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rcv reorder queue bugfix
[cor_2_6_31.git] / drivers / scsi / mac53c94.c
blob18735b39b3d39c8547e27b8037fbef033a0df76a
1 /*
2 * SCSI low-level driver for the 53c94 SCSI bus adaptor found
3 * on Power Macintosh computers, controlling the external SCSI chain.
4 * We assume the 53c94 is connected to a DBDMA (descriptor-based DMA)
5 * controller.
6 *
7 * Paul Mackerras, August 1996.
8 * Copyright (C) 1996 Paul Mackerras.
9 */
10 #include <linux/kernel.h>
11 #include <linux/delay.h>
12 #include <linux/types.h>
13 #include <linux/string.h>
14 #include <linux/slab.h>
15 #include <linux/blkdev.h>
16 #include <linux/proc_fs.h>
17 #include <linux/stat.h>
18 #include <linux/spinlock.h>
19 #include <linux/interrupt.h>
20 #include <asm/dbdma.h>
21 #include <asm/io.h>
22 #include <asm/pgtable.h>
23 #include <asm/prom.h>
24 #include <asm/system.h>
25 #include <asm/pci-bridge.h>
26 #include <asm/macio.h>
27
28 #include <scsi/scsi.h>
29 #include <scsi/scsi_cmnd.h>
30 #include <scsi/scsi_device.h>
31 #include <scsi/scsi_host.h>
32
33 #include "mac53c94.h"
34
35 enum fsc_phase {
36 idle,
37 selecting,
38 dataing,
39 completing,
40 busfreeing,
41 };
42
43 struct fsc_state {
44 struct mac53c94_regs __iomem *regs;
45 int intr;
46 struct dbdma_regs __iomem *dma;
47 int dmaintr;
48 int clk_freq;
49 struct Scsi_Host *host;
50 struct scsi_cmnd *request_q;
51 struct scsi_cmnd *request_qtail;
52 struct scsi_cmnd *current_req; /* req we're currently working on */
53 enum fsc_phase phase; /* what we're currently trying to do */
54 struct dbdma_cmd *dma_cmds; /* space for dbdma commands, aligned */
55 void *dma_cmd_space;
56 struct pci_dev *pdev;
57 dma_addr_t dma_addr;
58 struct macio_dev *mdev;
59 };
60
61 static void mac53c94_init(struct fsc_state *);
62 static void mac53c94_start(struct fsc_state *);
63 static void mac53c94_interrupt(int, void *);
64 static irqreturn_t do_mac53c94_interrupt(int, void *);
65 static void cmd_done(struct fsc_state *, int result);
66 static void set_dma_cmds(struct fsc_state *, struct scsi_cmnd *);
67
68
69 static int mac53c94_queue(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
70 {
71 struct fsc_state *state;
72
73 #if 0
74 if (cmd->sc_data_direction == DMA_TO_DEVICE) {
75 int i;
76 printk(KERN_DEBUG "mac53c94_queue %p: command is", cmd);
77 for (i = 0; i < cmd->cmd_len; ++i)
78 printk(KERN_CONT " %.2x", cmd->cmnd[i]);
79 printk(KERN_CONT "\n");
80 printk(KERN_DEBUG "use_sg=%d request_bufflen=%d request_buffer=%p\n",
81 scsi_sg_count(cmd), scsi_bufflen(cmd), scsi_sglist(cmd));
82 }
83 #endif
84
85 cmd->scsi_done = done;
86 cmd->host_scribble = NULL;
87
88 state = (struct fsc_state *) cmd->device->host->hostdata;
89
90 if (state->request_q == NULL)
91 state->request_q = cmd;
92 else
93 state->request_qtail->host_scribble = (void *) cmd;
94 state->request_qtail = cmd;
95
96 if (state->phase == idle)
97 mac53c94_start(state);
98
99 return 0;
100 }
101
102 static int mac53c94_host_reset(struct scsi_cmnd *cmd)
103 {
104 struct fsc_state *state = (struct fsc_state *) cmd->device->host->hostdata;
105 struct mac53c94_regs __iomem *regs = state->regs;
