arch/arm/mach-ixp4xx/common-pci.c - SHIFTPHONES/mainline/linux - Gitiles

 /*
  * arch/arm/mach-ixp4xx/common-pci.c
  *
  * IXP4XX PCI routines for all platforms
  *
  * Maintainer: Deepak Saxena <dsaxena@plexity.net>
  *
  * Copyright (C) 2002 Intel Corporation.
  * Copyright (C) 2003 Greg Ungerer <gerg@snapgear.com>
  * Copyright (C) 2003-2004 MontaVista Software, Inc.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  */

 #include <linux/sched.h>
 #include <linux/kernel.h>
 #include <linux/pci.h>
 #include <linux/interrupt.h>
 #include <linux/mm.h>
 #include <linux/init.h>
 #include <linux/ioport.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <asm/dma-mapping.h>

 #include <asm/io.h>
 #include <asm/irq.h>
 #include <asm/sizes.h>
 #include <asm/system.h>
 #include <asm/mach/pci.h>
 #include <asm/hardware.h>


 /*
  * IXP4xx PCI read function is dependent on whether we are
  * running A0 or B0 (AppleGate) silicon.
  */
 int (*ixp4xx_pci_read)(u32 addr, u32 cmd, u32* data);

 /*
  * Base address for PCI regsiter region
  */
 unsigned long ixp4xx_pci_reg_base = 0;

 /*
  * PCI cfg an I/O routines are done by programming a
  * command/byte enable register, and then read/writing
  * the data from a data regsiter. We need to ensure
  * these transactions are atomic or we will end up
  * with corrupt data on the bus or in a driver.
  */
 static DEFINE_SPINLOCK(ixp4xx_pci_lock);

 /*
  * Read from PCI config space
  */
 static void crp_read(u32 ad_cbe, u32 *data)
 {
 	unsigned long flags;
 	spin_lock_irqsave(&ixp4xx_pci_lock, flags);
 	*PCI_CRP_AD_CBE = ad_cbe;
 	*data = *PCI_CRP_RDATA;
 	spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
 }

 /*
  * Write to PCI config space
  */
 static void crp_write(u32 ad_cbe, u32 data)
 {
 	unsigned long flags;
 	spin_lock_irqsave(&ixp4xx_pci_lock, flags);
 	*PCI_CRP_AD_CBE = CRP_AD_CBE_WRITE | ad_cbe;
 	*PCI_CRP_WDATA = data;
 	spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
 }

 static inline int check_master_abort(void)
 {
 	/* check Master Abort bit after access */
 	unsigned long isr = *PCI_ISR;

 	if (isr & PCI_ISR_PFE) {
 		/* make sure the Master Abort bit is reset */
 		*PCI_ISR = PCI_ISR_PFE;
 		pr_debug("%s failed\n", __FUNCTION__);
 		return 1;
 	}

 	return 0;
 }

 int ixp4xx_pci_read_errata(u32 addr, u32 cmd, u32* data)
 {
 	unsigned long flags;
 	int retval = 0;
 	int i;

 	spin_lock_irqsave(&ixp4xx_pci_lock, flags);

 	*PCI_NP_AD = addr;

 	/*
 	 * PCI workaround  - only works if NP PCI space reads have
 	 * no side effects!!! Read 8 times. last one will be good.
 	 */
 	for (i = 0; i < 8; i++) {
 		*PCI_NP_CBE = cmd;
 		*data = *PCI_NP_RDATA;
 		*data = *PCI_NP_RDATA;
 	}

 	if(check_master_abort())
 		retval = 1;

 	spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
 	return retval;
 }

 int ixp4xx_pci_read_no_errata(u32 addr, u32 cmd, u32* data)
 {
 	unsigned long flags;
 	int retval = 0;

 	spin_lock_irqsave(&ixp4xx_pci_lock, flags);

 	*PCI_NP_AD = addr;

 	/* set up and execute the read */
 	*PCI_NP_CBE = cmd;

