From patchwork Mon Oct 23 15:06:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matias Ezequiel Vara Larsen X-Patchwork-Id: 737582 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D53ABC07545 for ; Tue, 24 Oct 2023 08:48:29 +0000 (UTC) Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 95D7D86E; Tue, 24 Oct 2023 10:47:37 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 95D7D86E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1698137307; bh=uSJlIzNFJrZrtbejN9uximHiLF0JXHM5sHYHCpZl5/M=; h=Date:From:To:Cc:Subject:List-Id:List-Archive:List-Help:List-Owner: List-Post:List-Subscribe:List-Unsubscribe:From; b=ct73Vf36WArQfnJdOtYW+f99qEp241US/+lTQmEQGhoOG07D3Ii16NiiEsBQMZTjd h3bWMyY2tjmBgTtOtCYtvBkf538cDSB5U1pOMghNoy5Mb2G9muZK7ioZ+/l0Jb7+Sw MnIWk+6eaCTzw1vDdg8vvTJ1vymqlRVFQmaojvyc= Received: by alsa1.perex.cz (Postfix, from userid 50401) id DFA5CF80165; Tue, 24 Oct 2023 10:47:08 +0200 (CEST) Received: from mailman-core.alsa-project.org (mailman-core.alsa-project.org [10.254.200.10]) by alsa1.perex.cz (Postfix) with ESMTP id 3ADF2F8012B; Tue, 24 Oct 2023 10:47:08 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 86DA9F804F3; Mon, 23 Oct 2023 17:07:30 +0200 (CEST) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id D953DF8024E for ; Mon, 23 Oct 2023 17:07:16 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz D953DF8024E Authentication-Results: alsa1.perex.cz; dkim=pass (1024-bit key, unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=bqP3igib DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1698073635; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type; bh=cK9l2C0A+pqfOsEmA8BmMsk1GVm50G4Oa7jxSgBxcvs=; b=bqP3igibDGB/Q9bKaD+voMnibPBMbmbh9790k2lI9frNeK/68ldV6NOggGthvW6H/2/147 y87B3A4CFCla4/uD2nB9zQizMjD/hBNqCPW2Y9wnrr5LncqBreRv7apEnnhQ/mg2+WL6+v rxGdSXTXu+0JoPrHMT6uLgyhvhFMpDc= Received: from mail-qv1-f69.google.com (mail-qv1-f69.google.com [209.85.219.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-301-KSkuE0XBMWO_OvqOomdB8Q-1; Mon, 23 Oct 2023 11:07:02 -0400 X-MC-Unique: KSkuE0XBMWO_OvqOomdB8Q-1 Received: by mail-qv1-f69.google.com with SMTP id 6a1803df08f44-66d38d57f49so44307016d6.0 for ; Mon, 23 Oct 2023 08:07:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698073622; x=1698678422; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=cK9l2C0A+pqfOsEmA8BmMsk1GVm50G4Oa7jxSgBxcvs=; b=SnsaXpjiaB+72fsHHz7LGTmxy2ON+eTrLzCmwUL9WPw75fA/NRgYBocDYTO0RlKanw xgqJXihysOSRbGvt2ILVYS86J7V8zAbQRMwuL6CgkyX2QkB1T/HrP8XE2RxIH9GLlbHt 9utB+YzXBS0KwYa8sCbNdEwjHb85GcNQKg97H/AK2xcUx6cVtIZ/GTvSkXCxBqoJ9Ham hT1dStFzlJ/kphwazzdA3++sIYNdJ7kaL57XVOZIEKVqHtV2aWnAeQ+mPECCAULLScX/ AyQu00O3K5dhW13Weguxq6BwkZOH03IC60VguS49Wofz0uKb6m14Hh4y/Lzb9ir6bvJO b3GA== X-Gm-Message-State: AOJu0YwZalSmYH5SVq23CIhgc+/2DQo+zPsgOguxTK2lW3d87JIwX7y5 vfGQty+3tDomGjDXnRyrMIxlHl9PUqx92+wUQSp2rE3eSeXtni9Rn4V5cAyMVL/d2LUm3M9Hlpd YMqqlQx5d3Q3NMCOEtBCqCu4= X-Received: by 2002:a05:6214:c45:b0:66d:3a89:813c with SMTP id r5-20020a0562140c4500b0066d3a89813cmr13347561qvj.53.1698073622074; Mon, 23 Oct 2023 08:07:02 -0700 (PDT) X-Google-Smtp-Source: AGHT+IEUikCH+Dp3bAYPy/wefX94Xe9wxmONu1VfG8SxnmNbO1aSlUkA4XJgvxB5KhmZ12CHc/+ghg== X-Received: by 2002:a05:6214:c45:b0:66d:3a89:813c with SMTP id r5-20020a0562140c4500b0066d3a89813cmr13347518qvj.53.1698073621591; Mon, 23 Oct 2023 08:07:01 -0700 (PDT) Received: from fedora ([2a01:e0a:257:8c60:80f1:cdf8:48d0:b0a1]) by smtp.gmail.com with ESMTPSA id l19-20020a056214029300b0065afe8f149asm2873910qvv.69.2023.10.23.08.06.