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| author | Ian Abbott <abbotti@mev.co.uk> | 2025-04-15 14:35:58 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-04-25 16:53:19 +0300 |
| commit | 5117f28a7d78d00a44d03463115a0f295dbbb1ff (patch) | |
| tree | 6e05a8620ad468ffec943c7f0b34d300cbc26361 /include | |
| parent | e7199b6b591eead7dc516a639a5b618f1e3cd207 (diff) | |
| download | linux-5117f28a7d78d00a44d03463115a0f295dbbb1ff.tar.xz | |
comedi: remove the mapping of the Comedi buffer in vmalloc address space
Now that all the code that accesses the Comedi buffer data does so
page-by-page, using the `virt_addr` member of `struct comedi_buf_page`
to point to the data of each page, do not linearly map the buffer into
vmalloc address space (pointed to by the `prealloc_buf` member of
`struct comedi_async`). That was only done for convenience, but was not
done for those drivers that need a DMA coherent buffer, which is
allocated in a single chunk. Remove the `prealloc_buf` member as it is
no longer used.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20250415114008.5977-4-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/comedi/comedidev.h | 10 |
1 files changed, 2 insertions, 8 deletions
diff --git a/include/linux/comedi/comedidev.h b/include/linux/comedi/comedidev.h index c08416a7364b..4cb0400ad616 100644 --- a/include/linux/comedi/comedidev.h +++ b/include/linux/comedi/comedidev.h @@ -234,16 +234,12 @@ struct comedi_buf_page { * * A COMEDI data buffer is allocated as individual pages, either in * conventional memory or DMA coherent memory, depending on the attached, - * low-level hardware device. (The buffer pages also get mapped into the - * kernel's contiguous virtual address space pointed to by the 'prealloc_buf' - * member of &struct comedi_async.) + * low-level hardware device. * * The buffer is normally freed when the COMEDI device is detached from the * low-level driver (which may happen due to device removal), but if it happens * to be mmapped at the time, the pages cannot be freed until the buffer has - * been munmapped. That is what the reference counter is for. (The virtual - * address space pointed by 'prealloc_buf' is freed when the COMEDI device is - * detached.) + * been munmapped. That is what the reference counter is for. */ struct comedi_buf_map { struct device *dma_hw_dev; @@ -255,7 +251,6 @@ struct comedi_buf_map { /** * struct comedi_async - Control data for asynchronous COMEDI commands - * @prealloc_buf: Kernel virtual address of allocated acquisition buffer. * @prealloc_bufsz: Buffer size (in bytes). * @buf_map: Map of buffer pages. * @max_bufsize: Maximum allowed buffer size (in bytes). @@ -344,7 +339,6 @@ struct comedi_buf_map { * less than or equal to UINT_MAX). */ struct comedi_async { - void *prealloc_buf; unsigned int prealloc_bufsz; struct comedi_buf_map *buf_map; unsigned int max_bufsize; |