106 struct dbdma_regs __iomem *dma = state->dma;
107 unsigned long flags;
108
109 spin_lock_irqsave(cmd->device->host->host_lock, flags);
110
111 writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
112 writeb(CMD_SCSI_RESET, &regs->command); /* assert RST */
113 udelay(100); /* leave it on for a while (>= 25us) */
114 writeb(CMD_RESET, &regs->command);
115 udelay(20);
116 mac53c94_init(state);
117 writeb(CMD_NOP, &regs->command);
118
119 spin_unlock_irqrestore(cmd->device->host->host_lock, flags);
120 return SUCCESS;
121 }
122
123 static void mac53c94_init(struct fsc_state *state)
124 {
125 struct mac53c94_regs __iomem *regs = state->regs;
126 struct dbdma_regs __iomem *dma = state->dma;
127 int x;
128
129 writeb(state->host->this_id | CF1_PAR_ENABLE, &regs->config1);
130 writeb(TIMO_VAL(250), &regs->sel_timeout); /* 250ms */
131 writeb(CLKF_VAL(state->clk_freq), &regs->clk_factor);
132 writeb(CF2_FEATURE_EN, &regs->config2);
133 writeb(0, &regs->config3);
134 writeb(0, &regs->sync_period);
135 writeb(0, &regs->sync_offset);
136 x = readb(&regs->interrupt);
137 writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
138 }
139
140 /*
141 * Start the next command for a 53C94.
142 * Should be called with interrupts disabled.
143 */
144 static void mac53c94_start(struct fsc_state *state)
145 {
146 struct scsi_cmnd *cmd;
147 struct mac53c94_regs __iomem *regs = state->regs;
148 int i;
149
150 if (state->phase != idle || state->current_req != NULL)
151 panic("inappropriate mac53c94_start (state=%p)", state);
152 if (state->request_q == NULL)
153 return;
154 state->current_req = cmd = state->request_q;
155 state->request_q = (struct scsi_cmnd *) cmd->host_scribble;
156
157 /* Off we go */
158 writeb(0, &regs->count_lo);
159 writeb(0, &regs->count_mid);
160 writeb(0, &regs->count_hi);
161 writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
162 udelay(1);
163 writeb(CMD_FLUSH, &regs->command);
164 udelay(1);
165 writeb(cmd->device->id, &regs->dest_id);
166 writeb(0, &regs->sync_period);
167 writeb(0, &regs->sync_offset);
168
169 /* load the command into the FIFO */
170 for (i = 0; i < cmd->cmd_len; ++i)
171 writeb(cmd->cmnd[i], &regs->fifo);
172
173 /* do select without ATN XXX */
174 writeb(CMD_SELECT, &regs->command);
175 state->phase = selecting;
176
177 set_dma_cmds(state, cmd);
178 }
179
180 static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id)
181 {
182 unsigned long flags;
183 struct Scsi_Host *dev = ((struct fsc_state *) dev_id)->current_req->device->host;
184
185 spin_lock_irqsave(dev->host_lock, flags);
186 mac53c94_interrupt(irq, dev_id);
187 spin_unlock_irqrestore(dev->host_lock, flags);
188 return IRQ_HANDLED;
189 }
190
191 static void mac53c94_interrupt(int irq, void *dev_id)
192 {
193 struct fsc_state *state = (struct fsc_state *) dev_id;
194 struct mac53c94_regs __iomem *regs = state->regs;
195 struct dbdma_regs __iomem *dma = state->dma;
196 struct scsi_cmnd *cmd = state->current_req;
197 int nb, stat, seq, intr;
198 static int mac53c94_errors;
199
200 /*
201 * Apparently, reading the interrupt register unlatches
202 * the status and sequence step registers.
