p54: fix "‘ret’ may be used uninitialized" warning
[linux-2.6.git] / drivers / scsi / qla4xxx / ql4_iocb.c
blob912a67494adff6928cc52f760d34b2da89149e6e
1 /*
2 * QLogic iSCSI HBA Driver
3 * Copyright (c) 2003-2006 QLogic Corporation
5 * See LICENSE.qla4xxx for copyright and licensing details.
6 */
8 #include "ql4_def.h"
9 #include "ql4_glbl.h"
10 #include "ql4_dbg.h"
11 #include "ql4_inline.h"
14 #include <scsi/scsi_tcq.h>
16 /**
17 * qla4xxx_get_req_pkt - returns a valid entry in request queue.
18 * @ha: Pointer to host adapter structure.
19 * @queue_entry: Pointer to pointer to queue entry structure
21 * This routine performs the following tasks:
22 * - returns the current request_in pointer (if queue not full)
23 * - advances the request_in pointer
24 * - checks for queue full
25 **/
26 static int qla4xxx_get_req_pkt(struct scsi_qla_host *ha,
27 struct queue_entry **queue_entry)
29 uint16_t request_in;
30 uint8_t status = QLA_SUCCESS;
32 *queue_entry = ha->request_ptr;
34 /* get the latest request_in and request_out index */
35 request_in = ha->request_in;
36 ha->request_out = (uint16_t) le32_to_cpu(ha->shadow_regs->req_q_out);
38 /* Advance request queue pointer and check for queue full */
39 if (request_in == (REQUEST_QUEUE_DEPTH - 1)) {
40 request_in = 0;
41 ha->request_ptr = ha->request_ring;
42 } else {
43 request_in++;
44 ha->request_ptr++;
47 /* request queue is full, try again later */
48 if ((ha->iocb_cnt + 1) >= ha->iocb_hiwat) {
49 /* restore request pointer */
50 ha->request_ptr = *queue_entry;
51 status = QLA_ERROR;
52 } else {
53 ha->request_in = request_in;
54 memset(*queue_entry, 0, sizeof(**queue_entry));
57 return status;
60 /**
61 * qla4xxx_send_marker_iocb - issues marker iocb to HBA
62 * @ha: Pointer to host adapter structure.
63 * @ddb_entry: Pointer to device database entry
64 * @lun: SCSI LUN
65 * @marker_type: marker identifier
67 * This routine issues a marker IOCB.
68 **/
69 int qla4xxx_send_marker_iocb(struct scsi_qla_host *ha,
70 struct ddb_entry *ddb_entry, int lun, uint16_t mrkr_mod)
72 struct qla4_marker_entry *marker_entry;
73 unsigned long flags = 0;
74 uint8_t status = QLA_SUCCESS;
76 /* Acquire hardware specific lock */
77 spin_lock_irqsave(&ha->hardware_lock, flags);
79 /* Get pointer to the queue entry for the marker */
80 if (qla4xxx_get_req_pkt(ha, (struct queue_entry **) &marker_entry) !=
81 QLA_SUCCESS) {
82 status = QLA_ERROR;
83 goto exit_send_marker;
86 /* Put the marker in the request queue */
87 marker_entry->hdr.entryType = ET_MARKER;
88 marker_entry->hdr.entryCount = 1;
89 marker_entry->target = cpu_to_le16(ddb_entry->fw_ddb_index);
90 marker_entry->modifier = cpu_to_le16(mrkr_mod);
91 int_to_scsilun(lun, &marker_entry->lun);
92 wmb();
94 /* Tell ISP it's got a new I/O request */
95 writel(ha->request_in, &ha->reg->req_q_in);
96 readl(&ha->reg->req_q_in);
98 exit_send_marker:
99 spin_unlock_irqrestore(&ha->hardware_lock, flags);
100 return status;
103 static struct continuation_t1_entry* qla4xxx_alloc_cont_entry(
104 struct scsi_qla_host *ha)
106 struct continuation_t1_entry *cont_entry;
108 cont_entry = (struct continuation_t1_entry *)ha->request_ptr;
