[00/25] ALSA: Generic PCM copy ops using iov_iter

  Hi,

this is a revised patch set for cleaning up the PCM copy ops using
iov_iter to deal with kernel / user-space pointers consistently.

The previous patch set was based on sockptr_t:
  https://lore.kernel.org/r/20230731154718.31048-1-tiwai@suse.de
But this approach was NAK'ed as iov_iter is a preferred way for
achieving the purpose:
  https://lore.kernel.org/r/87edkce118.wl-tiwai@suse.de

The patch set starts with the missing export of import_ubuf()
function, followed by the new copy_ops using iov_iter, extensions of
some helpers and replacements of the existing code.  It resulted in a
good amount of code reduction.


Takashi

===

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andrey Utkin <andrey_utkin@fastmail.com>
Cc: Anton Sviridenko <anton@corp.bluecherry.net>
Cc: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Cc: Banajit Goswami <bgoswami@quicinc.com>
Cc: Bluecherry Maintainers <maintainers@bluecherrydvr.com>
Cc: Claudiu Beznea <claudiu.beznea@microchip.com>
Cc: Ismael Luceno <ismael@iodev.co.uk>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Mark Brown <broonie@kernel.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Cc: Olivier Moysan <olivier.moysan@foss.st.com>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: linux-media@vger.kernel.org
Cc: xen-devel@lists.xenproject.org

===

Takashi Iwai (25):
  iov_iter: Export import_ubuf()
  ALSA: pcm: Add copy ops with iov_iter
  ALSA: core: Add memory copy helpers between iov_iter and iomem
  ALSA: dummy: Convert to generic PCM copy ops
  ALSA: gus: Convert to generic PCM copy ops
  ALSA: emu8000: Convert to generic PCM copy ops
  ALSA: es1938: Convert to generic PCM copy ops
  ALSA: korg1212: Convert to generic PCM copy ops
  ALSA: nm256: Convert to generic PCM copy ops
  ALSA: rme32: Convert to generic PCM copy ops
  ALSA: rme96: Convert to generic PCM copy ops
  ALSA: hdsp: Convert to generic PCM copy ops
  ALSA: rme9652: Convert to generic PCM copy ops
  ALSA: sh: Convert to generic PCM copy ops
  ALSA: xen: Convert to generic PCM copy ops
  ALSA: pcmtest: Update comment about PCM copy ops
  media: solo6x10: Convert to generic PCM copy ops
  ASoC: component: Add generic PCM copy ops
  ASoC: mediatek: Convert to generic PCM copy ops
  ASoC: qcom: Convert to generic PCM copy ops
  ASoC: dmaengine: Convert to generic PCM copy ops
  ASoC: dmaengine: Use iov_iter for process callback, too
  ALSA: doc: Update description for the new PCM copy ops
  ASoC: pcm: Drop obsoleted PCM copy_user ops
  ALSA: pcm: Drop obsoleted PCM copy_user and copy_kernel ops

 .../kernel-api/writing-an-alsa-driver.rst     | 58 ++++-------
 drivers/media/pci/solo6x10/solo6x10-g723.c    | 38 +-------
 include/sound/dmaengine_pcm.h                 |  2 +-
 include/sound/pcm.h                           | 13 ++-
 include/sound/soc-component.h                 | 14 +--
 lib/iov_iter.c                                |  1 +
 sound/core/memory.c                           | 56 +++++++++--
 sound/core/pcm_lib.c                          | 95 ++++++++++---------
 sound/core/pcm_native.c                       |  2 +-
 sound/drivers/dummy.c                         | 12 +--
 sound/drivers/pcmtest.c                       |  2 +-
 sound/isa/gus/gus_pcm.c                       | 23 +----
 sound/isa/sb/emu8000_pcm.c                    | 74 ++++-----------
 sound/pci/es1938.c                            | 30 +-----
 sound/pci/korg1212/korg1212.c                 | 50 +++-------
 sound/pci/nm256/nm256.c                       | 42 ++------
 sound/pci/rme32.c                             | 50 +++-------
 sound/pci/rme96.c                             | 42 ++------
 sound/pci/rme9652/hdsp.c                      | 42 ++------
 sound/pci/rme9652/rme9652.c                   | 46 ++-------
 sound/sh/sh_dac_audio.c                       | 25 +----
 sound/soc/atmel/mchp-pdmc.c                   |  2 +-
 sound/soc/mediatek/common/mtk-btcvsd.c        | 23 ++---
 sound/soc/qcom/lpass-platform.c               | 13 +--
 sound/soc/soc-component.c                     | 10 +-
 sound/soc/soc-generic-dmaengine-pcm.c         | 18 ++--
 sound/soc/soc-pcm.c                           |  4 +-
 sound/soc/stm/stm32_sai_sub.c                 |  2 +-
 sound/xen/xen_snd_front_alsa.c                | 55 ++---------
 29 files changed, 263 insertions(+), 581 deletions(-)
  

