dm: always allow one page in dm_merge_bvec
[linux-2.6] / drivers / scsi / qla2xxx / qla_iocb.c
1 /*
2  * QLogic Fibre Channel HBA Driver
3  * Copyright (c)  2003-2008 QLogic Corporation
4  *
5  * See LICENSE.qla2xxx for copyright and licensing details.
6  */
7 #include "qla_def.h"
8
9 #include <linux/blkdev.h>
10 #include <linux/delay.h>
11
12 #include <scsi/scsi_tcq.h>
13
14 static request_t *qla2x00_req_pkt(scsi_qla_host_t *ha);
15 static void qla2x00_isp_cmd(scsi_qla_host_t *ha);
16
17 /**
18  * qla2x00_get_cmd_direction() - Determine control_flag data direction.
19  * @cmd: SCSI command
20  *
21  * Returns the proper CF_* direction based on CDB.
22  */
23 static inline uint16_t
24 qla2x00_get_cmd_direction(struct scsi_cmnd *cmd)
25 {
26         uint16_t cflags;
27
28         cflags = 0;
29
30         /* Set transfer direction */
31         if (cmd->sc_data_direction == DMA_TO_DEVICE)
32                 cflags = CF_WRITE;
33         else if (cmd->sc_data_direction == DMA_FROM_DEVICE)
34                 cflags = CF_READ;
35         return (cflags);
36 }
37
38 /**
39  * qla2x00_calc_iocbs_32() - Determine number of Command Type 2 and
40  * Continuation Type 0 IOCBs to allocate.
41  *
42  * @dsds: number of data segment decriptors needed
43  *
44  * Returns the number of IOCB entries needed to store @dsds.
45  */
46 uint16_t
47 qla2x00_calc_iocbs_32(uint16_t dsds)
48 {
49         uint16_t iocbs;
50
51         iocbs = 1;
52         if (dsds > 3) {
53                 iocbs += (dsds - 3) / 7;
54                 if ((dsds - 3) % 7)
55                         iocbs++;
56         }
57         return (iocbs);
58 }
59
60 /**
61  * qla2x00_calc_iocbs_64() - Determine number of Command Type 3 and
62  * Continuation Type 1 IOCBs to allocate.
63  *
64  * @dsds: number of data segment decriptors needed
65  *
66  * Returns the number of IOCB entries needed to store @dsds.
67  */
68 uint16_t
69 qla2x00_calc_iocbs_64(uint16_t dsds)
70 {
71         uint16_t iocbs;
72
73         iocbs = 1;
74         if (dsds > 2) {
75                 iocbs += (dsds - 2) / 5;
76                 if ((dsds - 2) % 5)
77                         iocbs++;
78         }
79         return (iocbs);
80 }
81
82 /**
83  * qla2x00_prep_cont_type0_iocb() - Initialize a Continuation Type 0 IOCB.
84  * @ha: HA context
85  *
86  * Returns a pointer to the Continuation Type 0 IOCB packet.
87  */
88 static inline cont_entry_t *
89 qla2x00_prep_cont_type0_iocb(scsi_qla_host_t *ha)
90 {
91         cont_entry_t *cont_pkt;
92
93         /* Adjust ring index. */
94         ha->req_ring_index++;
95         if (ha->req_ring_index == ha->request_q_length) {
96                 ha->req_ring_index = 0;
97                 ha->request_ring_ptr = ha->request_ring;
98         } else {
99                 ha->request_ring_ptr++;
100         }
101
102         cont_pkt = (cont_entry_t *)ha->request_ring_ptr;
103
104         /* Load packet defaults. */
105         *((uint32_t *)(&cont_pkt->entry_type)) =
106             __constant_cpu_to_le32(CONTINUE_TYPE);
107
108         return (cont_pkt);
109 }
110
111 /**
112  * qla2x00_prep_cont_type1_iocb() - Initialize a Continuation Type 1 IOCB.
113  * @ha: HA context
114  *
115  * Returns a pointer to the continuation type 1 IOCB packet.