203 */
204 seq = readb(&regs->seqstep);
205 stat = readb(&regs->status);
206 intr = readb(&regs->interrupt);
207
208 #if 0
209 printk(KERN_DEBUG "mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n",
210 intr, stat, seq, state->phase);
211 #endif
212
213 if (intr & INTR_RESET) {
214 /* SCSI bus was reset */
215 printk(KERN_INFO "external SCSI bus reset detected\n");
216 writeb(CMD_NOP, &regs->command);
217 writel(RUN << 16, &dma->control); /* stop dma */
218 cmd_done(state, DID_RESET << 16);
219 return;
220 }
221 if (intr & INTR_ILL_CMD) {
222 printk(KERN_ERR "53c94: invalid cmd, intr=%x stat=%x seq=%x phase=%d\n",
223 intr, stat, seq, state->phase);
224 cmd_done(state, DID_ERROR << 16);
225 return;
226 }
227 if (stat & STAT_ERROR) {
228 #if 0
229 /* XXX these seem to be harmless? */
230 printk("53c94: bad error, intr=%x stat=%x seq=%x phase=%d\n",
231 intr, stat, seq, state->phase);
232 #endif
233 ++mac53c94_errors;
234 writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
235 }
236 if (cmd == 0) {
237 printk(KERN_DEBUG "53c94: interrupt with no command active?\n");
238 return;
239 }
240 if (stat & STAT_PARITY) {
241 printk(KERN_ERR "mac53c94: parity error\n");
242 cmd_done(state, DID_PARITY << 16);
243 return;
244 }
245 switch (state->phase) {
246 case selecting:
247 if (intr & INTR_DISCONNECT) {
248 /* selection timed out */
249 cmd_done(state, DID_BAD_TARGET << 16);
250 return;
251 }
252 if (intr != INTR_BUS_SERV + INTR_DONE) {
253 printk(KERN_DEBUG "got intr %x during selection\n", intr);
254 cmd_done(state, DID_ERROR << 16);
255 return;
256 }
257 if ((seq & SS_MASK) != SS_DONE) {
258 printk(KERN_DEBUG "seq step %x after command\n", seq);
259 cmd_done(state, DID_ERROR << 16);
260 return;
261 }
262 writeb(CMD_NOP, &regs->command);
263 /* set DMA controller going if any data to transfer */
264 if ((stat & (STAT_MSG|STAT_CD)) == 0
265 && (scsi_sg_count(cmd) > 0 || scsi_bufflen(cmd))) {
266 nb = cmd->SCp.this_residual;
267 if (nb > 0xfff0)
268 nb = 0xfff0;
269 cmd->SCp.this_residual -= nb;
270 writeb(nb, &regs->count_lo);
271 writeb(nb >> 8, &regs->count_mid);
272 writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
273 writel(virt_to_phys(state->dma_cmds), &dma->cmdptr);
274 writel((RUN << 16) | RUN, &dma->control);
275 writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
276 state->phase = dataing;
277 break;
278 } else if ((stat & STAT_PHASE) == STAT_CD + STAT_IO) {
279 /* up to status phase already */
280 writeb(CMD_I_COMPLETE, &regs->command);
281 state->phase = completing;
282 } else {
283 printk(KERN_DEBUG "in unexpected phase %x after cmd\n",
284 stat & STAT_PHASE);
285 cmd_done(state, DID_ERROR << 16);
286 return;
287 }
288 break;
289
290 case dataing:
291 if (intr != INTR_BUS_SERV) {
292 printk(KERN_DEBUG "got intr %x before status\n", intr);
293 cmd_done(state, DID_ERROR << 16);
294 return;
295 }
296 if (cmd->SCp.this_residual != 0
297 && (stat & (STAT_MSG|STAT_CD)) == 0) {
298 /* Set up the count regs to transfer more */
299 nb = cmd->SCp.this_residual;
300 if (nb > 0xfff0)
301 nb = 0xfff0;
302 cmd->SCp.this_residual -= nb;
303 writeb(nb, &regs->count_lo);
304 writeb(nb >> 8, &regs->count_mid);
305 writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
306 writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
307 break;
308 }
309 if ((stat & STAT_PHASE) != STAT_CD + STAT_IO) {
310 printk(KERN_DEBUG "intr %x before data xfer complete\n", intr);
311 }
312 writel(RUN << 16, &dma->control); /* stop dma */
313 scsi_dma_unmap(cmd);
314 /* should check dma status */
315 writeb(CMD_I_COMPLETE, &regs->command);
316 state->phase = completing;
317 break;
318 case completing:
319 if (intr != INTR_DONE) {
320 printk(KERN_DEBUG "got intr %x on completion\n", intr);
321 cmd_done(state, DID_ERROR << 16);
322 return;
323 }
324 cmd->SCp.Status = readb(&regs->fifo);
325 cmd->SCp.Message = readb(&regs->fifo);
326 cmd->result = CMD_ACCEPT_MSG;
327 writeb(CMD_ACCEPT_MSG, &regs->command);
328 state->phase = busfreeing;
329 break;
330 case busfreeing:
331 if (intr != INTR_DISCONNECT) {
332 printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);
333 }
334 cmd_done(state, (DID_OK << 16) + (cmd->SCp.Message << 8)
335 + cmd->SCp.Status);
336 break;
337 default:
338 printk(KERN_DEBUG "don't know about phase %d\n", state->phase);
339 }
340 }
341
342 static void cmd_done(struct fsc_state *state, int result)
343 {
344 struct scsi_cmnd *cmd;
345
346 cmd = state->current_req;
347 if (cmd != 0) {
348 cmd->result = result;
349 (*cmd->scsi_done)(cmd);
350 state->current_req = NULL;
351 }
352 state->phase = idle;
353 mac53c94_start(state);
354 }
355
356 /*
357 * Set up DMA commands for transferring data.
