2820a708d5
So far the IOC treatment was global on ARC, being turned on (or off)
for all devices in the system. With this patch, this can now be done
per device using the "dma-coherent" DT property; IOW with this patch
we can use both HW-coherent and regular DMA peripherals simultaneously.
The changes involved are too many so enlisting the summary below:
1. common code calls ARC arch_setup_dma_ops() per device.
2. For coherent dma (IOC) it plugs in generic @dma_direct_ops which
doesn't need any arch specific backend: No need for any explicit
cache flushes or MMU mappings to provide for uncached access
- dma_(map|sync)_single* return early as corresponding dma ops callbacks
are NULL in generic code.
So arch_sync_dma_*() -> dma_cache_*() need not handle the coherent
dma case, hence drop ARC __dma_cache_*_ioc() which were no-op anyways
3. For noncoherent dma (non IOC) generic @dma_noncoherent_ops is used
which in turns calls ARC specific routines
- arch_dma_alloc() no longer checks for @ioc_enable since this is
called only for !IOC case.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: rewrote changelog]
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| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
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| COPYING | ||
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| Kbuild | ||
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| Makefile | ||
| README | ||
README
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 Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
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.