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mm: improve page_lock_anon_vma() comment
[linux-2.6.git] / drivers / scsi / mac53c94.c
blob6c42dff0f4d30d77e68dbfc445e961bfb55a786a
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_lck(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 DEF_SCSI_QCMD(mac53c94_queue)
103
104 static int mac53c94_host_reset(struct scsi_cmnd *cmd)
105 {
106 struct fsc_state *state = (struct fsc_state *) cmd->device->host->hostdata;
107 struct mac53c94_regs __iomem *regs = state->regs;
108 struct dbdma_regs __iomem *dma = state->dma;
109 unsigned long flags;
110
111 spin_lock_irqsave(cmd->device->host->host_lock, flags);
112
113 writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
114 writeb(CMD_SCSI_RESET, &regs->command); /* assert RST */
115 udelay(100); /* leave it on for a while (>= 25us) */
116 writeb(CMD_RESET, &regs->command);
117 udelay(20);
118 mac53c94_init(state);
119 writeb(CMD_NOP, &regs->command);
120
121 spin_unlock_irqrestore(cmd->device->host->host_lock, flags);
122 return SUCCESS;
123 }
124
125 static void mac53c94_init(struct fsc_state *state)
126 {
127 struct mac53c94_regs __iomem *regs = state->regs;
128 struct dbdma_regs __iomem *dma = state->dma;
129 int x;
130
131 writeb(state->host->this_id | CF1_PAR_ENABLE, &regs->config1);
132 writeb(TIMO_VAL(250), &regs->sel_timeout); /* 250ms */
133 writeb(CLKF_VAL(state->clk_freq), &regs->clk_factor);
134 writeb(CF2_FEATURE_EN, &regs->config2);
135 writeb(0, &regs->config3);
136 writeb(0, &regs->sync_period);
137 writeb(0, &regs->sync_offset);
138 x = readb(&regs->interrupt);
139 writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
140 }
141
142 /*
143 * Start the next command for a 53C94.
144 * Should be called with interrupts disabled.
145 */
146 static void mac53c94_start(struct fsc_state *state)
147 {
148 struct scsi_cmnd *cmd;
149 struct mac53c94_regs __iomem *regs = state->regs;
150 int i;
151
152 if (state->phase != idle || state->current_req != NULL)
153 panic("inappropriate mac53c94_start (state=%p)", state);
154 if (state->request_q == NULL)
155 return;
156 state->current_req = cmd = state->request_q;
157 state->request_q = (struct scsi_cmnd *) cmd->host_scribble;
158
159 /* Off we go */
160 writeb(0, &regs->count_lo);
161 writeb(0, &regs->count_mid);
162 writeb(0, &regs->count_hi);
163 writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
164 udelay(1);
165 writeb(CMD_FLUSH, &regs->command);
166 udelay(1);
167 writeb(cmd->device->id, &regs->dest_id);
168 writeb(0, &regs->sync_period);
169 writeb(0, &regs->sync_offset);
170
171 /* load the command into the FIFO */
172 for (i = 0; i < cmd->cmd_len; ++i)
173 writeb(cmd->cmnd[i], &regs->fifo);
174
175 /* do select without ATN XXX */
176 writeb(CMD_SELECT, &regs->command);
177 state->phase = selecting;
178
179 set_dma_cmds(state, cmd);
180 }
181
182 static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id)
183 {
184 unsigned long flags;
185 struct Scsi_Host *dev = ((struct fsc_state *) dev_id)->current_req->device->host;
186
187 spin_lock_irqsave(dev->host_lock, flags);
188 mac53c94_interrupt(irq, dev_id);
189 spin_unlock_irqrestore(dev->host_lock, flags);
190 return IRQ_HANDLED;
191 }
192
193 static void mac53c94_interrupt(int irq, void *dev_id)
194 {
195 struct fsc_state *state = (struct fsc_state *) dev_id;
196 struct mac53c94_regs __iomem *regs = state->regs;
197 struct dbdma_regs __iomem *dma = state->dma;
198 struct scsi_cmnd *cmd = state->current_req;
199 int nb, stat, seq, intr;
200 static int mac53c94_errors;
201
202 /*
203 * Apparently, reading the interrupt register unlatches
204 * the status and sequence step registers.