358 */
359 static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd)
360 {
361 int i, dma_cmd, total, nseg;
362 struct scatterlist *scl;
363 struct dbdma_cmd *dcmds;
364 dma_addr_t dma_addr;
365 u32 dma_len;
366
367 nseg = scsi_dma_map(cmd);
368 BUG_ON(nseg < 0);
369 if (!nseg)
370 return;
371
372 dma_cmd = cmd->sc_data_direction == DMA_TO_DEVICE ?
373 OUTPUT_MORE : INPUT_MORE;
374 dcmds = state->dma_cmds;
375 total = 0;
376
377 scsi_for_each_sg(cmd, scl, nseg, i) {
378 dma_addr = sg_dma_address(scl);
379 dma_len = sg_dma_len(scl);
380 if (dma_len > 0xffff)
381 panic("mac53c94: scatterlist element >= 64k");
382 total += dma_len;
383 st_le16(&dcmds->req_count, dma_len);
384 st_le16(&dcmds->command, dma_cmd);
385 st_le32(&dcmds->phy_addr, dma_addr);
386 dcmds->xfer_status = 0;
387 ++dcmds;
388 }
389
390 dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
391 st_le16(&dcmds[-1].command, dma_cmd);
392 st_le16(&dcmds->command, DBDMA_STOP);
393 cmd->SCp.this_residual = total;
394 }
395
396 static struct scsi_host_template mac53c94_template = {
397 .proc_name = "53c94",
398 .name = "53C94",
399 .queuecommand = mac53c94_queue,
400 .eh_host_reset_handler = mac53c94_host_reset,
401 .can_queue = 1,
402 .this_id = 7,
403 .sg_tablesize = SG_ALL,
404 .cmd_per_lun = 1,
405 .use_clustering = DISABLE_CLUSTERING,
406 };
407
408 static int mac53c94_probe(struct macio_dev *mdev, const struct of_device_id *match)
409 {
410 struct device_node *node = macio_get_of_node(mdev);
411 struct pci_dev *pdev = macio_get_pci_dev(mdev);
412 struct fsc_state *state;
413 struct Scsi_Host *host;
414 void *dma_cmd_space;
415 const unsigned char *clkprop;
416 int proplen, rc = -ENODEV;
417
418 if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
419 printk(KERN_ERR "mac53c94: expected 2 addrs and intrs"
420 " (got %d/%d)\n",
421 macio_resource_count(mdev), macio_irq_count(mdev));
422 return -ENODEV;
423 }
424
425 if (macio_request_resources(mdev, "mac53c94") != 0) {
426 printk(KERN_ERR "mac53c94: unable to request memory resources");
427 return -EBUSY;
428 }
429
430 host = scsi_host_alloc(&mac53c94_template, sizeof(struct fsc_state));
431 if (host == NULL) {
432 printk(KERN_ERR "mac53c94: couldn't register host");
433 rc = -ENOMEM;
434 goto out_release;
435 }
436
437 state = (struct fsc_state *) host->hostdata;
438 macio_set_drvdata(mdev, state);
439 state->host = host;
440 state->pdev = pdev;
441 state->mdev = mdev;
442
443 state->regs = (struct mac53c94_regs __iomem *)
444 ioremap(macio_resource_start(mdev, 0), 0x1000);
445 state->intr = macio_irq(mdev, 0);
446 state->dma = (struct dbdma_regs __iomem *)
447 ioremap(macio_resource_start(mdev, 1), 0x1000);
448 state->dmaintr = macio_irq(mdev, 1);
449 if (state->regs == NULL || state->dma == NULL) {
450 printk(KERN_ERR "mac53c94: ioremap failed for %s\n",
451 node->full_name);
452 goto out_free;
453 }
454
455 clkprop = of_get_property(node, "clock-frequency", &proplen);
456 if (clkprop == NULL || proplen != sizeof(int)) {
457 printk(KERN_ERR "%s: can't get clock frequency, "
458 "assuming 25MHz\n", node->full_name);
459 state->clk_freq = 25000000;
460 } else
461 state->clk_freq = *(int *)clkprop;
462
463 /* Space for dma command list: +1 for stop command,
464 * +1 to allow for aligning.