116  */
117 static inline cont_a64_entry_t *
118 qla2x00_prep_cont_type1_iocb(scsi_qla_host_t *ha)
119 {
120         cont_a64_entry_t *cont_pkt;
121
122         /* Adjust ring index. */
123         ha->req_ring_index++;
124         if (ha->req_ring_index == ha->request_q_length) {
125                 ha->req_ring_index = 0;
126                 ha->request_ring_ptr = ha->request_ring;
127         } else {
128                 ha->request_ring_ptr++;
129         }
130
131         cont_pkt = (cont_a64_entry_t *)ha->request_ring_ptr;
132
133         /* Load packet defaults. */
134         *((uint32_t *)(&cont_pkt->entry_type)) =
135             __constant_cpu_to_le32(CONTINUE_A64_TYPE);
136
137         return (cont_pkt);
138 }
139
140 /**
141  * qla2x00_build_scsi_iocbs_32() - Build IOCB command utilizing 32bit
142  * capable IOCB types.
143  *
144  * @sp: SRB command to process
145  * @cmd_pkt: Command type 2 IOCB
146  * @tot_dsds: Total number of segments to transfer
147  */
148 void qla2x00_build_scsi_iocbs_32(srb_t *sp, cmd_entry_t *cmd_pkt,
149     uint16_t tot_dsds)
150 {
151         uint16_t        avail_dsds;
152         uint32_t        *cur_dsd;
153         scsi_qla_host_t *ha;
154         struct scsi_cmnd *cmd;
155         struct scatterlist *sg;
156         int i;
157
158         cmd = sp->cmd;
159
160         /* Update entry type to indicate Command Type 2 IOCB */
161         *((uint32_t *)(&cmd_pkt->entry_type)) =
162             __constant_cpu_to_le32(COMMAND_TYPE);
163
164         /* No data transfer */
165         if (!scsi_bufflen(cmd) || cmd->sc_data_direction == DMA_NONE) {
166                 cmd_pkt->byte_count = __constant_cpu_to_le32(0);
167                 return;
168         }
169
170         ha = sp->ha;
171
172         cmd_pkt->control_flags |= cpu_to_le16(qla2x00_get_cmd_direction(cmd));
173
174         /* Three DSDs are available in the Command Type 2 IOCB */
175         avail_dsds = 3;
176         cur_dsd = (uint32_t *)&cmd_pkt->dseg_0_address;
177
178         /* Load data segments */
179         scsi_for_each_sg(cmd, sg, tot_dsds, i) {
180                 cont_entry_t *cont_pkt;
181
182                 /* Allocate additional continuation packets? */
183                 if (avail_dsds == 0) {
184                         /*
185                          * Seven DSDs are available in the Continuation
186                          * Type 0 IOCB.
187                          */
188                         cont_pkt = qla2x00_prep_cont_type0_iocb(ha);
189                         cur_dsd = (uint32_t *)&cont_pkt->dseg_0_address;
190                         avail_dsds = 7;
191                 }
192
193                 *cur_dsd++ = cpu_to_le32(sg_dma_address(sg));
194                 *cur_dsd++ = cpu_to_le32(sg_dma_len(sg));
195                 avail_dsds--;
196         }
197 }
198
199 /**
200  * qla2x00_build_scsi_iocbs_64() - Build IOCB command utilizing 64bit
201  * capable IOCB types.
