C++ HWGROUP函数代码示例

ide_startstop_t redwood_ide_intr (ide_drive_t *drive)
{
	int i;
	byte dma_stat;
	unsigned int nsect;
	ide_hwgroup_t *hwgroup = HWGROUP(drive);
	struct request *rq = hwgroup->rq;
	unsigned long block,b1,b2,b3,b4;

	nsect = rq->current_nr_sectors;

	dma_stat = HWIF(drive)->dmaproc(ide_dma_end, drive);

	rq->sector += nsect;
	rq->buffer += nsect<<9;
	rq->errors = 0;
	i = (rq->nr_sectors -= nsect);
	ide_end_request(1, HWGROUP(drive));
	if (i > 0) {
		b1 = IN_BYTE(IDE_SECTOR_REG);
		b2 = IN_BYTE(IDE_LCYL_REG);
		b3 = IN_BYTE(IDE_HCYL_REG);
		b4 = IN_BYTE(IDE_SELECT_REG);
		block = ((b4 & 0x0f) << 24) + (b3 << 16) + (b2 << 8) + (b1);
		block++;
		if (drive->select.b.lba) {
			OUT_BYTE(block,IDE_SECTOR_REG);
			OUT_BYTE(block>>=8,IDE_LCYL_REG);
			OUT_BYTE(block>>=8,IDE_HCYL_REG);
			OUT_BYTE(((block>>8)&0x0f)|drive->select.all,IDE_SELECT_REG);
		} else {

/*
 * 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_hwgroup_t *hwgroup	= HWGROUP(drive);
	ide_hwif_t *hwif	= HWIF(drive);
	u8 stat;

	SELECT_DRIVE(drive);
	udelay (10);

	if (OK_STAT(stat = hwif->INB(IDE_STATUS_REG), 0, BUSY_STAT)) {
		printk("%s: ATAPI reset complete\n", drive->name);
	} else {
		if (time_before(jiffies, hwgroup->poll_timeout)) {
			if (HWGROUP(drive)->handler != NULL)
				BUG();
			ide_set_handler(drive, &atapi_reset_pollfunc, HZ/20, NULL);
			/* continue polling */
			return ide_started;
		}
		/* end of polling */
		hwgroup->poll_timeout = 0;
		printk("%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 */
	hwgroup->poll_timeout = 0;
	return ide_stopped;
}

static void idepmac_wake_device(ide_drive_t *drive, int used_dma)
 {
	/* We force the IDE subdriver to check for a media change
	 * This must be done first or we may lost the condition
	 *
	 * Problem: This can schedule. I moved the block device
	 * wakeup almost late by priority because of that.
	 */
	if (DRIVER(drive) && DRIVER(drive)->media_change)
		DRIVER(drive)->media_change(drive);

	/* We kick the VFS too (see fix in ide.c revalidate) */
	check_disk_change(MKDEV(HWIF(drive)->major, (drive->select.b.unit) << PARTN_BITS));
	
#ifdef CONFIG_BLK_DEV_IDEDMA_PMAC
	/* We re-enable DMA on the drive if it was active. */
	/* This doesn't work with the CD-ROM in the media-bay, probably
	 * because of a pending unit attention. The problem if that if I
	 * clear the error, the filesystem dies.
	 */
	if (used_dma && !ide_spin_wait_hwgroup(drive)) {
		/* Lock HW group */
		HWGROUP(drive)->busy = 1;
		pmac_ide_check_dma(drive);
		HWGROUP(drive)->busy = 0;
		spin_unlock_irq(&io_request_lock);
	}
#endif /* CONFIG_BLK_DEV_IDEDMA_PMAC */
}

int ide_end_request (ide_drive_t *drive, int uptodate)
{
	struct request *rq;
	unsigned long flags;
	int ret = 1;

	spin_lock_irqsave(&io_request_lock, flags);
	rq = HWGROUP(drive)->rq;