On 14/Aug/2023 13:55, Takashi Iwai wrote:
> This patch converts the solo6x10 driver code to use the new unified
> PCM copy callback.  It's a straightforward conversion from *_user() to
> *_iter() variants.  As copy_to_iter() updates the internal offest at
> each write, we can drop the dst counter update in the loop, too.
> 
> Note that copy_from/to_iter() returns the copied bytes, hence the
> error condition is inverted from copy_from/to_user().
> 
> Cc: Bluecherry Maintainers <maintainers@bluecherrydvr.com>
> Cc: Anton Sviridenko <anton@corp.bluecherry.net>
> Cc: Andrey Utkin <andrey_utkin@fastmail.com>
> Cc: Ismael Luceno <ismael@iodev.co.uk>
> Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
> Cc: linux-media@vger.kernel.org
> Signed-off-by: Takashi Iwai <tiwai@suse.de>
> ---
>  drivers/media/pci/solo6x10/solo6x10-g723.c | 38 +++-------------------
>  1 file changed, 5 insertions(+), 33 deletions(-)
> 
> diff --git a/drivers/media/pci/solo6x10/solo6x10-g723.c b/drivers/media/pci/solo6x10/solo6x10-g723.c
> index 6cebad665565..aceacb822cab 100644
> --- a/drivers/media/pci/solo6x10/solo6x10-g723.c
> +++ b/drivers/media/pci/solo6x10/solo6x10-g723.c
> @@ -204,9 +204,9 @@ static snd_pcm_uframes_t snd_solo_pcm_pointer(struct snd_pcm_substream *ss)
>  	return idx * G723_FRAMES_PER_PAGE;
>  }
>  
> -static int snd_solo_pcm_copy_user(struct snd_pcm_substream *ss, int channel,
> -				  unsigned long pos, void __user *dst,
> -				  unsigned long count)
> +static int snd_solo_pcm_copy(struct snd_pcm_substream *ss, int channel,
> +			     unsigned long pos, struct iov_iter *dst,
> +			     unsigned long count)
>  {
>  	struct solo_snd_pcm *solo_pcm = snd_pcm_substream_chip(ss);
>  	struct solo_dev *solo_dev = solo_pcm->solo_dev;
> @@ -223,35 +223,8 @@ static int snd_solo_pcm_copy_user(struct snd_pcm_substream *ss, int channel,
>  		if (err)
>  			return err;
>  
> -		if (copy_to_user(dst, solo_pcm->g723_buf, G723_PERIOD_BYTES))
> +		if (!copy_to_iter(solo_pcm->g723_buf, G723_PERIOD_BYTES, dst))
>  			return -EFAULT;
> -		dst += G723_PERIOD_BYTES;
> -	}
> -
> -	return 0;
> -}
> -
> -static int snd_solo_pcm_copy_kernel(struct snd_pcm_substream *ss, int channel,
> -				    unsigned long pos, void *dst,
> -				    unsigned long count)
> -{
> -	struct solo_snd_pcm *solo_pcm = snd_pcm_substream_chip(ss);
> -	struct solo_dev *solo_dev = solo_pcm->solo_dev;
> -	int err, i;
> -
> -	for (i = 0; i < (count / G723_FRAMES_PER_PAGE); i++) {
> -		int page = (pos / G723_FRAMES_PER_PAGE) + i;
> -
> -		err = solo_p2m_dma_t(solo_dev, 0, solo_pcm->g723_dma,
> -				     SOLO_G723_EXT_ADDR(solo_dev) +
> -				     (page * G723_PERIOD_BLOCK) +
> -				     (ss->number * G723_PERIOD_BYTES),
> -				     G723_PERIOD_BYTES, 0, 0);
> -		if (err)
> -			return err;
> -
> -		memcpy(dst, solo_pcm->g723_buf, G723_PERIOD_BYTES);
> -		dst += G723_PERIOD_BYTES;
>  	}
>  
>  	return 0;
> @@ -263,8 +236,7 @@ static const struct snd_pcm_ops snd_solo_pcm_ops = {
>  	.prepare = snd_solo_pcm_prepare,
>  	.trigger = snd_solo_pcm_trigger,
>  	.pointer = snd_solo_pcm_pointer,
> -	.copy_user = snd_solo_pcm_copy_user,
> -	.copy_kernel = snd_solo_pcm_copy_kernel,
> +	.copy = snd_solo_pcm_copy,
>  };
>  
>  static int snd_solo_capture_volume_info(struct snd_kcontrol *kcontrol,
> -- 
> 2.35.3
> 