202  *
203  * @sp: SRB command to process
204  * @cmd_pkt: Command type 3 IOCB
205  * @tot_dsds: Total number of segments to transfer
206  */
207 void qla2x00_build_scsi_iocbs_64(srb_t *sp, cmd_entry_t *cmd_pkt,
208     uint16_t tot_dsds)
209 {
210         uint16_t        avail_dsds;
211         uint32_t        *cur_dsd;
212         scsi_qla_host_t *ha;
213         struct scsi_cmnd *cmd;
214         struct scatterlist *sg;
215         int i;
216
217         cmd = sp->cmd;
218
219         /* Update entry type to indicate Command Type 3 IOCB */
220         *((uint32_t *)(&cmd_pkt->entry_type)) =
221             __constant_cpu_to_le32(COMMAND_A64_TYPE);
222
223         /* No data transfer */
224         if (!scsi_bufflen(cmd) || cmd->sc_data_direction == DMA_NONE) {
225                 cmd_pkt->byte_count = __constant_cpu_to_le32(0);
226                 return;
227         }
228
229         ha = sp->ha;
230
231         cmd_pkt->control_flags |= cpu_to_le16(qla2x00_get_cmd_direction(cmd));
232
233         /* Two DSDs are available in the Command Type 3 IOCB */
234         avail_dsds = 2;
235         cur_dsd = (uint32_t *)&cmd_pkt->dseg_0_address;
236
237         /* Load data segments */
238         scsi_for_each_sg(cmd, sg, tot_dsds, i) {
239                 dma_addr_t      sle_dma;
240                 cont_a64_entry_t *cont_pkt;
241
242                 /* Allocate additional continuation packets? */
243                 if (avail_dsds == 0) {
244                         /*
245                          * Five DSDs are available in the Continuation
246                          * Type 1 IOCB.
247                          */
248                         cont_pkt = qla2x00_prep_cont_type1_iocb(ha);
249                         cur_dsd = (uint32_t *)cont_pkt->dseg_0_address;
250                         avail_dsds = 5;
251                 }
252
253                 sle_dma = sg_dma_address(sg);
254                 *cur_dsd++ = cpu_to_le32(LSD(sle_dma));
255                 *cur_dsd++ = cpu_to_le32(MSD(sle_dma));
256                 *cur_dsd++ = cpu_to_le32(sg_dma_len(sg));
257                 avail_dsds--;
258         }
259 }
260
261 /**
262  * qla2x00_start_scsi() - Send a SCSI command to the ISP
263  * @sp: command to send to the ISP
264  *
265  * Returns non-zero if a failure occured, else zero.
266  */
267 int
268 qla2x00_start_scsi(srb_t *sp)
269 {
270         int             ret, nseg;
271         unsigned long   flags;
272         scsi_qla_host_t *ha;
273         struct scsi_cmnd *cmd;
274         uint32_t        *clr_ptr;
275         uint32_t        index;
276         uint32_t        handle;
277         cmd_entry_t     *cmd_pkt;
278         uint16_t        cnt;
279         uint16_t        req_cnt;
280         uint16_t        tot_dsds;
281         struct device_reg_2xxx __iomem *reg;
282
283         /* Setup device pointers. */
284         ret = 0;
285         ha = sp->ha;
286         reg = &ha->iobase->isp;
287         cmd = sp->cmd;
288         /* So we know we haven't pci_map'ed anything yet */
289         tot_dsds = 0;
290
291         /* Send marker if required */
292         if (ha->marker_needed != 0) {
293                 if (qla2x00_marker(ha, 0, 0, MK_SYNC_ALL) != QLA_SUCCESS) {
294                         return (QLA_FUNCTION_FAILED);
295                 }
296                 ha->marker_needed = 0;
297         }
298
299         /* Acquire ring specific lock */
300         spin_lock_irqsave(&ha->hardware_lock, flags);
301
302         /* Check for room in outstanding command list. */
303         handle = ha->current_outstanding_cmd;
304         for (index = 1; index < MAX_OUTSTANDING_COMMANDS; index++) {
305                 handle++;
306                 if (handle == MAX_OUTSTANDING_COMMANDS)
307                         handle = 1;
308                 if (!ha->outstanding_cmds[handle])
309                         break;
