drivers/target/tcm_fc/tfc_io.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2010 Cisco Systems, Inc.
   4  *
   5  * Portions based on tcm_loop_fabric_scsi.c and libfc/fc_fcp.c
   6  *
   7  * Copyright (c) 2007 Intel Corporation. All rights reserved.
   8  * Copyright (c) 2008 Red Hat, Inc.  All rights reserved.
   9  * Copyright (c) 2008 Mike Christie
  10  * Copyright (c) 2009 Rising Tide, Inc.
  11  * Copyright (c) 2009 Linux-iSCSI.org
  12  * Copyright (c) 2009 Nicholas A. Bellinger <nab@linux-iscsi.org>
  13  */
  14
  15 /* XXX TBD some includes may be extraneous */
  16
  17 #include <linux/module.h>
  18 #include <linux/moduleparam.h>
  19 #include <linux/utsname.h>
  20 #include <linux/init.h>
  21 #include <linux/slab.h>
  22 #include <linux/kthread.h>
  23 #include <linux/types.h>
  24 #include <linux/string.h>
  25 #include <linux/configfs.h>
  26 #include <linux/ctype.h>
  27 #include <linux/hash.h>
  28 #include <linux/ratelimit.h>
  29 #include <asm/unaligned.h>
  30 #include <scsi/libfc.h>
  31 #include <scsi/fc_encode.h>
  32
  33 #include <target/target_core_base.h>
  34 #include <target/target_core_fabric.h>
  35
  36 #include "tcm_fc.h"
  37
  38 /*
  39  * Deliver read data back to initiator.
  40  * XXX TBD handle resource problems later.
  41  */
  42 int ft_queue_data_in(struct se_cmd *se_cmd)
  43 {
  44         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
  45         struct fc_frame *fp = NULL;
  46         struct fc_exch *ep;
  47         struct fc_lport *lport;
  48         struct scatterlist *sg = NULL;
  49         size_t remaining;
  50         u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
  51         u32 mem_off = 0;
  52         u32 fh_off = 0;
  53         u32 frame_off = 0;
  54         size_t frame_len = 0;
  55         size_t mem_len = 0;
  56         size_t tlen;
  57         size_t off_in_page;
  58         struct page *page = NULL;
  59         int use_sg;
  60         int error;
  61         void *page_addr;
  62         void *from;
  63         void *to = NULL;
  64
  65         if (cmd->aborted)
  66                 return 0;
  67
  68         if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL)
  69                 goto queue_status;
  70
  71         ep = fc_seq_exch(cmd->seq);
  72         lport = ep->lp;
  73         cmd->seq = fc_seq_start_next(cmd->seq);
  74
  75         remaining = se_cmd->data_length;
  76
  77         /*
  78          * Setup to use first mem list entry, unless no data.
  79          */
  80         BUG_ON(remaining && !se_cmd->t_data_sg);
  81         if (remaining) {
  82                 sg = se_cmd->t_data_sg;
  83                 mem_len = sg->length;
  84                 mem_off = sg->offset;
  85                 page = sg_page(sg);
  86         }
  87
  88         /* no scatter/gather in skb for odd word length due to fc_seq_send() */
  89         use_sg = !(remaining % 4);
  90
  91         while (remaining) {
  92                 struct fc_seq *seq = cmd->seq;
  93
  94                 if (!seq) {
  95                         pr_debug("%s: Command aborted, xid 0x%x\n",
  96                                  __func__, ep->xid);
  97                         break;
  98                 }
  99                 if (!mem_len) {
 100                         sg = sg_next(sg);
 101                         mem_len = min((size_t)sg->length, remaining);
 102                         mem_off = sg->offset;
 103                         page = sg_page(sg);
 104                 }
 105                 if (!frame_len) {
 106                         /*
 107                          * If lport's has capability of Large Send Offload LSO)
 108                          * , then allow 'frame_len' to be as big as 'lso_max'
 109                          * if indicated transfer length is >= lport->lso_max
 110                          */
 111                         frame_len = (lport->seq_offload) ? lport->lso_max :
 112                                                           cmd->sess->max_frame;
 113                         frame_len = min(frame_len, remaining);
 114                         fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len);
 115                         if (!fp)
 116                                 return -ENOMEM;
 117                         to = fc_frame_payload_get(fp, 0);
 118                         fh_off = frame_off;
 119                         frame_off += frame_len;
 120                         /*
 121                          * Setup the frame's max payload which is used by base
 122                          * driver to indicate HW about max frame size, so that
 123                          * HW can do fragmentation appropriately based on
 124                          * "gso_max_size" of underline netdev.