110 /* Advance request queue pointer */
111 if (ha->request_in == (REQUEST_QUEUE_DEPTH - 1)) {
112 ha->request_in = 0;
113 ha->request_ptr = ha->request_ring;
114 } else {
115 ha->request_in++;
116 ha->request_ptr++;
119 /* Load packet defaults */
120 cont_entry->hdr.entryType = ET_CONTINUE;
121 cont_entry->hdr.entryCount = 1;
122 cont_entry->hdr.systemDefined = (uint8_t) cpu_to_le16(ha->request_in);
124 return cont_entry;
127 static uint16_t qla4xxx_calc_request_entries(uint16_t dsds)
129 uint16_t iocbs;
131 iocbs = 1;
132 if (dsds > COMMAND_SEG) {
133 iocbs += (dsds - COMMAND_SEG) / CONTINUE_SEG;
134 if ((dsds - COMMAND_SEG) % CONTINUE_SEG)
135 iocbs++;
137 return iocbs;
140 static void qla4xxx_build_scsi_iocbs(struct srb *srb,
141 struct command_t3_entry *cmd_entry,
142 uint16_t tot_dsds)
144 struct scsi_qla_host *ha;
145 uint16_t avail_dsds;
146 struct data_seg_a64 *cur_dsd;
147 struct scsi_cmnd *cmd;
148 struct scatterlist *sg;
149 int i;
151 cmd = srb->cmd;
152 ha = srb->ha;
154 if (!scsi_bufflen(cmd) || cmd->sc_data_direction == DMA_NONE) {
155 /* No data being transferred */
156 cmd_entry->ttlByteCnt = __constant_cpu_to_le32(0);
157 return;
160 avail_dsds = COMMAND_SEG;
161 cur_dsd = (struct data_seg_a64 *) & (cmd_entry->dataseg[0]);
163 scsi_for_each_sg(cmd, sg, tot_dsds, i) {
164 dma_addr_t sle_dma;
166 /* Allocate additional continuation packets? */
167 if (avail_dsds == 0) {
168 struct continuation_t1_entry *cont_entry;
170 cont_entry = qla4xxx_alloc_cont_entry(ha);
171 cur_dsd =
172 (struct data_seg_a64 *)
173 &cont_entry->dataseg[0];
174 avail_dsds = CONTINUE_SEG;
177 sle_dma = sg_dma_address(sg);
178 cur_dsd->base.addrLow = cpu_to_le32(LSDW(sle_dma));
179 cur_dsd->base.addrHigh = cpu_to_le32(MSDW(sle_dma));
180 cur_dsd->count = cpu_to_le32(sg_dma_len(sg));
181 avail_dsds--;
183 cur_dsd++;
188 * qla4xxx_send_command_to_isp - issues command to HBA
189 * @ha: pointer to host adapter structure.
190 * @srb: pointer to SCSI Request Block to be sent to ISP
192 * This routine is called by qla4xxx_queuecommand to build an ISP
193 * command and pass it to the ISP for execution.
195 int qla4xxx_send_command_to_isp(struct scsi_qla_host *ha, struct srb * srb)
197 struct scsi_cmnd *cmd = srb->cmd;
198 struct ddb_entry *ddb_entry;
199 struct command_t3_entry *cmd_entry;
201 int nseg;
202 uint16_t tot_dsds;
203 uint16_t req_cnt;
205 unsigned long flags;
206 uint16_t cnt;
207 uint32_t index;
208 char tag[2];
210 /* Get real lun and adapter */
211 ddb_entry = srb->ddb;
213 tot_dsds = 0;
215 /* Acquire hardware specific lock */
216 spin_lock_irqsave(&ha->hardware_lock, flags);
218 index = (uint32_t)cmd->request->tag;
220 /* Calculate the number of request entries needed. */
221 nseg = scsi_dma_map(cmd);
222 if (nseg < 0)
223 goto queuing_error;
224 tot_dsds = nseg;
226 req_cnt = qla4xxx_calc_request_entries(tot_dsds);
228 if (ha->req_q_count < (req_cnt + 2)) {
229 cnt = (uint16_t) le32_to_cpu(ha->shadow_regs->req_q_out);
230 if (ha->request_in < cnt)
231 ha->req_q_count = cnt - ha->request_in;
232 else
233 ha->req_q_count = REQUEST_QUEUE_DEPTH -
