From e42d98ebe7d754a2c9fbccd6186721d3ca8679f6 Mon Sep 17 00:00:00 2001 From: Alexandre Bounine Date: Thu, 31 May 2012 16:26:38 -0700 Subject: [PATCH] rapidio: add DMA engine support for RIO data transfers Adds DMA Engine framework support into RapidIO subsystem. Uses DMA Engine DMA_SLAVE interface to generate data transfers to/from remote RapidIO target devices. Introduces RapidIO-specific wrapper for prep_slave_sg() interface with an extra parameter to pass target specific information. Uses scatterlist to describe local data buffer. Address flat data buffer on a remote side. Signed-off-by: Alexandre Bounine Cc: Dan Williams Acked-by: Vinod Koul Cc: Li Yang Cc: Matt Porter Cc: Paul Gortmaker Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rapidio/Kconfig | 14 +++++++ drivers/rapidio/rio.c | 81 +++++++++++++++++++++++++++++++++++++++ include/linux/dmaengine.h | 12 ++++++ include/linux/rio.h | 47 +++++++++++++++++++++++ include/linux/rio_drv.h | 9 +++++ 5 files changed, 163 insertions(+) diff --git a/drivers/rapidio/Kconfig b/drivers/rapidio/Kconfig index bc871923879..6194d35ebb9 100644 --- a/drivers/rapidio/Kconfig +++ b/drivers/rapidio/Kconfig @@ -22,6 +22,20 @@ config RAPIDIO_ENABLE_RX_TX_PORTS ports for Input/Output direction to allow other traffic than Maintenance transfers. +config RAPIDIO_DMA_ENGINE + bool "DMA Engine support for RapidIO" + depends on RAPIDIO + select DMADEVICES + select DMA_ENGINE + help + Say Y here if you want to use DMA Engine frameork for RapidIO data + transfers to/from target RIO devices. RapidIO uses NREAD and + NWRITE (NWRITE_R, SWRITE) requests to transfer data between local + memory and memory on remote target device. You need a DMA controller + capable to perform data transfers to/from RapidIO. + + If you are unsure about this, say Y here. + config RAPIDIO_DEBUG bool "RapidIO subsystem debug messages" depends on RAPIDIO diff --git a/drivers/rapidio/rio.c b/drivers/rapidio/rio.c index 86c9a091a2f..c40665a4fa3 100644 --- a/drivers/rapidio/rio.c +++ b/drivers/rapidio/rio.c @@ -1121,6 +1121,87 @@ int rio_std_route_clr_table(struct rio_mport *mport, u16 destid, u8 hopcount, return 0; } +#ifdef CONFIG_RAPIDIO_DMA_ENGINE + +static bool rio_chan_filter(struct dma_chan *chan, void *arg) +{ + struct rio_dev *rdev = arg; + + /* Check that DMA device belongs to the right MPORT */ + return (rdev->net->hport == + container_of(chan->device, struct rio_mport, dma)); +} + +/** + * rio_request_dma - request RapidIO capable DMA channel that supports + * specified target RapidIO device. + * @rdev: RIO device control structure + * + * Returns pointer to allocated DMA channel or NULL if failed. + */ +struct dma_chan *rio_request_dma(struct rio_dev *rdev) +{ + dma_cap_mask_t mask; + struct dma_chan *dchan; + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + dchan = dma_request_channel(mask, rio_chan_filter, rdev); + + return dchan; +} +EXPORT_SYMBOL_GPL(rio_request_dma); + +/** + * rio_release_dma - release specified DMA channel + * @dchan: DMA channel to release + */ +void rio_release_dma(struct dma_chan *dchan) +{ + dma_release_channel(dchan); +} +EXPORT_SYMBOL_GPL(rio_release_dma); + +/** + * rio_dma_prep_slave_sg - RapidIO specific wrapper + * for device_prep_slave_sg callback defined by DMAENGINE. + * @rdev: RIO device control structure + * @dchan: DMA channel to configure + * @data: RIO specific data descriptor + * @direction: DMA data transfer direction (TO or FROM the device) + * @flags: dmaengine defined flags + * + * Initializes RapidIO capable DMA channel for the specified data transfer. + * Uses DMA channel private extension to pass information related to remote + * target RIO device. + * Returns pointer to DMA transaction descriptor or NULL if failed. + */ +struct dma_async_tx_descriptor *rio_dma_prep_slave_sg(struct rio_dev *rdev, + struct dma_chan *dchan, struct rio_dma_data *data, + enum dma_transfer_direction direction, unsigned long flags) +{ + struct dma_async_tx_descriptor *txd = NULL; + struct rio_dma_ext rio_ext; + + if (dchan->device->device_prep_slave_sg == NULL) { + pr_err("%s: prep_rio_sg == NULL\n", __func__); + return NULL; + } + + rio_ext.destid = rdev->destid; + rio_ext.rio_addr_u = data->rio_addr_u; + rio_ext.rio_addr = data->rio_addr; + rio_ext.wr_type = data->wr_type; + + txd = dmaengine_prep_rio_sg(dchan, data->sg, data->sg_len, + direction, flags, &rio_ext); + + return txd; +} +EXPORT_SYMBOL_GPL(rio_dma_prep_slave_sg); + +#endif /* CONFIG_RAPIDIO_DMA_ENGINE */ + static void rio_fixup_device(struct rio_dev *dev) { } diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index d3fec584e8c..56377df3912 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -635,6 +635,18 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_sg( dir, flags, NULL); } +#ifdef CONFIG_RAPIDIO_DMA_ENGINE +struct rio_dma_ext; +static inline struct dma_async_tx_descriptor *dmaengine_prep_rio_sg( + struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len, + enum dma_transfer_direction dir, unsigned long flags, + struct rio_dma_ext *rio_ext) +{ + return chan->device->device_prep_slave_sg(chan, sgl, sg_len, + dir, flags, rio_ext); +} +#endif + static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_cyclic( struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, size_t period_len, enum dma_transfer_direction dir) diff --git a/include/linux/rio.h b/include/linux/rio.h index 4d50611112b..a90ebadd9da 100644 --- a/include/linux/rio.h +++ b/include/linux/rio.h @@ -20,6 +20,9 @@ #include #include #include +#ifdef CONFIG_RAPIDIO_DMA_ENGINE +#include +#endif #define RIO_NO_HOPCOUNT -1 #define RIO_INVALID_DESTID 0xffff @@ -254,6 +257,9 @@ struct rio_mport { u32 phys_efptr; unsigned char name[40]; void *priv; /* Master port private data */ +#ifdef CONFIG_RAPIDIO_DMA_ENGINE + struct dma_device dma; +#endif }; /** @@ -395,6 +401,47 @@ union rio_pw_msg { u32 raw[RIO_PW_MSG_SIZE/sizeof(u32)]; }; +#ifdef CONFIG_RAPIDIO_DMA_ENGINE + +/** + * enum rio_write_type - RIO write transaction types used in DMA transfers + * + * Note: RapidIO specification defines write (NWRITE) and + * write-with-response (NWRITE_R) data transfer operations. + * Existing DMA controllers that service RapidIO may use one of these operations + * for entire data transfer or their combination with only the last data packet + * requires response. + */ +enum rio_write_type { + RDW_DEFAULT, /* default method used by DMA driver */ + RDW_ALL_NWRITE, /* all packets use NWRITE */ + RDW_ALL_NWRITE_R, /* all packets use NWRITE_R */ + RDW_LAST_NWRITE_R, /* last packet uses NWRITE_R, others - NWRITE */ +}; + +struct rio_dma_ext { + u16 destid; + u64 rio_addr; /* low 64-bits of 66-bit RapidIO address */ + u8 rio_addr_u; /* upper 2-bits of 66-bit RapidIO address */ + enum rio_write_type wr_type; /* preferred RIO write operation type */ +}; + +struct rio_dma_data { + /* Local data (as scatterlist) */ + struct scatterlist *sg; /* I/O scatter list */ + unsigned int sg_len; /* size of scatter list */ + /* Remote device address (flat buffer) */ + u64 rio_addr; /* low 64-bits of 66-bit RapidIO address */ + u8 rio_addr_u; /* upper 2-bits of 66-bit RapidIO address */ + enum rio_write_type wr_type; /* preferred RIO write operation type */ +}; + +static inline struct rio_mport *dma_to_mport(struct dma_device *ddev) +{ + return container_of(ddev, struct rio_mport, dma); +} +#endif /* CONFIG_RAPIDIO_DMA_ENGINE */ + /* Architecture and hardware-specific functions */ extern int rio_register_mport(struct rio_mport *); extern int rio_open_inb_mbox(struct rio_mport *, void *, int, int); diff --git a/include/linux/rio_drv.h b/include/linux/rio_drv.h index 7f07470e1ed..31ad146be31 100644 --- a/include/linux/rio_drv.h +++ b/include/linux/rio_drv.h @@ -377,6 +377,15 @@ void rio_unregister_driver(struct rio_driver *); struct rio_dev *rio_dev_get(struct rio_dev *); void rio_dev_put(struct rio_dev *); +#ifdef CONFIG_RAPIDIO_DMA_ENGINE +extern struct dma_chan *rio_request_dma(struct rio_dev *rdev); +extern void rio_release_dma(struct dma_chan *dchan); +extern struct dma_async_tx_descriptor *rio_dma_prep_slave_sg( + struct rio_dev *rdev, struct dma_chan *dchan, + struct rio_dma_data *data, + enum dma_transfer_direction direction, unsigned long flags); +#endif + /** * rio_name - Get the unique RIO device identifier * @rdev: RIO device