310         }
311         if (index == MAX_OUTSTANDING_COMMANDS)
312                 goto queuing_error;
313
314         /* Map the sg table so we have an accurate count of sg entries needed */
315         if (scsi_sg_count(cmd)) {
316                 nseg = dma_map_sg(&ha->pdev->dev, scsi_sglist(cmd),
317                     scsi_sg_count(cmd), cmd->sc_data_direction);
318                 if (unlikely(!nseg))
319                         goto queuing_error;
320         } else
321                 nseg = 0;
322
323         tot_dsds = nseg;
324
325         /* Calculate the number of request entries needed. */
326         req_cnt = ha->isp_ops->calc_req_entries(tot_dsds);
327         if (ha->req_q_cnt < (req_cnt + 2)) {
328                 cnt = RD_REG_WORD_RELAXED(ISP_REQ_Q_OUT(ha, reg));
329                 if (ha->req_ring_index < cnt)
330                         ha->req_q_cnt = cnt - ha->req_ring_index;
331                 else
332                         ha->req_q_cnt = ha->request_q_length -
333                             (ha->req_ring_index - cnt);
334         }
335         if (ha->req_q_cnt < (req_cnt + 2))
336                 goto queuing_error;
337
338         /* Build command packet */
339         ha->current_outstanding_cmd = handle;
340         ha->outstanding_cmds[handle] = sp;
341         sp->ha = ha;
342         sp->cmd->host_scribble = (unsigned char *)(unsigned long)handle;
343         ha->req_q_cnt -= req_cnt;
344
345         cmd_pkt = (cmd_entry_t *)ha->request_ring_ptr;
346         cmd_pkt->handle = handle;
347         /* Zero out remaining portion of packet. */
348         clr_ptr = (uint32_t *)cmd_pkt + 2;
349         memset(clr_ptr, 0, REQUEST_ENTRY_SIZE - 8);
350         cmd_pkt->dseg_count = cpu_to_le16(tot_dsds);
351
352         /* Set target ID and LUN number*/
353         SET_TARGET_ID(ha, cmd_pkt->target, sp->fcport->loop_id);
354         cmd_pkt->lun = cpu_to_le16(sp->cmd->device->lun);
355
356         /* Update tagged queuing modifier */
357         cmd_pkt->control_flags = __constant_cpu_to_le16(CF_SIMPLE_TAG);
358
359         /* Load SCSI command packet. */
360         memcpy(cmd_pkt->scsi_cdb, cmd->cmnd, cmd->cmd_len);
361         cmd_pkt->byte_count = cpu_to_le32((uint32_t)scsi_bufflen(cmd));
362
363         /* Build IOCB segments */
364         ha->isp_ops->build_iocbs(sp, cmd_pkt, tot_dsds);
365
366         /* Set total data segment count. */
367         cmd_pkt->entry_count = (uint8_t)req_cnt;
368         wmb();
369
370         /* Adjust ring index. */
371         ha->req_ring_index++;
372         if (ha->req_ring_index == ha->request_q_length) {
373                 ha->req_ring_index = 0;
374                 ha->request_ring_ptr = ha->request_ring;
375         } else
376                 ha->request_ring_ptr++;
377
378         sp->flags |= SRB_DMA_VALID;
379
380         /* Set chip new ring index. */
381         WRT_REG_WORD(ISP_REQ_Q_IN(ha, reg), ha->req_ring_index);
382         RD_REG_WORD_RELAXED(ISP_REQ_Q_IN(ha, reg));     /* PCI Posting. */
383
384         /* Manage unprocessed RIO/ZIO commands in response queue. */
385         if (ha->flags.process_response_queue &&
386             ha->response_ring_ptr->signature != RESPONSE_PROCESSED)
387                 qla2x00_process_response_queue(ha);
388
389         spin_unlock_irqrestore(&ha->hardware_lock, flags);
390         return (QLA_SUCCESS);
391
392 queuing_error:
393         if (tot_dsds)
394                 scsi_dma_unmap(cmd);
395
396         spin_unlock_irqrestore(&ha->hardware_lock, flags);
397
398         return (QLA_FUNCTION_FAILED);
399 }
400
401 /**
402  * qla2x00_marker() - Send a marker IOCB to the firmware.
403  * @ha: HA context
404  * @loop_id: loop ID
405  * @lun: LUN
406  * @type: marker modifier
407  *
408  * Can be called from both normal and interrupt context.
409  *
410  * Returns non-zero if a failure occured, else zero.
