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Commit b277d2aa authored by Yi Zou's avatar Yi Zou Committed by James Bottomley
Browse files

[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: default avatarYi Zou <yi.zou@intel.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent 39ca9a06

drivers/scsi/libfc/fc_exch.c

+3 −1
Original line number Diff line number Diff line
@@ -489,7 +489,7 @@ static u16 fc_em_alloc_xid(struct fc_exch_mgr *mp, const struct fc_frame *fp) 
	struct fc_exch *ep = NULL;



	if (mp->max_read) {

		if (fc_frame_is_read(fp)) {

		if (fc_fcp_is_read(fr_fsp(fp))) {

			min = mp->min_xid;

			max = mp->max_read;

			plast = &mp->last_read;
@@ -1841,6 +1841,8 @@ struct fc_seq *fc_exch_seq_send(struct fc_lport *lp, 
	fc_exch_setup_hdr(ep, fp, ep->f_ctl);

	sp->cnt++;



	fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);



	if (unlikely(lp->tt.frame_send(lp, fp)))

		goto err;

drivers/scsi/libfc/fc_fcp.c

+60 −1
Original line number Diff line number Diff line
@@ -264,6 +264,56 @@ static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp) 
	fc_fcp_complete_locked(fsp);

}



/*

 * fc_fcp_ddp_setup - calls to LLD's ddp_setup to set up DDP

 * transfer for a read I/O indicated by the fc_fcp_pkt.

 * @fsp: ptr to the fc_fcp_pkt

 *

 * This is called in exch_seq_send() when we have a newly allocated

 * exchange with a valid exchange id to setup ddp.

 *

 * returns: none

 */

void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid)

{

	struct fc_lport *lp;



	if (!fsp)

		return;



	lp = fsp->lp;

	if ((fsp->req_flags & FC_SRB_READ) &&

	    (lp->lro_enabled) && (lp->tt.ddp_setup)) {

		if (lp->tt.ddp_setup(lp, xid, scsi_sglist(fsp->cmd),

				     scsi_sg_count(fsp->cmd)))

			fsp->xfer_ddp = xid;

	}

}

EXPORT_SYMBOL(fc_fcp_ddp_setup);



/*

 * fc_fcp_ddp_done - calls to LLD's ddp_done to release any

 * DDP related resources for this I/O if it is initialized

 * as a ddp transfer

 * @fsp: ptr to the fc_fcp_pkt

 *

 * returns: none

 */

static void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)

{

	struct fc_lport *lp;



	if (!fsp)

		return;



	lp = fsp->lp;

	if (fsp->xfer_ddp && lp->tt.ddp_done) {

		fsp->xfer_len = lp->tt.ddp_done(lp, fsp->xfer_ddp);

		fsp->xfer_ddp = 0;

	}

}





/*

 * Receive SCSI data from target.

 * Called after receiving solicited data.
@@ -289,6 +339,9 @@ static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp) 
	len = fr_len(fp) - sizeof(*fh);

	buf = fc_frame_payload_get(fp, 0);



	/* if this I/O is ddped, update xfer len */

	fc_fcp_ddp_done(fsp);



	if (offset + len > fsp->data_len) {

		/* this should never happen */

		if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
@@ -750,6 +803,9 @@ static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp) 
	fsp->scsi_comp_flags = flags;

	expected_len = fsp->data_len;



	/* if ddp, update xfer len */

	fc_fcp_ddp_done(fsp);



	if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {

		rp_ex = (void *)(fc_rp + 1);

		if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
@@ -1012,7 +1068,7 @@ static int fc_fcp_cmd_send(struct fc_lport *lp, struct fc_fcp_pkt *fsp, 
	}



	memcpy(fc_frame_payload_get(fp, len), &fsp->cdb_cmd, len);

	fr_cmd(fp) = fsp->cmd;

	fr_fsp(fp) = fsp;

	rport = fsp->rport;

	fsp->max_payload = rport->maxframe_size;

	rp = rport->dd_data;
@@ -1746,6 +1802,9 @@ static void fc_io_compl(struct fc_fcp_pkt *fsp) 
	struct fc_lport *lp;

	unsigned long flags;



