drivers/ide/pci/sgiioc4.c - kernel/msm-4.19 - Gitiles

 /*
  * Copyright (c) 2003-2006 Silicon Graphics, Inc.  All Rights Reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of version 2 of the GNU General Public License
  * as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it would be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  *
  * You should have received a copy of the GNU General Public
  * License along with this program; if not, write the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  *
  * For further information regarding this notice, see:
  *
  * http://oss.sgi.com/projects/GenInfo/NoticeExplan
  */

 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/pci.h>
 #include <linux/delay.h>
 #include <linux/hdreg.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/timer.h>
 #include <linux/mm.h>
 #include <linux/ioport.h>
 #include <linux/blkdev.h>
 #include <linux/ioc4.h>
 #include <asm/io.h>

 #include <linux/ide.h>

 /* IOC4 Specific Definitions */
 #define IOC4_CMD_OFFSET		0x100
 #define IOC4_CTRL_OFFSET	0x120
 #define IOC4_DMA_OFFSET		0x140
 #define IOC4_INTR_OFFSET	0x0

 #define IOC4_TIMING		0x00
 #define IOC4_DMA_PTR_L		0x01
 #define IOC4_DMA_PTR_H		0x02
 #define IOC4_DMA_ADDR_L		0x03
 #define IOC4_DMA_ADDR_H		0x04
 #define IOC4_BC_DEV		0x05
 #define IOC4_BC_MEM		0x06
 #define	IOC4_DMA_CTRL		0x07
 #define	IOC4_DMA_END_ADDR	0x08

 /* Bits in the IOC4 Control/Status Register */
 #define	IOC4_S_DMA_START	0x01
 #define	IOC4_S_DMA_STOP		0x02
 #define	IOC4_S_DMA_DIR		0x04
 #define	IOC4_S_DMA_ACTIVE	0x08
 #define	IOC4_S_DMA_ERROR	0x10
 #define	IOC4_ATA_MEMERR		0x02

 /* Read/Write Directions */
 #define	IOC4_DMA_WRITE		0x04
 #define	IOC4_DMA_READ		0x00

 /* Interrupt Register Offsets */
 #define IOC4_INTR_REG		0x03
 #define	IOC4_INTR_SET		0x05
 #define	IOC4_INTR_CLEAR		0x07

 #define IOC4_IDE_CACHELINE_SIZE	128
 #define IOC4_CMD_CTL_BLK_SIZE	0x20
 #define IOC4_SUPPORTED_FIRMWARE_REV 46

 typedef struct {
 	u32 timing_reg0;
 	u32 timing_reg1;
 	u32 low_mem_ptr;
 	u32 high_mem_ptr;
 	u32 low_mem_addr;
 	u32 high_mem_addr;
 	u32 dev_byte_count;
 	u32 mem_byte_count;
 	u32 status;
 } ioc4_dma_regs_t;

 /* Each Physical Region Descriptor Entry size is 16 bytes (2 * 64 bits) */
 /* IOC4 has only 1 IDE channel */
 #define IOC4_PRD_BYTES       16
 #define IOC4_PRD_ENTRIES     (PAGE_SIZE /(4*IOC4_PRD_BYTES))


 static void
 sgiioc4_init_hwif_ports(hw_regs_t * hw, unsigned long data_port,
 			unsigned long ctrl_port, unsigned long irq_port)
 {
 	unsigned long reg = data_port;
 	int i;

 	/* Registers are word (32 bit) aligned */
 	for (i = IDE_DATA_OFFSET; i <= IDE_STATUS_OFFSET; i++)
 		hw->io_ports[i] = reg + i * 4;

 	if (ctrl_port)
 		hw->io_ports[IDE_CONTROL_OFFSET] = ctrl_port;

 	if (irq_port)
 		hw->io_ports[IDE_IRQ_OFFSET] = irq_port;
 }

 static void
 sgiioc4_maskproc(ide_drive_t * drive, int mask)
 {
 	ide_hwif_t *hwif = HWIF(drive);
 	hwif->OUTB(mask ? (drive->ctl | 2) : (drive->ctl & ~2),
 		   IDE_CONTROL_REG);
 }


 static int
 sgiioc4_checkirq(ide_hwif_t * hwif)
 {
 	u8 intr_reg =
 	    hwif->INL(hwif->io_ports[IDE_IRQ_OFFSET] + IOC4_INTR_REG * 4);

 	if (intr_reg & 0x03)
 		return 1;

 	return 0;
 }


 static int
 sgiioc4_clearirq(ide_drive_t * drive)
 {
 	u32 intr_reg;
 	ide_hwif_t *hwif = HWIF(drive);
 	unsigned long other_ir =
 	    hwif->io_ports[IDE_IRQ_OFFSET] + (IOC4_INTR_REG << 2);

 	/* Code to check for PCI error conditions */
 	intr_reg = hwif->INL(other_ir);
 	if (intr_reg & 0x03) { /* Valid IOC4-IDE interrupt */
 		/*
 		 * Using hwif->INB to read the IDE_STATUS_REG has a side effect
 		 * of clearing the interrupt.  The first read should clear it
 		 * if it is set.  The second read should return a "clear" status
 		 * if it got cleared.  If not, then spin for a bit trying to
 		 * clear it.
 		 */
 		u8 stat = hwif->INB(IDE_STATUS_REG);
 		int count = 0;
 		stat = hwif->INB(IDE_STATUS_REG);
 		while ((stat & 0x80) && (count++ < 100)) {
 			udelay(1);
 			stat = hwif->INB(IDE_STATUS_REG);
 		}

 		if (intr_reg & 0x02) {
 			/* Error when transferring DMA data on PCI bus */
 			u32 pci_err_addr_low, pci_err_addr_high,
 			    pci_stat_cmd_reg;

 			pci_err_addr_low =
 				hwif->INL(hwif->io_ports[IDE_IRQ_OFFSET]);
 			pci_err_addr_high =
 				hwif->INL(hwif->io_ports[IDE_IRQ_OFFSET] + 4);
 			pci_read_config_dword(hwif->pci_dev, PCI_COMMAND,
 					      &pci_stat_cmd_reg);
 			printk(KERN_ERR
 			       "%s(%s) : PCI Bus Error when doing DMA:"
 				   " status-cmd reg is 0x%x\n",
 			       __FUNCTION__, drive->name, pci_stat_cmd_reg);
 			printk(KERN_ERR
 			       "%s(%s) : PCI Error Address is 0x%x%x\n",
 			       __FUNCTION__, drive->name,
 			       pci_err_addr_high, pci_err_addr_low);
 			/* Clear the PCI Error indicator */
 			pci_write_config_dword(hwif->pci_dev, PCI_COMMAND,
 					       0x00000146);
 		}