 	/* the result of the read is now in NP_RDATA */
 	*data = *PCI_NP_RDATA;

 	if(check_master_abort())
 		retval = 1;

 	spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
 	return retval;
 }

 int ixp4xx_pci_write(u32 addr, u32 cmd, u32 data)
 {
 	unsigned long flags;
 	int retval = 0;

 	spin_lock_irqsave(&ixp4xx_pci_lock, flags);

 	*PCI_NP_AD = addr;

 	/* set up the write */
 	*PCI_NP_CBE = cmd;

 	/* execute the write by writing to NP_WDATA */
 	*PCI_NP_WDATA = data;

 	if(check_master_abort())
 		retval = 1;

 	spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
 	return retval;
 }

 static u32 ixp4xx_config_addr(u8 bus_num, u16 devfn, int where)
 {
 	u32 addr;
 	if (!bus_num) {
 		/* type 0 */
 		addr = BIT(32-PCI_SLOT(devfn)) | ((PCI_FUNC(devfn)) << 8) |
 		    (where & ~3);
 	} else {
 		/* type 1 */
 		addr = (bus_num << 16) | ((PCI_SLOT(devfn)) << 11) |
 			((PCI_FUNC(devfn)) << 8) | (where & ~3) | 1;
 	}
 	return addr;
 }

 /*
  * Mask table, bits to mask for quantity of size 1, 2 or 4 bytes.
  * 0 and 3 are not valid indexes...
  */
 static u32 bytemask[] = {
 	/*0*/	0,
 	/*1*/	0xff,
 	/*2*/	0xffff,
 	/*3*/	0,
 	/*4*/	0xffffffff,
 };

 static u32 local_byte_lane_enable_bits(u32 n, int size)
 {
 	if (size == 1)
 		return (0xf & ~BIT(n)) << CRP_AD_CBE_BESL;
 	if (size == 2)
 		return (0xf & ~(BIT(n) | BIT(n+1))) << CRP_AD_CBE_BESL;
 	if (size == 4)
 		return 0;
 	return 0xffffffff;
 }

 static int local_read_config(int where, int size, u32 *value)
 {
 	u32 n, data;
 	pr_debug("local_read_config from %d size %d\n", where, size);
 	n = where % 4;
 	crp_read(where & ~3, &data);
 	*value = (data >> (8*n)) & bytemask[size];
 	pr_debug("local_read_config read %#x\n", *value);
 	return PCIBIOS_SUCCESSFUL;
 }

 static int local_write_config(int where, int size, u32 value)
 {
 	u32 n, byte_enables, data;
 	pr_debug("local_write_config %#x to %d size %d\n", value, where, size);
 	n = where % 4;
 	byte_enables = local_byte_lane_enable_bits(n, size);
 	if (byte_enables == 0xffffffff)
 		return PCIBIOS_BAD_REGISTER_NUMBER;
 	data = value << (8*n);
 	crp_write((where & ~3) | byte_enables, data);
 	return PCIBIOS_SUCCESSFUL;
 }

 static u32 byte_lane_enable_bits(u32 n, int size)
 {
 	if (size == 1)
 		return (0xf & ~BIT(n)) << 4;
 	if (size == 2)
 		return (0xf & ~(BIT(n) | BIT(n+1))) << 4;
 	if (size == 4)
 		return 0;
 	return 0xffffffff;
 }

 static int ixp4xx_pci_read_config(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *value)
 {
 	u32 n, byte_enables, addr, data;
 	u8 bus_num = bus->number;

 	pr_debug("read_config from %d size %d dev %d:%d:%d\n", where, size,
 		bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn));

 	*value = 0xffffffff;
 	n = where % 4;
 	byte_enables = byte_lane_enable_bits(n, size);
 	if (byte_enables == 0xffffffff)
 		return PCIBIOS_BAD_REGISTER_NUMBER;

 	addr = ixp4xx_config_addr(bus_num, devfn, where);
 	if (ixp4xx_pci_read(addr, byte_enables | NP_CMD_CONFIGREAD, &data))
 		return PCIBIOS_DEVICE_NOT_FOUND;