205 */
206 seq = readb(&regs->seqstep);
207 stat = readb(&regs->status);
208 intr = readb(&regs->interrupt);
209
210 #if 0
211 printk(KERN_DEBUG "mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n",
212 intr, stat, seq, state->phase);
213 #endif
214
215 if (intr & INTR_RESET) {
216 /* SCSI bus was reset */
217 printk(KERN_INFO "external SCSI bus reset detected\n");
218 writeb(CMD_NOP, &regs->command);
219 writel(RUN << 16, &dma->control); /* stop dma */
220 cmd_done(state, DID_RESET << 16);
221 return;
222 }
223 if (intr & INTR_ILL_CMD) {
224 printk(KERN_ERR "53c94: invalid cmd, intr=%x stat=%x seq=%x phase=%d\n",
225 intr, stat, seq, state->phase);
226 cmd_done(state, DID_ERROR << 16);
227 return;
228 }
229 if (stat & STAT_ERROR) {
230 #if 0
231 /* XXX these seem to be harmless? */
232 printk("53c94: bad error, intr=%x stat=%x seq=%x phase=%d\n",
233 intr, stat, seq, state->phase);
234 #endif
235 ++mac53c94_errors;
236 writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
237 }
238 if (cmd == 0) {
239 printk(KERN_DEBUG "53c94: interrupt with no command active?\n");
240 return;
241 }
242 if (stat & STAT_PARITY) {
243 printk(KERN_ERR "mac53c94: parity error\n");
244 cmd_done(state, DID_PARITY << 16);
245 return;
246 }
247 switch (state->phase) {
248 case selecting:
249 if (intr & INTR_DISCONNECT) {
250 /* selection timed out */
251 cmd_done(state, DID_BAD_TARGET << 16);
252 return;
253 }
254 if (intr != INTR_BUS_SERV + INTR_DONE) {
255 printk(KERN_DEBUG "got intr %x during selection\n", intr);
256 cmd_done(state, DID_ERROR << 16);
257 return;
258 }
259 if ((seq & SS_MASK) != SS_DONE) {
260 printk(KERN_DEBUG "seq step %x after command\n", seq);
261 cmd_done(state, DID_ERROR << 16);
262 return;
263 }
264 writeb(CMD_NOP, &regs->command);
265 /* set DMA controller going if any data to transfer */
266 if ((stat & (STAT_MSG|STAT_CD)) == 0
267 && (scsi_sg_count(cmd) > 0 || scsi_bufflen(cmd))) {
268 nb = cmd->SCp.this_residual;
269 if (nb > 0xfff0)
270 nb = 0xfff0;
271 cmd->SCp.this_residual -= nb;
272 writeb(nb, &regs->count_lo);
273 writeb(nb >> 8, &regs->count_mid);
274 writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
275 writel(virt_to_phys(state->dma_cmds), &dma->cmdptr);
276 writel((RUN << 16) | RUN, &dma->control);
277 writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
278 state->phase = dataing;
279 break;
280 } else if ((stat & STAT_PHASE) == STAT_CD + STAT_IO) {
281 /* up to status phase already */
282 writeb(CMD_I_COMPLETE, &regs->command);
283 state->phase = completing;
284 } else {
285 printk(KERN_DEBUG "in unexpected phase %x after cmd\n",
286 stat & STAT_PHASE);
287 cmd_done(state, DID_ERROR << 16);
288 return;
289 }
290 break;
291
292 case dataing:
293 if (intr != INTR_BUS_SERV) {
294 printk(KERN_DEBUG "got intr %x before status\n", intr);
295 cmd_done(state, DID_ERROR << 16);
296 return;
297 }
298 if (cmd->SCp.this_residual != 0
299 && (stat & (STAT_MSG|STAT_CD)) == 0) {
300 /* Set up the count regs to transfer more */
301 nb = cmd->SCp.this_residual;
302 if (nb > 0xfff0)
303 nb = 0xfff0;
304 cmd->SCp.this_residual -= nb;
305 writeb(nb, &regs->count_lo);
306 writeb(nb >> 8, &regs->count_mid);
307 writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
308 writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
309 break;
310 }
311 if ((stat & STAT_PHASE) != STAT_CD + STAT_IO) {
312 printk(KERN_DEBUG "intr %x before data xfer complete\n", intr);
313 }
314 writel(RUN << 16, &dma->control); /* stop dma */
315 scsi_dma_unmap(cmd);
316 /* should check dma status */
317 writeb(CMD_I_COMPLETE, &regs->command);
318 state->phase = completing;
319 break;
320 case completing:
321 if (intr != INTR_DONE) {
322 printk(KERN_DEBUG "got intr %x on completion\n", intr);
323 cmd_done(state, DID_ERROR << 16);
324 return;
325 }
326 cmd->SCp.Status = readb(&regs->fifo);
327 cmd->SCp.Message = readb(&regs->fifo);
328 cmd->result = CMD_ACCEPT_MSG;
329 writeb(CMD_ACCEPT_MSG, &regs->command);
