> -----Original Message----- > From: Peter Ujfalusi [mailto:peter.ujfalusi@xxxxxx] > Sent: Friday, June 1, 2018 3:54 PM > To: Radhey Shyam Pandey <radheys@xxxxxxxxxx>; vinod.koul@xxxxxxxxx > Cc: lars@xxxxxxxxxx; michal.simek@xxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; dmaengine@xxxxxxxxxxxxxxx; > dan.j.williams@xxxxxxxxx; Appana Durga Kedareswara Rao > <appanad@xxxxxxxxxx>; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > Subject: [RFC] dmaengine: Add metadat_ops for dma_async_tx_descriptor > > If the DMA supports per descriptor metadata it can implement the attach, > get_ptr/set_len callbacks. > > Client drivers must only use either attach or get_ptr/set_len to avoid > miss configuration. > > Wrappers are also added for the metadata_ops: > dmaengine_desc_attach_metadata() > dmaengine_desc_get_metadata_ptr() > dmaengine_desc_set_metadata_len() > > Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx> > --- > Hi, > > since attachments are bouncing back, I send the patch separately > > Regards, > Peter > > include/linux/dmaengine.h | 50 > +++++++++++++++++++++++++++++++++++++++ > 1 file changed, 50 insertions(+) > > diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h > index 51fbb861e84b..ac42ace36aa3 100644 > --- a/include/linux/dmaengine.h > +++ b/include/linux/dmaengine.h > @@ -491,6 +491,18 @@ struct dmaengine_unmap_data { > dma_addr_t addr[0]; > }; > > +struct dma_async_tx_descriptor; > + > +struct dma_descriptor_metadata_ops { > + int (*attach)(struct dma_async_tx_descriptor *desc, void *data, > + size_t len); > + > + void *(*get_ptr)(struct dma_async_tx_descriptor *desc, > + size_t *payload_len, size_t *max_len); > + int (*set_len)(struct dma_async_tx_descriptor *desc, > + size_t payload_len); > +}; > + > /** > * struct dma_async_tx_descriptor - async transaction descriptor > * ---dma generic offload fields--- > @@ -520,6 +532,7 @@ struct dma_async_tx_descriptor { > dma_async_tx_callback_result callback_result; > void *callback_param; > struct dmaengine_unmap_data *unmap; > + struct dma_descriptor_metadata_ops *metadata_ops; > #ifdef CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH > struct dma_async_tx_descriptor *next; > struct dma_async_tx_descriptor *parent; > @@ -932,6 +945,43 @@ static inline struct dma_async_tx_descriptor > *dmaengine_prep_dma_memcpy( > len, flags); > } > > +static inline int dmaengine_desc_attach_metadata( > + struct dma_async_tx_descriptor *desc, void *data, size_t > len) > +{ > + if (!desc) > + return 0; > + > + if (!desc->metadata_ops || !desc->metadata_ops->attach) > + return -ENOTSUPP; > + > + return desc->metadata_ops->attach(desc, data, len); > +} > + > +static inline void *dmaengine_desc_get_metadata_ptr( > + struct dma_async_tx_descriptor *desc, size_t *payload_len, > + size_t *max_len) > +{ > + if (!desc) > + return NULL; > + > + if (!desc->metadata_ops || !desc->metadata_ops->get_ptr) > + return ERR_PTR(-ENOTSUPP); > + > + return desc->metadata_ops->get_ptr(desc, payload_len, max_len); > +} > + > +static inline int dmaengine_desc_set_metadata_len( > + struct dma_async_tx_descriptor *desc, size_t payload_len) > +{ > + if (!desc) > + return 0; > + > + if (!desc->metadata_ops || !desc->metadata_ops->set_len) > + return -ENOTSUPP; > + > + return desc->metadata_ops->set_len(desc, payload_len); > +} > + Thanks for the RFC patchset. It looks fine to me. We also need to update documentation. Let's wait for Vinod/Lars feedback. > /** > * dmaengine_terminate_all() - Terminate all active DMA transfers > * @chan: The channel for which to terminate the transfers > -- > Peter > > Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. > Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