 	*value = (data >> (8*n)) & bytemask[size];
 	pr_debug("read_config_byte read %#x\n", *value);
 	return PCIBIOS_SUCCESSFUL;
 }

 static int ixp4xx_pci_write_config(struct pci_bus *bus,  unsigned int devfn, int where, int size, u32 value)
 {
 	u32 n, byte_enables, addr, data;
 	u8 bus_num = bus->number;

 	pr_debug("write_config_byte %#x to %d size %d dev %d:%d:%d\n", value, where,
 		size, bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn));

 	n = where % 4;
 	byte_enables = byte_lane_enable_bits(n, size);
 	if (byte_enables == 0xffffffff)
 		return PCIBIOS_BAD_REGISTER_NUMBER;

 	addr = ixp4xx_config_addr(bus_num, devfn, where);
 	data = value << (8*n);
 	if (ixp4xx_pci_write(addr, byte_enables | NP_CMD_CONFIGWRITE, data))
 		return PCIBIOS_DEVICE_NOT_FOUND;

 	return PCIBIOS_SUCCESSFUL;
 }

 struct pci_ops ixp4xx_ops = {
 	.read =  ixp4xx_pci_read_config,
 	.write = ixp4xx_pci_write_config,
 };

 /*
  * PCI abort handler
  */
 static int abort_handler(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 {
 	u32 isr, status;

 	isr = *PCI_ISR;
 	local_read_config(PCI_STATUS, 2, &status);
 	pr_debug("PCI: abort_handler addr = %#lx, isr = %#x, "
 		"status = %#x\n", addr, isr, status);

 	/* make sure the Master Abort bit is reset */
 	*PCI_ISR = PCI_ISR_PFE;
 	status |= PCI_STATUS_REC_MASTER_ABORT;
 	local_write_config(PCI_STATUS, 2, status);

 	/*
 	 * If it was an imprecise abort, then we need to correct the
 	 * return address to be _after_ the instruction.
 	 */
 	if (fsr & (1 << 10))
 		regs->ARM_pc += 4;

 	return 0;
 }


 /*
  * Setup DMA mask to 64MB on PCI devices. Ignore all other devices.
  */
 static int ixp4xx_pci_platform_notify(struct device *dev)
 {
 	if(dev->bus == &pci_bus_type) {
 		*dev->dma_mask =  SZ_64M - 1;
 		dev->coherent_dma_mask = SZ_64M - 1;
 		dmabounce_register_dev(dev, 2048, 4096);
 	}
 	return 0;
 }

 static int ixp4xx_pci_platform_notify_remove(struct device *dev)
 {
 	if(dev->bus == &pci_bus_type) {
 		dmabounce_unregister_dev(dev);
 	}
 	return 0;
 }

 int dma_needs_bounce(struct device *dev, dma_addr_t dma_addr, size_t size)
 {
 	return (dev->bus == &pci_bus_type ) && ((dma_addr + size) >= SZ_64M);
 }

 void __init ixp4xx_pci_preinit(void)
 {
 	unsigned long processor_id;

 	asm("mrc p15, 0, %0, cr0, cr0, 0;" : "=r"(processor_id) :);

 	/*
 	 * Determine which PCI read method to use.
 	 * Rev 0 IXP425 requires workaround.
 	 */
 	if (!(processor_id & 0xf) && !cpu_is_ixp46x()) {
 		printk("PCI: IXP42x A0 silicon detected - "
 			"PCI Non-Prefetch Workaround Enabled\n");
 		ixp4xx_pci_read = ixp4xx_pci_read_errata;
 	} else
 		ixp4xx_pci_read = ixp4xx_pci_read_no_errata;