330 state->phase = busfreeing;
331 break;
332 case busfreeing:
333 if (intr != INTR_DISCONNECT) {
334 printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);
335 }
336 cmd_done(state, (DID_OK << 16) + (cmd->SCp.Message << 8)
337 + cmd->SCp.Status);
338 break;
339 default:
340 printk(KERN_DEBUG "don't know about phase %d\n", state->phase);
341 }
342 }
343
344 static void cmd_done(struct fsc_state *state, int result)
345 {
346 struct scsi_cmnd *cmd;
347
348 cmd = state->current_req;
349 if (cmd != 0) {
350 cmd->result = result;
351 (*cmd->scsi_done)(cmd);
352 state->current_req = NULL;
353 }
354 state->phase = idle;
355 mac53c94_start(state);
356 }
357
358 /*
359 * Set up DMA commands for transferring data.
360 */
361 static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd)
362 {
363 int i, dma_cmd, total, nseg;
364 struct scatterlist *scl;
365 struct dbdma_cmd *dcmds;
366 dma_addr_t dma_addr;
367 u32 dma_len;
368
369 nseg = scsi_dma_map(cmd);
370 BUG_ON(nseg < 0);
371 if (!nseg)
372 return;
373
374 dma_cmd = cmd->sc_data_direction == DMA_TO_DEVICE ?
375 OUTPUT_MORE : INPUT_MORE;
376 dcmds = state->dma_cmds;
377 total = 0;
378
379 scsi_for_each_sg(cmd, scl, nseg, i) {
380 dma_addr = sg_dma_address(scl);
381 dma_len = sg_dma_len(scl);
382 if (dma_len > 0xffff)
383 panic("mac53c94: scatterlist element >= 64k");
384 total += dma_len;
385 st_le16(&dcmds->req_count, dma_len);
386 st_le16(&dcmds->command, dma_cmd);
387 st_le32(&dcmds->phy_addr, dma_addr);
388 dcmds->xfer_status = 0;
389 ++dcmds;
390 }
391
392 dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
393 st_le16(&dcmds[-1].command, dma_cmd);
394 st_le16(&dcmds->command, DBDMA_STOP);
395 cmd->SCp.this_residual = total;
396 }
397
398 static struct scsi_host_template mac53c94_template = {
399 .proc_name = "53c94",
400 .name = "53C94",
401 .queuecommand = mac53c94_queue,
402 .eh_host_reset_handler = mac53c94_host_reset,
403 .can_queue = 1,
404 .this_id = 7,
405 .sg_tablesize = SG_ALL,
406 .cmd_per_lun = 1,
407 .use_clustering = DISABLE_CLUSTERING,
408 };
409
410 static int mac53c94_probe(struct macio_dev *mdev, const struct of_device_id *match)
411 {
412 struct device_node *node = macio_get_of_node(mdev);
413 struct pci_dev *pdev = macio_get_pci_dev(mdev);
414 struct fsc_state *state;
415 struct Scsi_Host *host;
416 void *dma_cmd_space;
417 const unsigned char *clkprop;
418 int proplen, rc = -ENODEV;
419
420 if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
421 printk(KERN_ERR "mac53c94: expected 2 addrs and intrs"
422 " (got %d/%d)\n",
423 macio_resource_count(mdev), macio_irq_count(mdev));
424 return -ENODEV;
425 }
426
427 if (macio_request_resources(mdev, "mac53c94") != 0) {
428 printk(KERN_ERR "mac53c94: unable to request memory resources");
429 return -EBUSY;
430 }
431
432 host = scsi_host_alloc(&mac53c94_template, sizeof(struct fsc_state));
433 if (host == NULL) {
434 printk(KERN_ERR "mac53c94: couldn't register host");
435 rc = -ENOMEM;
436 goto out_release;
437 }
438
439 state = (struct fsc_state *) host->hostdata;
440 macio_set_drvdata(mdev, state);
441 state->host = host;
442 state->pdev = pdev;
443 state->mdev = mdev;
444
445 state->regs = (struct mac53c94_regs __iomem *)
446 ioremap(macio_resource_start(mdev, 0), 0x1000);
447 state->intr = macio_irq(mdev, 0);
448 state->dma = (struct dbdma_regs __iomem *)
449 ioremap(macio_resource_start(mdev, 1), 0x1000);
450 state->dmaintr = macio_irq(mdev, 1);
451 if (state->regs == NULL || state->dma == NULL) {
452 printk(KERN_ERR "mac53c94: ioremap failed for %s\n",
453 node->full_name);
454 goto out_free;
455 }
456
457 clkprop = of_get_property(node, "clock-frequency", &proplen);
458 if (clkprop == NULL || proplen != sizeof(int)) {
459 printk(KERN_ERR "%s: can't get clock frequency, "
460 "assuming 25MHz\n", node->full_name);
461 state->clk_freq = 25000000;
462 } else
463 state->clk_freq = *(int *)clkprop;
464
465 /* Space for dma command list: +1 for stop command,
466 * +1 to allow for aligning.
