ide: move error handling code to ide-eh.c (v2)

Do some CodingStyle fixups in <linux/ide.h> while at it.

v2:
Add missing <linux/delay.h> include (reported by Stephen Rothwell).

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-eh.c b/drivers/ide/ide-eh.c
new file mode 100644
index 0000000..1231b5e
--- /dev/null
+++ b/drivers/ide/ide-eh.c
@@ -0,0 +1,428 @@
+
+#include <linux/kernel.h>
+#include <linux/ide.h>
+#include <linux/delay.h>
+
+static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq,
+				     u8 stat, u8 err)
+{
+	ide_hwif_t *hwif = drive->hwif;
+
+	if ((stat & ATA_BUSY) ||
+	    ((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) {
+		/* other bits are useless when BUSY */
+		rq->errors |= ERROR_RESET;
+	} else if (stat & ATA_ERR) {
+		/* err has different meaning on cdrom and tape */
+		if (err == ATA_ABORTED) {
+			if ((drive->dev_flags & IDE_DFLAG_LBA) &&
+			    /* some newer drives don't support ATA_CMD_INIT_DEV_PARAMS */
+			    hwif->tp_ops->read_status(hwif) == ATA_CMD_INIT_DEV_PARAMS)
+				return ide_stopped;
+		} else if ((err & BAD_CRC) == BAD_CRC) {
+			/* UDMA crc error, just retry the operation */
+			drive->crc_count++;
+		} else if (err & (ATA_BBK | ATA_UNC)) {
+			/* retries won't help these */
+			rq->errors = ERROR_MAX;
+		} else if (err & ATA_TRK0NF) {
+			/* help it find track zero */
+			rq->errors |= ERROR_RECAL;
+		}
+	}
+
+	if ((stat & ATA_DRQ) && rq_data_dir(rq) == READ &&
+	    (hwif->host_flags & IDE_HFLAG_ERROR_STOPS_FIFO) == 0) {
+		int nsect = drive->mult_count ? drive->mult_count : 1;
+
+		ide_pad_transfer(drive, READ, nsect * SECTOR_SIZE);
+	}
+
+	if (rq->errors >= ERROR_MAX || blk_noretry_request(rq)) {
+		ide_kill_rq(drive, rq);
+		return ide_stopped;
+	}
+
+	if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY | ATA_DRQ))
+		rq->errors |= ERROR_RESET;
+
+	if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
+		++rq->errors;
+		return ide_do_reset(drive);
+	}
+
+	if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
+		drive->special.b.recalibrate = 1;
+
+	++rq->errors;
+
+	return ide_stopped;
+}
+
+static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq,
+				       u8 stat, u8 err)
+{
+	ide_hwif_t *hwif = drive->hwif;
+
+	if ((stat & ATA_BUSY) ||
+	    ((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) {
+		/* other bits are useless when BUSY */
+		rq->errors |= ERROR_RESET;
+	} else {
+		/* add decoding error stuff */
+	}
+
+	if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY | ATA_DRQ))
+		/* force an abort */
+		hwif->tp_ops->exec_command(hwif, ATA_CMD_IDLEIMMEDIATE);
+
+	if (rq->errors >= ERROR_MAX) {
+		ide_kill_rq(drive, rq);
+	} else {
+		if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
+			++rq->errors;
+			return ide_do_reset(drive);
+		}
+		++rq->errors;
+	}
+
+	return ide_stopped;
+}
+
+static ide_startstop_t __ide_error(ide_drive_t *drive, struct request *rq,
+				   u8 stat, u8 err)
+{
+	if (drive->media == ide_disk)
+		return ide_ata_error(drive, rq, stat, err);
+	return ide_atapi_error(drive, rq, stat, err);
+}
+
+/**
+ *	ide_error	-	handle an error on the IDE
+ *	@drive: drive the error occurred on
+ *	@msg: message to report
+ *	@stat: status bits
+ *
+ *	ide_error() takes action based on the error returned by the drive.
+ *	For normal I/O that may well include retries. We deal with
+ *	both new-style (taskfile) and old style command handling here.
