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f7c924aba3
ipu6_mmu_map() operated on a per-page basis, it leads frequent spin_lock/unlock() and clflush_cache_range() for each page, it will cause inefficiencies especially when handling dma-bufs with large number of pages. However, the pages are likely concentrated pages by IOMMU DMA driver, IPU MMU driver can map the concentrated pages into less entries in l1 table. This change enhances ipu6_mmu_map() with batching process multiple contiguous pages. It significantly reduces calls for spin_lock/unlock and clflush_cache_range() and improve the performance. Signed-off-by: Bingbu Cao <bingbu.cao@intel.com> Signed-off-by: Jianhui Dai <jianhui.j.dai@intel.com> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.