	/*
	 * decide whether to reenable DMA -- 3 is a random magic for now,
	 * if we DMA timeout more than 3 times, just stay in PIO
	 */
	if (drive->state == DMA_PIO_RETRY && drive->retry_pio <= 3) {
		drive->state = 0;
		HWGROUP(drive)->hwif->ide_dma_on(drive);
	}

	if (!end_that_request_first(rq, uptodate, drive->name)) {
		add_blkdev_randomness(MAJOR(rq->rq_dev));
		blkdev_dequeue_request(rq);
		HWGROUP(drive)->rq = NULL;
		end_that_request_last(rq);
		ret = 0;
	}

	spin_unlock_irqrestore(&io_request_lock, flags);
	return ret;
}

/*
 * 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_hwgroup_t *hwgroup	= HWGROUP(drive);
	ide_hwif_t *hwif	= HWIF(drive);
	u8 tmp;

	if (hwif->reset_poll != NULL) {
		if (hwif->reset_poll(drive)) {
			printk(KERN_ERR "%s: host reset_poll failure for %s.\n",
				hwif->name, drive->name);
			return ide_stopped;
		}
	}

	if (!OK_STAT(tmp = hwif->INB(IDE_STATUS_REG), 0, BUSY_STAT)) {
		if (time_before(jiffies, hwgroup->poll_timeout)) {
			if (HWGROUP(drive)->handler != NULL)
				BUG();
			ide_set_handler(drive, &reset_pollfunc, HZ/20, NULL);
			/* continue polling */
			return ide_started;
		}
		printk("%s: reset timed-out, status=0x%02x\n", hwif->name, tmp);
		drive->failures++;
	} else  {
		printk("%s: reset: ", hwif->name);
		if ((tmp = hwif->INB(IDE_ERROR_REG)) == 1) {
			printk("success\n");
			drive->failures = 0;
		} else {
			drive->failures++;
#if FANCY_STATUS_DUMPS
			printk("master: ");
			switch (tmp & 0x7f) {
				case 1: printk("passed");
					break;
				case 2: printk("formatter device error");
					break;
				case 3: printk("sector buffer error");
					break;
				case 4: printk("ECC circuitry error");
					break;
				case 5: printk("controlling MPU error");
					break;
				default:printk("error (0x%02x?)", tmp);
			}
			if (tmp & 0x80)
				printk("; slave: failed");
			printk("\n");
#else
			printk("failed\n");
#endif /* FANCY_STATUS_DUMPS */
		}
	}
	hwgroup->poll_timeout = 0;	/* done polling */
	return ide_stopped;
}

/*
 * promise_read_intr() is the handler for disk read/multread interrupts
 */
static ide_startstop_t promise_read_intr (ide_drive_t *drive)
{
	byte stat;
	int i;
	unsigned int sectors_left, sectors_avail, nsect;
	struct request *rq;

	if (!OK_STAT(stat=GET_STAT(),DATA_READY,BAD_R_STAT)) {
		return ide_error(drive, "promise_read_intr", stat);
	}

read_again:
	do {
	    sectors_left = IN_BYTE(IDE_NSECTOR_REG);
	    IN_BYTE(IDE_SECTOR_REG);
	} while (IN_BYTE(IDE_NSECTOR_REG) != sectors_left);
	rq = HWGROUP(drive)->rq;
	sectors_avail = rq->nr_sectors - sectors_left;

read_next:
	rq = HWGROUP(drive)->rq;
	if ((nsect = rq->current_nr_sectors) > sectors_avail)
		nsect = sectors_avail;
	sectors_avail -= nsect;
	ide_input_data(drive, rq->buffer, nsect * SECTOR_WORDS);
#ifdef DEBUG
	printk("%s:  promise_read: sectors(%ld-%ld), buffer=0x%08lx, "
	       "remaining=%ld\n", drive->name, rq->sector, rq->sector+nsect-1, 
	       (unsigned long) rq->buffer+(nsect<<9), rq->nr_sectors-nsect);
#endif
	rq->sector += nsect;
	rq->buffer += nsect<<9;
	rq->errors = 0;
	i = (rq->nr_sectors -= nsect);
	if ((rq->current_nr_sectors -= nsect) <= 0)
		ide_end_request(1, HWGROUP(drive));
	if (i > 0) {
		if (sectors_avail)
		    goto read_next;
		stat = GET_STAT();
		if(stat & DRQ_STAT)
		    goto read_again;
		if(stat & BUSY_STAT) {
		    ide_set_handler (drive, &promise_read_intr, WAIT_CMD, NULL);
		    return ide_started;
		}
		printk("Ah! promise read intr: sectors left !DRQ !BUSY\n");
		return ide_error(drive, "promise read intr", stat);
	}
	return ide_stopped;
}

