--- /dev/null
+/*
+ * Copyright (c) 2010 Cisco Systems, Inc.
+ *
+ * Portions based on tcm_loop_fabric_scsi.c and libfc/fc_fcp.c
+ *
+ * Copyright (c) 2007 Intel Corporation. All rights reserved.
+ * Copyright (c) 2008 Red Hat, Inc. All rights reserved.
+ * Copyright (c) 2008 Mike Christie
+ * Copyright (c) 2009 Rising Tide, Inc.
+ * Copyright (c) 2009 Linux-iSCSI.org
+ * Copyright (c) 2009 Nicholas A. Bellinger <nab@linux-iscsi.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/* XXX TBD some includes may be extraneous */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/utsname.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/kthread.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/configfs.h>
+#include <linux/ctype.h>
+#include <linux/hash.h>
+#include <linux/ratelimit.h>
+#include <asm/unaligned.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/libfc.h>
+#include <scsi/fc_encode.h>
+
+#include <target/target_core_base.h>
+#include <target/target_core_fabric.h>
+#include <target/target_core_configfs.h>
+#include <target/configfs_macros.h>
+
+#include "tcm_fc.h"
+
+/*
+ * Deliver read data back to initiator.
+ * XXX TBD handle resource problems later.
+ */
+int ft_queue_data_in(struct se_cmd *se_cmd)
+{
+ struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
+ struct fc_frame *fp = NULL;
+ struct fc_exch *ep;
+ struct fc_lport *lport;
+ struct scatterlist *sg = NULL;
+ size_t remaining;
+ u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
+ u32 mem_off = 0;
+ u32 fh_off = 0;
+ u32 frame_off = 0;
+ size_t frame_len = 0;
+ size_t mem_len = 0;
+ size_t tlen;
+ size_t off_in_page;
+ struct page *page = NULL;
+ int use_sg;
+ int error;
+ void *page_addr;
+ void *from;
+ void *to = NULL;
+
+ if (cmd->aborted)
+ return 0;
+
+ if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL)
+ goto queue_status;
+
+ ep = fc_seq_exch(cmd->seq);
+ lport = ep->lp;
+ cmd->seq = lport->tt.seq_start_next(cmd->seq);
+
+ remaining = se_cmd->data_length;
+
+ /*
+ * Setup to use first mem list entry, unless no data.
+ */
+ BUG_ON(remaining && !se_cmd->t_data_sg);
+ if (remaining) {
+ sg = se_cmd->t_data_sg;
+ mem_len = sg->length;
+ mem_off = sg->offset;
+ page = sg_page(sg);
+ }
+
+ /* no scatter/gather in skb for odd word length due to fc_seq_send() */
+ use_sg = !(remaining % 4);
+
+ while (remaining) {
+ struct fc_seq *seq = cmd->seq;
+
+ if (!seq) {
+ pr_debug("%s: Command aborted, xid 0x%x\n",
+ __func__, ep->xid);
+ break;
+ }
+ if (!mem_len) {
+ sg = sg_next(sg);
+ mem_len = min((size_t)sg->length, remaining);
+ mem_off = sg->offset;
+ page = sg_page(sg);
+ }
+ if (!frame_len) {
+ /*
+ * If lport's has capability of Large Send Offload LSO)
+ * , then allow 'frame_len' to be as big as 'lso_max'
+ * if indicated transfer length is >= lport->lso_max
+ */
+ frame_len = (lport->seq_offload) ? lport->lso_max :
+ cmd->sess->max_frame;
+ frame_len = min(frame_len, remaining);
+ fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len);
+ if (!fp)
+ return -ENOMEM;
+ to = fc_frame_payload_get(fp, 0);
+ fh_off = frame_off;
+ frame_off += frame_len;
+ /*
+ * Setup the frame's max payload which is used by base
+ * driver to indicate HW about max frame size, so that
+ * HW can do fragmentation appropriately based on
+ * "gso_max_size" of underline netdev.
