diff options
| -rw-r--r-- | drivers/dma/dmaengine.c | 73 | ||||
| -rw-r--r-- | include/linux/dmaengine.h | 112 |
2 files changed, 185 insertions, 0 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 4ac77456e830..158aeb1b6a8a 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -1348,6 +1348,79 @@ void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx, } EXPORT_SYMBOL(dma_async_tx_descriptor_init); +static inline int desc_check_and_set_metadata_mode( + struct dma_async_tx_descriptor *desc, enum dma_desc_metadata_mode mode) +{ + /* Make sure that the metadata mode is not mixed */ + if (!desc->desc_metadata_mode) { + if (dmaengine_is_metadata_mode_supported(desc->chan, mode)) + desc->desc_metadata_mode = mode; + else + return -ENOTSUPP; + } else if (desc->desc_metadata_mode != mode) { + return -EINVAL; + } + + return 0; +} + +int dmaengine_desc_attach_metadata(struct dma_async_tx_descriptor *desc, + void *data, size_t len) +{ + int ret; + + if (!desc) + return -EINVAL; + + ret = desc_check_and_set_metadata_mode(desc, DESC_METADATA_CLIENT); + if (ret) + return ret; + + if (!desc->metadata_ops || !desc->metadata_ops->attach) + return -ENOTSUPP; + + return desc->metadata_ops->attach(desc, data, len); +} +EXPORT_SYMBOL_GPL(dmaengine_desc_attach_metadata); + +void *dmaengine_desc_get_metadata_ptr(struct dma_async_tx_descriptor *desc, + size_t *payload_len, size_t *max_len) +{ + int ret; + + if (!desc) + return ERR_PTR(-EINVAL); + + ret = desc_check_and_set_metadata_mode(desc, DESC_METADATA_ENGINE); + if (ret) + return ERR_PTR(ret); + + if (!desc->metadata_ops || !desc->metadata_ops->get_ptr) + return ERR_PTR(-ENOTSUPP); + + return desc->metadata_ops->get_ptr(desc, payload_len, max_len); +} +EXPORT_SYMBOL_GPL(dmaengine_desc_get_metadata_ptr); + +int dmaengine_desc_set_metadata_len(struct dma_async_tx_descriptor *desc, + size_t payload_len) +{ + int ret; + + if (!desc) + return -EINVAL; + + ret = desc_check_and_set_metadata_mode(desc, DESC_METADATA_ENGINE); + if (ret) + return ret; + + if (!desc->metadata_ops || !desc->metadata_ops->set_len) + return -ENOTSUPP; + + return desc->metadata_ops->set_len(desc, payload_len); +} +EXPORT_SYMBOL_GPL(dmaengine_desc_set_metadata_len); + /* dma_wait_for_async_tx - spin wait for a transaction to complete * @tx: in-flight transaction to wait on */ diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 7927731e3716..68b361891a61 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -219,6 +219,62 @@ typedef struct { DECLARE_BITMAP(bits, DMA_TX_TYPE_END); } dma_cap_mask_t; * @bytes_transferred: byte counter */ +/** + * enum dma_desc_metadata_mode - per descriptor metadata mode types supported + * @DESC_METADATA_CLIENT - the metadata buffer is allocated/provided by the + * client driver and it is attached (via the dmaengine_desc_attach_metadata() + * helper) to the descriptor. + * + * Client drivers interested to use this mode can follow: + * - DMA_MEM_TO_DEV / DEV_MEM_TO_MEM: + * 1. prepare the descriptor (dmaengine_prep_*) + * construct the metadata in the client's buffer + * 2. use dmaengine_desc_attach_metadata() to attach the buffer to the + * descriptor + * 3. submit the transfer + * - DMA_DEV_TO_MEM: + * 1. prepare the descriptor (dmaengine_prep_*) + * 2. use dmaengine_desc_attach_metadata() to attach the buffer to the + * descriptor + * 3. submit the transfer + * 4. when the transfer is completed, the metadata should be available in the + * attached buffer + * + * @DESC_METADATA_ENGINE - the metadata buffer is allocated/managed by the DMA + * driver. The client driver can ask for the pointer, maximum size and the + * currently used size of the metadata and can directly update or read it. + * dmaengine_desc_get_metadata_ptr() and dmaengine_desc_set_metadata_len() is + * provided as helper functions. + * + * Note: the metadata area for the descriptor is no longer valid after the + * transfer has been completed (valid up to the point when the completion + * callback returns if used). + * + * Client drivers