 	/* hook in our fault handler for PCI errors */
 	hook_fault_code(16+6, abort_handler, SIGBUS, "imprecise external abort");

 	pr_debug("setup PCI-AHB(inbound) and AHB-PCI(outbound) address mappings\n");

 	/*
 	 * We use identity AHB->PCI address translation
 	 * in the 0x48000000 to 0x4bffffff address space
 	 */
 	*PCI_PCIMEMBASE = 0x48494A4B;

 	/*
 	 * We also use identity PCI->AHB address translation
 	 * in 4 16MB BARs that begin at the physical memory start
 	 */
 	*PCI_AHBMEMBASE = (PHYS_OFFSET & 0xFF000000) +
 		((PHYS_OFFSET & 0xFF000000) >> 8) +
 		((PHYS_OFFSET & 0xFF000000) >> 16) +
 		((PHYS_OFFSET & 0xFF000000) >> 24) +
 		0x00010203;

 	if (*PCI_CSR & PCI_CSR_HOST) {
 		printk("PCI: IXP4xx is host\n");

 		pr_debug("setup BARs in controller\n");

 		/*
 		 * We configure the PCI inbound memory windows to be
 		 * 1:1 mapped to SDRAM
 		 */
 		local_write_config(PCI_BASE_ADDRESS_0, 4, PHYS_OFFSET + 0x00000000);
 		local_write_config(PCI_BASE_ADDRESS_1, 4, PHYS_OFFSET + 0x01000000);
 		local_write_config(PCI_BASE_ADDRESS_2, 4, PHYS_OFFSET + 0x02000000);
 		local_write_config(PCI_BASE_ADDRESS_3, 4, PHYS_OFFSET + 0x03000000);

 		/*
 		 * Enable CSR window at 0xff000000.
 		 */
 		local_write_config(PCI_BASE_ADDRESS_4, 4, 0xff000008);

 		/*
 		 * Enable the IO window to be way up high, at 0xfffffc00
 		 */
 		local_write_config(PCI_BASE_ADDRESS_5, 4, 0xfffffc01);
 	} else {
 		printk("PCI: IXP4xx is target - No bus scan performed\n");
 	}

 	printk("PCI: IXP4xx Using %s access for memory space\n",
 #ifndef CONFIG_IXP4XX_INDIRECT_PCI
 			"direct"
 #else
 			"indirect"
 #endif
 		);

 	pr_debug("clear error bits in ISR\n");
 	*PCI_ISR = PCI_ISR_PSE | PCI_ISR_PFE | PCI_ISR_PPE | PCI_ISR_AHBE;

 	/*
 	 * Set Initialize Complete in PCI Control Register: allow IXP4XX to
 	 * respond to PCI configuration cycles. Specify that the AHB bus is
 	 * operating in big endian mode. Set up byte lane swapping between
 	 * little-endian PCI and the big-endian AHB bus
 	 */
 #ifdef __ARMEB__
 	*PCI_CSR = PCI_CSR_IC | PCI_CSR_ABE | PCI_CSR_PDS | PCI_CSR_ADS;
 #else
 	*PCI_CSR = PCI_CSR_IC;
 #endif

 	pr_debug("DONE\n");
 }

 int ixp4xx_setup(int nr, struct pci_sys_data *sys)
 {
 	struct resource *res;

 	if (nr >= 1)
 		return 0;

 	res = kmalloc(sizeof(*res) * 2, GFP_KERNEL);
 	if (res == NULL) {
 		/*
 		 * If we're out of memory this early, something is wrong,
 		 * so we might as well catch it here.
 		 */
 		panic("PCI: unable to allocate resources?\n");
 	}
 	memset(res, 0, sizeof(*res) * 2);

 	local_write_config(PCI_COMMAND, 2, PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY);

 	res[0].name = "PCI I/O Space";
 	res[0].start = 0x00001000;
 	res[0].end = 0xffff0000;
 	res[0].flags = IORESOURCE_IO;

