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/libfc.h>
  43 #include <scsi/fc_encode.h>
  44
  45 #include <target/target_core_base.h>
  46 #include <target/target_core_fabric.h>
  47 #include <target/configfs_macros.h>
  48
  49 #include "tcm_fc.h"
  50
  51 /*
  52  * Deliver read data back to initiator.
  53  * XXX TBD handle resource problems later.
  54  */
  55 int ft_queue_data_in(struct se_cmd *se_cmd)
  56 {
  57         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
  58         struct fc_frame *fp = NULL;
  59         struct fc_exch *ep;
  60         struct fc_lport *lport;
  61         struct scatterlist *sg = NULL;
  62         size_t remaining;
  63         u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
  64         u32 mem_off = 0;
  65         u32 fh_off = 0;
  66         u32 frame_off = 0;
  67         size_t frame_len = 0;
  68         size_t mem_len = 0;
  69         size_t tlen;
  70         size_t off_in_page;
  71         struct page *page = NULL;
  72         int use_sg;
  73         int error;
  74         void *page_addr;
  75         void *from;
  76         void *to = NULL;
  77
  78         if (cmd->aborted)
  79                 return 0;
  80
  81         if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL)
  82                 goto queue_status;
  83
  84         ep = fc_seq_exch(cmd->seq);
  85         lport = ep->lp;
  86         cmd->seq = lport->tt.seq_start_next(cmd->seq);
  87
  88         remaining = se_cmd->data_length;
  89
  90         /*
  91          * Setup to use first mem list entry, unless no data.
  92          */
  93         BUG_ON(remaining && !se_cmd->t_data_sg);
  94         if (remaining) {
  95                 sg = se_cmd->t_data_sg;
  96                 mem_len = sg->length;
  97                 mem_off = sg->offset;
  98                 page = sg_page(sg);
  99         }
 100
 101         /* no scatter/gather in skb for odd word length due to fc_seq_send() */
 102         use_sg = !(remaining % 4);
 103
 104         while (remaining) {
 105                 struct fc_seq *seq = cmd->seq;
 106
 107                 if (!seq) {
 108                         pr_debug("%s: Command aborted, xid 0x%x\n",
 109                                  __func__, ep->xid);
 110                         break;
 111                 }
 112                 if (!mem_len) {
 113                         sg = sg_next(sg);
 114                         mem_len = min((size_t)sg->length, remaining);
 115                         mem_off = sg->offset;
 116                         page = sg_page(sg);
 117                 }
 118                 if (!frame_len) {
 119                         /*
 120                          * If lport's has capability of Large Send Offload LSO)
 121                          * , then allow 'frame_len' to be as big as 'lso_max'
 122                          * if indicated transfer length is >= lport->lso_max
 123                          */
 124                         frame_len = (lport->seq_offload) ? lport->lso_max :
 125                                                           cmd->sess->max_frame;
 126                         frame_len = min(frame_len, remaining);
 127                         fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len);
 128                         if (!fp)
 129                                 return -ENOMEM;
 130                         to = fc_frame_payload_get(fp, 0);
 131                         fh_off = frame_off;
 132                         frame_off += frame_len;
 133                         /*
 134                          * Setup the frame's max payload which is used by base
 135                          * driver to indicate HW about max frame size, so that
 136                          * HW can do fragmentation appropriately based on
 137                          * "gso_max_size" of underline netdev.
