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 <generated/utsrelease.h>
  32 #include <linux/utsname.h>
  33 #include <linux/init.h>
  34 #include <linux/slab.h>
  35 #include <linux/kthread.h>
  36 #include <linux/types.h>
  37 #include <linux/string.h>
  38 #include <linux/configfs.h>
  39 #include <linux/ctype.h>
  40 #include <linux/hash.h>
  41 #include <linux/ratelimit.h>
  42 #include <asm/unaligned.h>
  43 #include <scsi/scsi.h>
  44 #include <scsi/scsi_host.h>
  45 #include <scsi/scsi_device.h>
  46 #include <scsi/scsi_cmnd.h>
  47 #include <scsi/libfc.h>
  48 #include <scsi/fc_encode.h>
  49
  50 #include <target/target_core_base.h>
  51 #include <target/target_core_fabric.h>
  52 #include <target/target_core_configfs.h>
  53 #include <target/configfs_macros.h>
  54
  55 #include "tcm_fc.h"
  56
  57 /*
  58  * Deliver read data back to initiator.
  59  * XXX TBD handle resource problems later.
  60  */
  61 int ft_queue_data_in(struct se_cmd *se_cmd)
  62 {
  63         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
  64         struct fc_frame *fp = NULL;
  65         struct fc_exch *ep;
  66         struct fc_lport *lport;
  67         struct scatterlist *sg = NULL;
  68         size_t remaining;
  69         u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
  70         u32 mem_off = 0;
  71         u32 fh_off = 0;
  72         u32 frame_off = 0;
  73         size_t frame_len = 0;
  74         size_t mem_len = 0;
  75         size_t tlen;
  76         size_t off_in_page;
  77         struct page *page = NULL;
  78         int use_sg;
  79         int error;
  80         void *page_addr;
  81         void *from;
  82         void *to = NULL;
  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                 if (!mem_len) {
 106                         sg = sg_next(sg);
 107                         mem_len = min((size_t)sg->length, remaining);
 108                         mem_off = sg->offset;
 109                         page = sg_page(sg);
 110                 }
 111                 if (!frame_len) {
 112                         /*
 113                          * If lport's has capability of Large Send Offload LSO)
 114                          * , then allow 'frame_len' to be as big as 'lso_max'
 115                          * if indicated transfer length is >= lport->lso_max
 116                          */
 117                         frame_len = (lport->seq_offload) ? lport->lso_max :
 118                                                           cmd->sess->max_frame;
 119                         frame_len = min(frame_len, remaining);
 120                         fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len);
 121                         if (!fp)
 122                                 return -ENOMEM;
 123                         to = fc_frame_payload_get(fp, 0);
 124                         fh_off = frame_off;
 125                         frame_off += frame_len;
 126                         /*
 127                          * Setup the frame's max payload which is used by base
 128                          * driver to indicate HW about max frame size, so that
 129                          * HW can do fragmentation appropriately based on
 130                          * "gso_max_size" of underline netdev.
 131                          */
 132                         fr_max_payload(fp) = cmd->sess->max_frame;
 133                 }
 134                 tlen = min(mem_len, frame_len);
 135
 136                 if (use_sg) {
 137                         off_in_page = mem_off;
 138                         BUG_ON(!page);
 139                         get_page(page);
 140                         skb_fill_page_desc(fp_skb(fp),
 141                                            skb_shinfo(fp_skb(fp))->nr_frags,
 142                                            page, off_in_page, tlen);
 143                         fr_len(fp) += tlen;
 144                         fp_skb(fp)->data_len += tlen;
 145                         fp_skb(fp)->truesize +=
 146                                         PAGE_SIZE << compound_order(page);
 147                 } else {
 148                         BUG_ON(!page);
 149                         from = kmap_atomic(page + (mem_off >> PAGE_SHIFT),
 150                                            KM_SOFTIRQ0);
 151                         page_addr = from;
 152                         from += mem_off & ~PAGE_MASK;
 153                         tlen = min(tlen, (size_t)(PAGE_SIZE -
 154                                                 (mem_off & ~PAGE_MASK)));
 155                         memcpy(to, from, tlen);
 156                         kunmap_atomic(page_addr, KM_SOFTIRQ0);
 157                         to += tlen;
 158                 }
 159
 160                 mem_off += tlen;
 161                 mem_len -= tlen;
 162                 frame_len -= tlen;
 163                 remaining -= tlen;
 164
 165                 if (frame_len &&
 166                     (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN))
 167                         continue;
 168                 if (!remaining)
 169                         f_ctl |= FC_FC_END_SEQ;
 170                 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
 171                                FC_TYPE_FCP, f_ctl, fh_off);
 172                 error = lport->tt.seq_send(lport, cmd->seq, fp);
 173                 if (error) {
 174                         /* XXX For now, initiator will retry */
 175                         pr_err_ratelimited("%s: Failed to send frame %p, "
 176                                                 "xid <0x%x>, remaining %zu, "
 177                                                 "lso_max <0x%x>\n",
 178                                                 __func__, fp, ep->xid,
 179                                                 remaining, lport->lso_max);
 180                 }
 181         }
 182         return ft_queue_status(se_cmd);
 183 }
 184
 185 /*
 186  * Receive write data frame.
