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[v3,0/5] iio: core: Add mmap interface infrastructure

Message ID 20210215143234.3248-1-alexandru.ardelean@analog.com (mailing list archive)
Headers show
Series iio: core: Add mmap interface infrastructure | expand

Message

Alexandru Ardelean Feb. 15, 2021, 2:32 p.m. UTC 
Changelog v2 -> v3:
* https://lore.kernel.org/linux-iio/20210212101143.18993-1-alexandru.ardelean@analog.com/T/#u
* added 'Documentation: iio: add doc for high-speed buffer API'
* add 'iio: buffer-dma: split iio_dma_buffer_fileio_free() function'
* patch 'iio: buffer-dma: Add mmap support'
   - unwind free on error path in iio_dma_buffer_alloc_blocks()
   - removed double mm.h include
* patch 'tools: iio: add example for high-speed buffer support'
   - call IIO_BUFFER_BLOCK_FREE_IOCTL on the error path of the
     enable_high_speed() function

Changelog v1 -> v2:
* https://lore.kernel.org/linux-iio/20210211123353.78963-1-alexandru.ardelean@analog.com/T/#t
* removed IIO_BUFFER_BLOCK_FLAG_CYCLIC flag; will be added in a later
  patch
* removed extra line in tools/iio/iio_generic_buffer.c
* patch 'iio: core: Add mmap interface infrastructure'
  added docstrings for new hooks (alloc_blocks, mmap, etc)

This is basically Lars' work adapted from branch:
  https://github.com/larsclausen/linux/commits/iio-high-speed-5.10
[hopefully i got the stuff correctly from that branch]

What is different, is that this one is adapted on top of the multibuffer
support (currently at v5) discussed here:
  https://lore.kernel.org/linux-iio/20210211122452.78106-1-alexandru.ardelean@analog.com/T/#t

Also, adapted an example for high-speed/mmap support in
'tools/iio/iio_generic_buffer.c'

The example is adapted from libiio:
  https://github.com/analogdevicesinc/libiio/blob/master/local.c#L51
but will all the ioctl()s organized after the one that are reserved
(hopefully) for IIO

Tested that mmap() works.
Moved (artifically) valid buffer0 as buffer2 and the operation still
works.

Alexandru Ardelean (3):
  Documentation: iio: add doc for high-speed buffer API
  iio: buffer-dma: split iio_dma_buffer_fileio_free() function
  tools: iio: add example for high-speed buffer support

Lars-Peter Clausen (2):
  iio: core: Add mmap interface infrastructure
  iio: buffer-dma: Add mmap support

 Documentation/iio/iio_high_speed_buffers.rst  | 100 ++++++
 Documentation/iio/index.rst                   |   2 +
 drivers/iio/buffer/industrialio-buffer-dma.c  | 324 ++++++++++++++++--
 .../buffer/industrialio-buffer-dmaengine.c    |  22 +-
 drivers/iio/industrialio-buffer.c             | 158 +++++++++
 include/linux/iio/buffer-dma.h                |  27 +-
 include/linux/iio/buffer_impl.h               |  23 ++
 include/uapi/linux/iio/buffer.h               |  49 +++
 tools/iio/iio_generic_buffer.c                | 184 +++++++++-
 9 files changed, 841 insertions(+), 48 deletions(-)
 create mode 100644 Documentation/iio/iio_high_speed_buffers.rst

Comments

Jonathan Cameron Feb. 16, 2021, 8 p.m. UTC | #1 
On Mon, 15 Feb 2021 16:32:29 +0200
Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:


Hi Alex,

I'm a little nervous about adding the userspace interface used in this
series, but it seems reasonable and as you say below, is close to what
Analog have been using for years.

So I've applied it to the togreg branch of iio.git and pushed out as
testing as normal.   I'm not going to push that out as anything I can't
rebase for at least a few weeks, so if anyone else wants to take a look
that would be great.  

One slight tweak was needed. I forced it with min_t(size_t,...
as it should always be at least as bit as __u32 so should be fine.

