From nobody Fri Dec 19 03:45:43 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C5533C41513 for ; Mon, 14 Aug 2023 11:57:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230512AbjHNL4w (ORCPT ); Mon, 14 Aug 2023 07:56:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233054AbjHNL4R (ORCPT ); Mon, 14 Aug 2023 07:56:17 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34B3719A8 for ; Mon, 14 Aug 2023 04:56:00 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 2604A21999; Mon, 14 Aug 2023 11:55:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1692014144; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PjigMRXLLwFiO9MVxJuREvNKaLKvWTiGPYNpYq6YtnM=; b=vI3AtIo7QqzcfTCjEfuewVnjhZaljIeMMEPzIAkYAY5biza01E4+r56FXxYkCXIskGewGQ WqHpyUNdC8tW3zJVAtekGh033u0TFcuqTRodFw5cR0YSUUfUD9F5LlyLo49AGE52rTYhDF M/Lbo3u8DD8+YvxV0iz6NpPVWOFgpPY= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1692014144; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PjigMRXLLwFiO9MVxJuREvNKaLKvWTiGPYNpYq6YtnM=; b=Y10qq8KhM3fcZxJwRRXm0Fe0PHJz2b6zETO8DuKZkAgeibshowl/1PEra2vn3H26Yhm3Rh eEHAK3KAix1dYcCQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 04957138EE; Mon, 14 Aug 2023 11:55:44 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id mB5YAEAW2mRnMAAAMHmgww (envelope-from ); Mon, 14 Aug 2023 11:55:44 +0000 From: Takashi Iwai To: alsa-devel@alsa-project.org Cc: linux-kernel@vger.kernel.org, Takashi Iwai Subject: [PATCH 02/25] ALSA: pcm: Add copy ops with iov_iter Date: Mon, 14 Aug 2023 13:55:00 +0200 Message-Id: <20230814115523.15279-3-tiwai@suse.de> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20230814115523.15279-1-tiwai@suse.de> References: <20230814115523.15279-1-tiwai@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" iov_iter is a universal interface to copy the data chunk from/to user-space and kernel in a unified manner. This API can fit for ALSA PCM copy ops, too; we had to split to copy_user and copy_kernel in the past, and those can be unified to a single ops with iov_iter. This patch adds a new PCM copy ops that passes iov_iter for copying both kernel and user-space in the same way. This patch touches only the ALSA PCM core part, and the actual users will be replaced in the following patches. The expansion of iov_iter is done in the PCM core right before calling each copy callback. It's a bit suboptimal, but I took this now as it's the most straightforward replacement. The more conversion to iov_iter in the caller side is a TODO for future. As of now, the old copy_user and copy_kernel ops are still kept. Once after all users are converted, we'll drop the old copy_user and copy_kernel ops, too. Signed-off-by: Takashi Iwai --- include/sound/pcm.h | 3 ++ sound/core/pcm_lib.c | 111 ++++++++++++++++++++++++---------------- sound/core/pcm_native.c | 2 +- 3 files changed, 71 insertions(+), 45 deletions(-) diff --git a/include/sound/pcm.h b/include/sound/pcm.h index 19f564606ac4..ff4a0c1c93a2 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -16,6 +16,7 @@ #include #include #include +#include =20 #define snd_pcm_substream_chip(substream) ((substream)->private_data) #define snd_pcm_chip(pcm) ((pcm)->private_data) @@ -68,6 +69,8 @@ struct snd_pcm_ops { struct snd_pcm_audio_tstamp_report *audio_tstamp_report); int (*fill_silence)(struct snd_pcm_substream *substream, int channel, unsigned long pos, unsigned long bytes); + int (*copy)(struct snd_pcm_substream *substream, int channel, + unsigned long pos, struct iov_iter *iter, unsigned long bytes); int (*copy_user)(struct snd_pcm_substream *substream, int channel, unsigned long pos, void __user *buf, unsigned long bytes); diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 9c121a921b04..3303914c58ea 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -1973,10 +1973,11 @@ static int wait_for_avail(struct snd_pcm_substream = *substream, =09 typedef int (*pcm_transfer_f)(struct snd_pcm_substream *substream, int channel, unsigned long hwoff, - void *buf, unsigned long bytes); + struct iov_iter *iter, unsigned long bytes); =20 typedef int (*pcm_copy_f)(struct snd_pcm_substream *, snd_pcm_uframes_t, v= oid *, - snd_pcm_uframes_t, snd_pcm_uframes_t, pcm_transfer_f); + snd_pcm_uframes_t, snd_pcm_uframes_t, pcm_transfer_f, + bool); =20 /* calculate the target DMA-buffer position to be written/read */ static void *get_dma_ptr(struct snd_pcm_runtime *runtime, @@ -1986,32 +1987,24 @@ static void *get_dma_ptr(struct snd_pcm_runtime *ru= ntime, channel * (runtime->dma_bytes / runtime->channels); } =20 -/* default copy_user ops for write; used for both interleaved and non- mod= es */ +/* default copy ops for write; used for both interleaved and non- modes */ static int default_write_copy(struct snd_pcm_substream *substream, int channel, unsigned long hwoff, - void *buf, unsigned long bytes) + struct iov_iter *iter, unsigned long bytes) { - if (copy_from_user(get_dma_ptr(substream->runtime, channel, hwoff), - (void __user *)buf, bytes)) + if (!copy_from_iter(get_dma_ptr(substream->runtime, channel, hwoff), + bytes, iter)) return -EFAULT; return 0; } =20 -/* default copy_kernel ops for write */ -static int default_write_copy_kernel(struct snd_pcm_substream *substream, - int channel, unsigned long hwoff, - void *buf, unsigned long bytes) -{ - memcpy(get_dma_ptr(substream->runtime, channel, hwoff), buf, bytes); - return 0; -} - /* fill silence instead of copy data; called as a transfer helper * from __snd_pcm_lib_write() or directly from noninterleaved_copy() when * a NULL buffer is passed */ static int fill_silence(struct snd_pcm_substream *substream, int channel, - unsigned long hwoff, void *buf, unsigned long bytes) + unsigned long hwoff, struct iov_iter *iter, + unsigned long bytes) { struct snd_pcm_runtime *runtime =3D substream->runtime; =20 @@ -2027,25 +2020,54 @@ static int fill_silence(struct snd_pcm_substream *s= ubstream, int channel, return 0; } =20 -/* default copy_user ops for read; used for both interleaved and non- mode= s */ +/* default copy ops for read; used for both interleaved and non- modes */ static int default_read_copy(struct snd_pcm_substream *substream, int channel, unsigned long hwoff, - void *buf, unsigned long bytes) + struct iov_iter *iter, unsigned long bytes) { - if (copy_to_user((void __user *)buf, - get_dma_ptr(substream->runtime, channel, hwoff), - bytes)) + if (!copy_to_iter(get_dma_ptr(substream->runtime, channel, hwoff), + bytes, iter)) return -EFAULT; return 0; } =20 -/* default copy_kernel ops for read */ -static int default_read_copy_kernel(struct snd_pcm_substream *substream, - int channel, unsigned long hwoff, - void *buf, unsigned long bytes) +/* a wrapper for calling old copy_kernel or copy_user ops */ +static int call_old_copy(struct snd_pcm_substream *substream, + int channel, unsigned long hwoff, + struct iov_iter *iter, unsigned long bytes) { - memcpy(buf, get_dma_ptr(substream->runtime, channel, hwoff), bytes); - return 0; + if (iov_iter_is_kvec(iter)) + return substream->ops->copy_kernel(substream, channel, hwoff, + iter_iov_addr(iter), bytes); + else + return substream->ops->copy_user(substream, channel, hwoff, + iter_iov_addr(iter), bytes); +} + +/* call transfer with the filled iov_iter */ +static int do_transfer(struct snd_pcm_substream *substream, int c, + unsigned long hwoff, void *data, unsigned long bytes, + pcm_transfer_f transfer, bool in_kernel) +{ + struct iov_iter iter; + int err, type; + + if (substream->stream =3D=3D SNDRV_PCM_STREAM_PLAYBACK) + type =3D ITER_SOURCE; + else + type =3D ITER_DEST; + + if (in_kernel) { + struct kvec kvec =3D { data, bytes }; + + iov_iter_kvec(&iter, type, &kvec, 1, bytes); + return transfer(substream, c, hwoff, &iter, bytes); + } + + err =3D import_ubuf(type, (__force void __user *)data, bytes, &iter); + if (err) + return err; + return transfer(substream, c, hwoff, &iter, bytes); } =20 /* call transfer function with the converted pointers and sizes; @@ -2055,7 +2077,8 @@ static int