 138                          */
 139                         fr_max_payload(fp) = cmd->sess->max_frame;
 140                 }
 141                 tlen = min(mem_len, frame_len);
 142
 143                 if (use_sg) {
 144                         off_in_page = mem_off;
 145                         BUG_ON(!page);
 146                         get_page(page);
 147                         skb_fill_page_desc(fp_skb(fp),
 148                                            skb_shinfo(fp_skb(fp))->nr_frags,
 149                                            page, off_in_page, tlen);
 150                         fr_len(fp) += tlen;
 151                         fp_skb(fp)->data_len += tlen;
 152                         fp_skb(fp)->truesize +=
 153                                         PAGE_SIZE << compound_order(page);
 154                 } else {
 155                         BUG_ON(!page);
 156                         from = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
 157                         page_addr = from;
 158                         from += mem_off & ~PAGE_MASK;
 159                         tlen = min(tlen, (size_t)(PAGE_SIZE -
 160                                                 (mem_off & ~PAGE_MASK)));
 161                         memcpy(to, from, tlen);
 162                         kunmap_atomic(page_addr);
 163                         to += tlen;
 164                 }
 165
 166                 mem_off += tlen;
 167                 mem_len -= tlen;
 168                 frame_len -= tlen;
 169                 remaining -= tlen;
 170
 171                 if (frame_len &&
 172                     (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN))
 173                         continue;
 174                 if (!remaining)
 175                         f_ctl |= FC_FC_END_SEQ;
 176                 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
 177                                FC_TYPE_FCP, f_ctl, fh_off);
 178                 error = lport->tt.seq_send(lport, seq, fp);
 179                 if (error) {
 180                         pr_info_ratelimited("%s: Failed to send frame %p, "
 181                                                 "xid <0x%x>, remaining %zu, "
 182                                                 "lso_max <0x%x>\n",
 183                                                 __func__, fp, ep->xid,
 184                                                 remaining, lport->lso_max);
 185                         /*
 186                          * Go ahead and set TASK_SET_FULL status ignoring the
 187                          * rest of the DataIN, and immediately attempt to
 188                          * send the response via ft_queue_status() in order
 189                          * to notify the initiator that it should reduce it's
 190                          * per LUN queue_depth.
 191                          */
 192                         se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
 193                         break;
 194                 }
 195         }
 196 queue_status:
 197         return ft_queue_status(se_cmd);
 198 }
 199
 200 static void ft_execute_work(struct work_struct *work)
 201 {
 202         struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
 203
 204         target_execute_cmd(&cmd->se_cmd);
 205 }
 206
 207 /*
 208  * Receive write data frame.
 209  */
 210 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
 211 {
 212         struct se_cmd *se_cmd = &cmd->se_cmd;
 213         struct fc_seq *seq = cmd->seq;
 214         struct fc_exch *ep;
 215         struct fc_lport *lport;
 216         struct fc_frame_header *fh;
 217         struct scatterlist *sg = NULL;
 218         u32 mem_off = 0;
 219         u32 rel_off;
 220         size_t frame_len;
 221         size_t mem_len = 0;
 222         size_t tlen;
 223         struct page *page = NULL;
 224         void *page_addr;
 225         void *from;
 226         void *to;
 227         u32 f_ctl;
 228         void *buf;
 229
 230         fh = fc_frame_header_get(fp);
 231         if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF))
 232                 goto drop;
 233
 234         f_ctl = ntoh24(fh->fh_f_ctl);
 235         ep = fc_seq_exch(seq);
 236         lport = ep->lp;
 237         if (cmd->was_ddp_setup) {
 238                 BUG_ON(!ep);
 239                 BUG_ON(!lport);
 240                 /*
 241                  * Since DDP (Large Rx offload) was setup for this request,
 242                  * payload is expected to be copied directly to user buffers.
 243                  */
 244                 buf = fc_frame_payload_get(fp, 1);
 245                 if (buf)
 246                         pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, "
 247                                 "cmd->sg_cnt 0x%x. DDP was setup"
 248                                 " hence not expected to receive frame with "
 249                                 "payload, Frame will be dropped if"
 250                                 "'Sequence Initiative' bit in f_ctl is"
 251                                 "not set\n", __func__, ep->xid, f_ctl,
 252                                 se_cmd->t_data_sg, se_cmd->t_data_nents);
 253                 /*
 254                  * Invalidate HW DDP context if it was setup for respective
 255                  * command. Invalidation of HW DDP context is requited in both
 256                  * situation (success and error).
 257                  */
 258                 ft_invl_hw_context(cmd);
 259
 260                 /*
 261                  * If "Sequence Initiative (TSI)" bit set in f_ctl, means last
 262                  * write data frame is received successfully where payload is
 263                  * posted directly to user buffer and only the last frame's
 264                  * header is posted in receive queue.