  CHECK   drivers/iio/industrialio-core.c
In file included from ./include/linux/kernel.h:14,
                 from ./include/asm-generic/bug.h:20,
                 from ./arch/x86/include/asm/bug.h:93,
                 from ./include/linux/bug.h:5,
                 from ./include/linux/mmdebug.h:5,
                 from ./include/linux/gfp.h:5,
                 from ./include/linux/slab.h:15,
                 from drivers/iio/buffer/industrialio-buffer-dmaengine.c:7:
drivers/iio/buffer/industrialio-buffer-dmaengine.c: In function ‘iio_dmaengine_buffer_submit_block’:
./include/linux/minmax.h:18:28: warning: comparison of distinct pointer types lacks a cast
   18 |  (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1))) 
      |                            ^~
./include/linux/minmax.h:32:4: note: in expansion of macro ‘__typecheck’
   32 |   (__typecheck(x, y) && __no_side_effects(x, y))
      |    ^~~~~~~~~~~
./include/linux/minmax.h:42:24: note: in expansion of macro ‘__safe_cmp’
   42 |  __builtin_choose_expr(__safe_cmp(x, y), \
      |                        ^~~~~~~~~~
./include/linux/minmax.h:51:19: note: in expansion of macro ‘__careful_cmp’
   51 | #define min(x, y) __careful_cmp(x, y, <)
      |                   ^~~~~~~~~~~~~
drivers/iio/buffer/industrialio-buffer-dmaengine.c:69:28: note: in expansion of macro ‘min’
   69 |  block->block.bytes_used = min(block->block.size,
      |                            ^~~
  CHECK   drivers/iio/buffer/industrialio-buffer-dmaengine.c
  CHECK   drivers/iio/industrialio-buffer.c
drivers/iio/buffer/industrialio-buffer-dmaengine.c:69:35: error: incompatible types in comparison expression (different type sizes):
drivers/iio/buffer/industrialio-buffer-dmaengine.c:69:35:    unsigned int *
drivers/iio/buffer/industrialio-buffer-dmaengine.c:69:35:    unsigned long *

