drivers/target/tcm_fc/tfc_io.c

   1 /*
   2  * Copyright (c) 2010 Cisco Systems, Inc.
   3  *
   4  * Portions based on tcm_loop_fabric_scsi.c and libfc/fc_fcp.c
   5  *
   6  * Copyright (c) 2007 Intel Corporation. All rights reserved.
   7  * Copyright (c) 2008 Red Hat, Inc.  All rights reserved.
   8  * Copyright (c) 2008 Mike Christie
   9  * Copyright (c) 2009 Rising Tide, Inc.
  10  * Copyright (c) 2009 Linux-iSCSI.org
  11  * Copyright (c) 2009 Nicholas A. Bellinger <nab@linux-iscsi.org>
  12  *
  13  * This program is free software; you can redistribute it and/or modify it
  14  * under the terms and conditions of the GNU General Public License,
  15  * version 2, as published by the Free Software Foundation.
  16  *
  17  * This program is distributed in the hope it will be useful, but WITHOUT
  18  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  20  * more details.
  21  *
  22  * You should have received a copy of the GNU General Public License along with
  23  * this program; if not, write to the Free Software Foundation, Inc.,
  24  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  25  */
  26
  27 /* XXX TBD some includes may be extraneous */
  28
  29 #include <linux/module.h>
  30 #include <linux/moduleparam.h>
  31 #include <linux/utsname.h>
  32 #include <linux/init.h>
  33 #include <linux/slab.h>
  34 #include <linux/kthread.h>
  35 #include <linux/types.h>
  36 #include <linux/string.h>
  37 #include <linux/configfs.h>
  38 #include <linux/ctype.h>
  39 #include <linux/hash.h>
  40 #include <linux/ratelimit.h>
  41 #include <asm/unaligned.h>
  42 #include <scsi/scsi.h>
  43 #include <scsi/scsi_host.h>
  44 #include <scsi/scsi_device.h>
  45 #include <scsi/scsi_cmnd.h>
  46 #include <scsi/libfc.h>
  47 #include <scsi/fc_encode.h>
  48
  49 #include <target/target_core_base.h>
  50 #include <target/target_core_fabric.h>
  51 #include <target/target_core_configfs.h>
  52 #include <target/configfs_macros.h>
  53
  54 #include "tcm_fc.h"
  55
  56 /*
  57  * Deliver read data back to initiator.
  58  * XXX TBD handle resource problems later.
  59  */
  60 int ft_queue_data_in(struct se_cmd *se_cmd)
  61 {
  62         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
  63         struct fc_frame *fp = NULL;
  64         struct fc_exch *ep;
  65         struct fc_lport *lport;
  66         struct scatterlist *sg = NULL;
  67         size_t remaining;
  68         u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
  69         u32 mem_off = 0;
  70         u32 fh_off = 0;
  71         u32 frame_off = 0;
  72         size_t frame_len = 0;
  73         size_t mem_len = 0;
  74         size_t tlen;
  75         size_t off_in_page;
  76         struct page *page = NULL;
  77         int use_sg;
  78         int error;
  79         void *page_addr;
  80         void *from;
  81         void *to = NULL;
  82
  83         if (cmd->aborted)
  84                 return 0;
  85         ep = fc_seq_exch(cmd->seq);
  86         lport = ep->lp;
  87         cmd->seq = lport->tt.seq_start_next(cmd->seq);
  88
  89         remaining = se_cmd->data_length;
  90
  91         /*
  92          * Setup to use first mem list entry, unless no data.
  93          */
  94         BUG_ON(remaining && !se_cmd->t_data_sg);
  95         if (remaining) {
  96                 sg = se_cmd->t_data_sg;
  97                 mem_len = sg->length;
  98                 mem_off = sg->offset;
  99                 page = sg_page(sg);
 100         }
 101
 102         /* no scatter/gather in skb for odd word length due to fc_seq_send() */
 103         use_sg = !(remaining % 4);
 104
 105         while (remaining) {
 106                 struct fc_seq *seq = cmd->seq;
 107
 108                 if (!seq) {
 109                         pr_debug("%s: Command aborted, xid 0x%x\n",
 110                                  __func__, ep->xid);
 111                         break;
 112                 }
 113                 if (!mem_len) {
 114                         sg = sg_next(sg);
 115                         mem_len = min((size_t)sg->length, remaining);
 116                         mem_off = sg->offset;
 117                         page = sg_page(sg);
 118                 }
 119                 if (!frame_len) {
 120                         /*
 121                          * If lport's has capability of Large Send Offload LSO)
 122                          * , then allow 'frame_len' to be as big as 'lso_max'
 123                          * if indicated transfer length is >= lport->lso_max
 124                          */
 125                         frame_len = (lport->seq_offload) ? lport->lso_max :
 126                                                           cmd->sess->max_frame;
 127                         frame_len = min(frame_len, remaining);
 128                         fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len);
 129                         if (!fp)
 130                                 return -ENOMEM;
 131                         to = fc_frame_payload_get(fp, 0);
 132                         fh_off = frame_off;
 133                         frame_off += frame_len;
 134                         /*
 135                          * Setup the frame's max payload which is used by base
 136                          * driver to indicate HW about max frame size, so that
 137                          * HW can do fragmentation appropriately based on
 138                          * "gso_max_size" of underline netdev.