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);

	if ((rq = HWGROUP(drive)->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;
	}

	if (rq->rq_disk) {
		ide_driver_t *drv;

		drv = *(ide_driver_t **)rq->rq_disk->private_data;
		return drv->error(drive, rq, stat, err);
	} else
		return __ide_error(drive, rq, stat, err);
}

int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors)
{
	unsigned int nr_bytes = nr_sectors << 9;
	struct request *rq = HWGROUP(drive)->rq;
	int rc, error = 0;

	if (!nr_bytes) {
		if (blk_pc_request(rq))
			nr_bytes = rq->data_len;
		else
			nr_bytes = rq->hard_cur_sectors << 9;
	}

	/*
	 * if failfast is set on a request, override number of sectors
	 * and complete the whole request right now
	 */
	if (blk_noretry_request(rq) && uptodate <= 0)
		nr_bytes = rq->hard_nr_sectors << 9;

	if (blk_fs_request(rq) == 0 && uptodate <= 0 && rq->errors == 0)
		rq->errors = -EIO;

	if (uptodate <= 0)
		error = uptodate ? uptodate : -EIO;

	rc = ide_end_rq(drive, rq, error, nr_bytes);
	if (rc == 0)
		drive->hwif->hwgroup->rq = NULL;

	return rc;
}

static int idescsi_end_request (ide_drive_t *drive, int uptodate, int nrsecs)
{
	idescsi_scsi_t *scsi = drive_to_idescsi(drive);
	struct request *rq = HWGROUP(drive)->rq;
	struct ide_atapi_pc *pc = (struct ide_atapi_pc *) rq->special;
	int log = test_bit(IDESCSI_LOG_CMD, &scsi->log);
	struct Scsi_Host *host;
	int errors = rq->errors;
	unsigned long flags;

	if (!blk_special_request(rq) && !blk_sense_request(rq)) {
		ide_end_request(drive, uptodate, nrsecs);
		return 0;
	}
	ide_end_drive_cmd (drive, 0, 0);
	if (blk_sense_request(rq)) {
		struct ide_atapi_pc *opc = (struct ide_atapi_pc *) rq->buffer;
		if (log) {
			printk ("ide-scsi: %s: wrap up check %lu, rst = ", drive->name, opc->scsi_cmd->serial_number);
			ide_scsi_hex_dump(pc->buf, 16);
		}
		memcpy((void *) opc->scsi_cmd->sense_buffer, pc->buf,
			SCSI_SENSE_BUFFERSIZE);
		kfree(pc->buf);
		kfree(pc);
		blk_put_request(rq);
		pc = opc;
		rq = pc->rq;
		pc->scsi_cmd->result = (CHECK_CONDITION << 1) |
				(((pc->flags & PC_FLAG_TIMEDOUT) ?
				  DID_TIME_OUT :
				  DID_OK) << 16);
	} else if (pc->flags & PC_FLAG_TIMEDOUT) {
		if (log)
			printk (KERN_WARNING "ide-scsi: %s: timed out for %lu\n",
					drive->name, pc->scsi_cmd->serial_number);
		pc->scsi_cmd->result = DID_TIME_OUT << 16;
	} else if (errors >= ERROR_MAX) {
		pc->scsi_cmd->result = DID_ERROR << 16;
		if (log)
			printk ("ide-scsi: %s: I/O error for %lu\n", drive->name, pc->scsi_cmd->serial_number);
	} else if (errors) {
		if (log)
			printk ("ide-scsi: %s: check condition for %lu\n", drive->name, pc->scsi_cmd->serial_number);
		if (!idescsi_check_condition(drive, rq))
			/* we started a request sense, so we'll be back, exit for now */
			return 0;
		pc->scsi_cmd->result = (CHECK_CONDITION << 1) | (DID_OK << 16);
	} else {
		pc->scsi_cmd->result = DID_OK << 16;
	}
	host = pc->scsi_cmd->device->host;
	spin_lock_irqsave(host->host_lock, flags);
	pc->done(pc->scsi_cmd);
	spin_unlock_irqrestore(host->host_lock, flags);
	kfree(pc);
	blk_put_request(rq);
	scsi->pc = NULL;
	return 0;
}

