ide-atapi.c revision ac77ef8b03677c8ae8afe77bccc5f6a969193a79 
1/*
2 * ATAPI support.
3 */
4
5#include <linux/kernel.h>
6#include <linux/delay.h>
7#include <linux/ide.h>
8#include <scsi/scsi.h>
9
10#ifdef DEBUG
11#define debug_log(fmt, args...) \
12	printk(KERN_INFO "ide: " fmt, ## args)
13#else
14#define debug_log(fmt, args...) do {} while (0)
15#endif
16
17/* TODO: unify the code thus making some arguments go away */
18ide_startstop_t ide_pc_intr(ide_drive_t *drive, struct ide_atapi_pc *pc,
19	ide_handler_t *handler, unsigned int timeout, ide_expiry_t *expiry,
20	void (*update_buffers)(ide_drive_t *, struct ide_atapi_pc *),
21	void (*retry_pc)(ide_drive_t *), void (*dsc_handle)(ide_drive_t *),
22	void (*io_buffers)(ide_drive_t *, struct ide_atapi_pc *, unsigned, int))
23{
24	ide_hwif_t *hwif = drive->hwif;
25	struct request *rq = hwif->hwgroup->rq;
26	const struct ide_tp_ops *tp_ops = hwif->tp_ops;
27	xfer_func_t *xferfunc;
28	unsigned int temp;
29	u16 bcount;
30	u8 stat, ireason, scsi = drive->scsi;
31
32	debug_log("Enter %s - interrupt handler\n", __func__);
33
34	if (pc->flags & PC_FLAG_TIMEDOUT) {
35		drive->pc_callback(drive);
36		return ide_stopped;
37	}
38
39	/* Clear the interrupt */
40	stat = tp_ops->read_status(hwif);
41
42	if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
43		if (hwif->dma_ops->dma_end(drive) ||
44		    (drive->media == ide_tape && !scsi && (stat & ERR_STAT))) {
45			if (drive->media == ide_floppy && !scsi)
46				printk(KERN_ERR "%s: DMA %s error\n",
47					drive->name, rq_data_dir(pc->rq)
48						     ? "write" : "read");
49			pc->flags |= PC_FLAG_DMA_ERROR;
50		} else {
51			pc->xferred = pc->req_xfer;
52			if (update_buffers)
53				update_buffers(drive, pc);
54		}
55		debug_log("%s: DMA finished\n", drive->name);
56	}
57
58	/* No more interrupts */
59	if ((stat & DRQ_STAT) == 0) {
60		debug_log("Packet command completed, %d bytes transferred\n",
61			  pc->xferred);
62
63		pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
64
65		local_irq_enable_in_hardirq();
66
67		if (drive->media == ide_tape && !scsi &&
68		    (stat & ERR_STAT) && rq->cmd[0] == REQUEST_SENSE)
69			stat &= ~ERR_STAT;
70
71		if ((stat & ERR_STAT) || (pc->flags & PC_FLAG_DMA_ERROR)) {
72			/* Error detected */
73			debug_log("%s: I/O error\n", drive->name);
74
75			if (drive->media != ide_tape || scsi) {
76				pc->rq->errors++;
77				if (scsi)
78					goto cmd_finished;
79			}
80
81			if (rq->cmd[0] == REQUEST_SENSE) {
82				printk(KERN_ERR "%s: I/O error in request sense"
83						" command\n", drive->name);
84				return ide_do_reset(drive);
85			}
86
87			debug_log("[cmd %x]: check condition\n", rq->cmd[0]);
88
89			/* Retry operation */
90			retry_pc(drive);
91
92			/* queued, but not started */
93			return ide_stopped;
94		}
95cmd_finished:
96		pc->error = 0;
97		if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) &&
98		    (stat & SEEK_STAT) == 0) {
99			dsc_handle(drive);
100			return ide_stopped;
101		}
102
103		/* Command finished - Call the callback function */
104		drive->pc_callback(drive);
105
106		return ide_stopped;