 		/* Clear the Interrupt, Error bits on the IOC4 */
 		hwif->OUTL(0x03, other_ir);

 		intr_reg = hwif->INL(other_ir);
 	}

 	return intr_reg & 3;
 }

 static void sgiioc4_ide_dma_start(ide_drive_t * drive)
 {
 	ide_hwif_t *hwif = HWIF(drive);
 	unsigned int reg = hwif->INL(hwif->dma_base + IOC4_DMA_CTRL * 4);
 	unsigned int temp_reg = reg | IOC4_S_DMA_START;

 	hwif->OUTL(temp_reg, hwif->dma_base + IOC4_DMA_CTRL * 4);
 }

 static u32
 sgiioc4_ide_dma_stop(ide_hwif_t *hwif, u64 dma_base)
 {
 	u32	ioc4_dma;
 	int	count;

 	count = 0;
 	ioc4_dma = hwif->INL(dma_base + IOC4_DMA_CTRL * 4);
 	while ((ioc4_dma & IOC4_S_DMA_STOP) && (count++ < 200)) {
 		udelay(1);
 		ioc4_dma = hwif->INL(dma_base + IOC4_DMA_CTRL * 4);
 	}
 	return ioc4_dma;
 }

 /* Stops the IOC4 DMA Engine */
 static int
 sgiioc4_ide_dma_end(ide_drive_t * drive)
 {
 	u32 ioc4_dma, bc_dev, bc_mem, num, valid = 0, cnt = 0;
 	ide_hwif_t *hwif = HWIF(drive);
 	u64 dma_base = hwif->dma_base;
 	int dma_stat = 0;
 	unsigned long *ending_dma = ide_get_hwifdata(hwif);

 	hwif->OUTL(IOC4_S_DMA_STOP, dma_base + IOC4_DMA_CTRL * 4);

 	ioc4_dma = sgiioc4_ide_dma_stop(hwif, dma_base);

 	if (ioc4_dma & IOC4_S_DMA_STOP) {
 		printk(KERN_ERR
 		       "%s(%s): IOC4 DMA STOP bit is still 1 :"
 		       "ioc4_dma_reg 0x%x\n",
 		       __FUNCTION__, drive->name, ioc4_dma);
 		dma_stat = 1;
 	}

 	/*
 	 * The IOC4 will DMA 1's to the ending dma area to indicate that
 	 * previous data DMA is complete.  This is necessary because of relaxed
 	 * ordering between register reads and DMA writes on the Altix.
 	 */
 	while ((cnt++ < 200) && (!valid)) {
 		for (num = 0; num < 16; num++) {
 			if (ending_dma[num]) {
 				valid = 1;
 				break;
 			}
 		}
 		udelay(1);
 	}
 	if (!valid) {
 		printk(KERN_ERR "%s(%s) : DMA incomplete\n", __FUNCTION__,
 		       drive->name);
 		dma_stat = 1;
 	}

 	bc_dev = hwif->INL(dma_base + IOC4_BC_DEV * 4);
 	bc_mem = hwif->INL(dma_base + IOC4_BC_MEM * 4);

 	if ((bc_dev & 0x01FF) || (bc_mem & 0x1FF)) {
 		if (bc_dev > bc_mem + 8) {
 			printk(KERN_ERR
 			       "%s(%s): WARNING!! byte_count_dev %d "
 			       "!= byte_count_mem %d\n",
 			       __FUNCTION__, drive->name, bc_dev, bc_mem);
 		}
 	}

 	drive->waiting_for_dma = 0;
 	ide_destroy_dmatable(drive);

 	return dma_stat;
 }

 static int
 sgiioc4_ide_dma_check(ide_drive_t * drive)
 {
 	if (ide_config_drive_speed(drive, XFER_MW_DMA_2) != 0) {
 		printk(KERN_INFO
 		       "Couldnot set %s in Multimode-2 DMA mode | "
 			   "Drive %s using PIO instead\n",
 		       drive->name, drive->name);
 		drive->using_dma = 0;
 	} else
 		drive->using_dma = 1;

 	return 0;
 }

 static int
 sgiioc4_ide_dma_on(ide_drive_t * drive)
 {
 	drive->using_dma = 1;

 	return HWIF(drive)->ide_dma_host_on(drive);
 }

 static int
 sgiioc4_ide_dma_off_quietly(ide_drive_t * drive)
 {
 	drive->using_dma = 0;

 	return HWIF(drive)->ide_dma_host_off(drive);
 }

 /* returns 1 if dma irq issued, 0 otherwise */
 static int
 sgiioc4_ide_dma_test_irq(ide_drive_t * drive)
 {
 	return sgiioc4_checkirq(HWIF(drive));
 }

 static int
 sgiioc4_ide_dma_host_on(ide_drive_t * drive)
 {
 	if (drive->using_dma)
 		return 0;

 	return 1;
 }

 static int
 sgiioc4_ide_dma_host_off(ide_drive_t * drive)
 {
 	sgiioc4_clearirq(drive);

 	return 0;
 }

 static int
 sgiioc4_ide_dma_lostirq(ide_drive_t * drive)
 {
 	HWIF(drive)->resetproc(drive);

 	return __ide_dma_lostirq(drive);
 }

 static void
 sgiioc4_resetproc(ide_drive_t * drive)
 {
 	sgiioc4_ide_dma_end(drive);
 	sgiioc4_clearirq(drive);
 }

 static u8
 sgiioc4_INB(unsigned long port)
 {
 	u8 reg = (u8) readb((void __iomem *) port);

 	if ((port & 0xFFF) == 0x11C) {	/* Status register of IOC4 */
 		if (reg & 0x51) {	/* Not busy...check for interrupt */
 			unsigned long other_ir = port - 0x110;
 			unsigned int intr_reg = (u32) readl((void __iomem *) other_ir);

 			/* Clear the Interrupt, Error bits on the IOC4 */
 			if (intr_reg & 0x03) {
 				writel(0x03, (void __iomem *) other_ir);
 				intr_reg = (u32) readl((void __iomem *) other_ir);
 			}
 		}
 	}

 	return reg;
 }

 /* Creates a dma map for the scatter-gather list entries */
 static void __devinit
 ide_dma_sgiioc4(ide_hwif_t * hwif, unsigned long dma_base)
 {
 	void __iomem *virt_dma_base;
 	int num_ports = sizeof (ioc4_dma_regs_t);
 	void *pad;

 	printk(KERN_INFO "%s: BM-DMA at 0x%04lx-0x%04lx\n", hwif->name,
 	       dma_base, dma_base + num_ports - 1);

 	if (!request_mem_region(dma_base, num_ports, hwif->name)) {
 		printk(KERN_ERR
 		       "%s(%s) -- ERROR, Addresses 0x%p to 0x%p "
 		       "ALREADY in use\n",
 		       __FUNCTION__, hwif->name, (void *) dma_base,
 		       (void *) dma_base + num_ports - 1);
 		goto dma_alloc_failure;
 	}

 	virt_dma_base = ioremap(dma_base, num_ports);
 	if (virt_dma_base == NULL) {
 		printk(KERN_ERR
 		       "%s(%s) -- ERROR, Unable to map addresses 0x%lx to 0x%lx\n",
 		       __FUNCTION__, hwif->name, dma_base, dma_base + num_ports - 1);
 		goto dma_remap_failure;
 	}
 	hwif->dma_base = (unsigned long) virt_dma_base;