+ */
+ fr_max_payload(fp) = cmd->sess->max_frame;
+ }
+ tlen = min(mem_len, frame_len);
+
+ if (use_sg) {
+ off_in_page = mem_off;
+ BUG_ON(!page);
+ get_page(page);
+ skb_fill_page_desc(fp_skb(fp),
+ skb_shinfo(fp_skb(fp))->nr_frags,
+ page, off_in_page, tlen);
+ fr_len(fp) += tlen;
+ fp_skb(fp)->data_len += tlen;
+ fp_skb(fp)->truesize +=
+ PAGE_SIZE << compound_order(page);
+ } else {
+ BUG_ON(!page);
+ from = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
+ page_addr = from;
+ from += mem_off & ~PAGE_MASK;
+ tlen = min(tlen, (size_t)(PAGE_SIZE -
+ (mem_off & ~PAGE_MASK)));
+ memcpy(to, from, tlen);
+ kunmap_atomic(page_addr);
+ to += tlen;
+ }
+
+ mem_off += tlen;
+ mem_len -= tlen;
+ frame_len -= tlen;
+ remaining -= tlen;
+
+ if (frame_len &&
+ (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN))
+ continue;
+ if (!remaining)
+ f_ctl |= FC_FC_END_SEQ;
+ fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
+ FC_TYPE_FCP, f_ctl, fh_off);
+ error = lport->tt.seq_send(lport, seq, fp);
+ if (error) {
+ pr_info_ratelimited("%s: Failed to send frame %p, "
+ "xid <0x%x>, remaining %zu, "
+ "lso_max <0x%x>\n",
+ __func__, fp, ep->xid,
+ remaining, lport->lso_max);
+ /*
+ * Go ahead and set TASK_SET_FULL status ignoring the
+ * rest of the DataIN, and immediately attempt to
+ * send the response via ft_queue_status() in order
+ * to notify the initiator that it should reduce it's
+ * per LUN queue_depth.
+ */
+ se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
+ break;
+ }
+ }
+queue_status:
+ return ft_queue_status(se_cmd);
+}
+
+static void ft_execute_work(struct work_struct *work)
+{
+ struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
+
+ target_execute_cmd(&cmd->se_cmd);
+}
+
+/*
+ * Receive write data frame.
+ */
+void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
+{
+ struct se_cmd *se_cmd = &cmd->se_cmd;
+ struct fc_seq *seq = cmd->seq;
+ struct fc_exch *ep;
+ struct fc_lport *lport;
+ struct fc_frame_header *fh;
+ struct scatterlist *sg = NULL;
+ u32 mem_off = 0;
+ u32 rel_off;
+ size_t frame_len;
+ size_t mem_len = 0;
+ size_t tlen;
+ struct page *page = NULL;
+ void *page_addr;
+ void *from;
+ void *to;
+ u32 f_ctl;
+ void *buf;
+
+ fh = fc_frame_header_get(fp);
+ if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF))
+ goto drop;
+
+ f_ctl = ntoh24(fh->fh_f_ctl);
+ ep = fc_seq_exch(seq);
+ lport = ep->lp;
+ if (cmd->was_ddp_setup) {
+ BUG_ON(!ep);
+ BUG_ON(!lport);
+ /*
+ * Since DDP (Large Rx offload) was setup for this request,
+ * payload is expected to be copied directly to user buffers.
+ */
+ buf = fc_frame_payload_get(fp, 1);
+ if (buf)
+ pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, "
+ "cmd->sg_cnt 0x%x. DDP was setup"
+ " hence not expected to receive frame with "
+ "payload, Frame will be dropped if"
+ "'Sequence Initiative' bit in f_ctl is"
+ "not set\n", __func__, ep->xid, f_ctl,
+ se_cmd->t_data_sg, se_cmd->t_data_nents);
+ /*
+ * Invalidate HW DDP context if it was setup for respective
+ * command. Invalidation of HW DDP context is requited in both
+ * situation (success and error).