411  */
412 int
413 __qla2x00_marker(scsi_qla_host_t *ha, uint16_t loop_id, uint16_t lun,
414     uint8_t type)
415 {
416         mrk_entry_t *mrk;
417         struct mrk_entry_24xx *mrk24;
418         scsi_qla_host_t *pha = to_qla_parent(ha);
419
420         mrk24 = NULL;
421         mrk = (mrk_entry_t *)qla2x00_req_pkt(pha);
422         if (mrk == NULL) {
423                 DEBUG2_3(printk("%s(%ld): failed to allocate Marker IOCB.\n",
424                     __func__, ha->host_no));
425
426                 return (QLA_FUNCTION_FAILED);
427         }
428
429         mrk->entry_type = MARKER_TYPE;
430         mrk->modifier = type;
431         if (type != MK_SYNC_ALL) {
432                 if (IS_FWI2_CAPABLE(ha)) {
433                         mrk24 = (struct mrk_entry_24xx *) mrk;
434                         mrk24->nport_handle = cpu_to_le16(loop_id);
435                         mrk24->lun[1] = LSB(lun);
436                         mrk24->lun[2] = MSB(lun);
437                         host_to_fcp_swap(mrk24->lun, sizeof(mrk24->lun));
438                         mrk24->vp_index = ha->vp_idx;
439                 } else {
440                         SET_TARGET_ID(ha, mrk->target, loop_id);
441                         mrk->lun = cpu_to_le16(lun);
442                 }
443         }
444         wmb();
445
446         qla2x00_isp_cmd(pha);
447
448         return (QLA_SUCCESS);
449 }
450
451 int
452 qla2x00_marker(scsi_qla_host_t *ha, uint16_t loop_id, uint16_t lun,
453     uint8_t type)
454 {
455         int ret;
456         unsigned long flags = 0;
457         scsi_qla_host_t *pha = to_qla_parent(ha);
458
459         spin_lock_irqsave(&pha->hardware_lock, flags);
460         ret = __qla2x00_marker(ha, loop_id, lun, type);
461         spin_unlock_irqrestore(&pha->hardware_lock, flags);
462
463         return (ret);
464 }
465
466 /**
467  * qla2x00_req_pkt() - Retrieve a request packet from the request ring.
468  * @ha: HA context
469  *
470  * Note: The caller must hold the hardware lock before calling this routine.
471  *
472  * Returns NULL if function failed, else, a pointer to the request packet.
473  */
474 static request_t *
475 qla2x00_req_pkt(scsi_qla_host_t *ha)
476 {
477         device_reg_t __iomem *reg = ha->iobase;
478         request_t       *pkt = NULL;
479         uint16_t        cnt;
480         uint32_t        *dword_ptr;
481         uint32_t        timer;
482         uint16_t        req_cnt = 1;
483
484         /* Wait 1 second for slot. */
485         for (timer = HZ; timer; timer--) {
486                 if ((req_cnt + 2) >= ha->req_q_cnt) {
487                         /* Calculate number of free request entries. */
488                         if (IS_FWI2_CAPABLE(ha))
489                                 cnt = (uint16_t)RD_REG_DWORD(
490                                     &reg->isp24.req_q_out);
491                         else
492                                 cnt = qla2x00_debounce_register(
493                                     ISP_REQ_Q_OUT(ha, &reg->isp));
494                         if  (ha->req_ring_index < cnt)
495                                 ha->req_q_cnt = cnt - ha->req_ring_index;
496                         else
497                                 ha->req_q_cnt = ha->request_q_length -
498                                     (ha->req_ring_index - cnt);
499                 }
500                 /* If room for request in request ring. */
501                 if ((req_cnt + 2) < ha->req_q_cnt) {
502                         ha->req_q_cnt--;
503                         pkt = ha->request_ring_ptr;
504
505                         /* Zero out packet. */
506                         dword_ptr = (uint32_t *)pkt;
507                         for (cnt = 0; cnt < REQUEST_ENTRY_SIZE / 4; cnt++)
508                                 *dword_ptr++ = 0;
509
510                         /* Set system defined field. */
511                         pkt->sys_define = (uint8_t)ha->req_ring_index;
512
513                         /* Set entry count. */
514                         pkt->entry_count = 1;
515
516                         break;
517                 }
518
519                 /* Release ring specific lock */
520                 spin_unlock(&ha->hardware_lock);
521
522                 udelay(2);   /* 2 us */
523
524                 /* Check for pending interrupts. */
525                 /* During init we issue marker directly */
526                 if (!ha->marker_needed && !ha->flags.init_done)
527                         qla2x00_poll(ha);
528
529                 spin_lock_irq(&ha->hardware_lock);
530         }
531         if (!pkt) {
532                 DEBUG2_3(printk("%s(): **** FAILED ****\n", __func__));
533         }
534
535         return (pkt);
536 }
537
538 /**
539  * qla2x00_isp_cmd() - Modify the request ring pointer.
