diff options
author | Alexandre Bounine <alexandre.bounine@idt.com> | 2012-05-31 19:26:38 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-31 20:49:31 -0400 |
commit | e42d98ebe7d754a2c9fbccd6186721d3ca8679f6 (patch) | |
tree | eed734672410f2eb8fab07fbd14f88bfaf8a882f /drivers/rapidio/rio.c | |
parent | ce2d52cc1364a22fc1a161781e60ee3cbb499a6d (diff) |
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 <alexandre.bounine@idt.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Acked-by: Vinod Koul <vinod.koul@linux.intel.com>
Cc: Li Yang <leoli@freescale.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/rapidio/rio.c')
-rw-r--r-- | drivers/rapidio/rio.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/drivers/rapidio/rio.c b/drivers/rapidio/rio.c index 86c9a091a2ff..c40665a4fa33 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, | |||
1121 | return 0; | 1121 | return 0; |
1122 | } | 1122 | } |
1123 | 1123 | ||
1124 | #ifdef CONFIG_RAPIDIO_DMA_ENGINE | ||
1125 | |||
1126 | static bool rio_chan_filter(struct dma_chan *chan, void *arg) | ||
1127 | { | ||
1128 | struct rio_dev *rdev = arg; | ||
1129 | |||
1130 | /* Check that DMA device belongs to the right MPORT */ | ||
1131 | return (rdev->net->hport == | ||
1132 | container_of(chan->device, struct rio_mport, dma)); | ||
1133 | } | ||
1134 | |||
1135 | /** | ||
1136 | * rio_request_dma - request RapidIO capable DMA channel that supports | ||
1137 | * specified target RapidIO device. | ||
1138 | * @rdev: RIO device control structure | ||
1139 | * | ||
1140 | * Returns pointer to allocated DMA channel or NULL if failed. | ||
1141 | */ | ||
1142 | struct dma_chan *rio_request_dma(struct rio_dev *rdev) | ||
1143 | { | ||
1144 | dma_cap_mask_t mask; | ||
1145 | struct dma_chan *dchan; | ||
1146 | |||
1147 | dma_cap_zero(mask); | ||
1148 | dma_cap_set(DMA_SLAVE, mask); | ||
1149 | dchan = dma_request_channel(mask, rio_chan_filter, rdev); | ||
1150 | |||
1151 | return dchan; | ||
1152 | } | ||
1153 | EXPORT_SYMBOL_GPL(rio_request_dma); | ||
1154 | |||
1155 | /** | ||
1156 | * rio_release_dma - release specified DMA channel | ||
1157 | * @dchan: DMA channel to release | ||
1158 | */ | ||
1159 | void rio_release_dma(struct dma_chan *dchan) | ||
1160 | { | ||
1161 | dma_release_channel(dchan); | ||
1162 | } | ||
1163 | EXPORT_SYMBOL_GPL(rio_release_dma); | ||
1164 | |||
1165 | /** | ||
1166 | * rio_dma_prep_slave_sg - RapidIO specific wrapper | ||
1167 | * for device_prep_slave_sg callback defined by DMAENGINE. | ||
1168 | * @rdev: RIO device control structure | ||
1169 | * @dchan: DMA channel to configure | ||
1170 | * @data: RIO specific data descriptor | ||
1171 | * @direction: DMA data transfer direction (TO or FROM the device) | ||
1172 | * @flags: dmaengine defined flags | ||
1173 | * | ||
1174 | * Initializes RapidIO capable DMA channel for the specified data transfer. | ||
1175 | * Uses DMA channel private extension to pass information related to remote | ||
1176 | * target RIO device. | ||
1177 | * Returns pointer to DMA transaction descriptor or NULL if failed. | ||
1178 | */ | ||
1179 | struct dma_async_tx_descriptor *rio_dma_prep_slave_sg(struct rio_dev *rdev, | ||
1180 | struct dma_chan *dchan, struct rio_dma_data *data, | ||
1181 | enum dma_transfer_direction direction, unsigned long flags) | ||
1182 | { | ||
1183 | struct dma_async_tx_descriptor *txd = NULL; | ||
1184 | struct rio_dma_ext rio_ext; | ||
1185 | |||
1186 | if (dchan->device->device_prep_slave_sg == NULL) { | ||
1187 | pr_err("%s: prep_rio_sg == NULL\n", __func__); | ||
1188 | return NULL; | ||
1189 | } | ||
1190 | |||
1191 | rio_ext.destid = rdev->destid; | ||
1192 | rio_ext.rio_addr_u = data->rio_addr_u; | ||
1193 | rio_ext.rio_addr = data->rio_addr; | ||
1194 | rio_ext.wr_type = data->wr_type; | ||
1195 | |||
1196 | txd = dmaengine_prep_rio_sg(dchan, data->sg, data->sg_len, | ||
1197 | direction, flags, &rio_ext); | ||
1198 | |||
1199 | return txd; | ||
1200 | } | ||
1201 | EXPORT_SYMBOL_GPL(rio_dma_prep_slave_sg); | ||
1202 | |||
1203 | #endif /* CONFIG_RAPIDIO_DMA_ENGINE */ | ||
1204 | |||
1124 | static void rio_fixup_device(struct rio_dev *dev) | 1205 | static void rio_fixup_device(struct rio_dev *dev) |
1125 | { | 1206 | { |
1126 | } | 1207 | } |