Commit Graph

4 Commits

Author SHA1 Message Date
Dan Williams
c211092313 dmaengine: driver for the iop32x, iop33x, and iop13xx raid engines
The Intel(R) IOP series of i/o processors integrate an Xscale core with
raid acceleration engines.  The capabilities per platform are:

iop219:
 (2) copy engines
iop321:
 (2) copy engines
 (1) xor and block fill engine
iop33x:
 (2) copy and crc32c engines
 (1) xor, xor zero sum, pq, pq zero sum, and block fill engine
iop34x (iop13xx):
 (2) copy, crc32c, xor, xor zero sum, and block fill engines
 (1) copy, crc32c, xor, xor zero sum, pq, pq zero sum, and block fill engine

The driver supports the features of the async_tx api:
* asynchronous notification of operation completion
* implicit (interupt triggered) handling of inter-channel transaction
  dependencies

The driver adapts to the platform it is running by two methods.
1/ #include <asm/arch/adma.h> which defines the hardware specific
   iop_chan_* and iop_desc_* routines as a series of static inline
   functions
2/ The private platform data attached to the platform_device defines the
   capabilities of the channels

20070626: Callbacks are run in a tasklet.  Given the recent discussion on
LKML about killing tasklets in favor of workqueues I did a quick conversion
of the driver.  Raid5 resync performance dropped from 50MB/s to 30MB/s, so
the tasklet implementation remains until a generic softirq interface is
available.

Changelog:
* fixed a slot allocation bug in do_iop13xx_adma_xor that caused too few
slots to be requested eventually leading to data corruption
* enabled the slot allocation routine to attempt to free slots before
returning -ENOMEM
* switched the cleanup routine to solely use the software chain and the
status register to determine if a descriptor is complete.  This is
necessary to support other IOP engines that do not have status writeback
capability
* make the driver iop generic
* modified the allocation routines to understand allocating a group of
slots for a single operation
* added a null xor initialization operation for the xor only channel on
iop3xx
* support xor operations on buffers larger than the hardware maximum
* split the do_* routines into separate prep, src/dest set, submit stages
* added async_tx support (dependent operations initiation at cleanup time)
* simplified group handling
* added interrupt support (callbacks via tasklets)
* brought the pending depth inline with ioat (i.e. 4 descriptors)
* drop dma mapping methods, suggested by Chris Leech
* don't use inline in C files, Adrian Bunk
* remove static tasklet declarations
* make iop_adma_alloc_slots easier to read and remove chances for a
  corrupted descriptor chain
* fix locking bug in iop_adma_alloc_chan_resources, Benjamin Herrenschmidt
* convert capabilities over to dma_cap_mask_t
* fixup sparse warnings
* add descriptor flush before iop_chan_enable
* checkpatch.pl fixes
* gpl v2 only correction
* move set_src, set_dest, submit to async_tx methods
* move group_list and phys to async_tx

Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2007-07-13 08:06:18 -07:00
Chris Leech
de5506e155 [I/OAT]: Utility functions for offloading sk_buff to iovec copies
Provides for pinning user space pages in memory, copying to iovecs,
and copying from sk_buffs including fragmented and chained sk_buffs.

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:25:46 -07:00
Chris Leech
0bbd5f4e97 [I/OAT]: Driver for the Intel(R) I/OAT DMA engine
Adds a new ioatdma driver

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:18:46 -07:00
Chris Leech
c13c8260da [I/OAT]: DMA memcpy subsystem
Provides an API for offloading memory copies to DMA devices

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:18:43 -07:00