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 Oct 2023 08:07:01 -0700 (PDT) Date: Mon, 23 Oct 2023 17:06:57 +0200 From: Matias Ezequiel Vara Larsen To: anton.yakovlev@opensynergy.com, mst@redhat.com Cc: mvaralar@redhat.com, perex@perex.cz, tiwai@suse.com, virtualization@lists.linux-foundation.org, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, stefanha@redhat.com, sgarzare@redhat.com, manos.pitsidianakis@linaro.org, mripard@redhat.com Subject: [PATCH v3] ALSA: virtio: use ack callback Message-ID: MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline X-MailFrom: mvaralar@redhat.com X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-alsa-devel.alsa-project.org-0; header-match-alsa-devel.alsa-project.org-1 Message-ID-Hash: B2HMXM5XXRN3JG3C22XCNJS7Q2OUAAYU X-Message-ID-Hash: B2HMXM5XXRN3JG3C22XCNJS7Q2OUAAYU X-Mailman-Approved-At: Tue, 24 Oct 2023 08:47:03 +0000 X-Mailman-Version: 3.3.8 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: This commit uses the ack() callback to determine when a buffer has been updated, then exposes it to guest. The current mechanism splits a dma buffer into descriptors that are exposed to the device. This dma buffer is shared with the user application. When the device consumes a buffer, the driver moves the request from the used ring to available ring. The driver exposes the buffer to the device without knowing if the content has been updated from the user. The section 2.8.21.1 of the virtio spec states that: "The device MAY access the descriptor chains the driver created and the memory they refer to immediately". If the device picks up buffers from the available ring just after it is notified, it happens that the content may be old. When the ack() callback is invoked, the driver exposes only the buffers that have already been updated, i.e., enqueued in the available ring. Thus, the device always picks up a buffer that is updated. For capturing, the driver starts by exposing all the available buffers to device. After device updates the content of a buffer, it enqueues it in the used ring. It is only after the ack() for capturing is issued that the driver re-enqueues the buffer in the available ring. Co-developed-by: Anton Yakovlev Signed-off-by: Anton Yakovlev Signed-off-by: Matias Ezequiel Vara Larsen --- Changelog: v2 -> v3: * Use ack() callback instead of copy()/fill_silence() * Change commit name * Rewrite commit message * Remove virtsnd_pcm_msg_send_locked() * Use single callback for both capture and playback * Fix kernel test robot warnings regarding documentation * v2 patch at: https://lore.kernel.org/lkml/87y1fzkq8c.wl-tiwai@suse.de/T/ v1 -> v2: * Use snd_pcm_set_managed_buffer_all()for buffer allocation/freeing. * Make virtsnd_pcm_msg_send() generic by specifying the offset and size for the modified part of the buffer; this way no assumptions need to be made. * Disable SNDRV_PCM_INFO_NO_REWINDS since now only sequential reading/writing of frames is supported. * Correct comment at virtsnd_pcm_msg_send(). * v1 patch at: https://lore.kernel.org/lkml/20231016151000.GE119987@fedora/t/ sound/virtio/virtio_pcm.c | 1 + sound/virtio/virtio_pcm.h | 6 ++- sound/virtio/virtio_pcm_msg.c | 80 ++++++++++++++++++++--------------- sound/virtio/virtio_pcm_ops.c | 30 +++++++++++-- 4 files changed, 79 insertions(+), 38 deletions(-) base-commit: 8a749fd1a8720d4619c91c8b6e7528c0a355c0aa diff --git a/sound/virtio/virtio_pcm.c b/sound/virtio/virtio_pcm.c index c10d91fff2fb..9cc5a95b4913 100644 --- a/sound/virtio/virtio_pcm.c +++ b/sound/virtio/virtio_pcm.c @@ -124,6 +124,7 @@ static int virtsnd_pcm_build_hw(struct virtio_pcm_substream *vss, values = le64_to_cpu(info->formats); vss->hw.formats = 0; + vss->appl_ptr = 0; for (i = 0; i < ARRAY_SIZE(g_v2a_format_map); ++i) if (values & (1ULL << i)) { diff --git a/sound/virtio/virtio_pcm.h b/sound/virtio/virtio_pcm.h index 062eb8e8f2cf..ea3c2845ae9b 100644 --- a/sound/virtio/virtio_pcm.h +++ b/sound/virtio/virtio_pcm.h @@ -27,6 +27,7 @@ struct virtio_pcm_msg; * substream operators. * @buffer_bytes: Current buffer size in bytes. * @hw_ptr: Substream hardware pointer value in bytes [0 ... buffer_bytes). + * @appl_ptr: Substream application pointer value in bytes [0 ... buffer_bytes). * @xfer_enabled: Data transfer state (0 - off, 1 - on). * @xfer_xrun: Data underflow/overflow state (0 - no xrun, 1 - xrun). * @stopped: True if the substream is stopped and must be released on the device @@ -51,13 +52,13 @@ struct virtio_pcm_substream { spinlock_t lock; size_t buffer_bytes; size_t hw_ptr; + size_t appl_ptr; bool xfer_enabled; bool xfer_xrun; bool stopped; bool suspended; struct virtio_pcm_msg **msgs; unsigned int nmsgs; - int msg_last_enqueued; unsigned int msg_count; wait_queue_head_t msg_empty; }; @@ -117,7 +118,8 @@ int virtsnd_pcm_msg_alloc(struct virtio_pcm_substream *vss, void virtsnd_pcm_msg_free(struct virtio_pcm_substream *vss); -int virtsnd_pcm_msg_send(struct virtio_pcm_substream *vss); +int virtsnd_pcm_msg_send(struct virtio_pcm_substream *vss, unsigned long offset, + unsigned long bytes); unsigned int virtsnd_pcm_msg_pending_num(struct virtio_pcm_substream *vss); diff --git a/sound/virtio/virtio_pcm_msg.c b/sound/virtio/virtio_pcm_msg.c index aca2dc1989ba..106e8e847746 100644 --- a/sound/virtio/virtio_pcm_msg.c +++ b/sound/virtio/virtio_pcm_msg.c @@ -155,7 +155,6 @@ int virtsnd_pcm_msg_alloc(struct virtio_pcm_substream *vss, sizeof(msg->xfer)); sg_init_one(&msg->sgs[PCM_MSG_SG_STATUS], &msg->status, sizeof(msg->status)); - msg->length = period_bytes; virtsnd_pcm_sg_from(&msg->sgs[PCM_MSG_SG_DATA], sg_num, data, period_bytes); @@ -181,66 +180,81 @@ void virtsnd_pcm_msg_free(struct virtio_pcm_substream *vss) vss->msgs = NULL; vss->nmsgs = 0; + vss->appl_ptr = 0; } /** * virtsnd_pcm_msg_send() - Send asynchronous I/O messages. * @vss: VirtIO PCM substream. + * @offset: starting position that has been updated + * @bytes: number of bytes that has been updated * * 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. + * virtqueue. For this, the function uses offset and bytes to calculate the + * messages that need to be added. * * Context: Any context. Expects the tx/rx queue and the VirtIO substream * spinlocks to be held by caller. * Return: 0 on success, -errno on failure. */ -int virtsnd_pcm_msg_send(struct virtio_pcm_substream *vss) +int virtsnd_pcm_msg_send(struct virtio_pcm_substream *vss, unsigned long offset, + unsigned long bytes) { - struct snd_pcm_runtime *runtime = vss->substream->runtime; struct virtio_snd *snd = vss->snd; struct virtio_device *vdev = snd->vdev; struct virtqueue *vqueue = virtsnd_pcm_queue(vss)->vqueue; - int i; - int n; + unsigned long period_bytes = snd_pcm_lib_period_bytes(vss->substream); + unsigned long start, end, i; + unsigned int msg_count = vss->msg_count; bool notify = false; + int rc; - i = (vss->msg_last_enqueued + 1) % runtime->periods; - n = runtime->periods - vss->msg_count; + start = offset / period_bytes; + end = (offset + bytes - 1) / period_bytes; - for (; n; --n, i = (i + 1) % runtime->periods) { + for (i = start; i <= end; i++) { struct virtio_pcm_msg *msg = vss->msgs[i]; struct scatterlist *psgs[] = { &msg->sgs[PCM_MSG_SG_XFER], &msg->sgs[PCM_MSG_SG_DATA], &msg->sgs[PCM_MSG_SG_STATUS] }; - int rc; - - msg->xfer.stream_id = cpu_to_le32(vss->sid); - memset(&msg->status, 