 125                          */
 126                         fr_max_payload(fp) = cmd->sess->max_frame;
 127                 }
 128                 tlen = min(mem_len, frame_len);
 129
 130                 if (use_sg) {
 131                         off_in_page = mem_off;
 132                         BUG_ON(!page);
 133                         get_page(page);
 134                         skb_fill_page_desc(fp_skb(fp),
 135                                            skb_shinfo(fp_skb(fp))->nr_frags,
 136                                            page, off_in_page, tlen);
 137                         fr_len(fp) += tlen;
 138                         fp_skb(fp)->data_len += tlen;
 139                         fp_skb(fp)->truesize += page_size(page);
 140                 } else {
 141                         BUG_ON(!page);
 142                         from = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
 143                         page_addr = from;
 144                         from += offset_in_page(mem_off);
 145                         tlen = min(tlen, (size_t)(PAGE_SIZE -
 146                                                 offset_in_page(mem_off)));
 147                         memcpy(to, from, tlen);
 148                         kunmap_atomic(page_addr);
 149                         to += tlen;
 150                 }
 151
 152                 mem_off += tlen;
 153                 mem_len -= tlen;
 154                 frame_len -= tlen;
 155                 remaining -= tlen;
 156
 157                 if (frame_len &&
 158                     (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN))
 159                         continue;
 160                 if (!remaining)
 161                         f_ctl |= FC_FC_END_SEQ;
 162                 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
 163                                FC_TYPE_FCP, f_ctl, fh_off);
 164                 error = fc_seq_send(lport, seq, fp);
 165                 if (error) {
 166                         pr_info_ratelimited("%s: Failed to send frame %p, "
 167                                                 "xid <0x%x>, remaining %zu, "
 168                                                 "lso_max <0x%x>\n",
 169                                                 __func__, fp, ep->xid,
 170                                                 remaining, lport->lso_max);
 171                         /*
 172                          * Go ahead and set TASK_SET_FULL status ignoring the
 173                          * rest of the DataIN, and immediately attempt to
 174                          * send the response via ft_queue_status() in order
 175                          * to notify the initiator that it should reduce it's
 176                          * per LUN queue_depth.
 177                          */
 178                         se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
 179                         break;
 180                 }
 181         }
 182 queue_status:
 183         return ft_queue_status(se_cmd);
 184 }
 185
 186 static void ft_execute_work(struct work_struct *work)
 187 {
 188         struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
 189
 190         target_execute_cmd(&cmd->se_cmd);
 191 }
 192
 193 /*
 194  * Receive write data frame.
 195  */
 196 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
 197 {
 198         struct se_cmd *se_cmd = &cmd->se_cmd;
 199         struct fc_seq *seq = cmd->seq;
 200         struct fc_exch *ep;
 201         struct fc_lport *lport;
 202         struct fc_frame_header *fh;
 203         struct scatterlist *sg = NULL;
 204         u32 mem_off = 0;
 205         u32 rel_off;
 206         size_t frame_len;
 207         size_t mem_len = 0;
 208         size_t tlen;
 209         struct page *page = NULL;
 210         void *page_addr;
 211         void *from;
 212         void *to;
 213         u32 f_ctl;
 214         void *buf;
 215
 216         fh = fc_frame_header_get(fp);
 217         if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF))
 218                 goto drop;
 219
 220         f_ctl = ntoh24(fh->fh_f_ctl);
 221         ep = fc_seq_exch(seq);
 222         lport = ep->lp;
 223         if (cmd->was_ddp_setup) {
 224                 BUG_ON(!ep);
 225                 BUG_ON(!lport);
 226                 /*
 227                  * Since DDP (Large Rx offload) was setup for this request,
 228                  * payload is expected to be copied directly to user buffers.
 229                  */
 230                 buf = fc_frame_payload_get(fp, 1);
 231                 if (buf)
 232                         pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, "
 233                                 "cmd->sg_cnt 0x%x. DDP was setup"
 234                                 " hence not expected to receive frame with "
 235                                 "payload, Frame will be dropped if"
 236                                 "'Sequence Initiative' bit in f_ctl is"
 237                                 "not set\n", __func__, ep->xid, f_ctl,
 238                                 se_cmd->t_data_sg, se_cmd->t_data_nents);
 239                 /*
 240                  * Invalidate HW DDP context if it was setup for respective
 241                  * command. Invalidation of HW DDP context is requited in both
 242                  * situation (success and error).