540  * @ha: HA context
541  *
542  * Note: The caller must hold the hardware lock before calling this routine.
543  */
544 static void
545 qla2x00_isp_cmd(scsi_qla_host_t *ha)
546 {
547         device_reg_t __iomem *reg = ha->iobase;
548
549         DEBUG5(printk("%s(): IOCB data:\n", __func__));
550         DEBUG5(qla2x00_dump_buffer(
551             (uint8_t *)ha->request_ring_ptr, REQUEST_ENTRY_SIZE));
552
553         /* Adjust ring index. */
554         ha->req_ring_index++;
555         if (ha->req_ring_index == ha->request_q_length) {
556                 ha->req_ring_index = 0;
557                 ha->request_ring_ptr = ha->request_ring;
558         } else
559                 ha->request_ring_ptr++;
560
561         /* Set chip new ring index. */
562         if (IS_FWI2_CAPABLE(ha)) {
563                 WRT_REG_DWORD(&reg->isp24.req_q_in, ha->req_ring_index);
564                 RD_REG_DWORD_RELAXED(&reg->isp24.req_q_in);
565         } else {
566                 WRT_REG_WORD(ISP_REQ_Q_IN(ha, &reg->isp), ha->req_ring_index);
567                 RD_REG_WORD_RELAXED(ISP_REQ_Q_IN(ha, &reg->isp));
568         }
569
570 }
571
572 /**
573  * qla24xx_calc_iocbs() - Determine number of Command Type 3 and
574  * Continuation Type 1 IOCBs to allocate.
575  *
576  * @dsds: number of data segment decriptors needed
577  *
578  * Returns the number of IOCB entries needed to store @dsds.
579  */
580 static inline uint16_t
581 qla24xx_calc_iocbs(uint16_t dsds)
582 {
583         uint16_t iocbs;
584
585         iocbs = 1;
586         if (dsds > 1) {
587                 iocbs += (dsds - 1) / 5;
588                 if ((dsds - 1) % 5)
589                         iocbs++;
590         }
591         return iocbs;
592 }
593
594 /**
595  * qla24xx_build_scsi_iocbs() - Build IOCB command utilizing Command Type 7
596  * IOCB types.
597  *
598  * @sp: SRB command to process
599  * @cmd_pkt: Command type 3 IOCB
600  * @tot_dsds: Total number of segments to transfer
601  */
602 static inline void
603 qla24xx_build_scsi_iocbs(srb_t *sp, struct cmd_type_7 *cmd_pkt,
604     uint16_t tot_dsds)
605 {
606         uint16_t        avail_dsds;
607         uint32_t        *cur_dsd;
608         scsi_qla_host_t *ha;
609         struct scsi_cmnd *cmd;
610         struct scatterlist *sg;
611         int i;
612
613         cmd = sp->cmd;
614
615         /* Update entry type to indicate Command Type 3 IOCB */
616         *((uint32_t *)(&cmd_pkt->entry_type)) =
617             __constant_cpu_to_le32(COMMAND_TYPE_7);
618
619         /* No data transfer */
620         if (!scsi_bufflen(cmd) || cmd->sc_data_direction == DMA_NONE) {
621                 cmd_pkt->byte_count = __constant_cpu_to_le32(0);
622                 return;
623         }
624
625         ha = sp->ha;
626
627         /* Set transfer direction */
628         if (cmd->sc_data_direction == DMA_TO_DEVICE)
629                 cmd_pkt->task_mgmt_flags =
630                     __constant_cpu_to_le16(TMF_WRITE_DATA);
631         else if (cmd->sc_data_direction == DMA_FROM_DEVICE)
632                 cmd_pkt->task_mgmt_flags =
633                     __constant_cpu_to_le16(TMF_READ_DATA);
634
635         /* One DSD is available in the Command Type 3 IOCB */
636         avail_dsds = 1;
637         cur_dsd = (uint32_t *)&cmd_pkt->dseg_0_address;
638
639         /* Load data segments */
640
641         scsi_for_each_sg(cmd, sg, tot_dsds, i) {
642                 dma_addr_t      sle_dma;
643                 cont_a64_entry_t *cont_pkt;
644
645                 /* Allocate additional continuation packets? */
646                 if (avail_dsds == 0) {
647                         /*
648                          * Five DSDs are available in the Continuation
649                          * Type 1 IOCB.