+ */
+ ft_invl_hw_context(cmd);
+
+ /*
+ * If "Sequence Initiative (TSI)" bit set in f_ctl, means last
+ * write data frame is received successfully where payload is
+ * posted directly to user buffer and only the last frame's
+ * header is posted in receive queue.
+ *
+ * If "Sequence Initiative (TSI)" bit is not set, means error
+ * condition w.r.t. DDP, hence drop the packet and let explict
+ * ABORTS from other end of exchange timer trigger the recovery.
+ */
+ if (f_ctl & FC_FC_SEQ_INIT)
+ goto last_frame;
+ else
+ goto drop;
+ }
+
+ rel_off = ntohl(fh->fh_parm_offset);
+ frame_len = fr_len(fp);
+ if (frame_len <= sizeof(*fh))
+ goto drop;
+ frame_len -= sizeof(*fh);
+ from = fc_frame_payload_get(fp, 0);
+ if (rel_off >= se_cmd->data_length)
+ goto drop;
+ if (frame_len + rel_off > se_cmd->data_length)
+ frame_len = se_cmd->data_length - rel_off;
+
+ /*
+ * Setup to use first mem list entry, unless no data.
+ */
+ BUG_ON(frame_len && !se_cmd->t_data_sg);
+ if (frame_len) {
+ sg = se_cmd->t_data_sg;
+ mem_len = sg->length;
+ mem_off = sg->offset;
+ page = sg_page(sg);
+ }
+
+ while (frame_len) {
+ if (!mem_len) {
+ sg = sg_next(sg);
+ mem_len = sg->length;
+ mem_off = sg->offset;
+ page = sg_page(sg);
+ }
+ if (rel_off >= mem_len) {
+ rel_off -= mem_len;
+ mem_len = 0;
+ continue;
+ }
+ mem_off += rel_off;
+ mem_len -= rel_off;
+ rel_off = 0;
+
+ tlen = min(mem_len, frame_len);
+
+ to = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
+ page_addr = to;
+ to += mem_off & ~PAGE_MASK;
+ tlen = min(tlen, (size_t)(PAGE_SIZE -
+ (mem_off & ~PAGE_MASK)));
+ memcpy(to, from, tlen);
+ kunmap_atomic(page_addr);
+
+ from += tlen;
+ frame_len -= tlen;
+ mem_off += tlen;
+ mem_len -= tlen;
+ cmd->write_data_len += tlen;
+ }
+last_frame:
+ if (cmd->write_data_len == se_cmd->data_length) {
+ INIT_WORK(&cmd->work, ft_execute_work);
+ queue_work(cmd->sess->tport->tpg->workqueue, &cmd->work);
+ }
+drop:
+ fc_frame_free(fp);
+}
+
+/*
+ * Handle and cleanup any HW specific resources if
+ * received ABORTS, errors, timeouts.
+ */
+void ft_invl_hw_context(struct ft_cmd *cmd)
+{
+ struct fc_seq *seq;
+ struct fc_exch *ep = NULL;
+ struct fc_lport *lport = NULL;
+
+ BUG_ON(!cmd);
+ seq = cmd->seq;
+
+ /* Cleanup the DDP context in HW if DDP was setup */
+ if (cmd->was_ddp_setup && seq) {
+ ep = fc_seq_exch(seq);
+ if (ep) {
+ lport = ep->lp;
+ if (lport && (ep->xid <= lport->lro_xid)) {
+ /*
+ * "ddp_done" trigger invalidation of HW
+ * specific DDP context
+ */
+ cmd->write_data_len = lport->tt.ddp_done(lport,
+ ep->xid);
+
+ /*
+ * Resetting same variable to indicate HW's
+ * DDP context has been invalidated to avoid
+ * re_invalidation of same context (context is
+ * identified using ep->xid)
+ */
+ cmd->was_ddp_setup = 0;
+ }
+ }
+ }
+}
Code Review / kvmfornfv.git / blobdiff