interleaved_copy(struct snd_pcm_substream = *substream, snd_pcm_uframes_t hwoff, void *data, snd_pcm_uframes_t off, snd_pcm_uframes_t frames, - pcm_transfer_f transfer) + pcm_transfer_f transfer, + bool in_kernel) { struct snd_pcm_runtime *runtime =3D substream->runtime; =20 @@ -2063,7 +2086,9 @@ static int interleaved_copy(struct snd_pcm_substream = *substream, hwoff =3D frames_to_bytes(runtime, hwoff); off =3D frames_to_bytes(runtime, off); frames =3D frames_to_bytes(runtime, frames); - return transfer(substream, 0, hwoff, data + off, frames); + + return do_transfer(substream, 0, hwoff, data + off, frames, transfer, + in_kernel); } =20 /* call transfer function with the converted pointers and sizes for each @@ -2073,7 +2098,8 @@ static int noninterleaved_copy(struct snd_pcm_substre= am *substream, snd_pcm_uframes_t hwoff, void *data, snd_pcm_uframes_t off, snd_pcm_uframes_t frames, - pcm_transfer_f transfer) + pcm_transfer_f transfer, + bool in_kernel) { struct snd_pcm_runtime *runtime =3D substream->runtime; int channels =3D runtime->channels; @@ -2091,8 +2117,8 @@ static int noninterleaved_copy(struct snd_pcm_substre= am *substream, if (!data || !*bufs) err =3D fill_silence(substream, c, hwoff, NULL, frames); else - err =3D transfer(substream, c, hwoff, *bufs + off, - frames); + err =3D do_transfer(substream, c, hwoff, *bufs + off, + frames, transfer, in_kernel); if (err < 0) return err; } @@ -2108,10 +2134,10 @@ static int fill_silence_frames(struct snd_pcm_subst= ream *substream, if (substream->runtime->access =3D=3D SNDRV_PCM_ACCESS_RW_INTERLEAVED || substream->runtime->access =3D=3D SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) return interleaved_copy(substream, off, NULL, 0, frames, - fill_silence); + fill_silence, true); else return noninterleaved_copy(substream, off, NULL, 0, frames, - fill_silence); + fill_silence, true); } =20 /* sanity-check for read/write methods */ @@ -2121,7 +2147,7 @@ static int pcm_sanity_check(struct snd_pcm_substream = *substream) if (PCM_RUNTIME_CHECK(substream)) return -ENXIO; runtime =3D substream->runtime; - if (snd_BUG_ON(!substream->ops->copy_user && !runtime->dma_area)) + if (snd_BUG_ON(!substream->ops->copy && !substream->ops->copy_user && !ru= ntime->dma_area)) return -EINVAL; if (runtime->state =3D=3D SNDRV_PCM_STATE_OPEN) return -EBADFD; @@ -2226,15 +2252,12 @@ snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm= _substream *substream, transfer =3D fill_silence; else return -EINVAL; - } else if (in_kernel) { - if (substream->ops->copy_kernel) - transfer =3D substream->ops->copy_kernel; - else - transfer =3D is_playback ? - default_write_copy_kernel : default_read_copy_kernel; } else { - if (substream->ops->copy_user) - transfer =3D (pcm_transfer_f)substream->ops->copy_user; + if (substream->ops->copy) + transfer =3D substream->ops->copy; + else if ((in_kernel && substream->ops->copy_kernel) || + (!in_kernel && substream->ops->copy_user)) + transfer =3D call_old_copy; else transfer =3D is_playback ? default_write_copy : default_read_copy; @@ -2307,7 +2330,7 @@ snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_s= ubstream *substream, if (!is_playback) snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_CPU); err =3D writer(substream, appl_ofs, data, offset, frames, - transfer); + transfer, in_kernel); if (is_playback) snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE); snd_pcm_stream_lock_irq(substream); diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 95fc56e403b1..34efd4d198d6 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -809,7 +809,7 @@ static int snd_pcm_hw_params(struct snd_pcm_substream *= substream, runtime->boundary *=3D 2; =20 /* clear the buffer for avoiding possible kernel info leaks */ - if (runtime->dma_area && !substream->ops->copy_user) { + if (runtime->dma_area && !substream->ops->copy && !substream->ops->copy_u= ser) { size_t size =3D runtime->dma_bytes; =20 if (runtime->info & SNDRV_PCM_INFO_MMAP) --=20 2.35.3