Thanks,

Jonathan
 

> Changelog v2 -> v3:
> * https://lore.kernel.org/linux-iio/20210212101143.18993-1-alexandru.ardelean@analog.com/T/#u
> * added 'Documentation: iio: add doc for high-speed buffer API'
> * add 'iio: buffer-dma: split iio_dma_buffer_fileio_free() function'
> * patch 'iio: buffer-dma: Add mmap support'
>    - unwind free on error path in iio_dma_buffer_alloc_blocks()
>    - removed double mm.h include
> * patch 'tools: iio: add example for high-speed buffer support'
>    - call IIO_BUFFER_BLOCK_FREE_IOCTL on the error path of the
>      enable_high_speed() function
> 
> Changelog v1 -> v2:
> * https://lore.kernel.org/linux-iio/20210211123353.78963-1-alexandru.ardelean@analog.com/T/#t
> * removed IIO_BUFFER_BLOCK_FLAG_CYCLIC flag; will be added in a later
>   patch
> * removed extra line in tools/iio/iio_generic_buffer.c
> * patch 'iio: core: Add mmap interface infrastructure'
>   added docstrings for new hooks (alloc_blocks, mmap, etc)
> 
> This is basically Lars' work adapted from branch:
>   https://github.com/larsclausen/linux/commits/iio-high-speed-5.10
> [hopefully i got the stuff correctly from that branch]
> 
> What is different, is that this one is adapted on top of the multibuffer
> support (currently at v5) discussed here:
>   https://lore.kernel.org/linux-iio/20210211122452.78106-1-alexandru.ardelean@analog.com/T/#t
> 
> Also, adapted an example for high-speed/mmap support in
> 'tools/iio/iio_generic_buffer.c'
> 
> The example is adapted from libiio:
>   https://github.com/analogdevicesinc/libiio/blob/master/local.c#L51
> but will all the ioctl()s organized after the one that are reserved
> (hopefully) for IIO
> 
> Tested that mmap() works.
> Moved (artifically) valid buffer0 as buffer2 and the operation still
> works.
> 
> Alexandru Ardelean (3):
>   Documentation: iio: add doc for high-speed buffer API
>   iio: buffer-dma: split iio_dma_buffer_fileio_free() function
>   tools: iio: add example for high-speed buffer support
> 
> Lars-Peter Clausen (2):
>   iio: core: Add mmap interface infrastructure
>   iio: buffer-dma: Add mmap support
> 
>  Documentation/iio/iio_high_speed_buffers.rst  | 100 ++++++
>  Documentation/iio/index.rst                   |   2 +
>  drivers/iio/buffer/industrialio-buffer-dma.c  | 324 ++++++++++++++++--
>  .../buffer/industrialio-buffer-dmaengine.c    |  22 +-
>  drivers/iio/industrialio-buffer.c             | 158 +++++++++
>  include/linux/iio/buffer-dma.h                |  27 +-
>  include/linux/iio/buffer_impl.h               |  23 ++
>  include/uapi/linux/iio/buffer.h               |  49 +++
>  tools/iio/iio_generic_buffer.c                | 184 +++++++++-
>  9 files changed, 841 insertions(+), 48 deletions(-)
>  create mode 100644 Documentation/iio/iio_high_speed_buffers.rst
>
Alexandru Ardelean Feb. 17, 2021, 7:18 a.m. UTC | #2 
On Tue, Feb 16, 2021 at 10:02 PM Jonathan Cameron <jic23@kernel.org> wrote:
>
> On Mon, 15 Feb 2021 16:32:29 +0200
> Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:
>
>
> Hi Alex,
>
> I'm a little nervous about adding the userspace interface used in this
> series, but it seems reasonable and as you say below, is close to what
> Analog have been using for years.
>
> So I've applied it to the togreg branch of iio.git and pushed out as
> testing as normal.   I'm not going to push that out as anything I can't
> rebase for at least a few weeks, so if anyone else wants to take a look
> that would be great.
>

Oops.
I actually was preparing a new version yesterday with a fix for this
and a few tweaks.
This issue seems to appear on 64 bit only.

Will send it.