650                          */
651                         cont_pkt = qla2x00_prep_cont_type1_iocb(ha);
652                         cur_dsd = (uint32_t *)cont_pkt->dseg_0_address;
653                         avail_dsds = 5;
654                 }
655
656                 sle_dma = sg_dma_address(sg);
657                 *cur_dsd++ = cpu_to_le32(LSD(sle_dma));
658                 *cur_dsd++ = cpu_to_le32(MSD(sle_dma));
659                 *cur_dsd++ = cpu_to_le32(sg_dma_len(sg));
660                 avail_dsds--;
661         }
662 }
663
664
665 /**
666  * qla24xx_start_scsi() - Send a SCSI command to the ISP
667  * @sp: command to send to the ISP
668  *
669  * Returns non-zero if a failure occured, else zero.
670  */
671 int
672 qla24xx_start_scsi(srb_t *sp)
673 {
674         int             ret, nseg;
675         unsigned long   flags;
676         scsi_qla_host_t *ha, *pha;
677         struct scsi_cmnd *cmd;
678         uint32_t        *clr_ptr;
679         uint32_t        index;
680         uint32_t        handle;
681         struct cmd_type_7 *cmd_pkt;
682         uint16_t        cnt;
683         uint16_t        req_cnt;
684         uint16_t        tot_dsds;
685         struct device_reg_24xx __iomem *reg;
686
687         /* Setup device pointers. */
688         ret = 0;
689         ha = sp->ha;
690         pha = to_qla_parent(ha);
691         reg = &ha->iobase->isp24;
692         cmd = sp->cmd;
693         /* So we know we haven't pci_map'ed anything yet */
694         tot_dsds = 0;
695
696         /* Send marker if required */
697         if (ha->marker_needed != 0) {
698                 if (qla2x00_marker(ha, 0, 0, MK_SYNC_ALL) != QLA_SUCCESS) {
699                         return QLA_FUNCTION_FAILED;
700                 }
701                 ha->marker_needed = 0;
702         }
703
704         /* Acquire ring specific lock */
705         spin_lock_irqsave(&pha->hardware_lock, flags);
706
707         /* Check for room in outstanding command list. */
708         handle = ha->current_outstanding_cmd;
709         for (index = 1; index < MAX_OUTSTANDING_COMMANDS; index++) {
710                 handle++;
711                 if (handle == MAX_OUTSTANDING_COMMANDS)
712                         handle = 1;
713                 if (!ha->outstanding_cmds[handle])
714                         break;
715         }
716         if (index == MAX_OUTSTANDING_COMMANDS)
717                 goto queuing_error;
718
719         /* Map the sg table so we have an accurate count of sg entries needed */
720         if (scsi_sg_count(cmd)) {
721                 nseg = dma_map_sg(&ha->pdev->dev, scsi_sglist(cmd),
722                     scsi_sg_count(cmd), cmd->sc_data_direction);
723                 if (unlikely(!nseg))
724                         goto queuing_error;
725         } else
726                 nseg = 0;
727
728         tot_dsds = nseg;
729
730         req_cnt = qla24xx_calc_iocbs(tot_dsds);
731         if (ha->req_q_cnt < (req_cnt + 2)) {
732                 cnt = (uint16_t)RD_REG_DWORD_RELAXED(&reg->req_q_out);
733                 if (ha->req_ring_index < cnt)
