ide-atapi.c revision db9d286988b9e905045c536f681e85fa5e3a728b 
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	const struct ide_tp_ops *tp_ops = hwif->tp_ops;
26	xfer_func_t *xferfunc;
27	unsigned int temp;
28	u16 bcount;
29	u8 stat, ireason, scsi = drive->scsi;
30
31	debug_log("Enter %s - interrupt handler\n", __func__);
32
33	if (pc->flags & PC_FLAG_TIMEDOUT) {
34		drive->pc_callback(drive);
35		return ide_stopped;
36	}
37
38	/* Clear the interrupt */
39	stat = tp_ops->read_status(hwif);
40
41	if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
42		if (hwif->dma_ops->dma_end(drive) ||
43		    (drive->media == ide_tape && !scsi && (stat & ERR_STAT))) {
44			if (drive->media == ide_floppy && !scsi)
45				printk(KERN_ERR "%s: DMA %s error\n",
46					drive->name, rq_data_dir(pc->rq)
47						     ? "write" : "read");
48			pc->flags |= PC_FLAG_DMA_ERROR;
49		} else {
50			pc->xferred = pc->req_xfer;
51			if (update_buffers)
52				update_buffers(drive, pc);
53		}
54		debug_log("%s: DMA finished\n", drive->name);
55	}
56
57	/* No more interrupts */
58	if ((stat & DRQ_STAT) == 0) {
59		debug_log("Packet command completed, %d bytes transferred\n",
60			  pc->xferred);
61
62		pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
63
64		local_irq_enable_in_hardirq();
65
66		if (drive->media == ide_tape && !scsi &&
67		    (stat & ERR_STAT) && pc->c[0] == REQUEST_SENSE)
68			stat &= ~ERR_STAT;
69		if ((stat & ERR_STAT) || (pc->flags & PC_FLAG_DMA_ERROR)) {
70			/* Error detected */
71			debug_log("%s: I/O error\n", drive->name);
72
73			if (drive->media != ide_tape || scsi) {
74				pc->rq->errors++;
75				if (scsi)
76					goto cmd_finished;
77			}
78
79			if (pc->c[0] == REQUEST_SENSE) {
80				printk(KERN_ERR "%s: I/O error in request sense"
81						" command\n", drive->name);
82				return ide_do_reset(drive);
83			}
84
85			debug_log("[cmd %x]: check condition\n", pc->c[0]);
86
87			/* Retry operation */
88			retry_pc(drive);
89			/* queued, but not started */
90			return ide_stopped;
91		}
92cmd_finished:
93		pc->error = 0;
94		if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) &&
95		    (stat & SEEK_STAT) == 0) {
96			dsc_handle(drive);
97			return ide_stopped;
98		}
99		/* Command finished - Call the callback function */
100		drive->pc_callback(drive);
101		return ide_stopped;
102	}
103
104	if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
105		pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
106		printk(KERN_ERR "%s: The device wants to issue more interrupts "
107				"in DMA mode\n", drive->name);
108		ide_dma_off(drive);
109		return ide_do_reset(drive);
110	}
111
112	/* Get the number of bytes to transfer on this interrupt. */
113	ide_read_bcount_and_ireason(drive, &bcount, &ireason);
114
115	if (ireason & CD) {
116		printk(KERN_ERR "%s: CoD != 0 in %s\n", drive->name, __func__);
117		return ide_do_reset(drive);
118	}
119	if (((ireason & IO) == IO) == !!(pc->flags & PC_FLAG_WRITING)) {
120		/* Hopefully, we will never get here */
121		printk(KERN_ERR "%s: We wanted to %s, but the device wants us "
122				"to %s!\n", drive->name,
123				(ireason & IO) ? "Write" : "Read",
124				(ireason & IO) ? "Read" : "Write");
125		return ide_do_reset(drive);
126	}
127	if (!(pc->flags & PC_FLAG_WRITING)) {
128		/* Reading - Check that we have enough space */
129		temp = pc->xferred + bcount;
130		if (temp > pc->req_xfer) {
131			if (temp > pc->buf_size) {
132				printk(KERN_ERR "%s: The device wants to send "
133						"us more data than expected - "
134						"discarding data\n",
135						drive->name);
136				if (scsi)
137					temp = pc->buf_size - pc->xferred;
138				else
139					temp = 0;
140				if (temp) {
141					if (pc->sg)
142						io_buffers(drive, pc, temp, 0);
143					else
144						tp_ops->input_data(drive, NULL,
145							pc->cur_pos, temp);
146					printk(KERN_ERR "%s: transferred %d of "
147							"%d bytes\n",
148							drive->name,
149							temp, bcount);
150				}
151				pc->xferred += temp;
152				pc->cur_pos += temp;
153				ide_pad_transfer(drive, 0, bcount - temp);
154				ide_set_handler(drive, handler, timeout,
155						expiry);
156				return ide_started;
157			}
158			debug_log("The device wants to send us more data than "