Signed-off-by: Ismael Luceno <ismael@iodev.co.uk>
  

On Mon, 14 Aug 2023 14:15:18 +0200,
Ismael Luceno wrote:
> 
> On 14/Aug/2023 13:55, Takashi Iwai wrote:
> > This patch converts the solo6x10 driver code to use the new unified
> > PCM copy callback.  It's a straightforward conversion from *_user() to
> > *_iter() variants.  As copy_to_iter() updates the internal offest at
> > each write, we can drop the dst counter update in the loop, too.
> > 
> > Note that copy_from/to_iter() returns the copied bytes, hence the
> > error condition is inverted from copy_from/to_user().
> > 
> > Cc: Bluecherry Maintainers <maintainers@bluecherrydvr.com>
> > Cc: Anton Sviridenko <anton@corp.bluecherry.net>
> > Cc: Andrey Utkin <andrey_utkin@fastmail.com>
> > Cc: Ismael Luceno <ismael@iodev.co.uk>
> > Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
> > Cc: linux-media@vger.kernel.org
> > Signed-off-by: Takashi Iwai <tiwai@suse.de>
> > ---
> >  drivers/media/pci/solo6x10/solo6x10-g723.c | 38 +++-------------------
> >  1 file changed, 5 insertions(+), 33 deletions(-)
> > 
> > diff --git a/drivers/media/pci/solo6x10/solo6x10-g723.c b/drivers/media/pci/solo6x10/solo6x10-g723.c
> > index 6cebad665565..aceacb822cab 100644
> > --- a/drivers/media/pci/solo6x10/solo6x10-g723.c
> > +++ b/drivers/media/pci/solo6x10/solo6x10-g723.c
> > @@ -204,9 +204,9 @@ static snd_pcm_uframes_t snd_solo_pcm_pointer(struct snd_pcm_substream *ss)
> >  	return idx * G723_FRAMES_PER_PAGE;
> >  }
> >  
> > -static int snd_solo_pcm_copy_user(struct snd_pcm_substream *ss, int channel,
> > -				  unsigned long pos, void __user *dst,
> > -				  unsigned long count)
> > +static int snd_solo_pcm_copy(struct snd_pcm_substream *ss, int channel,
> > +			     unsigned long pos, struct iov_iter *dst,
> > +			     unsigned long count)
> >  {
> >  	struct solo_snd_pcm *solo_pcm = snd_pcm_substream_chip(ss);
> >  	struct solo_dev *solo_dev = solo_pcm->solo_dev;
> > @@ -223,35 +223,8 @@ static int snd_solo_pcm_copy_user(struct snd_pcm_substream *ss, int channel,
> >  		if (err)
> >  			return err;
> >  
> > -		if (copy_to_user(dst, solo_pcm->g723_buf, G723_PERIOD_BYTES))
> > +		if (!copy_to_iter(solo_pcm->g723_buf, G723_PERIOD_BYTES, dst))
> >  			return -EFAULT;
> > -		dst += G723_PERIOD_BYTES;
> > -	}
> > -
> > -	return 0;
> > -}
> > -
> > -static int snd_solo_pcm_copy_kernel(struct snd_pcm_substream *ss, int channel,
> > -				    unsigned long pos, void *dst,
> > -				    unsigned long count)
> > -{
> > -	struct solo_snd_pcm *solo_pcm = snd_pcm_substream_chip(ss);
> > -	struct solo_dev *solo_dev = solo_pcm->solo_dev;
> > -	int err, i;
> > -
> > -	for (i = 0; i < (count / G723_FRAMES_PER_PAGE); i++) {
> > -		int page = (pos / G723_FRAMES_PER_PAGE) + i;
> > -
> > -		err = solo_p2m_dma_t(solo_dev, 0, solo_pcm->g723_dma,
> > -				     SOLO_G723_EXT_ADDR(solo_dev) +
> > -				     (page * G723_PERIOD_BLOCK) +
> > -				     (ss->number * G723_PERIOD_BYTES),
> > -				     G723_PERIOD_BYTES, 0, 0);
> > -		if (err)
> > -			return err;
> > -
> > -		memcpy(dst, solo_pcm->g723_buf, G723_PERIOD_BYTES);
> > -		dst += G723_PERIOD_BYTES;
> >  	}
> >  
> >  	return 0;
> > @@ -263,8 +236,7 @@ static const struct snd_pcm_ops snd_solo_pcm_ops = {
> >  	.prepare = snd_solo_pcm_prepare,
> >  	.trigger = snd_solo_pcm_trigger,
> >  	.pointer = snd_solo_pcm_pointer,
> > -	.copy_user = snd_solo_pcm_copy_user,
> > -	.copy_kernel = snd_solo_pcm_copy_kernel,
> > +	.copy = snd_solo_pcm_copy,
> >  };
> >  
> >  static int snd_solo_capture_volume_info(struct snd_kcontrol *kcontrol,
> > -- 
> > 2.35.3
> > 
> 
> Signed-off-by: Ismael Luceno <ismael@iodev.co.uk>