465 * XXX FIXME: Use DMA consistent routines
466 */
467 dma_cmd_space = kmalloc((host->sg_tablesize + 2) *
468 sizeof(struct dbdma_cmd), GFP_KERNEL);
469 if (dma_cmd_space == 0) {
470 printk(KERN_ERR "mac53c94: couldn't allocate dma "
471 "command space for %s\n", node->full_name);
472 rc = -ENOMEM;
473 goto out_free;
474 }
475 state->dma_cmds = (struct dbdma_cmd *)DBDMA_ALIGN(dma_cmd_space);
476 memset(state->dma_cmds, 0, (host->sg_tablesize + 1)
477 * sizeof(struct dbdma_cmd));
478 state->dma_cmd_space = dma_cmd_space;
479
480 mac53c94_init(state);
481
482 if (request_irq(state->intr, do_mac53c94_interrupt, 0, "53C94",state)) {
483 printk(KERN_ERR "mac53C94: can't get irq %d for %s\n",
484 state->intr, node->full_name);
485 goto out_free_dma;
486 }
487
488 rc = scsi_add_host(host, &mdev->ofdev.dev);
489 if (rc != 0)
490 goto out_release_irq;
491
492 scsi_scan_host(host);
493 return 0;
494
495 out_release_irq:
496 free_irq(state->intr, state);
497 out_free_dma:
498 kfree(state->dma_cmd_space);
499 out_free:
500 if (state->dma != NULL)
501 iounmap(state->dma);
502 if (state->regs != NULL)
503 iounmap(state->regs);
504 scsi_host_put(host);
505 out_release:
506 macio_release_resources(mdev);
507
508 return rc;
509 }
510
511 static int mac53c94_remove(struct macio_dev *mdev)
512 {
513 struct fsc_state *fp = (struct fsc_state *)macio_get_drvdata(mdev);
514 struct Scsi_Host *host = fp->host;
515
516 scsi_remove_host(host);
517
518 free_irq(fp->intr, fp);
519
520 if (fp->regs)
521 iounmap(fp->regs);
522 if (fp->dma)
523 iounmap(fp->dma);
524 kfree(fp->dma_cmd_space);
525
526 scsi_host_put(host);
527
528 macio_release_resources(mdev);
529
530 return 0;
531 }
532
533
534 static struct of_device_id mac53c94_match[] =
535 {
536 {
537 .name = "53c94",
538 },
539 {},
540 };
541 MODULE_DEVICE_TABLE (of, mac53c94_match);
542
543 static struct macio_driver mac53c94_driver =
544 {
545 .name = "mac53c94",
546 .match_table = mac53c94_match,
547 .probe = mac53c94_probe,
548 .remove = mac53c94_remove,
549 };
550
551
552 static int __init init_mac53c94(void)
553 {
554 return macio_register_driver(&mac53c94_driver);
555 }
556
557 static void __exit exit_mac53c94(void)
558 {
559 return macio_unregister_driver(&mac53c94_driver);
560 }
561
562 module_init(init_mac53c94);
563 module_exit(exit_mac53c94);
564
565 MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver");
566 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
567 MODULE_LICENSE("GPL");
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