+ *	In the case of taskfile command handling there is work left to
+ *	do
+ */
+
+ide_startstop_t ide_error(ide_drive_t *drive, const char *msg, u8 stat)
+{
+	struct request *rq;
+	u8 err;
+
+	err = ide_dump_status(drive, msg, stat);
+
+	rq = drive->hwif->rq;
+	if (rq == NULL)
+		return ide_stopped;
+
+	/* retry only "normal" I/O: */
+	if (!blk_fs_request(rq)) {
+		rq->errors = 1;
+		ide_end_drive_cmd(drive, stat, err);
+		return ide_stopped;
+	}
+
+	return __ide_error(drive, rq, stat, err);
+}
+EXPORT_SYMBOL_GPL(ide_error);
+
+static inline void ide_complete_drive_reset(ide_drive_t *drive, int err)
+{
+	struct request *rq = drive->hwif->rq;
+
+	if (rq && blk_special_request(rq) && rq->cmd[0] == REQ_DRIVE_RESET)
+		ide_end_request(drive, err ? err : 1, 0);
+}
+
+/* needed below */
+static ide_startstop_t do_reset1(ide_drive_t *, int);
+
+/*
+ * atapi_reset_pollfunc() gets invoked to poll the interface for completion
+ * every 50ms during an atapi drive reset operation.  If the drive has not yet
+ * responded, and we have not yet hit our maximum waiting time, then the timer
+ * is restarted for another 50ms.
+ */
+static ide_startstop_t atapi_reset_pollfunc(ide_drive_t *drive)
+{
+	ide_hwif_t *hwif = drive->hwif;
+	u8 stat;
+
+	SELECT_DRIVE(drive);
+	udelay(10);
+	stat = hwif->tp_ops->read_status(hwif);
+
+	if (OK_STAT(stat, 0, ATA_BUSY))
+		printk(KERN_INFO "%s: ATAPI reset complete\n", drive->name);
+	else {
+		if (time_before(jiffies, hwif->poll_timeout)) {
+			ide_set_handler(drive, &atapi_reset_pollfunc, HZ/20,
+					NULL);
+			/* continue polling */
+			return ide_started;
+		}
+		/* end of polling */
+		hwif->polling = 0;
+		printk(KERN_ERR "%s: ATAPI reset timed-out, status=0x%02x\n",
+			drive->name, stat);
+		/* do it the old fashioned way */
+		return do_reset1(drive, 1);
+	}
+	/* done polling */
+	hwif->polling = 0;
+	ide_complete_drive_reset(drive, 0);
+	return ide_stopped;
+}
+
+static void ide_reset_report_error(ide_hwif_t *hwif, u8 err)
+{
+	static const char *err_master_vals[] =
+		{ NULL, "passed", "formatter device error",
+		  "sector buffer error", "ECC circuitry error",
+		  "controlling MPU error" };
+
+	u8 err_master = err & 0x7f;
+
+	printk(KERN_ERR "%s: reset: master: ", hwif->name);
+	if (err_master && err_master < 6)
+		printk(KERN_CONT "%s", err_master_vals[err_master]);
+	else
+		printk(KERN_CONT "error (0x%02x?)", err);
+	if (err & 0x80)
+		printk(KERN_CONT "; slave: failed");
+	printk(KERN_CONT "\n");
+}
+
+/*
+ * reset_pollfunc() gets invoked to poll the interface for completion every 50ms
+ * during an ide reset operation. If the drives have not yet responded,
+ * and we have not yet hit our maximum waiting time, then the timer is restarted
+ * for another 50ms.