interested to use this mode can follow: + * - DMA_MEM_TO_DEV / DEV_MEM_TO_MEM: + * 1. prepare the descriptor (dmaengine_prep_*) + * 2. use dmaengine_desc_get_metadata_ptr() to get the pointer to the engine's + * metadata area + * 3. update the metadata at the pointer + * 4. use dmaengine_desc_set_metadata_len() to tell the DMA engine the amount + * of data the client has placed into the metadata buffer + * 5. submit the transfer + * - DMA_DEV_TO_MEM: + * 1. prepare the descriptor (dmaengine_prep_*) + * 2. submit the transfer + * 3. on transfer completion, use dmaengine_desc_get_metadata_ptr() to get the + * pointer to the engine's metadata area + * 4. Read out the metadata from the pointer + * + * Note: the two mode is not compatible and clients must use one mode for a + * descriptor. + */ +enum dma_desc_metadata_mode { + DESC_METADATA_NONE = 0, + DESC_METADATA_CLIENT = BIT(0), + DESC_METADATA_ENGINE = BIT(1), +}; + struct dma_chan_percpu { /* stats */ unsigned long memcpy_count; @@ -475,6 +531,18 @@ 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--- @@ -488,6 +556,11 @@ struct dmaengine_unmap_data { * descriptor pending. To be pushed on .issue_pending() call * @callback: routine to call after this operation is complete * @callback_param: general parameter to pass to the callback routine + * @desc_metadata_mode: core managed metadata mode to protect mixed use of + * DESC_METADATA_CLIENT or DESC_METADATA_ENGINE. Otherwise + * DESC_METADATA_NONE + * @metadata_ops: DMA driver provided metadata mode ops, need to be set by the + * DMA driver if metadata mode is supported with the descriptor * ---async_tx api specific fields--- * @next: at completion submit this descriptor * @parent: pointer to the next level up in the dependency chain @@ -504,6 +577,8 @@ struct dma_async_tx_descriptor { dma_async_tx_callback_result callback_result; void *callback_param; struct dmaengine_unmap_data *unmap; + enum dma_desc_metadata_mode desc_metadata_mode; + 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; @@ -666,6 +741,7 @@ struct dma_filter { * @global_node: list_head for global dma_device_list * @filter: information for device/slave to filter function/param mapping * @cap_mask: one or more dma_capability flags + * @desc_metadata_modes: supported metadata modes by the DMA device * @max_xor: maximum number of xor sources, 0 if no capability * @max_pq: maximum number of PQ sources and PQ-continue capability * @copy_align: alignment shift for memcpy operations @@ -733,6 +809,7 @@ struct dma_device { struct list_head global_node; struct dma_filter filter; dma_cap_mask_t cap_mask; + enum dma_desc_metadata_mode desc_metadata_modes; unsigned short max_xor; unsigned short max_pq; enum dmaengine_alignment copy_align; @@ -910,6 +987,41 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_memcpy( len, flags); } +static inline bool dmaengine_is_metadata_mode_supported(struct dma_chan *chan, + enum dma_desc_metadata_mode mode) +{ + if (!chan) + return false; + + return !!(chan->device->desc_metadata_modes & mode); +} + +#ifdef CONFIG_DMA_ENGINE +int dmaengine_desc_attach_metadata(struct dma_async_tx_descriptor *desc, + void *data, size_t len); +void *dmaengine_desc_get_metadata_ptr(struct dma_async_tx_descriptor *desc, + size_t *payload_len, size_t *max_len); +int dmaengine_desc_set_metadata_len(struct dma_async_tx_descriptor *desc, + size_t payload_len); +#else /* CONFIG_DMA_ENGINE */ +static inline int dmaengine_desc_attach_metadata( + struct dma_async_tx_descriptor *desc, void *data, size_t len) +{ + return -EINVAL; +} +static inline void *dmaengine_desc_get_metadata_ptr( + struct dma_async_tx_descriptor *desc, size_t *payload_len, + size_t *max_len) +{ + return NULL; +} +static inline int dmaengine_desc_set_metadata_len( + struct dma_async_tx_descriptor *desc, size_t payload_len) +{ + return -EINVAL; +} +#endif /* CONFIG_DMA_ENGINE */ + /** * dmaengine_terminate_all() - Terminate all active DMA transfers * @chan: The channel for which to terminate the transfers |