 265                  *
 266                  * If "Sequence Initiative (TSI)" bit is not set, means error
 267                  * condition w.r.t. DDP, hence drop the packet and let explict
 268                  * ABORTS from other end of exchange timer trigger the recovery.
 269                  */
 270                 if (f_ctl & FC_FC_SEQ_INIT)
 271                         goto last_frame;
 272                 else
 273                         goto drop;
 274         }
 275
 276         rel_off = ntohl(fh->fh_parm_offset);
 277         frame_len = fr_len(fp);
 278         if (frame_len <= sizeof(*fh))
 279                 goto drop;
 280         frame_len -= sizeof(*fh);
 281         from = fc_frame_payload_get(fp, 0);
 282         if (rel_off >= se_cmd->data_length)
 283                 goto drop;
 284         if (frame_len + rel_off > se_cmd->data_length)
 285                 frame_len = se_cmd->data_length - rel_off;
 286
 287         /*
 288          * Setup to use first mem list entry, unless no data.
 289          */
 290         BUG_ON(frame_len && !se_cmd->t_data_sg);
 291         if (frame_len) {
 292                 sg = se_cmd->t_data_sg;
 293                 mem_len = sg->length;
 294                 mem_off = sg->offset;
 295                 page = sg_page(sg);
 296         }
 297
 298         while (frame_len) {
 299                 if (!mem_len) {
 300                         sg = sg_next(sg);
 301                         mem_len = sg->length;
 302                         mem_off = sg->offset;
 303                         page = sg_page(sg);
 304                 }
 305                 if (rel_off >= mem_len) {
 306                         rel_off -= mem_len;
 307                         mem_len = 0;
 308                         continue;
 309                 }
 310                 mem_off += rel_off;
 311                 mem_len -= rel_off;
 312                 rel_off = 0;
 313
 314                 tlen = min(mem_len, frame_len);
 315
 316                 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
 317                 page_addr = to;
 318                 to += mem_off & ~PAGE_MASK;
 319                 tlen = min(tlen, (size_t)(PAGE_SIZE -
 320                                           (mem_off & ~PAGE_MASK)));
 321                 memcpy(to, from, tlen);
 322                 kunmap_atomic(page_addr);
 323
 324                 from += tlen;
 325                 frame_len -= tlen;
 326                 mem_off += tlen;
 327                 mem_len -= tlen;
 328                 cmd->write_data_len += tlen;
 329         }
 330 last_frame:
 331         if (cmd->write_data_len == se_cmd->data_length) {
 332                 INIT_WORK(&cmd->work, ft_execute_work);
 333                 queue_work(cmd->sess->tport->tpg->workqueue, &cmd->work);
 334         }
 335 drop:
 336         fc_frame_free(fp);
 337 }
 338
 339 /*
 340  * Handle and cleanup any HW specific resources if
 341  * received ABORTS, errors, timeouts.
 342  */
 343 void ft_invl_hw_context(struct ft_cmd *cmd)
 344 {
 345         struct fc_seq *seq;
 346         struct fc_exch *ep = NULL;
 347         struct fc_lport *lport = NULL;
 348
 349         BUG_ON(!cmd);
 350         seq = cmd->seq;
 351
 352         /* Cleanup the DDP context in HW if DDP was setup */
 353         if (cmd->was_ddp_setup && seq) {
 354                 ep = fc_seq_exch(seq);
 355                 if (ep) {
 356                         lport = ep->lp;
 357                         if (lport && (ep->xid <= lport->lro_xid)) {
 358                                 /*
 359                                  * "ddp_done" trigger invalidation of HW
 360                                  * specific DDP context
 361                                  */
 362                                 cmd->write_data_len = lport->tt.ddp_done(lport,
 363                                                                       ep->xid);
 364
 365                                 /*
 366                                  * Resetting same variable to indicate HW's
 367                                  * DDP context has been invalidated to avoid
 368                                  * re_invalidation of same context (context is
 369                                  * identified using ep->xid)
 370                                  */
 371                                 cmd->was_ddp_setup = 0;
 372                         }
 373                 }
 374         }
 375 }