From b277d2aa9a4d969002c4157bf77b76b9ad9ca04a Mon Sep 17 00:00:00 2001 From: Yi Zou Date: Fri, 27 Feb 2009 14:07:21 -0800 Subject: [SCSI] libfc: add support of large receive offload by ddp in fc_fcp When LLD supports direct data placement (ddp) for large receive of an scsi i/o coming into fc_fcp, we call into libfc_function_template's ddp_setup() to prepare for a ddp of large receive for this read I/O. When I/O is complete, we call the corresponding ddp_done() to get the length of data ddped as well as to let LLD do clean up. fc_fcp_ddp_setup()/fc_fcp_ddp_done() are added to setup and complete a ddped read I/O described by the given fc_fcp_pkt. They would call into corresponding ddp_setup/ddp_done implemented by the fcoe layer. Eventually, fcoe layer calls into LLD's ddp_setup/ddp_done provided through net_device Signed-off-by: Yi Zou Signed-off-by: James Bottomley --- include/scsi/libfc.h | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'include/scsi/libfc.h') diff --git a/include/scsi/libfc.h b/include/scsi/libfc.h index 61c746cf55f..a70eafaad08 100644 --- a/include/scsi/libfc.h +++ b/include/scsi/libfc.h @@ -245,6 +245,7 @@ struct fc_fcp_pkt { */ struct fcp_cmnd cdb_cmd; size_t xfer_len; + u16 xfer_ddp; /* this xfer is ddped */ u32 xfer_contig_end; /* offset of end of contiguous xfer */ u16 max_payload; /* max payload size in bytes */ @@ -267,6 +268,15 @@ struct fc_fcp_pkt { u8 recov_retry; /* count of recovery retries */ struct fc_seq *recov_seq; /* sequence for REC or SRR */ }; +/* + * FC_FCP HELPER FUNCTIONS + *****************************/ +static inline bool fc_fcp_is_read(const struct fc_fcp_pkt *fsp) +{ + if (fsp && fsp->cmd) + return fsp->cmd->sc_data_direction == DMA_FROM_DEVICE; + return false; +} /* * Structure and function definitions for managing Fibre Channel Exchanges @@ -399,6 +409,21 @@ struct libfc_function_template { void *arg), void *arg, unsigned int timer_msec); + /* + * Sets up the DDP context for a given exchange id on the given + * scatterlist if LLD supports DDP for large receive. + * + * STATUS: OPTIONAL + */ + int (*ddp_setup)(struct fc_lport *lp, u16 xid, + struct scatterlist *sgl, unsigned int sgc); + /* + * Completes the DDP transfer and returns the length of data DDPed + * for the given exchange id. + * + * STATUS: OPTIONAL + */ + int (*ddp_done)(struct fc_lport *lp, u16 xid); /* * Send a frame using an existing sequence and exchange. * @@ -821,6 +846,11 @@ int fc_change_queue_type(struct scsi_device *sdev, int tag_type); */ void fc_fcp_destroy(struct fc_lport *); +/* + * Set up direct-data placement for this I/O request + */ +void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid); + /* * ELS/CT interface *****************************/ -- cgit v1.2.3