You meant Reviewed-by or Acked-by?  Signed-off-by is a tag used when
you carry a patch.


thanks,

Takashi
  

On 14/Aug/2023 14:17, Takashi Iwai wrote:
> On Mon, 14 Aug 2023 14:15:18 +0200,
> Ismael Luceno wrote:
> > 
> > On 14/Aug/2023 13:55, Takashi Iwai wrote:
> > > This patch converts the solo6x10 driver code to use the new unified
> > > PCM copy callback.  It's a straightforward conversion from *_user() to
> > > *_iter() variants.  As copy_to_iter() updates the internal offest at
> > > each write, we can drop the dst counter update in the loop, too.
> > > 
> > > Note that copy_from/to_iter() returns the copied bytes, hence the
> > > error condition is inverted from copy_from/to_user().
> > > 
> > > Cc: Bluecherry Maintainers <maintainers@bluecherrydvr.com>
> > > Cc: Anton Sviridenko <anton@corp.bluecherry.net>
> > > Cc: Andrey Utkin <andrey_utkin@fastmail.com>
> > > Cc: Ismael Luceno <ismael@iodev.co.uk>
> > > Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
> > > Cc: linux-media@vger.kernel.org
> > > Signed-off-by: Takashi Iwai <tiwai@suse.de>
> > > ---
> > >  drivers/media/pci/solo6x10/solo6x10-g723.c | 38 +++-------------------
> > >  1 file changed, 5 insertions(+), 33 deletions(-)
> > > 
> > > diff --git a/drivers/media/pci/solo6x10/solo6x10-g723.c b/drivers/media/pci/solo6x10/solo6x10-g723.c
> > > index 6cebad665565..aceacb822cab 100644
> > > --- a/drivers/media/pci/solo6x10/solo6x10-g723.c
> > > +++ b/drivers/media/pci/solo6x10/solo6x10-g723.c
> > > @@ -204,9 +204,9 @@ static snd_pcm_uframes_t snd_solo_pcm_pointer(struct snd_pcm_substream *ss)
> > >  	return idx * G723_FRAMES_PER_PAGE;
> > >  }
> > >  
> > > -static int snd_solo_pcm_copy_user(struct snd_pcm_substream *ss, int channel,
> > > -				  unsigned long pos, void __user *dst,
> > > -				  unsigned long count)
> > > +static int snd_solo_pcm_copy(struct snd_pcm_substream *ss, int channel,
> > > +			     unsigned long pos, struct iov_iter *dst,
> > > +			     unsigned long count)
> > >  {
> > >  	struct solo_snd_pcm *solo_pcm = snd_pcm_substream_chip(ss);
> > >  	struct solo_dev *solo_dev = solo_pcm->solo_dev;
> > > @@ -223,35 +223,8 @@ static int snd_solo_pcm_copy_user(struct snd_pcm_substream *ss, int channel,
> > >  		if (err)
> > >  			return err;
> > >  
> > > -		if (copy_to_user(dst, solo_pcm->g723_buf, G723_PERIOD_BYTES))
> > > +		if (!copy_to_iter(solo_pcm->g723_buf, G723_PERIOD_BYTES, dst))
> > >  			return -EFAULT;
> > > -		dst += G723_PERIOD_BYTES;