 	res[1].name = "PCI Memory Space";
 	res[1].start = 0x48000000;
 #ifndef CONFIG_IXP4XX_INDIRECT_PCI
 	res[1].end = 0x4bffffff;
 #else
 	res[1].end = 0x4fffffff;
 #endif
 	res[1].flags = IORESOURCE_MEM;

 	request_resource(&ioport_resource, &res[0]);
 	request_resource(&iomem_resource, &res[1]);

 	sys->resource[0] = &res[0];
 	sys->resource[1] = &res[1];
 	sys->resource[2] = NULL;

 	platform_notify = ixp4xx_pci_platform_notify;
 	platform_notify_remove = ixp4xx_pci_platform_notify_remove;

 	return 1;
 }

 struct pci_bus *ixp4xx_scan_bus(int nr, struct pci_sys_data *sys)
 {
 	return pci_scan_bus(sys->busnr, &ixp4xx_ops, sys);
 }

 /*
  * We override these so we properly do dmabounce otherwise drivers
  * are able to set the dma_mask to 0xffffffff and we can no longer
  * trap bounces. :(
  *
  * We just return true on everyhing except for < 64MB in which case
  * we will fail miseralby and die since we can't handle that case.
  */
 int
 pci_set_dma_mask(struct pci_dev *dev, u64 mask)
 {
 	if (mask >= SZ_64M - 1 )
 		return 0;

 	return -EIO;
 }

 int
 pci_dac_set_dma_mask(struct pci_dev *dev, u64 mask)
 {
 	if (mask >= SZ_64M - 1 )
 		return 0;

 	return -EIO;
 }

 int
 pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
 {
 	if (mask >= SZ_64M - 1 )
 		return 0;

 	return -EIO;
 }

 EXPORT_SYMBOL(pci_set_dma_mask);
 EXPORT_SYMBOL(pci_dac_set_dma_mask);
 EXPORT_SYMBOL(pci_set_consistent_dma_mask);
 EXPORT_SYMBOL(ixp4xx_pci_read);
 EXPORT_SYMBOL(ixp4xx_pci_write);
	/*
	* arch/arm/mach-ixp4xx/common-pci.c
	*
	* IXP4XX PCI routines for all platforms
	*
	* Maintainer: Deepak Saxena <dsaxena@plexity.net>
	*
	* Copyright (C) 2002 Intel Corporation.
	* Copyright (C) 2003 Greg Ungerer <gerg@snapgear.com>
	* Copyright (C) 2003-2004 MontaVista Software, Inc.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	*/

	#include <linux/sched.h>
	#include <linux/kernel.h>
	#include <linux/pci.h>
	#include <linux/interrupt.h>
	#include <linux/mm.h>
	#include <linux/init.h>
	#include <linux/ioport.h>
	#include <linux/slab.h>
	#include <linux/delay.h>
	#include <linux/device.h>
	#include <asm/dma-mapping.h>

	#include <asm/io.h>
	#include <asm/irq.h>
	#include <asm/sizes.h>
	#include <asm/system.h>
	#include <asm/mach/pci.h>
	#include <asm/hardware.h>


	/*
	* IXP4xx PCI read function is dependent on whether we are
	* running A0 or B0 (AppleGate) silicon.
	*/
	int (ixp4xx_pci_read)(u32 addr, u32 cmd, u32 data);

	/*
	* Base address for PCI regsiter region
	*/
	unsigned long ixp4xx_pci_reg_base = 0;

	/*
	* PCI cfg an I/O routines are done by programming a
	* command/byte enable register, and then read/writing
	* the data from a data regsiter. We need to ensure
	* these transactions are atomic or we will end up
	* with corrupt data on the bus or in a driver.
	*/
	static DEFINE_SPINLOCK(ixp4xx_pci_lock);

	/*
	* Read from PCI config space
	*/
	static void crp_read(u32 ad_cbe, u32 *data)
	{
	unsigned long flags;
	spin_lock_irqsave(&ixp4xx_pci_lock, flags);
	*PCI_CRP_AD_CBE = ad_cbe;
	data = PCI_CRP_RDATA;
	spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
	}

