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path: root/drivers/dma/ioat/registers.h
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2009-09-08ioat: switch watchdog and reset handler from workqueue to timerDan Williams
In order to support dynamic resizing of the descriptor ring or polling for a descriptor in the presence of a hung channel the reset handler needs to make progress while in a non-preemptible context. The current workqueue implementation precludes polling channel reset completion under spin_lock(). This conversion also allows us to return to opportunistic cleanup in the ioat2 case as the timer implementation guarantees at least one cleanup after every descriptor is submitted. This means the worst case completion latency becomes the timer frequency (for exceptional circumstances), but with the benefit of avoiding busy waiting when the lock is contended. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-08ioat: preserve chanctrl bits when re-arming interruptsDan Williams
The register write in ioat_dma_cleanup_tasklet is unfortunate in two ways: 1/ It clears the extra 'enable' bits that we set at alloc_chan_resources time 2/ It gives the impression that it disables interrupts when it is in fact re-arming interrupts [ Impact: fix, persist the value of the chanctrl register when re-arming ] Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-08ioat: cleanup completion status readsDan Williams
The cleanup path makes an effort to only perform an atomic read of the 64-bit completion address. However in the 32-bit case it does not matter if we read the upper-32 and lower-32 non-atomically because the upper-32 will always be zero. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-07-28ioat: move to drivers/dma/ioat/Dan Williams
When first created the ioat driver was the only inhabitant of drivers/dma/. Now, it is the only multi-file (more than a .c and a .h) driver in the directory. Moving it to an ioat/ subdirectory allows the naming convention to be cleaned up, and allows for future splitting of the source files by hardware version (v1, v2, and v3). Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>