 187  */
 188 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
 189 {
 190         struct se_cmd *se_cmd = &cmd->se_cmd;
 191         struct fc_seq *seq = cmd->seq;
 192         struct fc_exch *ep;
 193         struct fc_lport *lport;
 194         struct fc_frame_header *fh;
 195         struct scatterlist *sg = NULL;
 196         u32 mem_off = 0;
 197         u32 rel_off;
 198         size_t frame_len;
 199         size_t mem_len = 0;
 200         size_t tlen;
 201         struct page *page = NULL;
 202         void *page_addr;
 203         void *from;
 204         void *to;
 205         u32 f_ctl;
 206         void *buf;
 207
 208         fh = fc_frame_header_get(fp);
 209         if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF))
 210                 goto drop;
 211
 212         f_ctl = ntoh24(fh->fh_f_ctl);
 213         ep = fc_seq_exch(seq);
 214         lport = ep->lp;
 215         if (cmd->was_ddp_setup) {
 216                 BUG_ON(!ep);
 217                 BUG_ON(!lport);
 218                 /*
 219                  * Since DDP (Large Rx offload) was setup for this request,
 220                  * payload is expected to be copied directly to user buffers.
 221                  */
 222                 buf = fc_frame_payload_get(fp, 1);
 223                 if (buf)
 224                         pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, "
 225                                 "cmd->sg_cnt 0x%x. DDP was setup"
 226                                 " hence not expected to receive frame with "
 227                                 "payload, Frame will be dropped if"
 228                                 "'Sequence Initiative' bit in f_ctl is"
 229                                 "not set\n", __func__, ep->xid, f_ctl,
 230                                 cmd->sg, cmd->sg_cnt);
 231                 /*
 232                  * Invalidate HW DDP context if it was setup for respective
 233                  * command. Invalidation of HW DDP context is requited in both
 234                  * situation (success and error).
 235                  */
 236                 ft_invl_hw_context(cmd);
 237
 238                 /*
 239                  * If "Sequence Initiative (TSI)" bit set in f_ctl, means last
 240                  * write data frame is received successfully where payload is
 241                  * posted directly to user buffer and only the last frame's
 242                  * header is posted in receive queue.
 243                  *
 244                  * If "Sequence Initiative (TSI)" bit is not set, means error
 245                  * condition w.r.t. DDP, hence drop the packet and let explict
 246                  * ABORTS from other end of exchange timer trigger the recovery.
 247                  */
 248                 if (f_ctl & FC_FC_SEQ_INIT)
 249                         goto last_frame;
 250                 else
 251                         goto drop;
 252         }
 253
 254         rel_off = ntohl(fh->fh_parm_offset);
 255         frame_len = fr_len(fp);
 256         if (frame_len <= sizeof(*fh))
 257                 goto drop;
 258         frame_len -= sizeof(*fh);
 259         from = fc_frame_payload_get(fp, 0);
 260         if (rel_off >= se_cmd->data_length)
 261                 goto drop;
 262         if (frame_len + rel_off > se_cmd->data_length)
 263                 frame_len = se_cmd->data_length - rel_off;
 264
 265         /*
 266          * Setup to use first mem list entry, unless no data.
 267          */
 268         BUG_ON(frame_len && !se_cmd->t_data_sg);
 269         if (frame_len) {
 270                 sg = se_cmd->t_data_sg;
 271                 mem_len = sg->length;
 272                 mem_off = sg->offset;
 273                 page = sg_page(sg);
 274         }
 275
 276         while (frame_len) {
 277                 if (!mem_len) {
 278                         sg = sg_next(sg);
 279                         mem_len = sg->length;
 280                         mem_off = sg->offset;
 281                         page = sg_page(sg);
 282                 }
 283                 if (rel_off >= mem_len) {
 284                         rel_off -= mem_len;
 285                         mem_len = 0;
 286                         continue;
 287                 }
 288                 mem_off += rel_off;
 289                 mem_len -= rel_off;
 290                 rel_off = 0;
 291
 292                 tlen = min(mem_len, frame_len);
 293
 294                 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT),
 295                                  KM_SOFTIRQ0);
 296                 page_addr = to;
 297                 to += mem_off & ~PAGE_MASK;
 298                 tlen = min(tlen, (size_t)(PAGE_SIZE -
 299                                           (mem_off & ~PAGE_MASK)));
 300                 memcpy(to, from, tlen);
 301                 kunmap_atomic(page_addr, KM_SOFTIRQ0);
 302
 303                 from += tlen;
 304                 frame_len -= tlen;
 305                 mem_off += tlen;
 306                 mem_len -= tlen;
 307                 cmd->write_data_len += tlen;
 308         }
 309 last_frame:
 310         if (cmd->write_data_len == se_cmd->data_length)
 311                 transport_generic_handle_data(se_cmd);
 312 drop:
 313         fc_frame_free(fp);
 314 }
 315
 316 /*
 317  * Handle and cleanup any HW specific resources if
 318  * received ABORTS, errors, timeouts.
 319  */
 320 void ft_invl_hw_context(struct ft_cmd *cmd)
 321 {
 322         struct fc_seq *seq = cmd->seq;
 323         struct fc_exch *ep = NULL;
 324         struct fc_lport *lport = NULL;
 325
 326         BUG_ON(!cmd);
 327
 328         /* Cleanup the DDP context in HW if DDP was setup */
 329         if (cmd->was_ddp_setup && seq) {
 330                 ep = fc_seq_exch(seq);
 331                 if (ep) {
 332                         lport = ep->lp;
 333                         if (lport && (ep->xid <= lport->lro_xid))
 334                                 /*
 335                                  * "ddp_done" trigger invalidation of HW
 336                                  * specific DDP context
 337                                  */
 338                                 cmd->write_data_len = lport->tt.ddp_done(lport,
 339                                                                       ep->xid);
 340
 341                                 /*
 342                                  * Resetting same variable to indicate HW's
 343                                  * DDP context has been invalidated to avoid
 344                                  * re_invalidation of same context (context is
 345                                  * identified using ep->xid)
 346                                  */
 347                                 cmd->was_ddp_setup = 0;
 348                 }
 349         }
 350 }