	/*
	* Write to PCI config space
	*/
	static void crp_write(u32 ad_cbe, u32 data)
	{
	unsigned long flags;
	spin_lock_irqsave(&ixp4xx_pci_lock, flags);
	*PCI_CRP_AD_CBE = CRP_AD_CBE_WRITE \| ad_cbe;
	*PCI_CRP_WDATA = data;
	spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
	}

	static inline int check_master_abort(void)
	{
	/* check Master Abort bit after access */
	unsigned long isr = *PCI_ISR;

	if (isr & PCI_ISR_PFE) {
	/* make sure the Master Abort bit is reset */
	*PCI_ISR = PCI_ISR_PFE;
	pr_debug("%s failed\n", __FUNCTION__);
	return 1;
	}

	return 0;
	}

	int ixp4xx_pci_read_errata(u32 addr, u32 cmd, u32* data)
	{
	unsigned long flags;
	int retval = 0;
	int i;

	spin_lock_irqsave(&ixp4xx_pci_lock, flags);

	*PCI_NP_AD = addr;

	/*
	* PCI workaround - only works if NP PCI space reads have
	* no side effects!!! Read 8 times. last one will be good.
	*/
	for (i = 0; i < 8; i++) {
	*PCI_NP_CBE = cmd;
	data = PCI_NP_RDATA;
	data = PCI_NP_RDATA;
	}

	if(check_master_abort())
	retval = 1;

	spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
	return retval;
	}

	int ixp4xx_pci_read_no_errata(u32 addr, u32 cmd, u32* data)
	{
	unsigned long flags;
	int retval = 0;

	spin_lock_irqsave(&ixp4xx_pci_lock, flags);

	*PCI_NP_AD = addr;

	/* set up and execute the read */
	*PCI_NP_CBE = cmd;

	/* the result of the read is now in NP_RDATA */
	data = PCI_NP_RDATA;

	if(check_master_abort())
	retval = 1;

	spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
	return retval;
	}

	int ixp4xx_pci_write(u32 addr, u32 cmd, u32 data)
	{
	unsigned long flags;
	int retval = 0;

	spin_lock_irqsave(&ixp4xx_pci_lock, flags);

	*PCI_NP_AD = addr;

	/* set up the write */
	*PCI_NP_CBE = cmd;

	/* execute the write by writing to NP_WDATA */
	*PCI_NP_WDATA = data;

	if(check_master_abort())
	retval = 1;

	spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
	return retval;
	}

	static u32 ixp4xx_config_addr(u8 bus_num, u16 devfn, int where)
	{
	u32 addr;
	if (!bus_num) {
	/* type 0 */
	addr = BIT(32-PCI_SLOT(devfn)) \| ((PCI_FUNC(devfn)) << 8) \|
	(where & ~3);
	} else {
	/* type 1 */
	addr = (bus_num << 16) \| ((PCI_SLOT(devfn)) << 11) \|
	((PCI_FUNC(devfn)) << 8) \| (where & ~3) \| 1;
	}
	return addr;
	}

	/*
	* Mask table, bits to mask for quantity of size 1, 2 or 4 bytes.
	* 0 and 3 are not valid indexes...
	*/
	static u32 bytemask[] = {
	/0/ 0,
	/1/ 0xff,
	/2/ 0xffff,
	/3/ 0,
	/4/ 0xffffffff,
	};

	static u32 local_byte_lane_enable_bits(u32 n, int size)
	{
	if (size == 1)
	return (0xf & ~BIT(n)) << CRP_AD_CBE_BESL;
	if (size == 2)
	return (0xf & ~(BIT(n) \| BIT(n+1))) << CRP_AD_CBE_BESL;
	if (size == 4)
	return 0;
	return 0xffffffff;
	}