107	}
108
109	if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
110		pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
111		printk(KERN_ERR "%s: The device wants to issue more interrupts "
112				"in DMA mode\n", drive->name);
113		ide_dma_off(drive);
114		return ide_do_reset(drive);
115	}
116
117	/* Get the number of bytes to transfer on this interrupt. */
118	ide_read_bcount_and_ireason(drive, &bcount, &ireason);
119
120	if (ireason & CD) {
121		printk(KERN_ERR "%s: CoD != 0 in %s\n", drive->name, __func__);
122		return ide_do_reset(drive);
123	}
124
125	if (((ireason & IO) == IO) == !!(pc->flags & PC_FLAG_WRITING)) {
126		/* Hopefully, we will never get here */
127		printk(KERN_ERR "%s: We wanted to %s, but the device wants us "
128				"to %s!\n", drive->name,
129				(ireason & IO) ? "Write" : "Read",
130				(ireason & IO) ? "Read" : "Write");
131		return ide_do_reset(drive);
132	}
133
134	if (!(pc->flags & PC_FLAG_WRITING)) {
135		/* Reading - Check that we have enough space */
136		temp = pc->xferred + bcount;
137		if (temp > pc->req_xfer) {
138			if (temp > pc->buf_size) {
139				printk(KERN_ERR "%s: The device wants to send "
140						"us more data than expected - "
141						"discarding data\n",
142						drive->name);
143				if (scsi)
144					temp = pc->buf_size - pc->xferred;
145				else
146					temp = 0;
147				if (temp) {
148					if (pc->sg)
149						io_buffers(drive, pc, temp, 0);
150					else
151						tp_ops->input_data(drive, NULL,
152							pc->cur_pos, temp);
153					printk(KERN_ERR "%s: transferred %d of "
154							"%d bytes\n",
155							drive->name,
156							temp, bcount);
157				}
158				pc->xferred += temp;
159				pc->cur_pos += temp;
160				ide_pad_transfer(drive, 0, bcount - temp);
161				ide_set_handler(drive, handler, timeout,
162						expiry);
163				return ide_started;
164			}
165			debug_log("The device wants to send us more data than "
166				  "expected - allowing transfer\n");
167		}
168		xferfunc = tp_ops->input_data;
169	} else
170		xferfunc = tp_ops->output_data;
171
172	if ((drive->media == ide_floppy && !scsi && !pc->buf) ||
173	    (drive->media == ide_tape && !scsi && pc->bh) ||
174	    (scsi && pc->sg))
175		io_buffers(drive, pc, bcount, !!(pc->flags & PC_FLAG_WRITING));
176	else
177		xferfunc(drive, NULL, pc->cur_pos, bcount);
178
179	/* Update the current position */
180	pc->xferred += bcount;
181	pc->cur_pos += bcount;
182
183	debug_log("[cmd %x] transferred %d bytes on that intr.\n",
184		  rq->cmd[0], bcount);
185
186	/* And set the interrupt handler again */
187	ide_set_handler(drive, handler, timeout, expiry);
188	return ide_started;
189}
190EXPORT_SYMBOL_GPL(ide_pc_intr);
191
192static u8 ide_read_ireason(ide_drive_t *drive)
193{
194	ide_task_t task;
195
196	memset(&task, 0, sizeof(task));
197	task.tf_flags = IDE_TFLAG_IN_NSECT;
198
199	drive->hwif->tp_ops->tf_read(drive, &task);
200
201	return task.tf.nsect & 3;
202}
203
204static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason)
205{
206	int retries = 100;
207
208	while (retries-- && ((ireason & CD) == 0 || (ireason & IO))) {