static int sgiioc4_ide_dma_setup(ide_drive_t *drive)
{
	struct request *rq = HWGROUP(drive)->rq;
	unsigned int count = 0;
	int ddir;

	if (rq_data_dir(rq))
		ddir = PCI_DMA_TODEVICE;
	else
		ddir = PCI_DMA_FROMDEVICE;

	if (!(count = sgiioc4_build_dma_table(drive, rq, ddir))) {
		/* try PIO instead of DMA */
		ide_map_sg(drive, rq);
		return 1;
	}

	if (rq_data_dir(rq))
		/* Writes TO the IOC4 FROM Main Memory */
		ddir = IOC4_DMA_READ;
	else
		/* Writes FROM the IOC4 TO Main Memory */
		ddir = IOC4_DMA_WRITE;

	sgiioc4_configure_for_dma(ddir, drive);

	return 0;
}

static int scc_dma_setup(ide_drive_t *drive)
{
	ide_hwif_t *hwif = drive->hwif;
	struct request *rq = HWGROUP(drive)->rq;
	unsigned int reading;
	u8 dma_stat;

	if (rq_data_dir(rq))
		reading = 0;
	else
		reading = 1 << 3;

	/* fall back to pio! */
	if (!ide_build_dmatable(drive, rq)) {
		ide_map_sg(drive, rq);
		return 1;
	}

	/* PRD table */
	out_be32((void __iomem *)(hwif->dma_base + 8), hwif->dmatable_dma);

	/* specify r/w */
	out_be32((void __iomem *)hwif->dma_base, reading);

	/* read DMA status for INTR & ERROR flags */
	dma_stat = in_be32((void __iomem *)(hwif->dma_base + 4));

	/* clear INTR & ERROR flags */
	out_be32((void __iomem *)(hwif->dma_base + 4), dma_stat | 6);
	drive->waiting_for_dma = 1;
	return 0;
}

void ide_execute_command(ide_drive_t *drive, task_ioreg_t cmd, ide_handler_t *handler, unsigned timeout, ide_expiry_t *expiry)
{
	unsigned long flags;
	ide_hwgroup_t *hwgroup = HWGROUP(drive);
	ide_hwif_t *hwif = HWIF(drive);
	
	spin_lock_irqsave(&io_request_lock, flags);
	
	if(hwgroup->handler)
		BUG();
	hwgroup->handler	= handler;
	hwgroup->expiry		= expiry;
	hwgroup->timer.expires	= jiffies + timeout;
	add_timer(&hwgroup->timer);
	hwif->OUTBSYNC(drive, cmd, IDE_COMMAND_REG);
	/* Drive takes 400nS to respond, we must avoid the IRQ being
	   serviced before that. 
	   