	static int local_read_config(int where, int size, u32 *value)
	{
	u32 n, data;
	pr_debug("local_read_config from %d size %d\n", where, size);
	n = where % 4;
	crp_read(where & ~3, &data);
	value = (data >> (8n)) & bytemask[size];
	pr_debug("local_read_config read %#x\n", *value);
	return PCIBIOS_SUCCESSFUL;
	}

	static int local_write_config(int where, int size, u32 value)
	{
	u32 n, byte_enables, data;
	pr_debug("local_write_config %#x to %d size %d\n", value, where, size);
	n = where % 4;
	byte_enables = local_byte_lane_enable_bits(n, size);
	if (byte_enables == 0xffffffff)
	return PCIBIOS_BAD_REGISTER_NUMBER;
	data = value << (8*n);
	crp_write((where & ~3) \| byte_enables, data);
	return PCIBIOS_SUCCESSFUL;
	}

	static u32 byte_lane_enable_bits(u32 n, int size)
	{
	if (size == 1)
	return (0xf & ~BIT(n)) << 4;
	if (size == 2)
	return (0xf & ~(BIT(n) \| BIT(n+1))) << 4;
	if (size == 4)
	return 0;
	return 0xffffffff;
	}

	static int ixp4xx_pci_read_config(struct pci_bus bus, unsigned int devfn, int where, int size, u32 value)
	{
	u32 n, byte_enables, addr, data;
	u8 bus_num = bus->number;

	pr_debug("read_config from %d size %d dev %d:%d:%d\n", where, size,
	bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn));

	*value = 0xffffffff;
	n = where % 4;
	byte_enables = byte_lane_enable_bits(n, size);
	if (byte_enables == 0xffffffff)
	return PCIBIOS_BAD_REGISTER_NUMBER;

	addr = ixp4xx_config_addr(bus_num, devfn, where);
	if (ixp4xx_pci_read(addr, byte_enables \| NP_CMD_CONFIGREAD, &data))
	return PCIBIOS_DEVICE_NOT_FOUND;

	value = (data >> (8n)) & bytemask[size];
	pr_debug("read_config_byte read %#x\n", *value);
	return PCIBIOS_SUCCESSFUL;
	}

	static int ixp4xx_pci_write_config(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 value)
	{
	u32 n, byte_enables, addr, data;
	u8 bus_num = bus->number;

	pr_debug("write_config_byte %#x to %d size %d dev %d:%d:%d\n", value, where,
	size, bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn));

	n = where % 4;
	byte_enables = byte_lane_enable_bits(n, size);
	if (byte_enables == 0xffffffff)
	return PCIBIOS_BAD_REGISTER_NUMBER;

	addr = ixp4xx_config_addr(bus_num, devfn, where);
	data = value << (8*n);
	if (ixp4xx_pci_write(addr, byte_enables \| NP_CMD_CONFIGWRITE, data))
	return PCIBIOS_DEVICE_NOT_FOUND;

	return PCIBIOS_SUCCESSFUL;
	}

	struct pci_ops ixp4xx_ops = {
	.read = ixp4xx_pci_read_config,
	.write = ixp4xx_pci_write_config,
	};

	/*
	* PCI abort handler
	*/
	static int abort_handler(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
	{
	u32 isr, status;

	isr = *PCI_ISR;
	local_read_config(PCI_STATUS, 2, &status);
	pr_debug("PCI: abort_handler addr = %#lx, isr = %#x, "
	"status = %#x\n", addr, isr, status);

	/* make sure the Master Abort bit is reset */
	*PCI_ISR = PCI_ISR_PFE;
	status \|= PCI_STATUS_REC_MASTER_ABORT;
	local_write_config(PCI_STATUS, 2, status);