 	hwif->dmatable_cpu = pci_alloc_consistent(hwif->pci_dev,
 					  IOC4_PRD_ENTRIES * IOC4_PRD_BYTES,
 					  &hwif->dmatable_dma);

 	if (!hwif->dmatable_cpu)
 		goto dma_pci_alloc_failure;

 	hwif->sg_max_nents = IOC4_PRD_ENTRIES;

 	pad = pci_alloc_consistent(hwif->pci_dev, IOC4_IDE_CACHELINE_SIZE,
 				   (dma_addr_t *) &(hwif->dma_status));

 	if (pad) {
 		ide_set_hwifdata(hwif, pad);
 		return;
 	}

 	pci_free_consistent(hwif->pci_dev,
 			    IOC4_PRD_ENTRIES * IOC4_PRD_BYTES,
 			    hwif->dmatable_cpu, hwif->dmatable_dma);
 	printk(KERN_INFO
 	       "%s() -- Error! Unable to allocate DMA Maps for drive %s\n",
 	       __FUNCTION__, hwif->name);
 	printk(KERN_INFO
 	       "Changing from DMA to PIO mode for Drive %s\n", hwif->name);

 dma_pci_alloc_failure:
 	iounmap(virt_dma_base);

 dma_remap_failure:
 	release_mem_region(dma_base, num_ports);

 dma_alloc_failure:
 	/* Disable DMA because we couldnot allocate any DMA maps */
 	hwif->autodma = 0;
 	hwif->atapi_dma = 0;
 }

 /* Initializes the IOC4 DMA Engine */
 static void
 sgiioc4_configure_for_dma(int dma_direction, ide_drive_t * drive)
 {
 	u32 ioc4_dma;
 	ide_hwif_t *hwif = HWIF(drive);
 	u64 dma_base = hwif->dma_base;
 	u32 dma_addr, ending_dma_addr;

 	ioc4_dma = hwif->INL(dma_base + IOC4_DMA_CTRL * 4);

 	if (ioc4_dma & IOC4_S_DMA_ACTIVE) {
 		printk(KERN_WARNING
 			"%s(%s):Warning!! DMA from previous transfer was still active\n",
 		       __FUNCTION__, drive->name);
 		hwif->OUTL(IOC4_S_DMA_STOP, dma_base + IOC4_DMA_CTRL * 4);
 		ioc4_dma = sgiioc4_ide_dma_stop(hwif, dma_base);

 		if (ioc4_dma & IOC4_S_DMA_STOP)
 			printk(KERN_ERR
 			       "%s(%s) : IOC4 Dma STOP bit is still 1\n",
 			       __FUNCTION__, drive->name);
 	}

 	ioc4_dma = hwif->INL(dma_base + IOC4_DMA_CTRL * 4);
 	if (ioc4_dma & IOC4_S_DMA_ERROR) {
 		printk(KERN_WARNING
 		       "%s(%s) : Warning!! - DMA Error during Previous"
 		       " transfer | status 0x%x\n",
 		       __FUNCTION__, drive->name, ioc4_dma);
 		hwif->OUTL(IOC4_S_DMA_STOP, dma_base + IOC4_DMA_CTRL * 4);
 		ioc4_dma = sgiioc4_ide_dma_stop(hwif, dma_base);

 		if (ioc4_dma & IOC4_S_DMA_STOP)
 			printk(KERN_ERR
 			       "%s(%s) : IOC4 DMA STOP bit is still 1\n",
 			       __FUNCTION__, drive->name);
 	}

 	/* Address of the Scatter Gather List */
 	dma_addr = cpu_to_le32(hwif->dmatable_dma);
 	hwif->OUTL(dma_addr, dma_base + IOC4_DMA_PTR_L * 4);

 	/* Address of the Ending DMA */
 	memset(ide_get_hwifdata(hwif), 0, IOC4_IDE_CACHELINE_SIZE);
 	ending_dma_addr = cpu_to_le32(hwif->dma_status);
 	hwif->OUTL(ending_dma_addr, dma_base + IOC4_DMA_END_ADDR * 4);

 	hwif->OUTL(dma_direction, dma_base + IOC4_DMA_CTRL * 4);
 	drive->waiting_for_dma = 1;
 }

 /* IOC4 Scatter Gather list Format 					 */
 /* 128 Bit entries to support 64 bit addresses in the future		 */
 /* The Scatter Gather list Entry should be in the BIG-ENDIAN Format	 */
 /* --------------------------------------------------------------------- */
 /* | Upper 32 bits - Zero           |	 	Lower 32 bits- address | */
 /* --------------------------------------------------------------------- */
 /* | Upper 32 bits - Zero	    |EOL| 15 unused     | 16 Bit Length| */
 /* --------------------------------------------------------------------- */
 /* Creates the scatter gather list, DMA Table */
 static unsigned int
 sgiioc4_build_dma_table(ide_drive_t * drive, struct request *rq, int ddir)
 {
 	ide_hwif_t *hwif = HWIF(drive);
 	unsigned int *table = hwif->dmatable_cpu;
 	unsigned int count = 0, i = 1;
 	struct scatterlist *sg;

 	hwif->sg_nents = i = ide_build_sglist(drive, rq);

 	if (!i)
 		return 0;	/* sglist of length Zero */

 	sg = hwif->sg_table;
 	while (i && sg_dma_len(sg)) {
 		dma_addr_t cur_addr;
 		int cur_len;
 		cur_addr = sg_dma_address(sg);
 		cur_len = sg_dma_len(sg);

 		while (cur_len) {
 			if (count++ >= IOC4_PRD_ENTRIES) {
 				printk(KERN_WARNING
 				       "%s: DMA table too small\n",
 				       drive->name);
 				goto use_pio_instead;
 			} else {
 				u32 bcount =
 				    0x10000 - (cur_addr & 0xffff);

 				if (bcount > cur_len)
 					bcount = cur_len;

 				/* put the addr, length in
 				 * the IOC4 dma-table format */
 				*table = 0x0;
 				table++;
 				*table = cpu_to_be32(cur_addr);
 				table++;
 				*table = 0x0;
 				table++;