> > > -	}
> > > -
> > > -	return 0;
> > > -}
> > > -
> > > -static int snd_solo_pcm_copy_kernel(struct snd_pcm_substream *ss, int channel,
> > > -				    unsigned long pos, void *dst,
> > > -				    unsigned long count)
> > > -{
> > > -	struct solo_snd_pcm *solo_pcm = snd_pcm_substream_chip(ss);
> > > -	struct solo_dev *solo_dev = solo_pcm->solo_dev;
> > > -	int err, i;
> > > -
> > > -	for (i = 0; i < (count / G723_FRAMES_PER_PAGE); i++) {
> > > -		int page = (pos / G723_FRAMES_PER_PAGE) + i;
> > > -
> > > -		err = solo_p2m_dma_t(solo_dev, 0, solo_pcm->g723_dma,
> > > -				     SOLO_G723_EXT_ADDR(solo_dev) +
> > > -				     (page * G723_PERIOD_BLOCK) +
> > > -				     (ss->number * G723_PERIOD_BYTES),
> > > -				     G723_PERIOD_BYTES, 0, 0);
> > > -		if (err)
> > > -			return err;
> > > -
> > > -		memcpy(dst, solo_pcm->g723_buf, G723_PERIOD_BYTES);
> > > -		dst += G723_PERIOD_BYTES;
> > >  	}
> > >  
> > >  	return 0;
> > > @@ -263,8 +236,7 @@ static const struct snd_pcm_ops snd_solo_pcm_ops = {
> > >  	.prepare = snd_solo_pcm_prepare,
> > >  	.trigger = snd_solo_pcm_trigger,
> > >  	.pointer = snd_solo_pcm_pointer,
> > > -	.copy_user = snd_solo_pcm_copy_user,
> > > -	.copy_kernel = snd_solo_pcm_copy_kernel,
> > > +	.copy = snd_solo_pcm_copy,
> > >  };
> > >  
> > >  static int snd_solo_capture_volume_info(struct snd_kcontrol *kcontrol,
> > > -- 
> > > 2.35.3
> > > 
> > 
> > Signed-off-by: Ismael Luceno <ismael@iodev.co.uk>
> 
> You meant Reviewed-by or Acked-by?  Signed-off-by is a tag used when
> you carry a patch.
> 
> 
> thanks,
> 
> Takashi

Yes, sorry, I meant "Acked-by".
  

On Mon, Aug 14, 2023 at 01:55:17PM +0200, Takashi Iwai wrote:
> This patch converts the mediatek BT SCO driver code to use the new
> unified PCM copy callback.  It's a straightforward conversion from
> *_user() to *_iter() variants.  As copy_form/to_iter() updates the
> internal offset at each read/write, we can drop the cur_*_idx counter
> in the loop, too.

Reviewed-by: Mark Brown <broonie@kernel.org>
  

On Mon, Aug 14, 2023 at 01:55:20PM +0200, Takashi Iwai wrote:
> Along with the conversion to PCM copy ops, use the iov_iter for the
> pointer to be passed to the dmaengine process callback, too.  It
> avoids the direct reference of iter_iov_addr(), and it can potentially
> help for the drivers to access memory properly (although both atmel
> and stm drivers don't use the given buffer address at all for now).

Reviewed-by: Mark Brown <broonie@kernel.org>