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The LITMUS^RT kernel.

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author	David Daney <david.daney@cavium.com>	2011-11-22 09:46:14 -0500
committer	Ralf Baechle <ralf@linux-mips.org>	2011-12-07 17:03:28 -0500
commit	506d24be55d510c7ff79a0cdcabd00649b979bc9 (patch)
tree	be0beb75a03e77beaade87ce1eb4a5b9e7521b4a /tools/perf/scripts/python
parent	5611cc4572e889b62a7b4c72a413536bf6a9c416 (diff)

MIPS: Octeon: Update struct cvmx_bootinfo to v3.

Bootloaders can pass version 3 of this structure. Add the new fields so we can support the Device Tree. Signed-off-by: David Daney <david.daney@cavium.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/2938/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Diffstat (limited to 'tools/perf/scripts/python')

0 files changed, 0 insertions, 0 deletions

apos;t dereference the pointer returned by dma_alloc_attr(). You can threat it as a cookie that must be passed to dma_mmap_attrs() and dma_free_attrs(). Make sure that both of these also get this attribute set on each call. Since it is optional for platforms to implement DMA_ATTR_NO_KERNEL_MAPPING, those that do not will simply ignore the attribute and exhibit default behavior. DMA_ATTR_SKIP_CPU_SYNC ---------------------- By default dma_map_{single,page,sg} functions family transfer a given buffer from CPU domain to device domain. Some advanced use cases might require sharing a buffer between more than one device. This requires having a mapping created separately for each device and is usually performed by calling dma_map_{single,page,sg} function more than once for the given buffer with device pointer to each device taking part in the buffer sharing. The first call transfers a buffer from 'CPU' domain to 'device' domain, what synchronizes CPU caches for the given region (usually it means that the cache has been flushed or invalidated depending on the dma direction). However, next calls to dma_map_{single,page,sg}() for other devices will perform exactly the same sychronization operation on the CPU cache. CPU cache sychronization might be a time consuming operation, especially if the buffers are large, so it is highly recommended to avoid it if possible. DMA_ATTR_SKIP_CPU_SYNC allows platform code to skip synchronization of the CPU cache for the given buffer assuming that it has been already transferred to 'device' domain. This attribute can be also used for dma_unmap_{single,page,sg} functions family to force buffer to stay in device domain after releasing a mapping for it. Use this attribute with care!


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