 				*table = cpu_to_be32(bcount);
 				table++;

 				cur_addr += bcount;
 				cur_len -= bcount;
 			}
 		}

 		sg++;
 		i--;
 	}

 	if (count) {
 		table--;
 		*table |= cpu_to_be32(0x80000000);
 		return count;
 	}

 use_pio_instead:
 	pci_unmap_sg(hwif->pci_dev, hwif->sg_table, hwif->sg_nents,
 		     hwif->sg_dma_direction);

 	return 0;		/* revert to PIO for this request */
 }

 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 void __devinit
 ide_init_sgiioc4(ide_hwif_t * hwif)
 {
 	hwif->mmio = 2;
 	hwif->autodma = 1;
 	hwif->atapi_dma = 1;
 	hwif->ultra_mask = 0x0;	/* Disable Ultra DMA */
 	hwif->mwdma_mask = 0x2;	/* Multimode-2 DMA  */
 	hwif->swdma_mask = 0x2;
 	hwif->tuneproc = NULL;	/* Sets timing for PIO mode */
 	hwif->speedproc = NULL;	/* Sets timing for DMA &/or PIO modes */
 	hwif->selectproc = NULL;/* Use the default routine to select drive */
 	hwif->reset_poll = NULL;/* No HBA specific reset_poll needed */
 	hwif->pre_reset = NULL;	/* No HBA specific pre_set needed */
 	hwif->resetproc = &sgiioc4_resetproc;/* Reset DMA engine,
 						clear interrupts */
 	hwif->intrproc = NULL;	/* Enable or Disable interrupt from drive */
 	hwif->maskproc = &sgiioc4_maskproc;	/* Mask on/off NIEN register */
 	hwif->quirkproc = NULL;
 	hwif->busproc = NULL;

 	hwif->dma_setup = &sgiioc4_ide_dma_setup;
 	hwif->dma_start = &sgiioc4_ide_dma_start;
 	hwif->ide_dma_end = &sgiioc4_ide_dma_end;
 	hwif->ide_dma_check = &sgiioc4_ide_dma_check;
 	hwif->ide_dma_on = &sgiioc4_ide_dma_on;
 	hwif->ide_dma_off_quietly = &sgiioc4_ide_dma_off_quietly;
 	hwif->ide_dma_test_irq = &sgiioc4_ide_dma_test_irq;
 	hwif->ide_dma_host_on = &sgiioc4_ide_dma_host_on;
 	hwif->ide_dma_host_off = &sgiioc4_ide_dma_host_off;
 	hwif->ide_dma_lostirq = &sgiioc4_ide_dma_lostirq;
 	hwif->ide_dma_timeout = &__ide_dma_timeout;

 	hwif->INB = &sgiioc4_INB;
 }

 static int __devinit
 sgiioc4_ide_setup_pci_device(struct pci_dev *dev, ide_pci_device_t * d)
 {
 	unsigned long cmd_base, dma_base, irqport;
 	unsigned long bar0, cmd_phys_base, ctl;
 	void __iomem *virt_base;
 	ide_hwif_t *hwif;
 	int h;

 	/*
 	 * Find an empty HWIF; if none available, return -ENOMEM.
 	 */
 	for (h = 0; h < MAX_HWIFS; ++h) {
 		hwif = &ide_hwifs[h];
 		if (hwif->chipset == ide_unknown)
 			break;
 	}
 	if (h == MAX_HWIFS) {
 		printk(KERN_ERR "%s: too many IDE interfaces, no room in table\n", d->name);
 		return -ENOMEM;
 	}

 	/*  Get the CmdBlk and CtrlBlk Base Registers */
 	bar0 = pci_resource_start(dev, 0);
 	virt_base = ioremap(bar0, pci_resource_len(dev, 0));
 	if (virt_base == NULL) {
 		printk(KERN_ERR "%s: Unable to remap BAR 0 address: 0x%lx\n",
 			d->name, bar0);
 		return -ENOMEM;
 	}
 	cmd_base = (unsigned long) virt_base + IOC4_CMD_OFFSET;
 	ctl = (unsigned long) virt_base + IOC4_CTRL_OFFSET;
 	irqport = (unsigned long) virt_base + IOC4_INTR_OFFSET;
 	dma_base = pci_resource_start(dev, 0) + IOC4_DMA_OFFSET;

 	cmd_phys_base = bar0 + IOC4_CMD_OFFSET;
 	if (!request_mem_region(cmd_phys_base, IOC4_CMD_CTL_BLK_SIZE,
 	    hwif->name)) {
 		printk(KERN_ERR
 			"%s : %s -- ERROR, Addresses "
 			"0x%p to 0x%p ALREADY in use\n",
 		       __FUNCTION__, hwif->name, (void *) cmd_phys_base,
 		       (void *) cmd_phys_base + IOC4_CMD_CTL_BLK_SIZE);
 		return -ENOMEM;
 	}

 	if (hwif->io_ports[IDE_DATA_OFFSET] != cmd_base) {
 		/* Initialize the IO registers */
 		sgiioc4_init_hwif_ports(&hwif->hw, cmd_base, ctl, irqport);
 		memcpy(hwif->io_ports, hwif->hw.io_ports,
 		       sizeof (hwif->io_ports));
 		hwif->noprobe = !hwif->io_ports[IDE_DATA_OFFSET];
 	}

 	hwif->irq = dev->irq;
 	hwif->chipset = ide_pci;
 	hwif->pci_dev = dev;
 	hwif->channel = 0;	/* Single Channel chip */
 	hwif->cds = (struct ide_pci_device_s *) d;
 	hwif->gendev.parent = &dev->dev;/* setup proper ancestral information */

 	/* The IOC4 uses MMIO rather than Port IO. */
 	default_hwif_mmiops(hwif);

 	/* Initializing chipset IRQ Registers */
 	hwif->OUTL(0x03, irqport + IOC4_INTR_SET * 4);

 	ide_init_sgiioc4(hwif);

 	if (dma_base)
 		ide_dma_sgiioc4(hwif, dma_base);
 	else
 		printk(KERN_INFO "%s: %s Bus-Master DMA disabled\n",
 		       hwif->name, d->name);

 	if (probe_hwif_init(hwif))
 		return -EIO;

 	/* Create /proc/ide entries */
 	create_proc_ide_interfaces();

 	return 0;
 }

 static unsigned int __devinit
 pci_init_sgiioc4(struct pci_dev *dev, ide_pci_device_t * d)
 {
 	unsigned int class_rev;
 	int ret;

 	pci_read_config_dword(dev, PCI_CLASS_REVISION, &class_rev);
 	class_rev &= 0xff;
 	printk(KERN_INFO "%s: IDE controller at PCI slot %s, revision %d\n",
 			d->name, pci_name(dev), class_rev);
 	if (class_rev < IOC4_SUPPORTED_FIRMWARE_REV) {
 		printk(KERN_ERR "Skipping %s IDE controller in slot %s: "
 			"firmware is obsolete - please upgrade to revision"
 			"46 or higher\n", d->name, pci_name(dev));
 		ret = -EAGAIN;
 		goto out;
 	}
 	ret = sgiioc4_ide_setup_pci_device(dev, d);
 out:
 	return ret;
 }

 static ide_pci_device_t sgiioc4_chipsets[] __devinitdata = {
 	{
 	 /* Channel 0 */
 	 .name = "SGIIOC4",
 	 .init_hwif = ide_init_sgiioc4,
 	 .init_dma = ide_dma_sgiioc4,
 	 .channels = 1,
 	 .autodma = AUTODMA,
 	 /* SGI IOC4 doesn't have enablebits. */
 	 .bootable = ON_BOARD,
 	}
 };

 int
 ioc4_ide_attach_one(struct ioc4_driver_data *idd)
 {
 	/* PCI-RT does not bring out IDE connection.
 	 * Do not attach to this particular IOC4.
 	 */
 	if (idd->idd_variant == IOC4_VARIANT_PCI_RT)
 		return 0;

 	return pci_init_sgiioc4(idd->idd_pdev,
 				&sgiioc4_chipsets[idd->idd_pci_id->driver_data]);
 }