0, sizeof(msg->status)); - - if (vss->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) { - dev_err(&vdev->dev, - "SID %u: failed to send I/O message\n", - vss->sid); - return rc; + unsigned long n; + + n = period_bytes - (offset % period_bytes); + if (n > bytes) + n = bytes; + + msg->length += n; + if (msg->length == period_bytes) { + msg->xfer.stream_id = cpu_to_le32(vss->sid); + memset(&msg->status, 0, sizeof(msg->status)); + + if (vss->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) { + dev_err(&vdev->dev, + "SID %u: failed to send I/O message\n", + vss->sid); + return rc; + } + + vss->msg_count++; } - vss->msg_last_enqueued = i; - vss->msg_count++; + offset = 0; + bytes -= n; } + if (msg_count == vss->msg_count) + return 0; + if (!(vss->features & (1U << VIRTIO_SND_PCM_F_MSG_POLLING))) notify = virtqueue_kick_prepare(vqueue); @@ -309,6 +323,8 @@ static void virtsnd_pcm_msg_complete(struct virtio_pcm_msg *msg, if (vss->hw_ptr >= vss->buffer_bytes) vss->hw_ptr -= vss->buffer_bytes; + msg->length = 0; + vss->xfer_xrun = false; vss->msg_count--; @@ -320,8 +336,6 @@ static void virtsnd_pcm_msg_complete(struct virtio_pcm_msg *msg, le32_to_cpu(msg->status.latency_bytes)); schedule_work(&vss->elapsed_period); - - virtsnd_pcm_msg_send(vss); } else if (!vss->msg_count) { wake_up_all(&vss->msg_empty); } diff --git a/sound/virtio/virtio_pcm_ops.c b/sound/virtio/virtio_pcm_ops.c index f8bfb87624be..21cde37ecfa3 100644 --- a/sound/virtio/virtio_pcm_ops.c +++ b/sound/virtio/virtio_pcm_ops.c @@ -282,7 +282,6 @@ static int virtsnd_pcm_prepare(struct snd_pcm_substream *substream) vss->buffer_bytes = snd_pcm_lib_buffer_bytes(substream); vss->hw_ptr = 0; - vss->msg_last_enqueued = -1; } else { struct snd_pcm_runtime *runtime = substream->runtime; unsigned int buffer_bytes = snd_pcm_lib_buffer_bytes(substream); @@ -324,7 +323,7 @@ static int virtsnd_pcm_trigger(struct snd_pcm_substream *substream, int command) struct virtio_snd_queue *queue; struct virtio_snd_msg *msg; unsigned long flags; - int rc; + int rc = 0; switch (command) { case SNDRV_PCM_TRIGGER_START: @@ -333,7 +332,8 @@ static int virtsnd_pcm_trigger(struct snd_pcm_substream *substream, int command) spin_lock_irqsave(&queue->lock, flags); spin_lock(&vss->lock); - rc = virtsnd_pcm_msg_send(vss); + if (vss->direction == SNDRV_PCM_STREAM_CAPTURE) + rc = virtsnd_pcm_msg_send(vss, 0, vss->buffer_bytes); if (!rc) vss->xfer_enabled = true; spin_unlock(&vss->lock); @@ -450,6 +450,29 @@ virtsnd_pcm_pointer(struct snd_pcm_substream *substream) return hw_ptr; } +static int virtsnd_pcm_ack(struct snd_pcm_substream *substream) +{ + struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); + struct virtio_snd_queue *queue = virtsnd_pcm_queue(vss); + unsigned long flags; + struct snd_pcm_runtime *runtime = vss->substream->runtime; + ssize_t appl_pos = frames_to_bytes(runtime, runtime->control->appl_ptr); + ssize_t buf_size = frames_to_bytes(runtime, runtime->buffer_size); + int rc; + + spin_lock_irqsave(&queue->lock, flags); + spin_lock(&vss->lock); + + ssize_t bytes = (appl_pos - vss->appl_ptr) % buf_size; + + rc = virtsnd_pcm_msg_send(vss, vss->appl_ptr % buf_size, bytes); + vss->appl_ptr += bytes; + + spin_unlock(&vss->lock); + spin_unlock_irqrestore(&queue->lock, flags); + return rc; +} + /* PCM substream operators map. */ const struct snd_pcm_ops virtsnd_pcm_ops = { .open = virtsnd_pcm_open, @@ -461,4 +484,5 @@ const struct snd_pcm_ops virtsnd_pcm_ops = { .trigger = virtsnd_pcm_trigger, .sync_stop = virtsnd_pcm_sync_stop, .pointer = virtsnd_pcm_pointer, + .ack = virtsnd_pcm_ack, };