+ */
+static ide_startstop_t reset_pollfunc(ide_drive_t *drive)
+{
+	ide_hwif_t *hwif = drive->hwif;
+	const struct ide_port_ops *port_ops = hwif->port_ops;
+	u8 tmp;
+	int err = 0;
+
+	if (port_ops && port_ops->reset_poll) {
+		err = port_ops->reset_poll(drive);
+		if (err) {
+			printk(KERN_ERR "%s: host reset_poll failure for %s.\n",
+				hwif->name, drive->name);
+			goto out;
+		}
+	}
+
+	tmp = hwif->tp_ops->read_status(hwif);
+
+	if (!OK_STAT(tmp, 0, ATA_BUSY)) {
+		if (time_before(jiffies, hwif->poll_timeout)) {
+			ide_set_handler(drive, &reset_pollfunc, HZ/20, NULL);
+			/* continue polling */
+			return ide_started;
+		}
+		printk(KERN_ERR "%s: reset timed-out, status=0x%02x\n",
+			hwif->name, tmp);
+		drive->failures++;
+		err = -EIO;
+	} else  {
+		tmp = ide_read_error(drive);
+
+		if (tmp == 1) {
+			printk(KERN_INFO "%s: reset: success\n", hwif->name);
+			drive->failures = 0;
+		} else {
+			ide_reset_report_error(hwif, tmp);
+			drive->failures++;
+			err = -EIO;
+		}
+	}
+out:
+	hwif->polling = 0;	/* done polling */
+	ide_complete_drive_reset(drive, err);
+	return ide_stopped;
+}
+
+static void ide_disk_pre_reset(ide_drive_t *drive)
+{
+	int legacy = (drive->id[ATA_ID_CFS_ENABLE_2] & 0x0400) ? 0 : 1;
+
+	drive->special.all = 0;
+	drive->special.b.set_geometry = legacy;
+	drive->special.b.recalibrate  = legacy;
+
+	drive->mult_count = 0;
+	drive->dev_flags &= ~IDE_DFLAG_PARKED;
+
+	if ((drive->dev_flags & IDE_DFLAG_KEEP_SETTINGS) == 0 &&
+	    (drive->dev_flags & IDE_DFLAG_USING_DMA) == 0)
+		drive->mult_req = 0;
+
+	if (drive->mult_req != drive->mult_count)
+		drive->special.b.set_multmode = 1;
+}
+
+static void pre_reset(ide_drive_t *drive)
+{
+	const struct ide_port_ops *port_ops = drive->hwif->port_ops;
+
+	if (drive->media == ide_disk)
+		ide_disk_pre_reset(drive);
+	else
+		drive->dev_flags |= IDE_DFLAG_POST_RESET;
+
+	if (drive->dev_flags & IDE_DFLAG_USING_DMA) {
+		if (drive->crc_count)
+			ide_check_dma_crc(drive);
+		else
+			ide_dma_off(drive);
+	}
+
+	if ((drive->dev_flags & IDE_DFLAG_KEEP_SETTINGS) == 0) {
+		if ((drive->dev_flags & IDE_DFLAG_USING_DMA) == 0) {
+			drive->dev_flags &= ~IDE_DFLAG_UNMASK;
+			drive->io_32bit = 0;
+		}
+		return;
+	}
+
+	if (port_ops && port_ops->pre_reset)
+		port_ops->pre_reset(drive);
+
+	if (drive->current_speed != 0xff)
+		drive->desired_speed = drive->current_speed;
+	drive->current_speed = 0xff;
+}
+
+/*
+ * do_reset1() attempts to recover a confused drive by resetting it.
+ * Unfortunately, resetting a disk drive actually resets all devices on
+ * the same interface, so it can really be thought of as resetting the
+ * interface rather than resetting the drive.
+ *
+ * ATAPI devices have their own reset mechanism which allows them to be
+ * individually reset without clobbering other devices on the same interface.
+ *
+ * Unfortunately, the IDE interface does not generate an interrupt to let
+ * us know when the reset operation has finished, so we must poll for this.
+ * Equally poor, though, is the fact that this may a very long time to complete,
+ * (up to 30 seconds worstcase).  So, instead of busy-waiting here for it,
+ * we set a timer to poll at 50ms intervals.