 static struct ioc4_submodule ioc4_ide_submodule = {
 	.is_name = "IOC4_ide",
 	.is_owner = THIS_MODULE,
 	.is_probe = ioc4_ide_attach_one,
 /*	.is_remove = ioc4_ide_remove_one,	*/
 };

 static int __init ioc4_ide_init(void)
 {
 	return ioc4_register_submodule(&ioc4_ide_submodule);
 }

 late_initcall(ioc4_ide_init); /* Call only after IDE init is done */

 MODULE_AUTHOR("Aniket Malatpure/Jeremy Higdon");
 MODULE_DESCRIPTION("IDE PCI driver module for SGI IOC4 Base-IO Card");
 MODULE_LICENSE("GPL");
	/*
	* Copyright (c) 2003-2006 Silicon Graphics, Inc. All Rights Reserved.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of version 2 of the GNU General Public License
	* as published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it would be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
	*
	* You should have received a copy of the GNU General Public
	* License along with this program; if not, write the Free Software
	* Foundation, Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
	*
	* For further information regarding this notice, see:
	*
	* http://oss.sgi.com/projects/GenInfo/NoticeExplan
	*/

	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/pci.h>
	#include <linux/delay.h>
	#include <linux/hdreg.h>
	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/timer.h>
	#include <linux/mm.h>
	#include <linux/ioport.h>
	#include <linux/blkdev.h>
	#include <linux/ioc4.h>
	#include <asm/io.h>

	#include <linux/ide.h>

	/* IOC4 Specific Definitions */
	#define IOC4_CMD_OFFSET 0x100
	#define IOC4_CTRL_OFFSET 0x120
	#define IOC4_DMA_OFFSET 0x140
	#define IOC4_INTR_OFFSET 0x0

	#define IOC4_TIMING 0x00
	#define IOC4_DMA_PTR_L 0x01
	#define IOC4_DMA_PTR_H 0x02
	#define IOC4_DMA_ADDR_L 0x03
	#define IOC4_DMA_ADDR_H 0x04
	#define IOC4_BC_DEV 0x05
	#define IOC4_BC_MEM 0x06
	#define IOC4_DMA_CTRL 0x07
	#define IOC4_DMA_END_ADDR 0x08

	/* Bits in the IOC4 Control/Status Register */
	#define IOC4_S_DMA_START 0x01
	#define IOC4_S_DMA_STOP 0x02
	#define IOC4_S_DMA_DIR 0x04
	#define IOC4_S_DMA_ACTIVE 0x08
	#define IOC4_S_DMA_ERROR 0x10
	#define IOC4_ATA_MEMERR 0x02

	/* Read/Write Directions */
	#define IOC4_DMA_WRITE 0x04
	#define IOC4_DMA_READ 0x00

	/* Interrupt Register Offsets */
	#define IOC4_INTR_REG 0x03
	#define IOC4_INTR_SET 0x05
	#define IOC4_INTR_CLEAR 0x07

	#define IOC4_IDE_CACHELINE_SIZE 128
	#define IOC4_CMD_CTL_BLK_SIZE 0x20
	#define IOC4_SUPPORTED_FIRMWARE_REV 46

	typedef struct {
	u32 timing_reg0;
	u32 timing_reg1;
	u32 low_mem_ptr;
	u32 high_mem_ptr;
	u32 low_mem_addr;
	u32 high_mem_addr;
	u32 dev_byte_count;
	u32 mem_byte_count;
	u32 status;
	} ioc4_dma_regs_t;

	/* Each Physical Region Descriptor Entry size is 16 bytes (2 * 64 bits) */
	/* IOC4 has only 1 IDE channel */
	#define IOC4_PRD_BYTES 16
	#define IOC4_PRD_ENTRIES (PAGE_SIZE /(4*IOC4_PRD_BYTES))


	static void
	sgiioc4_init_hwif_ports(hw_regs_t * hw, unsigned long data_port,
	unsigned long ctrl_port, unsigned long irq_port)
	{
	unsigned long reg = data_port;
	int i;

	/* Registers are word (32 bit) aligned */
	for (i = IDE_DATA_OFFSET; i <= IDE_STATUS_OFFSET; i++)
	hw->io_ports[i] = reg + i * 4;

	if (ctrl_port)
	hw->io_ports[IDE_CONTROL_OFFSET] = ctrl_port;

	if (irq_port)
	hw->io_ports[IDE_IRQ_OFFSET] = irq_port;
	}

	static void
	sgiioc4_maskproc(ide_drive_t * drive, int mask)
	{
	ide_hwif_t *hwif = HWIF(drive);
	hwif->OUTB(mask ? (drive->ctl \| 2) : (drive->ctl & ~2),
	IDE_CONTROL_REG);
	}


	static int
	sgiioc4_checkirq(ide_hwif_t * hwif)
	{
	u8 intr_reg =
	hwif->INL(hwif->io_ports[IDE_IRQ_OFFSET] + IOC4_INTR_REG * 4);

	if (intr_reg & 0x03)
	return 1;

	return 0;
	}


	static int
	sgiioc4_clearirq(ide_drive_t * drive)
	{
	u32 intr_reg;
	ide_hwif_t *hwif = HWIF(drive);
	unsigned long other_ir =
	hwif->io_ports[IDE_IRQ_OFFSET] + (IOC4_INTR_REG << 2);

	/* Code to check for PCI error conditions */
	intr_reg = hwif->INL(other_ir);
	if (intr_reg & 0x03) { /* Valid IOC4-IDE interrupt */
	/*
	* Using hwif->INB to read the IDE_STATUS_REG has a side effect
	* of clearing the interrupt. The first read should clear it
	* if it is set. The second read should return a "clear" status
	* if it got cleared. If not, then spin for a bit trying to
	* clear it.
	*/
	u8 stat = hwif->INB(IDE_STATUS_REG);
	int count = 0;
	stat = hwif->INB(IDE_STATUS_REG);
	while ((stat & 0x80) && (count++ < 100)) {
	udelay(1);
	stat = hwif->INB(IDE_STATUS_REG);
	}

	if (intr_reg & 0x02) {
	/* Error when transferring DMA data on PCI bus */
	u32 pci_err_addr_low, pci_err_addr_high,
	pci_stat_cmd_reg;

	pci_err_addr_low =
	hwif->INL(hwif->io_ports[IDE_IRQ_OFFSET]);
	pci_err_addr_high =
	hwif->INL(hwif->io_ports[IDE_IRQ_OFFSET] + 4);
	pci_read_config_dword(hwif->pci_dev, PCI_COMMAND,
	&pci_stat_cmd_reg);
	printk(KERN_ERR
	"%s(%s) : PCI Bus Error when doing DMA:"
	" status-cmd reg is 0x%x\n",
	__FUNCTION__, drive->name, pci_stat_cmd_reg);
	printk(KERN_ERR
	"%s(%s) : PCI Error Address is 0x%x%x\n",
	__FUNCTION__, drive->name,
	pci_err_addr_high, pci_err_addr_low);
	/* Clear the PCI Error indicator */
	pci_write_config_dword(hwif->pci_dev, PCI_COMMAND,
	0x00000146);
	}

