user/sven/linux.git/include/linux/dmaengine.h, branch v2.6.27.8

async_tx: make async_tx_test_ack a boolean routine

2008-07-18T00:59:56Z

Signed-off-by: Dan Williams

dmaengine: Add slave DMA interface

2008-07-08T18:59:35Z

This patch adds the necessary interfaces to the DMA Engine framework to use functionality found on most embedded DMA controllers: DMA from and to I/O registers with hardware handshaking. In this context, hardware hanshaking means that the peripheral that owns the I/O registers in question is able to tell the DMA controller when more data is available for reading, or when there is room for more data to be written. This usually happens internally on the chip, but these signals may also be exported outside the chip for things like IDE DMA, etc. A new struct dma_slave is introduced. This contains information that the DMA engine driver needs to set up slave transfers to and from a slave device. Most engines supporting DMA slave transfers will want to extend this structure with controller-specific parameters. This additional information is usually passed from the platform/board code through the client driver. A "slave" pointer is added to the dma_client struct. This must point to a valid dma_slave structure iff the DMA_SLAVE capability is requested. The DMA engine driver may use this information in its device_alloc_chan_resources hook to configure the DMA controller for slave transfers from and to the given slave device. A new operation for preparing slave DMA transfers is added to struct dma_device. This takes a scatterlist and returns a single descriptor representing the whole transfer. Another new operation for terminating all pending transfers is added as well. The latter is needed because there may be errors outside the scope of the DMA Engine framework that may require DMA operations to be terminated prematurely. DMA Engine drivers may extend the dma_device, dma_chan and/or dma_slave_descriptor structures to allow controller-specific operations. The client driver can detect such extensions by looking at the DMA Engine's struct device, or it can request a specific DMA Engine device by setting the dma_dev field in struct dma_slave. dmaslave interface changes since v4: * Fix checkpatch errors * Fix changelog (there are no slave descriptors anymore) dmaslave interface changes since v3: * Use dma_data_direction instead of a new enum * Submit slave transfers as scatterlists * Remove the DMA slave descriptor struct dmaslave interface changes since v2: * Add a dma_dev field to struct dma_slave. If set, the client can only be bound to the DMA controller that corresponds to this device. This allows controller-specific extensions of the dma_slave structure; if the device matches, the controller may safely assume its extensions are present. * Move reg_width into struct dma_slave as there are currently no users that need to be able to set the width on a per-transfer basis. dmaslave interface changes since v1: * Drop the set_direction and set_width descriptor hooks. Pass the direction and width to the prep function instead. * Declare a dma_slave struct with fixed information about a slave, i.e. register addresses, handshake interfaces and such. * Add pointer to a dma_slave struct to dma_client. Can be NULL if the DMA_SLAVE capability isn't requested. * Drop the set_slave device hook since the alloc_chan_resources hook now has enough information to set up the channel for slave transfers. Acked-by: Maciej Sosnowski Signed-off-by: Haavard Skinnemoen Signed-off-by: Dan Williams

dmaengine: add DMA_COMPL_SKIP_{SRC,DEST}_UNMAP flags to control dma unmap

2008-07-08T18:59:12Z

In some cases client code may need the dma-driver to skip the unmap of source and/or destination buffers. Setting these flags indicates to the driver to skip the unmap step. In this regard async_xor is currently broken in that it allows the destination buffer to be unmapped while an operation is still in progress, i.e. when the number of sources exceeds the hardware channel's maximum (fixed in a subsequent patch). Acked-by: Saeed Bishara Acked-by: Maciej Sosnowski Acked-by: Haavard Skinnemoen Signed-off-by: Dan Williams

dmaengine: Add dma_client parameter to device_alloc_chan_resources

2008-07-08T18:58:58Z

A DMA controller capable of doing slave transfers may need to know a few things about the slave when preparing the channel. We don't want to add this information to struct dma_channel since the channel hasn't yet been bound to a client at this point. Instead, pass a reference to the client requesting the channel to the driver's device_alloc_chan_resources hook so that it can pick the necessary information from the dma_client struct by itself. [dan.j.williams@intel.com: fixed up fsldma and mv_xor] Acked-by: Maciej Sosnowski Signed-off-by: Haavard Skinnemoen Signed-off-by: Dan Williams

dmaengine: track the number of clients using a channel

2008-07-08T18:58:21Z

Haavard's dma-slave interface would like to test for exclusive access to a channel. The standard channel refcounting is not sufficient in that it tracks more than just client references, it is also inaccurate as reference counts are percpu until the channel is removed. This change also enables a future fix to deallocate resources when a client declines to use a capable channel. Acked-by: Haavard Skinnemoen Signed-off-by: Dan Williams

DMA engine: typo fixes

2008-04-21T22:38:45Z

Spelling fixes for dmaengine.[ch] Signed-off-by: Sebastian Siewior Acked-by: Maciej Sosnowski Signed-off-by: Jesper Juhl

dmaengine: ack to flags: make use of the unused bits in the 'ack' field

2008-04-17T20:25:54Z

'ack' is currently a simple integer that flags whether or not a client is done touching fields in the given descriptor. It is effectively just a single bit of information. Converting this to a flags parameter allows the other bits to be put to use to control completion actions, like dma-unmap, and capture results, like xor-zero-sum == 0. Changes are one of: 1/ convert all open-coded ->ack manipulations to use async_tx_ack and async_tx_test_ack. 2/ set the ack bit at prep time where possible 3/ make drivers store the flags at prep time 4/ add flags to the device_prep_dma_interrupt prototype Acked-by: Maciej Sosnowski Signed-off-by: Dan Williams

async_tx: kill ->device_dependency_added

2008-04-17T20:25:54Z

DMA drivers no longer need to be notified of dependency submission events as async_tx_run_dependencies and async_tx_channel_switch will handle the scheduling and execution of dependent operations. [sfr@canb.auug.org.au: extend this for fsldma] Acked-by: Shannon Nelson Signed-off-by: Dan Williams

async_tx: fix multiple dependency submission

2008-04-17T20:25:05Z

Shrink struct dma_async_tx_descriptor and introduce async_tx_channel_switch to properly inject a channel switch interrupt in the descriptor stream. This simplifies the locking model as drivers no longer need to handle dma_async_tx_descriptor.lock. Acked-by: Shannon Nelson Signed-off-by: Dan Williams

dma_page_list ->base_address is a userland pointer

2008-03-30T21:20:23Z

Signed-off-by: Al Viro Signed-off-by: Linus Torvalds