	   FIXME: we could skip this delay with care on non shared
	   devices 
	   
	   For DMA transfers highpoint have a neat trick we could
	   use. When they take an IRQ they check STS but also that
	   the DMA count is not zero (see hpt's own driver)
	*/
	ndelay(400);
	spin_unlock_irqrestore(&io_request_lock, flags);
}

int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors)
{
	unsigned int nr_bytes = nr_sectors << 9;
	struct request *rq;
	unsigned long flags;
	int ret = 1;

	/*
	 * room for locking improvements here, the calls below don't
	 * need the queue lock held at all
	 */
	spin_lock_irqsave(&ide_lock, flags);
	rq = HWGROUP(drive)->rq;

	if (!nr_bytes) {
		if (blk_pc_request(rq))
			nr_bytes = rq->data_len;
		else
			nr_bytes = rq->hard_cur_sectors << 9;
	}

	ret = __ide_end_request(drive, rq, uptodate, nr_bytes, 1);

	spin_unlock_irqrestore(&ide_lock, flags);
	return ret;
}

/*
 * Handler for command with PIO data-in phase (Read/Read Multiple).
 */
static ide_startstop_t task_in_intr(ide_drive_t *drive)
{
	ide_hwif_t *hwif = drive->hwif;
	struct request *rq = HWGROUP(drive)->rq;
	u8 stat = ide_read_status(drive);

	/* Error? */
	if (stat & ERR_STAT)
		return task_error(drive, rq, __func__, stat);

	/* Didn't want any data? Odd. */
	if (!(stat & DRQ_STAT))
		return task_in_unexpected(drive, rq, stat);

	ide_pio_datablock(drive, rq, 0);

	/* Are we done? Check status and finish transfer. */
	if (!hwif->nleft) {
		stat = wait_drive_not_busy(drive);
		if (!OK_STAT(stat, 0, BAD_STAT))
			return task_error(drive, rq, __func__, stat);
		task_end_request(drive, rq, stat);
		return ide_stopped;
	}

	/* Still data left to transfer. */
	ide_set_handler(drive, &task_in_intr, WAIT_WORSTCASE, NULL);

	return ide_started;
}

/*
 * build_dmatable() prepares a dma request.
 * Returns 0 if all went okay, returns 1 otherwise.
 */
static int build_dmatable (ide_drive_t *drive)
{
	struct request *rq = HWGROUP(drive)->rq;
	struct buffer_head *bh = rq->bh;
	unsigned long size, addr, *table = HWIF(drive)->dmatable;
	unsigned int count = 0;

	do {
		/*
		 * Determine addr and size of next buffer area.  We assume that
		 * individual virtual buffers are always composed linearly in
		 * physical memory.  For example, we assume that any 8kB buffer
		 * is always composed of two adjacent physical 4kB pages rather
		 * than two possibly non-adjacent physical 4kB pages.
		 */
		if (bh == NULL) {  /* paging and tape requests have (rq->bh == NULL) */
			addr = virt_to_bus (rq->buffer);
#ifdef CONFIG_BLK_DEV_IDETAPE
			if (drive->media == ide_tape)
				size = drive->tape.pc->request_transfer;
			else
#endif /* CONFIG_BLK_DEV_IDETAPE */	
			size = rq->nr_sectors << 9;
		} else {
			/* group sequential buffers into one large buffer */
			addr = virt_to_bus (bh->b_data);
			size = bh->b_size;
			while ((bh = bh->b_reqnext) != NULL) {
				if ((addr + size) != virt_to_bus (bh->b_data))
					break;
				size += bh->b_size;
			}
		}

		/*
		 * Fill in the dma table, without crossing any 64kB boundaries.
		 * We assume 16-bit alignment of all blocks.
		 */
		while (size) {
			if (++count >= PRD_ENTRIES) {
				printk("%s: DMA table too small\n", drive->name);
				return 1; /* revert to PIO for this request */
			} else {
				unsigned long bcount = 0x10000 - (addr & 0xffff);
				if (bcount > size)
					bcount = size;
				*table++ = addr;
				*table++ = bcount;
				addr += bcount;
				size -= bcount;
			}
		}
	} while (bh != NULL);
	if (count) {
		*--table |= 0x80000000;	/* set End-Of-Table (EOT) bit */
		return 0;
	}
	printk("%s: empty DMA table?\n", drive->name);
	return 1;	/* let the PIO routines handle this weirdness */
}