	/* Clear the Interrupt, Error bits on the IOC4 */
	hwif->OUTL(0x03, other_ir);

	intr_reg = hwif->INL(other_ir);
	}

	return intr_reg & 3;
	}

	static void sgiioc4_ide_dma_start(ide_drive_t * drive)
	{
	ide_hwif_t *hwif = HWIF(drive);
	unsigned int reg = hwif->INL(hwif->dma_base + IOC4_DMA_CTRL * 4);
	unsigned int temp_reg = reg \| IOC4_S_DMA_START;

	hwif->OUTL(temp_reg, hwif->dma_base + IOC4_DMA_CTRL * 4);
	}

	static u32
	sgiioc4_ide_dma_stop(ide_hwif_t *hwif, u64 dma_base)
	{
	u32 ioc4_dma;
	int count;

	count = 0;
	ioc4_dma = hwif->INL(dma_base + IOC4_DMA_CTRL * 4);
	while ((ioc4_dma & IOC4_S_DMA_STOP) && (count++ < 200)) {
	udelay(1);
	ioc4_dma = hwif->INL(dma_base + IOC4_DMA_CTRL * 4);
	}
	return ioc4_dma;
	}

	/* Stops the IOC4 DMA Engine */
	static int
	sgiioc4_ide_dma_end(ide_drive_t * drive)
	{
	u32 ioc4_dma, bc_dev, bc_mem, num, valid = 0, cnt = 0;
	ide_hwif_t *hwif = HWIF(drive);
	u64 dma_base = hwif->dma_base;
	int dma_stat = 0;
	unsigned long *ending_dma = ide_get_hwifdata(hwif);

	hwif->OUTL(IOC4_S_DMA_STOP, dma_base + IOC4_DMA_CTRL * 4);

	ioc4_dma = sgiioc4_ide_dma_stop(hwif, dma_base);

	if (ioc4_dma & IOC4_S_DMA_STOP) {
	printk(KERN_ERR
	"%s(%s): IOC4 DMA STOP bit is still 1 :"
	"ioc4_dma_reg 0x%x\n",
	__FUNCTION__, drive->name, ioc4_dma);
	dma_stat = 1;
	}

	/*
	* The IOC4 will DMA 1's to the ending dma area to indicate that
	* previous data DMA is complete. This is necessary because of relaxed
	* ordering between register reads and DMA writes on the Altix.
	*/
	while ((cnt++ < 200) && (!valid)) {
	for (num = 0; num < 16; num++) {
	if (ending_dma[num]) {
	valid = 1;
	break;
	}
	}
	udelay(1);
	}
	if (!valid) {
	printk(KERN_ERR "%s(%s) : DMA incomplete\n", __FUNCTION__,
	drive->name);
	dma_stat = 1;
	}

	bc_dev = hwif->INL(dma_base + IOC4_BC_DEV * 4);
	bc_mem = hwif->INL(dma_base + IOC4_BC_MEM * 4);

	if ((bc_dev & 0x01FF) \|\| (bc_mem & 0x1FF)) {
	if (bc_dev > bc_mem + 8) {
	printk(KERN_ERR
	"%s(%s): WARNING!! byte_count_dev %d "
	"!= byte_count_mem %d\n",
	__FUNCTION__, drive->name, bc_dev, bc_mem);
	}
	}

	drive->waiting_for_dma = 0;
	ide_destroy_dmatable(drive);

	return dma_stat;
	}

	static int
	sgiioc4_ide_dma_check(ide_drive_t * drive)
	{
	if (ide_config_drive_speed(drive, XFER_MW_DMA_2) != 0) {
	printk(KERN_INFO
	"Couldnot set %s in Multimode-2 DMA mode \| "
	"Drive %s using PIO instead\n",
	drive->name, drive->name);
	drive->using_dma = 0;
	} else
	drive->using_dma = 1;

	return 0;
	}

	static int
	sgiioc4_ide_dma_on(ide_drive_t * drive)
	{
	drive->using_dma = 1;

	return HWIF(drive)->ide_dma_host_on(drive);
	}

	static int
	sgiioc4_ide_dma_off_quietly(ide_drive_t * drive)
	{
	drive->using_dma = 0;

	return HWIF(drive)->ide_dma_host_off(drive);
	}

	/* returns 1 if dma irq issued, 0 otherwise */
	static int
	sgiioc4_ide_dma_test_irq(ide_drive_t * drive)
	{
	return sgiioc4_checkirq(HWIF(drive));
	}

	static int
	sgiioc4_ide_dma_host_on(ide_drive_t * drive)
	{
	if (drive->using_dma)
	return 0;

	return 1;
	}

	static int
	sgiioc4_ide_dma_host_off(ide_drive_t * drive)
	{
	sgiioc4_clearirq(drive);

	return 0;
	}

	static int
	sgiioc4_ide_dma_lostirq(ide_drive_t * drive)
	{
	HWIF(drive)->resetproc(drive);

	return __ide_dma_lostirq(drive);
	}

	static void
	sgiioc4_resetproc(ide_drive_t * drive)
	{
	sgiioc4_ide_dma_end(drive);
	sgiioc4_clearirq(drive);
	}

	static u8
	sgiioc4_INB(unsigned long port)
	{
	u8 reg = (u8) readb((void __iomem *) port);

	if ((port & 0xFFF) == 0x11C) { /* Status register of IOC4 */
	if (reg & 0x51) { /* Not busy...check for interrupt */
	unsigned long other_ir = port - 0x110;
	unsigned int intr_reg = (u32) readl((void __iomem *) other_ir);

	/* Clear the Interrupt, Error bits on the IOC4 */
	if (intr_reg & 0x03) {
	writel(0x03, (void __iomem *) other_ir);
	intr_reg = (u32) readl((void __iomem *) other_ir);
	}
	}
	}

	return reg;
	}

	/* Creates a dma map for the scatter-gather list entries */
	static void __devinit
	ide_dma_sgiioc4(ide_hwif_t * hwif, unsigned long dma_base)
	{
	void __iomem *virt_dma_base;
	int num_ports = sizeof (ioc4_dma_regs_t);
	void *pad;

	printk(KERN_INFO "%s: BM-DMA at 0x%04lx-0x%04lx\n", hwif->name,
	dma_base, dma_base + num_ports - 1);

	if (!request_mem_region(dma_base, num_ports, hwif->name)) {
	printk(KERN_ERR
	"%s(%s) -- ERROR, Addresses 0x%p to 0x%p "
	"ALREADY in use\n",
	__FUNCTION__, hwif->name, (void *) dma_base,
	(void *) dma_base + num_ports - 1);
	goto dma_alloc_failure;
	}

	virt_dma_base = ioremap(dma_base, num_ports);
	if (virt_dma_base == NULL) {
	printk(KERN_ERR
	"%s(%s) -- ERROR, Unable to map addresses 0x%lx to 0x%lx\n",
	__FUNCTION__, hwif->name, dma_base, dma_base + num_ports - 1);
	goto dma_remap_failure;
	}
	hwif->dma_base = (unsigned long) virt_dma_base;

