user/sven/linux.git/include/linux/scatterlist.h, branch v3.9

lib/scatterlist: use page iterator in the mapping iterator

2013-02-28T03:10:10Z

For better code reuse use the newly added page iterator to iterate through the pages. The offset, length within the page is still calculated by the mapping iterator as well as the actual mapping. Idea from Tejun Heo. Signed-off-by: Imre Deak Cc: Maxim Levitsky Cc: Tejun Heo Cc: Daniel Vetter Cc: James Hogan Cc: Stephen Warren Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib/scatterlist: add simple page iterator

2013-02-28T03:10:10Z

Add an iterator to walk through a scatter list a page at a time starting at a specific page offset. As opposed to the mapping iterator this is meant to be small, performing well even in simple loops like collecting all pages on the scatterlist into an array or setting up an iommu table based on the pages' DMA address. Signed-off-by: Imre Deak Cc: Maxim Levitsky Cc: Tejun Heo Cc: Daniel Vetter Tested-by: Stephen Warren Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

scatterlist: add sg_nents

2012-09-27T10:45:28Z

Useful helper to know the number of entries in scatterlist. Signed-off-by: Maxim Levitsky Cc: Alex Dubov Acked-by: Tejun Heo Cc: Jens Axboe Signed-off-by: Jens Axboe

scatterlist: add sg_alloc_table_from_pages function

2012-07-30T10:25:44Z

This patch adds a new constructor for an sg table. The table is constructed from an array of struct pages. All contiguous chunks of the pages are merged into a single sg nodes. A user may provide an offset and a size of a buffer if the buffer is not page-aligned. The function is dedicated for DMABUF exporters which often perform conversion from an page array to a scatterlist. Moreover the scatterlist should be squashed in order to save memory and to speed-up the process of DMA mapping using dma_map_sg. The code is based on the patch 'v4l: vb2-dma-contig: add support for scatterlist in userptr mode' and hints from Laurent Pinchart. Signed-off-by: Tomasz Stanislawski Signed-off-by: Kyungmin Park Acked-by: Daniel Vetter Acked-by: Laurent Pinchart Signed-off-by: Marek Szyprowski CC: Andrew Morton

BUG: headers with BUG/BUG_ON etc. need linux/bug.h

2012-03-04T22:54:34Z

If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any other BUG variant in a static inline (i.e. not in a #define) then that header really should be including and not just expecting it to be implicitly present. We can make this change risk-free, since if the files using these headers didn't have exposure to linux/bug.h already, they would have been causing compile failures/warnings. Signed-off-by: Paul Gortmaker

lib/scatterlist: add a flags to signalize mapping direction

2009-07-31T10:28:45Z

sg_miter_start() is currently unaware of the direction of the copy process (to or from the scatter list). It is important to know the direction because the page has to be flushed in case the data written is seen on a different mapping in user land on cache incoherent architectures. Signed-off-by: Sebastian Andrzej Siewior Acked-by: FUJITA Tomonori Acked-by: Tejun Heo Signed-off-by: Pierre Ossman

sg: reimplement sg mapping iterator

2008-07-23T12:42:09Z

This is alternative implementation of sg content iterator introduced by commit 83e7d317... from Pierre Ossman in next-20080716. As there's already an sg iterator which iterates over sg entries themselves, name this sg_mapping_iterator. Slightly edited description from the original implementation follows. Iteration over a sg list is not that trivial when you take into account that memory pages might have to be mapped before being used. Unfortunately, that means that some parts of the kernel restrict themselves to directly accesible memory just to not have to deal with the mess. This patch adds a simple iterator system that allows any code to easily traverse an sg list and not have to deal with all the details. The user can decide to consume part of the iteration. Also, iteration can be stopped and resumed later if releasing the kmap between iteration steps is necessary. These features are useful to implement piecemeal sg copying for interrupt drive PIO for example. Signed-off-by: Tejun Heo Signed-off-by: Pierre Ossman

[SCSI] block: add sg buffer copy helper functions

2008-04-07T17:15:45Z

This patch adds new three helper functions to copy data between an SG list and a linear buffer. - sg_copy_from_buffer copies data from linear buffer to an SG list - sg_copy_to_buffer copies data from an SG list to a linear buffer When the APIs copy data from a linear buffer to an SG list, flush_kernel_dcache_page is called. It's not necessary for everyone but it's a no-op on most architectures and in general the API is not used in performance critical path. Signed-off-by: FUJITA Tomonori Acked-by: Jens Axboe Signed-off-by: James Bottomley

SG: work with the SCSI fixed maximum allocations.

2008-01-28T09:54:49Z

SCSI sg table allocation has a maximum size (of SCSI_MAX_SG_SEGMENTS, currently 128) and this will cause a BUG_ON() in SCSI if something tries an allocation over it. This patch adds a size limit to the chaining allocator to allow the specification of the maximum allocation size for chaining, so we always chain in units of the maximum SCSI allocation size. Signed-off-by: James Bottomley Signed-off-by: Jens Axboe

SG: Move functions to lib/scatterlist.c and add sg chaining allocator helpers

2008-01-28T09:05:27Z

Manually doing chained sg lists is not trivial, so add some helpers to make sure that drivers get it right. Signed-off-by: Jens Axboe