From 074cc47679f8b0931d7d5384e95822d82768f149 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Sat, 1 May 2010 15:22:55 -0700 Subject: ioat2,3: convert to producer/consumer locking Use separate locks for the descriptor prep (producer) and descriptor cleanup (consumer) paths. Allows the producer path to run concurrently with the cleanup path. Inspired by Documentation/circular-buffer.txt. Cc: David Howells Cc: Paul E. McKenney Cc: Maciej Sosnowski Signed-off-by: Dan Williams --- drivers/dma/ioat/dma_v2.h | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) (limited to 'drivers/dma/ioat/dma_v2.h') diff --git a/drivers/dma/ioat/dma_v2.h b/drivers/dma/ioat/dma_v2.h index d7b64f1..a2c413b 100644 --- a/drivers/dma/ioat/dma_v2.h +++ b/drivers/dma/ioat/dma_v2.h @@ -50,8 +50,9 @@ extern int ioat_ring_alloc_order; * @tail: cleanup index * @dmacount: identical to 'head' except for occasionally resetting to zero * @alloc_order: log2 of the number of allocated descriptors + * @produce: number of descriptors to produce at submit time * @ring: software ring buffer implementation of hardware ring - * @ring_lock: protects ring attributes + * @prep_lock: serializes descriptor preparation (producers) */ struct ioat2_dma_chan { struct ioat_chan_common base; @@ -61,8 +62,9 @@ struct ioat2_dma_chan { u16 tail; u16 dmacount; u16 alloc_order; + u16 produce; struct ioat_ring_ent **ring; - spinlock_t ring_lock; + spinlock_t prep_lock; }; static inline struct ioat2_dma_chan *to_ioat2_chan(struct dma_chan *c) @@ -94,13 +96,6 @@ static inline u16 ioat2_ring_space(struct ioat2_dma_chan *ioat) return ioat2_ring_size(ioat) - ioat2_ring_active(ioat); } -/* assumes caller already checked space */ -static inline u16 ioat2_desc_alloc(struct ioat2_dma_chan *ioat, u16 len) -{ - ioat->head += len; - return ioat->head - len; -} - static inline u16 ioat2_xferlen_to_descs(struct ioat2_dma_chan *ioat, size_t len) { u16 num_descs = len >> ioat->xfercap_log; @@ -164,7 +159,7 @@ int __devinit ioat2_dma_probe(struct ioatdma_device *dev, int dca); int __devinit ioat3_dma_probe(struct ioatdma_device *dev, int dca); struct dca_provider * __devinit ioat2_dca_init(struct pci_dev *pdev, void __iomem *iobase); struct dca_provider * __devinit ioat3_dca_init(struct pci_dev *pdev, void __iomem *iobase); -int ioat2_alloc_and_lock(u16 *idx, struct ioat2_dma_chan *ioat, int num_descs); +int ioat2_check_space_lock(struct ioat2_dma_chan *ioat, int num_descs); int ioat2_enumerate_channels(struct ioatdma_device *device); struct dma_async_tx_descriptor * ioat2_dma_prep_memcpy_lock(struct dma_chan *c, dma_addr_t dma_dest, -- cgit v1.1