	hwif->dmatable_cpu = pci_alloc_consistent(hwif->pci_dev,
	IOC4_PRD_ENTRIES * IOC4_PRD_BYTES,
	&hwif->dmatable_dma);

	if (!hwif->dmatable_cpu)
	goto dma_pci_alloc_failure;

	hwif->sg_max_nents = IOC4_PRD_ENTRIES;

	pad = pci_alloc_consistent(hwif->pci_dev, IOC4_IDE_CACHELINE_SIZE,
	(dma_addr_t *) &(hwif->dma_status));

	if (pad) {
	ide_set_hwifdata(hwif, pad);
	return;
	}

	pci_free_consistent(hwif->pci_dev,
	IOC4_PRD_ENTRIES * IOC4_PRD_BYTES,
	hwif->dmatable_cpu, hwif->dmatable_dma);
	printk(KERN_INFO
	"%s() -- Error! Unable to allocate DMA Maps for drive %s\n",
	__FUNCTION__, hwif->name);
	printk(KERN_INFO
	"Changing from DMA to PIO mode for Drive %s\n", hwif->name);

	dma_pci_alloc_failure:
	iounmap(virt_dma_base);

	dma_remap_failure:
	release_mem_region(dma_base, num_ports);

	dma_alloc_failure:
	/* Disable DMA because we couldnot allocate any DMA maps */
	hwif->autodma = 0;
	hwif->atapi_dma = 0;
	}

	/* Initializes the IOC4 DMA Engine */
	static void
	sgiioc4_configure_for_dma(int dma_direction, ide_drive_t * drive)
	{
	u32 ioc4_dma;
	ide_hwif_t *hwif = HWIF(drive);
	u64 dma_base = hwif->dma_base;
	u32 dma_addr, ending_dma_addr;

	ioc4_dma = hwif->INL(dma_base + IOC4_DMA_CTRL * 4);

	if (ioc4_dma & IOC4_S_DMA_ACTIVE) {
	printk(KERN_WARNING
	"%s(%s):Warning!! DMA from previous transfer was still active\n",
	__FUNCTION__, drive->name);
	hwif->OUTL(IOC4_S_DMA_STOP, dma_base + IOC4_DMA_CTRL * 4);
	ioc4_dma = sgiioc4_ide_dma_stop(hwif, dma_base);

	if (ioc4_dma & IOC4_S_DMA_STOP)
	printk(KERN_ERR
	"%s(%s) : IOC4 Dma STOP bit is still 1\n",
	__FUNCTION__, drive->name);
	}

	ioc4_dma = hwif->INL(dma_base + IOC4_DMA_CTRL * 4);
	if (ioc4_dma & IOC4_S_DMA_ERROR) {
	printk(KERN_WARNING
	"%s(%s) : Warning!! - DMA Error during Previous"
	" transfer \| status 0x%x\n",
	__FUNCTION__, drive->name, ioc4_dma);
	hwif->OUTL(IOC4_S_DMA_STOP, dma_base + IOC4_DMA_CTRL * 4);
	ioc4_dma = sgiioc4_ide_dma_stop(hwif, dma_base);

	if (ioc4_dma & IOC4_S_DMA_STOP)
	printk(KERN_ERR
	"%s(%s) : IOC4 DMA STOP bit is still 1\n",
	__FUNCTION__, drive->name);
	}

	/* Address of the Scatter Gather List */
	dma_addr = cpu_to_le32(hwif->dmatable_dma);
	hwif->OUTL(dma_addr, dma_base + IOC4_DMA_PTR_L * 4);

	/* Address of the Ending DMA */
	memset(ide_get_hwifdata(hwif), 0, IOC4_IDE_CACHELINE_SIZE);
	ending_dma_addr = cpu_to_le32(hwif->dma_status);
	hwif->OUTL(ending_dma_addr, dma_base + IOC4_DMA_END_ADDR * 4);

	hwif->OUTL(dma_direction, dma_base + IOC4_DMA_CTRL * 4);
	drive->waiting_for_dma = 1;
	}

	/* IOC4 Scatter Gather list Format */
	/* 128 Bit entries to support 64 bit addresses in the future */
	/* The Scatter Gather list Entry should be in the BIG-ENDIAN Format */
	/* --------------------------------------------------------------------- */
	/* \| Upper 32 bits - Zero \| Lower 32 bits- address \| */
	/* --------------------------------------------------------------------- */
	/* \| Upper 32 bits - Zero \|EOL\| 15 unused \| 16 Bit Length\| */
	/* --------------------------------------------------------------------- */
	/* Creates the scatter gather list, DMA Table */
	static unsigned int
	sgiioc4_build_dma_table(ide_drive_t * drive, struct request *rq, int ddir)
	{
	ide_hwif_t *hwif = HWIF(drive);
	unsigned int *table = hwif->dmatable_cpu;
	unsigned int count = 0, i = 1;
	struct scatterlist *sg;

	hwif->sg_nents = i = ide_build_sglist(drive, rq);

	if (!i)
	return 0; /* sglist of length Zero */

	sg = hwif->sg_table;
	while (i && sg_dma_len(sg)) {
	dma_addr_t cur_addr;
	int cur_len;
	cur_addr = sg_dma_address(sg);
	cur_len = sg_dma_len(sg);

	while (cur_len) {
	if (count++ >= IOC4_PRD_ENTRIES) {
	printk(KERN_WARNING
	"%s: DMA table too small\n",
	drive->name);
	goto use_pio_instead;
	} else {
	u32 bcount =
	0x10000 - (cur_addr & 0xffff);

	if (bcount > cur_len)
	bcount = cur_len;

	/* put the addr, length in
	* the IOC4 dma-table format */
	*table = 0x0;
	table++;
	*table = cpu_to_be32(cur_addr);
	table++;
	*table = 0x0;
	table++;

	*table = cpu_to_be32(bcount);
	table++;

	cur_addr += bcount;
	cur_len -= bcount;
	}
	}

	sg++;
	i--;
	}

	if (count) {
	table--;
	*table \|= cpu_to_be32(0x80000000);
	return count;
	}

	use_pio_instead:
	pci_unmap_sg(hwif->pci_dev, hwif->sg_table, hwif->sg_nents,
	hwif->sg_dma_direction);

	return 0; /* revert to PIO for this request */
	}

	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 void __devinit
	ide_init_sgiioc4(ide_hwif_t * hwif)
	{
	hwif->mmio = 2;
	hwif->autodma = 1;
	hwif->atapi_dma = 1;
	hwif->ultra_mask = 0x0; /* Disable Ultra DMA */
	hwif->mwdma_mask = 0x2; /* Multimode-2 DMA */
	hwif->swdma_mask = 0x2;
	hwif->tuneproc = NULL; /* Sets timing for PIO mode */
	hwif->speedproc = NULL; /* Sets timing for DMA &/or PIO modes */
	hwif->selectproc = NULL;/* Use the default routine to select drive */
	hwif->reset_poll = NULL;/* No HBA specific reset_poll needed */
	hwif->pre_reset = NULL; /* No HBA specific pre_set needed */
	hwif->resetproc = &sgiioc4_resetproc;/* Reset DMA engine,
	clear interrupts */
	hwif->intrproc = NULL; /* Enable or Disable interrupt from drive */
	hwif->maskproc = &sgiioc4_maskproc; /* Mask on/off NIEN register */
	hwif->quirkproc = NULL;
	hwif->busproc = NULL;