 139                          */
 140                         fr_max_payload(fp) = cmd->sess->max_frame;
 141                 }
 142                 tlen = min(mem_len, frame_len);
 143
 144                 if (use_sg) {
 145                         off_in_page = mem_off;
 146                         BUG_ON(!page);
 147                         get_page(page);
 148                         skb_fill_page_desc(fp_skb(fp),
 149                                            skb_shinfo(fp_skb(fp))->nr_frags,
 150                                            page, off_in_page, tlen);
 151                         fr_len(fp) += tlen;
 152                         fp_skb(fp)->data_len += tlen;
 153                         fp_skb(fp)->truesize +=
 154                                         PAGE_SIZE << compound_order(page);
 155                 } else {
 156                         BUG_ON(!page);
 157                         from = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
 158                         page_addr = from;
 159                         from += mem_off & ~PAGE_MASK;
 160                         tlen = min(tlen, (size_t)(PAGE_SIZE -
 161                                                 (mem_off & ~PAGE_MASK)));
 162                         memcpy(to, from, tlen);
 163                         kunmap_atomic(page_addr);
 164                         to += tlen;
 165                 }
 166
 167                 mem_off += tlen;
 168                 mem_len -= tlen;
 169                 frame_len -= tlen;
 170                 remaining -= tlen;
 171
 172                 if (frame_len &&
 173                     (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN))
 174                         continue;
 175                 if (!remaining)
 176                         f_ctl |= FC_FC_END_SEQ;
 177                 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
 178                                FC_TYPE_FCP, f_ctl, fh_off);
 179                 error = lport->tt.seq_send(lport, seq, fp);
 180                 if (error) {
 181                         /* XXX For now, initiator will retry */
 182                         pr_err_ratelimited("%s: Failed to send frame %p, "
 183                                                 "xid <0x%x>, remaining %zu, "
 184                                                 "lso_max <0x%x>\n",
 185                                                 __func__, fp, ep->xid,
 186                                                 remaining, lport->lso_max);
 187                 }
 188         }
 189         return ft_queue_status(se_cmd);
 190 }
 191
 192 static void ft_execute_work(struct work_struct *work)
 193 {
 194         struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
 195
 196         target_execute_cmd(&cmd->se_cmd);
 197 }
 198
 199 /*
 200  * Receive write data frame.
 201  */
 202 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
 203 {
 204         struct se_cmd *se_cmd = &cmd->se_cmd;
 205         struct fc_seq *seq = cmd->seq;
 206         struct fc_exch *ep;
 207         struct fc_lport *lport;
 208         struct fc_frame_header *fh;
 209         struct scatterlist *sg = NULL;
 210         u32 mem_off = 0;
 211         u32 rel_off;
 212         size_t frame_len;
 213         size_t mem_len = 0;
 214         size_t tlen;
 215         struct page *page = NULL;
 216         void *page_addr;
 217         void *from;
 218         void *to;
 219         u32 f_ctl;
 220         void *buf;
 221
 222         fh = fc_frame_header_get(fp);
 223         if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF))
 224                 goto drop;
 225
 226         f_ctl = ntoh24(fh->fh_f_ctl);
 227         ep = fc_seq_exch(seq);
 228         lport = ep->lp;
 229         if (cmd->was_ddp_setup) {
 230                 BUG_ON(!ep);
 231                 BUG_ON(!lport);
 232                 /*
 233                  * Since DDP (Large Rx offload) was setup for this request,
 234                  * payload is expected to be copied directly to user buffers.
 235                  */
 236                 buf = fc_frame_payload_get(fp, 1);
 237                 if (buf)
 238                         pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, "
 239                                 "cmd->sg_cnt 0x%x. DDP was setup"
 240                                 " hence not expected to receive frame with "
 241                                 "payload, Frame will be dropped if"
 242                                 "'Sequence Initiative' bit in f_ctl is"
 243                                 "not set\n", __func__, ep->xid, f_ctl,
 244                                 se_cmd->t_data_sg, se_cmd->t_data_nents);
 245                 /*
 246                  * Invalidate HW DDP context if it was setup for respective
 247                  * command. Invalidation of HW DDP context is requited in both
 248                  * situation (success and error).