> One slight tweak was needed. I forced it with min_t(size_t,...
> as it should always be at least as bit as __u32 so should be fine.
>
>   CHECK   drivers/iio/industrialio-core.c
> In file included from ./include/linux/kernel.h:14,
>                  from ./include/asm-generic/bug.h:20,
>                  from ./arch/x86/include/asm/bug.h:93,
>                  from ./include/linux/bug.h:5,
>                  from ./include/linux/mmdebug.h:5,
>                  from ./include/linux/gfp.h:5,
>                  from ./include/linux/slab.h:15,
>                  from drivers/iio/buffer/industrialio-buffer-dmaengine.c:7:
> drivers/iio/buffer/industrialio-buffer-dmaengine.c: In function ‘iio_dmaengine_buffer_submit_block’:
> ./include/linux/minmax.h:18:28: warning: comparison of distinct pointer types lacks a cast
>    18 |  (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
>       |                            ^~
> ./include/linux/minmax.h:32:4: note: in expansion of macro ‘__typecheck’
>    32 |   (__typecheck(x, y) && __no_side_effects(x, y))
>       |    ^~~~~~~~~~~
> ./include/linux/minmax.h:42:24: note: in expansion of macro ‘__safe_cmp’
>    42 |  __builtin_choose_expr(__safe_cmp(x, y), \
>       |                        ^~~~~~~~~~
> ./include/linux/minmax.h:51:19: note: in expansion of macro ‘__careful_cmp’
>    51 | #define min(x, y) __careful_cmp(x, y, <)
>       |                   ^~~~~~~~~~~~~
> drivers/iio/buffer/industrialio-buffer-dmaengine.c:69:28: note: in expansion of macro ‘min’
>    69 |  block->block.bytes_used = min(block->block.size,
>       |                            ^~~
>   CHECK   drivers/iio/buffer/industrialio-buffer-dmaengine.c
>   CHECK   drivers/iio/industrialio-buffer.c
> drivers/iio/buffer/industrialio-buffer-dmaengine.c:69:35: error: incompatible types in comparison expression (different type sizes):
> drivers/iio/buffer/industrialio-buffer-dmaengine.c:69:35:    unsigned int *
> drivers/iio/buffer/industrialio-buffer-dmaengine.c:69:35:    unsigned long *
>
> Thanks,
>
> Jonathan
>
>
> > Changelog v2 -> v3:
> > * https://lore.kernel.org/linux-iio/20210212101143.18993-1-alexandru.ardelean@analog.com/T/#u
> > * added 'Documentation: iio: add doc for high-speed buffer API'
> > * add 'iio: buffer-dma: split iio_dma_buffer_fileio_free() function'
> > * patch 'iio: buffer-dma: Add mmap support'
> >    - unwind free on error path in iio_dma_buffer_alloc_blocks()
> >    - removed double mm.h include
> > * patch 'tools: iio: add example for high-speed buffer support'
> >    - call IIO_BUFFER_BLOCK_FREE_IOCTL on the error path of the
> >      enable_high_speed() function
> >
> > Changelog v1 -> v2:
> > * https://lore.kernel.org/linux-iio/20210211123353.78963-1-alexandru.ardelean@analog.com/T/#t
> > * removed IIO_BUFFER_BLOCK_FLAG_CYCLIC flag; will be added in a later
> >   patch
> > * removed extra line in tools/iio/iio_generic_buffer.c
> > * patch 'iio: core: Add mmap interface infrastructure'
> >   added docstrings for new hooks (alloc_blocks, mmap, etc)
> >
> > This is basically Lars' work adapted from branch:
> >   https://github.com/larsclausen/linux/commits/iio-high-speed-5.10
> > [hopefully i got the stuff correctly from that branch]
> >
> > What is different, is that this one is adapted on top of the multibuffer
> > support (currently at v5) discussed here:
> >   https://lore.kernel.org/linux-iio/20210211122452.78106-1-alexandru.ardelean@analog.com/T/#t
> >
> > Also, adapted an example for high-speed/mmap support in
> > 'tools/iio/iio_generic_buffer.c'
> >
> > The example is adapted from libiio:
> >   https://github.com/analogdevicesinc/libiio/blob/master/local.c#L51
> > but will all the ioctl()s organized after the one that are reserved
> > (hopefully) for IIO
> >
> > Tested that mmap() works.
> > Moved (artifically) valid buffer0 as buffer2 and the operation still
> > works.
> >
> > Alexandru Ardelean (3):
> >   Documentation: iio: add doc for high-speed buffer API
> >   iio: buffer-dma: split iio_dma_buffer_fileio_free() function
> >   tools: iio: add example for high-speed buffer support
> >
> > Lars-Peter Clausen (2):
> >   iio: core: Add mmap interface infrastructure
> >   iio: buffer-dma: Add mmap support
> >
> >  Documentation/iio/iio_high_speed_buffers.rst  | 100 ++++++
> >  Documentation/iio/index.rst                   |   2 +
> >  drivers/iio/buffer/industrialio-buffer-dma.c  | 324 ++++++++++++++++--
> >  .../buffer/industrialio-buffer-dmaengine.c    |  22 +-
> >  drivers/iio/industrialio-buffer.c             | 158 +++++++++
> >  include/linux/iio/buffer-dma.h                |  27 +-
> >  include/linux/iio/buffer_impl.h               |  23 ++
> >  include/uapi/linux/iio/buffer.h               |  49 +++
> >  tools/iio/iio_generic_buffer.c                | 184 +++++++++-
> >  9 files changed, 841 insertions(+), 48 deletions(-)
> >  create mode 100644 Documentation/iio/iio_high_speed_buffers.rst
> >
>