	/* release outstanding ddp context */

	fc_fcp_ddp_done(fsp);



	fsp->state |= FC_SRB_COMPL;

	if (!(fsp->state & FC_SRB_FCP_PROCESSING_TMO)) {

		spin_unlock_bh(&fsp->scsi_pkt_lock);

include/scsi/fc_frame.h

+2 −17
Original line number Diff line number Diff line
@@ -54,8 +54,7 @@ 
#define fr_eof(fp)	(fr_cb(fp)->fr_eof)

#define fr_flags(fp)	(fr_cb(fp)->fr_flags)

#define fr_max_payload(fp)	(fr_cb(fp)->fr_max_payload)

#define fr_cmd(fp)	(fr_cb(fp)->fr_cmd)

#define fr_dir(fp)	(fr_cmd(fp)->sc_data_direction)

#define fr_fsp(fp)	(fr_cb(fp)->fr_fsp)

#define fr_crc(fp)	(fr_cb(fp)->fr_crc)



struct fc_frame {
@@ -66,7 +65,7 @@ struct fcoe_rcv_info { 
	struct packet_type  *ptype;

	struct fc_lport	*fr_dev;	/* transport layer private pointer */

	struct fc_seq	*fr_seq;	/* for use with exchange manager */

	struct scsi_cmnd *fr_cmd;	/* for use of scsi command */

	struct fc_fcp_pkt *fr_fsp;	/* for the corresponding fcp I/O */

	u32		fr_crc;

	u16		fr_max_payload;	/* max FC payload */

	enum fc_sof	fr_sof;		/* start of frame delimiter */
@@ -218,20 +217,6 @@ static inline bool fc_frame_is_cmd(const struct fc_frame *fp) 
	return fc_frame_rctl(fp) == FC_RCTL_DD_UNSOL_CMD;

}



static inline bool fc_frame_is_read(const struct fc_frame *fp)

{

	if (fc_frame_is_cmd(fp) && fr_cmd(fp))

		return fr_dir(fp) == DMA_FROM_DEVICE;

	return false;

}



static inline bool fc_frame_is_write(const struct fc_frame *fp)

{

	if (fc_frame_is_cmd(fp) && fr_cmd(fp))

		return fr_dir(fp) == DMA_TO_DEVICE;

	return false;

}



/*

 * Check for leaks.

 * Print the frame header of any currently allocated frame, assuming there

include/scsi/libfc.h

+30 −0
Original line number Diff line number Diff line
@@ -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

 *****************************/

include/scsi/libfcoe.h

+0 −18
Original line number Diff line number Diff line
@@ -124,24 +124,6 @@ static inline u16 skb_fc_rxid(const struct sk_buff *skb) 
	return be16_to_cpu(skb_fc_header(skb)->fh_rx_id);

}



/* FIXME - DMA_BIDIRECTIONAL ? */

#define skb_cb(skb)	((struct fcoe_rcv_info *)&((skb)->cb[0]))

#define skb_cmd(skb)	(skb_cb(skb)->fr_cmd)

#define skb_dir(skb)	(skb_cmd(skb)->sc_data_direction)

static inline bool skb_fc_is_read(const struct sk_buff *skb)

{

	if (skb_fc_is_cmd(skb) && skb_cmd(skb))

		return skb_dir(skb) == DMA_FROM_DEVICE;

	return false;

}



static inline bool skb_fc_is_write(const struct sk_buff *skb)

{

	if (skb_fc_is_cmd(skb) && skb_cmd(skb))

		return skb_dir(skb) == DMA_TO_DEVICE;

	return false;

}



/* libfcoe funcs */

int fcoe_reset(struct Scsi_Host *shost);

u64 fcoe_wwn_from_mac(unsigned char mac[MAX_ADDR_LEN],