 243                  */
 244                 ft_invl_hw_context(cmd);
 245
 246                 /*
 247                  * If "Sequence Initiative (TSI)" bit set in f_ctl, means last
 248                  * write data frame is received successfully where payload is
 249                  * posted directly to user buffer and only the last frame's
 250                  * header is posted in receive queue.
 251                  *
 252                  * If "Sequence Initiative (TSI)" bit is not set, means error
 253                  * condition w.r.t. DDP, hence drop the packet and let explict
 254                  * ABORTS from other end of exchange timer trigger the recovery.
 255                  */
 256                 if (f_ctl & FC_FC_SEQ_INIT)
 257                         goto last_frame;
 258                 else
 259                         goto drop;
 260         }
 261
 262         rel_off = ntohl(fh->fh_parm_offset);
 263         frame_len = fr_len(fp);
 264         if (frame_len <= sizeof(*fh))
 265                 goto drop;
 266         frame_len -= sizeof(*fh);
 267         from = fc_frame_payload_get(fp, 0);
 268         if (rel_off >= se_cmd->data_length)
 269                 goto drop;
 270         if (frame_len + rel_off > se_cmd->data_length)
 271                 frame_len = se_cmd->data_length - rel_off;
 272
 273         /*
 274          * Setup to use first mem list entry, unless no data.
 275          */
 276         BUG_ON(frame_len && !se_cmd->t_data_sg);
 277         if (frame_len) {
 278                 sg = se_cmd->t_data_sg;
 279                 mem_len = sg->length;
 280                 mem_off = sg->offset;
 281                 page = sg_page(sg);
 282         }
 283
 284         while (frame_len) {
 285                 if (!mem_len) {
 286                         sg = sg_next(sg);
 287                         mem_len = sg->length;
 288                         mem_off = sg->offset;
 289                         page = sg_page(sg);
 290                 }
 291                 if (rel_off >= mem_len) {
 292                         rel_off -= mem_len;
 293                         mem_len = 0;
 294                         continue;
 295                 }
 296                 mem_off += rel_off;
 297                 mem_len -= rel_off;
 298                 rel_off = 0;
 299
 300                 tlen = min(mem_len, frame_len);
 301
 302                 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
 303                 page_addr = to;
 304                 to += offset_in_page(mem_off);
 305                 tlen = min(tlen, (size_t)(PAGE_SIZE -
 306                                           offset_in_page(mem_off)));
 307                 memcpy(to, from, tlen);
 308                 kunmap_atomic(page_addr);
 309
 310                 from += tlen;
 311                 frame_len -= tlen;
 312                 mem_off += tlen;
 313                 mem_len -= tlen;
 314                 cmd->write_data_len += tlen;
 315         }
 316 last_frame:
 317         if (cmd->write_data_len == se_cmd->data_length) {
 318                 INIT_WORK(&cmd->work, ft_execute_work);
 319                 queue_work(cmd->sess->tport->tpg->workqueue, &cmd->work);
 320         }
 321 drop:
 322         fc_frame_free(fp);
 323 }
 324
 325 /*
 326  * Handle and cleanup any HW specific resources if
 327  * received ABORTS, errors, timeouts.
 328  */
 329 void ft_invl_hw_context(struct ft_cmd *cmd)
 330 {
 331         struct fc_seq *seq;
 332         struct fc_exch *ep = NULL;
 333         struct fc_lport *lport = NULL;
 334
 335         BUG_ON(!cmd);
 336         seq = cmd->seq;
 337
 338         /* Cleanup the DDP context in HW if DDP was setup */
 339         if (cmd->was_ddp_setup && seq) {
 340                 ep = fc_seq_exch(seq);
 341                 if (ep) {
 342                         lport = ep->lp;
 343                         if (lport && (ep->xid <= lport->lro_xid)) {
 344                                 /*
 345                                  * "ddp_done" trigger invalidation of HW
 346                                  * specific DDP context
 347                                  */
 348                                 cmd->write_data_len = lport->tt.ddp_done(lport,
 349                                                                       ep->xid);
 350
 351                                 /*
 352                                  * Resetting same variable to indicate HW's
 353                                  * DDP context has been invalidated to avoid
 354                                  * re_invalidation of same context (context is
 355                                  * identified using ep->xid)
 356                                  */
 357                                 cmd->was_ddp_setup = 0;
 358                         }
 359                 }
 360         }
 361 }