734                         ha->req_q_cnt = cnt - ha->req_ring_index;
735                 else
736                         ha->req_q_cnt = ha->request_q_length -
737                                 (ha->req_ring_index - cnt);
738         }
739         if (ha->req_q_cnt < (req_cnt + 2))
740                 goto queuing_error;
741
742         /* Build command packet. */
743         ha->current_outstanding_cmd = handle;
744         ha->outstanding_cmds[handle] = sp;
745         sp->ha = ha;
746         sp->cmd->host_scribble = (unsigned char *)(unsigned long)handle;
747         ha->req_q_cnt -= req_cnt;
748
749         cmd_pkt = (struct cmd_type_7 *)ha->request_ring_ptr;
750         cmd_pkt->handle = handle;
751
752         /* Zero out remaining portion of packet. */
753         /*    tagged queuing modifier -- default is TSK_SIMPLE (0). */
754         clr_ptr = (uint32_t *)cmd_pkt + 2;
755         memset(clr_ptr, 0, REQUEST_ENTRY_SIZE - 8);
756         cmd_pkt->dseg_count = cpu_to_le16(tot_dsds);
757
758         /* Set NPORT-ID and LUN number*/
759         cmd_pkt->nport_handle = cpu_to_le16(sp->fcport->loop_id);
760         cmd_pkt->port_id[0] = sp->fcport->d_id.b.al_pa;
761         cmd_pkt->port_id[1] = sp->fcport->d_id.b.area;
762         cmd_pkt->port_id[2] = sp->fcport->d_id.b.domain;
763         cmd_pkt->vp_index = sp->fcport->vp_idx;
764
765         int_to_scsilun(sp->cmd->device->lun, &cmd_pkt->lun);
766         host_to_fcp_swap((uint8_t *)&cmd_pkt->lun, sizeof(cmd_pkt->lun));
767
768         /* Load SCSI command packet. */
769         memcpy(cmd_pkt->fcp_cdb, cmd->cmnd, cmd->cmd_len);
770         host_to_fcp_swap(cmd_pkt->fcp_cdb, sizeof(cmd_pkt->fcp_cdb));
771
772         cmd_pkt->byte_count = cpu_to_le32((uint32_t)scsi_bufflen(cmd));
773
774         /* Build IOCB segments */
775         qla24xx_build_scsi_iocbs(sp, cmd_pkt, tot_dsds);
776
777         /* Set total data segment count. */
778         cmd_pkt->entry_count = (uint8_t)req_cnt;
779         wmb();
780
781         /* Adjust ring index. */
782         ha->req_ring_index++;
783         if (ha->req_ring_index == ha->request_q_length) {
784                 ha->req_ring_index = 0;
785                 ha->request_ring_ptr = ha->request_ring;
786         } else
787                 ha->request_ring_ptr++;
788
789         sp->flags |= SRB_DMA_VALID;
790
791         /* Set chip new ring index. */
792         WRT_REG_DWORD(&reg->req_q_in, ha->req_ring_index);
793         RD_REG_DWORD_RELAXED(&reg->req_q_in);           /* PCI Posting. */
794
795         /* Manage unprocessed RIO/ZIO commands in response queue. */
796         if (ha->flags.process_response_queue &&
797             ha->response_ring_ptr->signature != RESPONSE_PROCESSED)
798                 qla24xx_process_response_queue(ha);
799
800         spin_unlock_irqrestore(&pha->hardware_lock, flags);
801         return QLA_SUCCESS;
802
803 queuing_error:
804         if (tot_dsds)
805                 scsi_dma_unmap(cmd);
806
807         spin_unlock_irqrestore(&pha->hardware_lock, flags);
808
809         return QLA_FUNCTION_FAILED;
810 }