From 7405f74badf46b5d023c5d2b670b4471525f6c91 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 2 Jan 2007 11:10:43 -0700 Subject: dmaengine: refactor dmaengine around dma_async_tx_descriptor The current dmaengine interface defines mutliple routines per operation, i.e. dma_async_memcpy_buf_to_buf, dma_async_memcpy_buf_to_page etc. Adding more operation types (xor, crc, etc) to this model would result in an unmanageable number of method permutations. Are we really going to add a set of hooks for each DMA engine whizbang feature? - Jeff Garzik The descriptor creation process is refactored using the new common dma_async_tx_descriptor structure. Instead of per driver do___to_ methods, drivers integrate dma_async_tx_descriptor into their private software descriptor and then define a 'prep' routine per operation. The prep routine allocates a descriptor and ensures that the tx_set_src, tx_set_dest, tx_submit routines are valid. Descriptor creation and submission becomes: struct dma_device *dev; struct dma_chan *chan; struct dma_async_tx_descriptor *tx; tx = dev->device_prep_dma_(chan, len, int_flag) tx->tx_set_src(dma_addr_t, tx, index /* for multi-source ops */) tx->tx_set_dest(dma_addr_t, tx, index) tx->tx_submit(tx) In addition to the refactoring, dma_async_tx_descriptor also lays the groundwork for definining cross-channel-operation dependencies, and a callback facility for asynchronous notification of operation completion. Changelog: * drop dma mapping methods, suggested by Chris Leech * fix ioat_dma_dependency_added, also caught by Andrew Morton * fix dma_sync_wait, change from Andrew Morton * uninline large functions, change from Andrew Morton * add tx->callback = NULL to dmaengine calls to interoperate with async_tx calls * hookup ioat_tx_submit * convert channel capabilities to a 'cpumask_t like' bitmap * removed DMA_TX_ARRAY_INIT, no longer needed * checkpatch.pl fixes * make set_src, set_dest, and tx_submit descriptor specific methods * fixup git-ioat merge * move group_list and phys to dma_async_tx_descriptor Cc: Jeff Garzik Cc: Chris Leech Signed-off-by: Shannon Nelson Signed-off-by: Dan Williams Acked-by: David S. Miller --- drivers/dma/ioatdma.h | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'drivers/dma/ioatdma.h') diff --git a/drivers/dma/ioatdma.h b/drivers/dma/ioatdma.h index 62b26a9be4c9..d3f69bb15fa0 100644 --- a/drivers/dma/ioatdma.h +++ b/drivers/dma/ioatdma.h @@ -105,21 +105,20 @@ struct ioat_dma_chan { /** * struct ioat_desc_sw - wrapper around hardware descriptor * @hw: hardware DMA descriptor - * @node: - * @cookie: - * @phys: + * @node: this descriptor will either be on the free list, + * or attached to a transaction list (async_tx.tx_list) + * @tx_cnt: number of descriptors required to complete the transaction + * @async_tx: the generic software descriptor for all engines */ - struct ioat_desc_sw { struct ioat_dma_descriptor *hw; struct list_head node; - dma_cookie_t cookie; - dma_addr_t phys; + int tx_cnt; DECLARE_PCI_UNMAP_ADDR(src) DECLARE_PCI_UNMAP_LEN(src_len) DECLARE_PCI_UNMAP_ADDR(dst) DECLARE_PCI_UNMAP_LEN(dst_len) + struct dma_async_tx_descriptor async_tx; }; #endif /* IOATDMA_H */ - -- cgit v1.2.3