234 (ha->request_in - cnt);
237 if (ha->req_q_count < (req_cnt + 2))
238 goto queuing_error;
240 /* total iocbs active */
241 if ((ha->iocb_cnt + req_cnt) >= REQUEST_QUEUE_DEPTH)
242 goto queuing_error;
244 /* Build command packet */
245 cmd_entry = (struct command_t3_entry *) ha->request_ptr;
246 memset(cmd_entry, 0, sizeof(struct command_t3_entry));
247 cmd_entry->hdr.entryType = ET_COMMAND;
248 cmd_entry->handle = cpu_to_le32(index);
249 cmd_entry->target = cpu_to_le16(ddb_entry->fw_ddb_index);
250 cmd_entry->connection_id = cpu_to_le16(ddb_entry->connection_id);
252 int_to_scsilun(cmd->device->lun, &cmd_entry->lun);
253 cmd_entry->cmdSeqNum = cpu_to_le32(ddb_entry->CmdSn);
254 cmd_entry->ttlByteCnt = cpu_to_le32(scsi_bufflen(cmd));
255 memcpy(cmd_entry->cdb, cmd->cmnd, cmd->cmd_len);
256 cmd_entry->dataSegCnt = cpu_to_le16(tot_dsds);
257 cmd_entry->hdr.entryCount = req_cnt;
259 /* Set data transfer direction control flags
260 * NOTE: Look at data_direction bits iff there is data to be
261 * transferred, as the data direction bit is sometimed filled
262 * in when there is no data to be transferred */
263 cmd_entry->control_flags = CF_NO_DATA;
264 if (scsi_bufflen(cmd)) {
265 if (cmd->sc_data_direction == DMA_TO_DEVICE)
266 cmd_entry->control_flags = CF_WRITE;
267 else if (cmd->sc_data_direction == DMA_FROM_DEVICE)
268 cmd_entry->control_flags = CF_READ;
270 ha->bytes_xfered += scsi_bufflen(cmd);
271 if (ha->bytes_xfered & ~0xFFFFF){
272 ha->total_mbytes_xferred += ha->bytes_xfered >> 20;
273 ha->bytes_xfered &= 0xFFFFF;
277 /* Set tagged queueing control flags */
278 cmd_entry->control_flags |= CF_SIMPLE_TAG;
279 if (scsi_populate_tag_msg(cmd, tag))
280 switch (tag[0]) {
281 case MSG_HEAD_TAG:
282 cmd_entry->control_flags |= CF_HEAD_TAG;
283 break;
284 case MSG_ORDERED_TAG:
285 cmd_entry->control_flags |= CF_ORDERED_TAG;
286 break;
290 /* Advance request queue pointer */
291 ha->request_in++;
292 if (ha->request_in == REQUEST_QUEUE_DEPTH) {
293 ha->request_in = 0;
294 ha->request_ptr = ha->request_ring;
295 } else
296 ha->request_ptr++;
299 qla4xxx_build_scsi_iocbs(srb, cmd_entry, tot_dsds);
300 wmb();
303 * Check to see if adapter is online before placing request on
304 * request queue. If a reset occurs and a request is in the queue,
305 * the firmware will still attempt to process the request, retrieving
306 * garbage for pointers.
308 if (!test_bit(AF_ONLINE, &ha->flags)) {
309 DEBUG2(printk("scsi%ld: %s: Adapter OFFLINE! "
310 "Do not issue command.\n",
311 ha->host_no, __func__));
312 goto queuing_error;
315 srb->cmd->host_scribble = (unsigned char *)srb;
317 /* update counters */
318 srb->state = SRB_ACTIVE_STATE;
319 srb->flags |= SRB_DMA_VALID;
321 /* Track IOCB used */
322 ha->iocb_cnt += req_cnt;
323 srb->iocb_cnt = req_cnt;
324 ha->req_q_count -= req_cnt;
326 /* Debug print statements */
327 writel(ha->request_in, &ha->reg->req_q_in);
328 readl(&ha->reg->req_q_in);
329 spin_unlock_irqrestore(&ha->hardware_lock, flags);
331 return QLA_SUCCESS;
333 queuing_error:
334 if (tot_dsds)
335 scsi_dma_unmap(cmd);
337 spin_unlock_irqrestore(&ha->hardware_lock, flags);
339 return QLA_ERROR;