	hwif->dma_setup = &sgiioc4_ide_dma_setup;
	hwif->dma_start = &sgiioc4_ide_dma_start;
	hwif->ide_dma_end = &sgiioc4_ide_dma_end;
	hwif->ide_dma_check = &sgiioc4_ide_dma_check;
	hwif->ide_dma_on = &sgiioc4_ide_dma_on;
	hwif->ide_dma_off_quietly = &sgiioc4_ide_dma_off_quietly;
	hwif->ide_dma_test_irq = &sgiioc4_ide_dma_test_irq;
	hwif->ide_dma_host_on = &sgiioc4_ide_dma_host_on;
	hwif->ide_dma_host_off = &sgiioc4_ide_dma_host_off;
	hwif->ide_dma_lostirq = &sgiioc4_ide_dma_lostirq;
	hwif->ide_dma_timeout = &__ide_dma_timeout;

	hwif->INB = &sgiioc4_INB;
	}

	static int __devinit
	sgiioc4_ide_setup_pci_device(struct pci_dev dev, ide_pci_device_t d)
	{
	unsigned long cmd_base, dma_base, irqport;
	unsigned long bar0, cmd_phys_base, ctl;
	void __iomem *virt_base;
	ide_hwif_t *hwif;
	int h;

	/*
	* Find an empty HWIF; if none available, return -ENOMEM.
	*/
	for (h = 0; h < MAX_HWIFS; ++h) {
	hwif = &ide_hwifs[h];
	if (hwif->chipset == ide_unknown)
	break;
	}
	if (h == MAX_HWIFS) {
	printk(KERN_ERR "%s: too many IDE interfaces, no room in table\n", d->name);
	return -ENOMEM;
	}

	/* Get the CmdBlk and CtrlBlk Base Registers */
	bar0 = pci_resource_start(dev, 0);
	virt_base = ioremap(bar0, pci_resource_len(dev, 0));
	if (virt_base == NULL) {
	printk(KERN_ERR "%s: Unable to remap BAR 0 address: 0x%lx\n",
	d->name, bar0);
	return -ENOMEM;
	}
	cmd_base = (unsigned long) virt_base + IOC4_CMD_OFFSET;
	ctl = (unsigned long) virt_base + IOC4_CTRL_OFFSET;
	irqport = (unsigned long) virt_base + IOC4_INTR_OFFSET;
	dma_base = pci_resource_start(dev, 0) + IOC4_DMA_OFFSET;

	cmd_phys_base = bar0 + IOC4_CMD_OFFSET;
	if (!request_mem_region(cmd_phys_base, IOC4_CMD_CTL_BLK_SIZE,
	hwif->name)) {
	printk(KERN_ERR
	"%s : %s -- ERROR, Addresses "
	"0x%p to 0x%p ALREADY in use\n",
	__FUNCTION__, hwif->name, (void *) cmd_phys_base,
	(void *) cmd_phys_base + IOC4_CMD_CTL_BLK_SIZE);
	return -ENOMEM;
	}

	if (hwif->io_ports[IDE_DATA_OFFSET] != cmd_base) {
	/* Initialize the IO registers */
	sgiioc4_init_hwif_ports(&hwif->hw, cmd_base, ctl, irqport);
	memcpy(hwif->io_ports, hwif->hw.io_ports,
	sizeof (hwif->io_ports));
	hwif->noprobe = !hwif->io_ports[IDE_DATA_OFFSET];
	}

	hwif->irq = dev->irq;
	hwif->chipset = ide_pci;
	hwif->pci_dev = dev;
	hwif->channel = 0; /* Single Channel chip */
	hwif->cds = (struct ide_pci_device_s *) d;
	hwif->gendev.parent = &dev->dev;/* setup proper ancestral information */

	/* The IOC4 uses MMIO rather than Port IO. */
	default_hwif_mmiops(hwif);

	/* Initializing chipset IRQ Registers */
	hwif->OUTL(0x03, irqport + IOC4_INTR_SET * 4);

	ide_init_sgiioc4(hwif);

	if (dma_base)
	ide_dma_sgiioc4(hwif, dma_base);
	else
	printk(KERN_INFO "%s: %s Bus-Master DMA disabled\n",
	hwif->name, d->name);

	if (probe_hwif_init(hwif))
	return -EIO;

	/* Create /proc/ide entries */
	create_proc_ide_interfaces();

	return 0;
	}

	static unsigned int __devinit
	pci_init_sgiioc4(struct pci_dev dev, ide_pci_device_t d)
	{
	unsigned int class_rev;
	int ret;

	pci_read_config_dword(dev, PCI_CLASS_REVISION, &class_rev);
	class_rev &= 0xff;
	printk(KERN_INFO "%s: IDE controller at PCI slot %s, revision %d\n",
	d->name, pci_name(dev), class_rev);
	if (class_rev < IOC4_SUPPORTED_FIRMWARE_REV) {
	printk(KERN_ERR "Skipping %s IDE controller in slot %s: "
	"firmware is obsolete - please upgrade to revision"
	"46 or higher\n", d->name, pci_name(dev));
	ret = -EAGAIN;
	goto out;
	}
	ret = sgiioc4_ide_setup_pci_device(dev, d);
	out:
	return ret;
	}

	static ide_pci_device_t sgiioc4_chipsets[] __devinitdata = {
	{
	/* Channel 0 */
	.name = "SGIIOC4",
	.init_hwif = ide_init_sgiioc4,
	.init_dma = ide_dma_sgiioc4,
	.channels = 1,
	.autodma = AUTODMA,
	/* SGI IOC4 doesn't have enablebits. */
	.bootable = ON_BOARD,
	}
	};

	int
	ioc4_ide_attach_one(struct ioc4_driver_data *idd)
	{
	/* PCI-RT does not bring out IDE connection.
	* Do not attach to this particular IOC4.
	*/
	if (idd->idd_variant == IOC4_VARIANT_PCI_RT)
	return 0;

	return pci_init_sgiioc4(idd->idd_pdev,
	&sgiioc4_chipsets[idd->idd_pci_id->driver_data]);
	}

	static struct ioc4_submodule ioc4_ide_submodule = {
	.is_name = "IOC4_ide",
	.is_owner = THIS_MODULE,
	.is_probe = ioc4_ide_attach_one,
	/* .is_remove = ioc4_ide_remove_one, */
	};

	static int __init ioc4_ide_init(void)
	{
	return ioc4_register_submodule(&ioc4_ide_submodule);
	}

	late_initcall(ioc4_ide_init); /* Call only after IDE init is done */

	MODULE_AUTHOR("Aniket Malatpure/Jeremy Higdon");
	MODULE_DESCRIPTION("IDE PCI driver module for SGI IOC4 Base-IO Card");
	MODULE_LICENSE("GPL");