+ */
+static ide_startstop_t do_reset1(ide_drive_t *drive, int do_not_try_atapi)
+{
+	ide_hwif_t *hwif = drive->hwif;
+	struct ide_io_ports *io_ports = &hwif->io_ports;
+	const struct ide_tp_ops *tp_ops = hwif->tp_ops;
+	const struct ide_port_ops *port_ops;
+	ide_drive_t *tdrive;
+	unsigned long flags, timeout;
+	int i;
+	DEFINE_WAIT(wait);
+
+	spin_lock_irqsave(&hwif->lock, flags);
+
+	/* We must not reset with running handlers */
+	BUG_ON(hwif->handler != NULL);
+
+	/* For an ATAPI device, first try an ATAPI SRST. */
+	if (drive->media != ide_disk && !do_not_try_atapi) {
+		pre_reset(drive);
+		SELECT_DRIVE(drive);
+		udelay(20);
+		tp_ops->exec_command(hwif, ATA_CMD_DEV_RESET);
+		ndelay(400);
+		hwif->poll_timeout = jiffies + WAIT_WORSTCASE;
+		hwif->polling = 1;
+		__ide_set_handler(drive, &atapi_reset_pollfunc, HZ/20, NULL);
+		spin_unlock_irqrestore(&hwif->lock, flags);
+		return ide_started;
+	}
+
+	/* We must not disturb devices in the IDE_DFLAG_PARKED state. */
+	do {
+		unsigned long now;
+
+		prepare_to_wait(&ide_park_wq, &wait, TASK_UNINTERRUPTIBLE);
+		timeout = jiffies;
+		ide_port_for_each_present_dev(i, tdrive, hwif) {
+			if ((tdrive->dev_flags & IDE_DFLAG_PARKED) &&
+			    time_after(tdrive->sleep, timeout))
+				timeout = tdrive->sleep;
+		}
+
+		now = jiffies;
+		if (time_before_eq(timeout, now))
+			break;
+
+		spin_unlock_irqrestore(&hwif->lock, flags);
+		timeout = schedule_timeout_uninterruptible(timeout - now);
+		spin_lock_irqsave(&hwif->lock, flags);
+	} while (timeout);
+	finish_wait(&ide_park_wq, &wait);
+
+	/*
+	 * First, reset any device state data we were maintaining
+	 * for any of the drives on this interface.
+	 */
+	ide_port_for_each_dev(i, tdrive, hwif)
+		pre_reset(tdrive);
+
+	if (io_ports->ctl_addr == 0) {
+		spin_unlock_irqrestore(&hwif->lock, flags);
+		ide_complete_drive_reset(drive, -ENXIO);
+		return ide_stopped;
+	}
+
+	/*
+	 * Note that we also set nIEN while resetting the device,
+	 * to mask unwanted interrupts from the interface during the reset.
+	 * However, due to the design of PC hardware, this will cause an
+	 * immediate interrupt due to the edge transition it produces.
+	 * This single interrupt gives us a "fast poll" for drives that
+	 * recover from reset very quickly, saving us the first 50ms wait time.
+	 *
+	 * TODO: add ->softreset method and stop abusing ->set_irq
+	 */
+	/* set SRST and nIEN */
+	tp_ops->set_irq(hwif, 4);
+	/* more than enough time */
+	udelay(10);
+	/* clear SRST, leave nIEN (unless device is on the quirk list) */
+	tp_ops->set_irq(hwif, drive->quirk_list == 2);
+	/* more than enough time */
+	udelay(10);
+	hwif->poll_timeout = jiffies + WAIT_WORSTCASE;
+	hwif->polling = 1;
+	__ide_set_handler(drive, &reset_pollfunc, HZ/20, NULL);
+
+	/*
+	 * Some weird controller like resetting themselves to a strange
+	 * state when the disks are reset this way. At least, the Winbond
+	 * 553 documentation says that
+	 */
+	port_ops = hwif->port_ops;
+	if (port_ops && port_ops->resetproc)
+		port_ops->resetproc(drive);
+
+	spin_unlock_irqrestore(&hwif->lock, flags);
+	return ide_started;
+}
+
+/*
+ * ide_do_reset() is the entry point to the drive/interface reset code.
+ */
+
+ide_startstop_t ide_do_reset(ide_drive_t *drive)
+{
+	return do_reset1(drive, 0);
+}
+EXPORT_SYMBOL(ide_do_reset);