomic_read(&substream->hw_ptr); + + /* + * If the capture substream returned an incorrect status, then just + * increase the hw_ptr by the period size. + */ + if (substream->direction == SNDRV_PCM_STREAM_PLAYBACK || + size <= sizeof(msg->status)) { + hw_ptr += substream->period_size; + } else { + size -= sizeof(msg->status); + hw_ptr += size / substream->frame_bytes; + } + + atomic_set(&substream->hw_ptr, (u32)(hw_ptr % substream->buffer_size)); + atomic_set(&substream->xfer_xrun, 0); + + msg_count = atomic_dec_return(&substream->msg_count); + + if (atomic_read(&substream->xfer_enabled)) { + struct snd_pcm_runtime *runtime = substream->substream->runtime; + + runtime->delay = + bytes_to_frames(runtime, + le32_to_cpu(msg->status.latency_bytes)); + + snd_pcm_period_elapsed(substream->substream); + + virtsnd_pcm_msg_send(substream); + } else if (!msg_count) { + wake_up_all(&substream->msg_empty); + } +} + +/** + * virtsnd_pcm_notify_cb() - Process all completed I/O messages. + * @vqueue: Underlying tx/rx virtqueue. + * + * If transmission is allowed, then each completed message is immediately placed + * back at the end of the queue. + * + * Context: Interrupt context. Takes and releases the tx/rx queue spinlock. + */ +static inline void virtsnd_pcm_notify_cb(struct virtio_snd_queue *queue) +{ + unsigned long flags; + + spin_lock_irqsave(&queue->lock, flags); + while (queue->vqueue) { + virtqueue_disable_cb(queue->vqueue); + + for (;;) { + struct virtio_pcm_msg *msg; + u32 length; + + msg = virtqueue_get_buf(queue->vqueue, &length); + if (!msg) + break; + + virtsnd_pcm_msg_complete(msg, length); + } + + if (unlikely(virtqueue_is_broken(queue->vqueue))) + break; + + if (virtqueue_enable_cb(queue->vqueue)) + break; + } + spin_unlock_irqrestore(&queue->lock, flags); +} + +/** + * virtsnd_pcm_tx_notify_cb() - Process all completed TX messages. + * @vqueue: Underlying tx virtqueue. + * + * Context: Interrupt context. + */ +void virtsnd_pcm_tx_notify_cb(struct virtqueue *vqueue) +{ + struct virtio_snd *snd = vqueue->vdev->priv; + + virtsnd_pcm_notify_cb(virtsnd_tx_queue(snd)); +} + +/** + * virtsnd_pcm_rx_notify_cb() - Process all completed RX messages. + * @vqueue: Underlying rx virtqueue. + * + * Context: Interrupt context. + */ +void virtsnd_pcm_rx_notify_cb(struct virtqueue *vqueue) +{ + struct virtio_snd *snd = vqueue->vdev->priv; + + virtsnd_pcm_notify_cb(virtsnd_rx_queue(snd)); +} + +/** + * virtsnd_pcm_ctl_msg_alloc() - Allocate and initialize the PCM device control + * message for the specified substream. + * @substream: VirtIO PCM substream. + * @command: Control request code (VIRTIO_SND_R_PCM_XXX). + * @gfp: Kernel flags for memory allocation. + * + * Context: Any context. May sleep if @gfp flags permit. + * Return: Allocated message on success, ERR_PTR(-errno) on failure. + */ +struct virtio_snd_msg * +virtsnd_pcm_ctl_msg_alloc(struct virtio_pcm_substream *substream, + unsigned int command, gfp_t gfp) +{ + struct virtio_device *vdev = substream->snd->vdev; + size_t request_size = sizeof(struct virtio_snd_pcm_hdr); + size_t response_size = sizeof(struct virtio_snd_hdr); + struct virtio_snd_msg *msg; + + switch (command) { + case VIRTIO_SND_R_PCM_SET_PARAMS: { + request_size = sizeof(struct virtio_snd_pcm_set_params); + break; + } + } + + msg = virtsnd_ctl_msg_alloc(vdev, request_size, response_size, gfp); + if (!IS_ERR(msg)) { + struct virtio_snd_pcm_hdr *hdr = sg_virt(&msg->sg_request); + + hdr->hdr.code = cpu_to_virtio32(vdev, command); + hdr->stream_id = cpu_to_virtio32(vdev, substream->sid); + } + + return msg; +}