159				  "expected - allowing transfer\n");
160		}
161		xferfunc = tp_ops->input_data;
162	} else
163		xferfunc = tp_ops->output_data;
164
165	if ((drive->media == ide_floppy && !scsi && !pc->buf) ||
166	    (drive->media == ide_tape && !scsi && pc->bh) ||
167	    (scsi && pc->sg))
168		io_buffers(drive, pc, bcount, !!(pc->flags & PC_FLAG_WRITING));
169	else
170		xferfunc(drive, NULL, pc->cur_pos, bcount);
171
172	/* Update the current position */
173	pc->xferred += bcount;
174	pc->cur_pos += bcount;
175
176	debug_log("[cmd %x] transferred %d bytes on that intr.\n",
177		  pc->c[0], bcount);
178
179	/* And set the interrupt handler again */
180	ide_set_handler(drive, handler, timeout, expiry);
181	return ide_started;
182}
183EXPORT_SYMBOL_GPL(ide_pc_intr);
184
185static u8 ide_read_ireason(ide_drive_t *drive)
186{
187	ide_task_t task;
188
189	memset(&task, 0, sizeof(task));
190	task.tf_flags = IDE_TFLAG_IN_NSECT;
191
192	drive->hwif->tp_ops->tf_read(drive, &task);
193
194	return task.tf.nsect & 3;
195}
196
197static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason)
198{
199	int retries = 100;
200
201	while (retries-- && ((ireason & CD) == 0 || (ireason & IO))) {
202		printk(KERN_ERR "%s: (IO,CoD != (0,1) while issuing "
203				"a packet command, retrying\n", drive->name);
204		udelay(100);
205		ireason = ide_read_ireason(drive);
206		if (retries == 0) {
207			printk(KERN_ERR "%s: (IO,CoD != (0,1) while issuing "
208					"a packet command, ignoring\n",
209					drive->name);
210			ireason |= CD;
211			ireason &= ~IO;
212		}
213	}
214
215	return ireason;
216}
217
218ide_startstop_t ide_transfer_pc(ide_drive_t *drive, struct ide_atapi_pc *pc,
219				ide_handler_t *handler, unsigned int timeout,
220				ide_expiry_t *expiry)
221{
222	ide_hwif_t *hwif = drive->hwif;
223	ide_startstop_t startstop;
224	u8 ireason;
225
226	if (ide_wait_stat(&startstop, drive, DRQ_STAT, BUSY_STAT, WAIT_READY)) {
227		printk(KERN_ERR "%s: Strange, packet command initiated yet "
228				"DRQ isn't asserted\n", drive->name);
229		return startstop;
230	}
231
232	ireason = ide_read_ireason(drive);
233	if (drive->media == ide_tape && !drive->scsi)
234		ireason = ide_wait_ireason(drive, ireason);
235
236	if ((ireason & CD) == 0 || (ireason & IO)) {
237		printk(KERN_ERR "%s: (IO,CoD) != (0,1) while issuing "
238				"a packet command\n", drive->name);
239		return ide_do_reset(drive);
240	}
241
242	/* Set the interrupt routine */
243	ide_set_handler(drive, handler, timeout, expiry);
244
245	/* Begin DMA, if necessary */
246	if (pc->flags & PC_FLAG_DMA_OK) {
247		pc->flags |= PC_FLAG_DMA_IN_PROGRESS;
248		hwif->dma_ops->dma_start(drive);
249	}
250
251	/* Send the actual packet */
252	if ((pc->flags & PC_FLAG_ZIP_DRIVE) == 0)
253		hwif->tp_ops->output_data(drive, NULL, pc->c, 12);
254
255	return ide_started;
256}
257EXPORT_SYMBOL_GPL(ide_transfer_pc);
258
259ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_atapi_pc *pc,
260			     ide_handler_t *handler, unsigned int timeout,
261			     ide_expiry_t *expiry)
262{
263	ide_hwif_t *hwif = drive->hwif;
264	u16 bcount;
265	u8 dma = 0;
266
267	/* We haven't transferred any data yet */
268	pc->xferred = 0;
269	pc->cur_pos = pc->buf;
270
271	/* Request to transfer the entire buffer at once */
272	if (drive->media == ide_tape && !drive->scsi)
273		bcount = pc->req_xfer;
274	else
275		bcount = min(pc->req_xfer, 63 * 1024);
276
277	if (pc->flags & PC_FLAG_DMA_ERROR) {
278		pc->flags &= ~PC_FLAG_DMA_ERROR;
279		ide_dma_off(drive);
280	}
281
282	if ((pc->flags & PC_FLAG_DMA_OK) && drive->using_dma) {
283		if (drive->scsi)
284			hwif->sg_mapped = 1;
285		dma = !hwif->dma_ops->dma_setup(drive);
286		if (drive->scsi)
287			hwif->sg_mapped = 0;
288	}
289
290	if (!dma)
291		pc->flags &= ~PC_FLAG_DMA_OK;
292
293	ide_pktcmd_tf_load(drive, drive->scsi ? 0 : IDE_TFLAG_OUT_DEVICE,
294			   bcount, dma);
295
296	/* Issue the packet command */
297	if (pc->flags & PC_FLAG_DRQ_INTERRUPT) {
298		ide_execute_command(drive, WIN_PACKETCMD, handler,
299				    timeout, NULL);
300		return ide_started;
301	} else {
302		ide_execute_pkt_cmd(drive);
303		return (*handler)(drive);
304	}
305}
306EXPORT_SYMBOL_GPL(ide_issue_pc);
307