forked from Minki/linux
2492c84518
1 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> |