467 * XXX FIXME: Use DMA consistent routines
468 */
469 dma_cmd_space = kmalloc((host->sg_tablesize + 2) *
470 sizeof(struct dbdma_cmd), GFP_KERNEL);
471 if (dma_cmd_space == 0) {
472 printk(KERN_ERR "mac53c94: couldn't allocate dma "
473 "command space for %s\n", node->full_name);
474 rc = -ENOMEM;
475 goto out_free;
476 }
477 state->dma_cmds = (struct dbdma_cmd *)DBDMA_ALIGN(dma_cmd_space);
478 memset(state->dma_cmds, 0, (host->sg_tablesize + 1)
479 * sizeof(struct dbdma_cmd));
480 state->dma_cmd_space = dma_cmd_space;
481
482 mac53c94_init(state);
483
484 if (request_irq(state->intr, do_mac53c94_interrupt, 0, "53C94",state)) {
485 printk(KERN_ERR "mac53C94: can't get irq %d for %s\n",
486 state->intr, node->full_name);
487 goto out_free_dma;
488 }
489
490 rc = scsi_add_host(host, &mdev->ofdev.dev);
491 if (rc != 0)
492 goto out_release_irq;
493
494 scsi_scan_host(host);
495 return 0;
496
497 out_release_irq:
498 free_irq(state->intr, state);
499 out_free_dma:
500 kfree(state->dma_cmd_space);
501 out_free:
502 if (state->dma != NULL)
503 iounmap(state->dma);
504 if (state->regs != NULL)
505 iounmap(state->regs);
506 scsi_host_put(host);
507 out_release:
508 macio_release_resources(mdev);
509
510 return rc;
511 }
512
513 static int mac53c94_remove(struct macio_dev *mdev)
514 {
515 struct fsc_state *fp = (struct fsc_state *)macio_get_drvdata(mdev);
516 struct Scsi_Host *host = fp->host;
517
518 scsi_remove_host(host);
519
520 free_irq(fp->intr, fp);
521
522 if (fp->regs)
523 iounmap(fp->regs);
524 if (fp->dma)
525 iounmap(fp->dma);
526 kfree(fp->dma_cmd_space);
527
528 scsi_host_put(host);
529
530 macio_release_resources(mdev);
531
532 return 0;
533 }
534
535
536 static struct of_device_id mac53c94_match[] =
537 {
538 {
539 .name = "53c94",
540 },
541 {},
542 };
543 MODULE_DEVICE_TABLE (of, mac53c94_match);
544
545 static struct macio_driver mac53c94_driver =
546 {
547 .driver = {
548 .name = "mac53c94",
549 .owner = THIS_MODULE,
550 .of_match_table = mac53c94_match,
551 },
552 .probe = mac53c94_probe,
553 .remove = mac53c94_remove,
554 };
555
556
557 static int __init init_mac53c94(void)
558 {
559 return macio_register_driver(&mac53c94_driver);
560 }
561
562 static void __exit exit_mac53c94(void)
563 {
564 return macio_unregister_driver(&mac53c94_driver);
565 }
566
567 module_init(init_mac53c94);
568 module_exit(exit_mac53c94);
569
570 MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver");
571 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
572 MODULE_LICENSE("GPL");
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