linux/crypto/async_tx
NeilBrown 5dd33c9a4c md/async: don't pass a memory pointer as a page pointer.
md/raid6 passes a list of 'struct page *' to the async_tx routines,
which then either DMA map them for offload, or take the page_address
for CPU based calculations.

For RAID6 we sometime leave 'blanks' in the list of pages.
For CPU based calcs, we want to treat theses as a page of zeros.
For offloaded calculations, we simply don't pass a page to the
hardware.

Currently the 'blanks' are encoded as a pointer to
raid6_empty_zero_page.  This is a 4096 byte memory region, not a
'struct page'.  This is mostly handled correctly but is rather ugly.

So change the code to pass and expect a NULL pointer for the blanks.
When taking page_address of a page, we need to check for a NULL and
in that case use raid6_empty_zero_page.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-10-16 16:40:25 +11:00
..
Kconfig async_tx: add support for asynchronous RAID6 recovery operations 2009-08-29 19:09:27 -07:00
Makefile async_tx: raid6 recovery self test 2009-08-29 19:09:28 -07:00
async_memcpy.c dmaengine, async_tx: support alignment checks 2009-09-08 17:42:53 -07:00
async_memset.c dmaengine, async_tx: support alignment checks 2009-09-08 17:42:53 -07:00
async_pq.c md/async: don't pass a memory pointer as a page pointer. 2009-10-16 16:40:25 +11:00
async_raid6_recov.c md/async: don't pass a memory pointer as a page pointer. 2009-10-16 16:40:25 +11:00
async_tx.c dmaengine, async_tx: add a "no channel switch" allocator 2009-09-08 17:42:51 -07:00
async_xor.c dmaengine, async_tx: support alignment checks 2009-09-08 17:42:53 -07:00
raid6test.c raid6test: fix stack overflow 2009-09-16 21:03:29 -07:00