 249                  */
 250                 ft_invl_hw_context(cmd);
 251
 252                 /*
 253                  * If "Sequence Initiative (TSI)" bit set in f_ctl, means last
 254                  * write data frame is received successfully where payload is
 255                  * posted directly to user buffer and only the last frame's
 256                  * header is posted in receive queue.
 257                  *
 258                  * If "Sequence Initiative (TSI)" bit is not set, means error
 259                  * condition w.r.t. DDP, hence drop the packet and let explict
 260                  * ABORTS from other end of exchange timer trigger the recovery.
 261                  */
 262                 if (f_ctl & FC_FC_SEQ_INIT)
 263                         goto last_frame;
 264                 else
 265                         goto drop;
 266         }
 267
 268         rel_off = ntohl(fh->fh_parm_offset);
 269         frame_len = fr_len(fp);
 270         if (frame_len <= sizeof(*fh))
 271                 goto drop;
 272         frame_len -= sizeof(*fh);
 273         from = fc_frame_payload_get(fp, 0);
 274         if (rel_off >= se_cmd->data_length)
 275                 goto drop;
 276         if (frame_len + rel_off > se_cmd->data_length)
 277                 frame_len = se_cmd->data_length - rel_off;
 278
 279         /*
 280          * Setup to use first mem list entry, unless no data.
 281          */
 282         BUG_ON(frame_len && !se_cmd->t_data_sg);
 283         if (frame_len) {
 284                 sg = se_cmd->t_data_sg;
 285                 mem_len = sg->length;
 286                 mem_off = sg->offset;
 287                 page = sg_page(sg);
 288         }
 289
 290         while (frame_len) {
 291                 if (!mem_len) {
 292                         sg = sg_next(sg);
 293                         mem_len = sg->length;
 294                         mem_off = sg->offset;
 295                         page = sg_page(sg);
 296                 }
 297                 if (rel_off >= mem_len) {
 298                         rel_off -= mem_len;
 299                         mem_len = 0;
 300                         continue;
 301                 }
 302                 mem_off += rel_off;
 303                 mem_len -= rel_off;
 304                 rel_off = 0;
 305
 306                 tlen = min(mem_len, frame_len);
 307
 308                 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
 309                 page_addr = to;
 310                 to += mem_off & ~PAGE_MASK;
 311                 tlen = min(tlen, (size_t)(PAGE_SIZE -
 312                                           (mem_off & ~PAGE_MASK)));
 313                 memcpy(to, from, tlen);
 314                 kunmap_atomic(page_addr);
 315
 316                 from += tlen;
 317                 frame_len -= tlen;
 318                 mem_off += tlen;
 319                 mem_len -= tlen;
 320                 cmd->write_data_len += tlen;
 321         }
 322 last_frame:
 323         if (cmd->write_data_len == se_cmd->data_length) {
 324                 INIT_WORK(&cmd->work, ft_execute_work);
 325                 queue_work(cmd->sess->tport->tpg->workqueue, &cmd->work);
 326         }
 327 drop:
 328         fc_frame_free(fp);
 329 }
 330
 331 /*
 332  * Handle and cleanup any HW specific resources if
 333  * received ABORTS, errors, timeouts.
 334  */
 335 void ft_invl_hw_context(struct ft_cmd *cmd)
 336 {
 337         struct fc_seq *seq;
 338         struct fc_exch *ep = NULL;
 339         struct fc_lport *lport = NULL;
 340
 341         BUG_ON(!cmd);
 342         seq = cmd->seq;
 343
 344         /* Cleanup the DDP context in HW if DDP was setup */
 345         if (cmd->was_ddp_setup && seq) {
 346                 ep = fc_seq_exch(seq);
 347                 if (ep) {
 348                         lport = ep->lp;
 349                         if (lport && (ep->xid <= lport->lro_xid))
 350                                 /*
 351                                  * "ddp_done" trigger invalidation of HW
 352                                  * specific DDP context
 353                                  */
 354                                 cmd->write_data_len = lport->tt.ddp_done(lport,
 355                                                                       ep->xid);
 356
 357                                 /*
 358                                  * Resetting same variable to indicate HW's
 359                                  * DDP context has been invalidated to avoid
 360                                  * re_invalidation of same context (context is
 361                                  * identified using ep->xid)
 362                                  */
 363                                 cmd->was_ddp_setup = 0;
 364                 }
 365         }
 366 }