[PATCH v3 00/15] dmaengine: Support polling for out of order completions

From: Ben Walker
Date: Wed Jun 22 2022 - 14:53:05 EST


This series adds support for polling async transactions for completion
even if interrupts are disabled and transactions can complete out of
order.

To do this, all DMA client assumptions about the behavior of
dma_cookie_t have to be removed. Prior to this series, dma_cookie_t was
a monotonically increasing integer and cookies could be compared to one
another to determine if earlier operations had completed (up until the
cookie wraps around, then it would break).

Fortunately, only one out of the many, many DMA clients had any
dependency on dma_cookie_t being anything more than an opaque handle.
This is the pxa_camera driver and it is dealt with in patch 7 of this
series.

The series also does some API clean up and documents how dma_cookie_t
should behave (i.e. there are no rules, it's just a handle).

This closes out by adding support for .device_tx_status() to the idxd
driver and then reverting the DMA_OUT_OF_ORDER patch that previously
allowed idxd to opt-out of support for polling, which I think is a nice
overall simplification to the dmaengine API.

Changes since version 2:
- None. Rebased as requested without conflict.

Changes since version 1:
- Broke up the change to remove dma_async_is_tx_complete into a single
patch for each driver
- Renamed dma_async_is_tx_complete to dmaengine_async_is_tx_complete.

Ben Walker (15):
dmaengine: Remove dma_async_is_complete from client API
dmaengine: Move dma_set_tx_state to the provider API header
dmaengine: Add dmaengine_async_is_tx_complete
crypto: stm32/hash: Use dmaengine_async_is_tx_complete
media: omap_vout: Use dmaengine_async_is_tx_complete
rapidio: Use dmaengine_async_is_tx_complete
media: pxa_camera: Use dmaengine_async_is_tx_complete
dmaengine: Remove dma_async_is_tx_complete
dmaengine: Remove last, used from dma_tx_state
dmaengine: Providers should prefer dma_set_residue over
dma_set_tx_state
dmaengine: Remove dma_set_tx_state
dmaengine: Add provider documentation on cookie assignment
dmaengine: idxd: idxd_desc.id is now a u16
dmaengine: idxd: Support device_tx_status
dmaengine: Revert "cookie bypass for out of order completion"

Documentation/driver-api/dmaengine/client.rst | 24 ++----
.../driver-api/dmaengine/provider.rst | 64 ++++++++------
drivers/crypto/stm32/stm32-hash.c | 3 +-
drivers/dma/amba-pl08x.c | 1 -
drivers/dma/at_hdmac.c | 3 +-
drivers/dma/dmaengine.c | 2 +-
drivers/dma/dmaengine.h | 12 ++-
drivers/dma/dmatest.c | 14 +--
drivers/dma/idxd/device.c | 1 +
drivers/dma/idxd/dma.c | 86 ++++++++++++++++++-
drivers/dma/idxd/idxd.h | 3 +-
drivers/dma/imx-sdma.c | 3 +-
drivers/dma/mmp_tdma.c | 3 +-
drivers/dma/mxs-dma.c | 3 +-
drivers/media/platform/intel/pxa_camera.c | 15 +++-
.../media/platform/ti/omap/omap_vout_vrfb.c | 2 +-
drivers/rapidio/devices/rio_mport_cdev.c | 3 +-
include/linux/dmaengine.h | 58 +------------
18 files changed, 164 insertions(+), 136 deletions(-)

--
2.35.1