209		printk(KERN_ERR "%s: (IO,CoD != (0,1) while issuing "
210				"a packet command, retrying\n", drive->name);
211		udelay(100);
212		ireason = ide_read_ireason(drive);
213		if (retries == 0) {
214			printk(KERN_ERR "%s: (IO,CoD != (0,1) while issuing "
215					"a packet command, ignoring\n",
216					drive->name);
217			ireason |= CD;
218			ireason &= ~IO;
219		}
220	}
221
222	return ireason;
223}
224
225ide_startstop_t ide_transfer_pc(ide_drive_t *drive, struct ide_atapi_pc *pc,
226				ide_handler_t *handler, unsigned int timeout,
227				ide_expiry_t *expiry)
228{
229	ide_hwif_t *hwif = drive->hwif;
230	struct request *rq = hwif->hwgroup->rq;
231	ide_startstop_t startstop;
232	u8 ireason;
233
234	if (ide_wait_stat(&startstop, drive, DRQ_STAT, BUSY_STAT, WAIT_READY)) {
235		printk(KERN_ERR "%s: Strange, packet command initiated yet "
236				"DRQ isn't asserted\n", drive->name);
237		return startstop;
238	}
239
240	ireason = ide_read_ireason(drive);
241	if (drive->media == ide_tape && !drive->scsi)
242		ireason = ide_wait_ireason(drive, ireason);
243
244	if ((ireason & CD) == 0 || (ireason & IO)) {
245		printk(KERN_ERR "%s: (IO,CoD) != (0,1) while issuing "
246				"a packet command\n", drive->name);
247		return ide_do_reset(drive);
248	}
249
250	/* Set the interrupt routine */
251	ide_set_handler(drive, handler, timeout, expiry);
252
253	/* Begin DMA, if necessary */
254	if (pc->flags & PC_FLAG_DMA_OK) {
255		pc->flags |= PC_FLAG_DMA_IN_PROGRESS;
256		hwif->dma_ops->dma_start(drive);
257	}
258
259	/* Send the actual packet */
260	if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0)
261		hwif->tp_ops->output_data(drive, NULL, rq->cmd, 12);
262
263	return ide_started;
264}
265EXPORT_SYMBOL_GPL(ide_transfer_pc);
266
267ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_atapi_pc *pc,
268			     ide_handler_t *handler, unsigned int timeout,
269			     ide_expiry_t *expiry)
270{
271	ide_hwif_t *hwif = drive->hwif;
272	u16 bcount;
273	u8 dma = 0;
274
275	/* We haven't transferred any data yet */
276	pc->xferred = 0;
277	pc->cur_pos = pc->buf;
278
279	/* Request to transfer the entire buffer at once */
280	if (drive->media == ide_tape && !drive->scsi)
281		bcount = pc->req_xfer;
282	else
283		bcount = min(pc->req_xfer, 63 * 1024);
284
285	if (pc->flags & PC_FLAG_DMA_ERROR) {
286		pc->flags &= ~PC_FLAG_DMA_ERROR;
287		ide_dma_off(drive);
288	}
289
290	if ((pc->flags & PC_FLAG_DMA_OK) && drive->using_dma) {
291		if (drive->scsi)
292			hwif->sg_mapped = 1;
293		dma = !hwif->dma_ops->dma_setup(drive);
294		if (drive->scsi)
295			hwif->sg_mapped = 0;
296	}
297
298	if (!dma)
299		pc->flags &= ~PC_FLAG_DMA_OK;
300
301	ide_pktcmd_tf_load(drive, drive->scsi ? 0 : IDE_TFLAG_OUT_DEVICE,
302			   bcount, dma);
303
304	/* Issue the packet command */
305	if (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT) {
306		ide_execute_command(drive, WIN_PACKETCMD, handler,
307				    timeout, NULL);
308		return ide_started;
309	} else {
310		ide_execute_pkt_cmd(drive);
311		return (*handler)(drive);
312	}
313}
314EXPORT_SYMBOL_GPL(ide_issue_pc);
315