	/*
	* If it was an imprecise abort, then we need to correct the
	* return address to be _after_ the instruction.
	*/
	if (fsr & (1 << 10))
	regs->ARM_pc += 4;

	return 0;
	}


	/*
	* Setup DMA mask to 64MB on PCI devices. Ignore all other devices.
	*/
	static int ixp4xx_pci_platform_notify(struct device *dev)
	{
	if(dev->bus == &pci_bus_type) {
	*dev->dma_mask = SZ_64M - 1;
	dev->coherent_dma_mask = SZ_64M - 1;
	dmabounce_register_dev(dev, 2048, 4096);
	}
	return 0;
	}

	static int ixp4xx_pci_platform_notify_remove(struct device *dev)
	{
	if(dev->bus == &pci_bus_type) {
	dmabounce_unregister_dev(dev);
	}
	return 0;
	}

	int dma_needs_bounce(struct device *dev, dma_addr_t dma_addr, size_t size)
	{
	return (dev->bus == &pci_bus_type ) && ((dma_addr + size) >= SZ_64M);
	}

	void __init ixp4xx_pci_preinit(void)
	{
	unsigned long processor_id;

	asm("mrc p15, 0, %0, cr0, cr0, 0;" : "=r"(processor_id) :);

	/*
	* Determine which PCI read method to use.
	* Rev 0 IXP425 requires workaround.
	*/
	if (!(processor_id & 0xf) && !cpu_is_ixp46x()) {
	printk("PCI: IXP42x A0 silicon detected - "
	"PCI Non-Prefetch Workaround Enabled\n");
	ixp4xx_pci_read = ixp4xx_pci_read_errata;
	} else
	ixp4xx_pci_read = ixp4xx_pci_read_no_errata;


	/* hook in our fault handler for PCI errors */
	hook_fault_code(16+6, abort_handler, SIGBUS, "imprecise external abort");

	pr_debug("setup PCI-AHB(inbound) and AHB-PCI(outbound) address mappings\n");

	/*
	* We use identity AHB->PCI address translation
	* in the 0x48000000 to 0x4bffffff address space
	*/
	*PCI_PCIMEMBASE = 0x48494A4B;

	/*
	* We also use identity PCI->AHB address translation
	* in 4 16MB BARs that begin at the physical memory start
	*/
	*PCI_AHBMEMBASE = (PHYS_OFFSET & 0xFF000000) +
	((PHYS_OFFSET & 0xFF000000) >> 8) +
	((PHYS_OFFSET & 0xFF000000) >> 16) +
	((PHYS_OFFSET & 0xFF000000) >> 24) +
	0x00010203;

	if (*PCI_CSR & PCI_CSR_HOST) {
	printk("PCI: IXP4xx is host\n");

	pr_debug("setup BARs in controller\n");

	/*
	* We configure the PCI inbound memory windows to be
	* 1:1 mapped to SDRAM
	*/
	local_write_config(PCI_BASE_ADDRESS_0, 4, PHYS_OFFSET + 0x00000000);
	local_write_config(PCI_BASE_ADDRESS_1, 4, PHYS_OFFSET + 0x01000000);
	local_write_config(PCI_BASE_ADDRESS_2, 4, PHYS_OFFSET + 0x02000000);
	local_write_config(PCI_BASE_ADDRESS_3, 4, PHYS_OFFSET + 0x03000000);

	/*
	* Enable CSR window at 0xff000000.
	*/
	local_write_config(PCI_BASE_ADDRESS_4, 4, 0xff000008);

	/*
	* Enable the IO window to be way up high, at 0xfffffc00
	*/
	local_write_config(PCI_BASE_ADDRESS_5, 4, 0xfffffc01);
	} else {
	printk("PCI: IXP4xx is target - No bus scan performed\n");
	}

	printk("PCI: IXP4xx Using %s access for memory space\n",
	#ifndef CONFIG_IXP4XX_INDIRECT_PCI
	"direct"
	#else
	"indirect"
	#endif
	);

	pr_debug("clear error bits in ISR\n");
	*PCI_ISR = PCI_ISR_PSE \| PCI_ISR_PFE \| PCI_ISR_PPE \| PCI_ISR_AHBE;

	/*
	* Set Initialize Complete in PCI Control Register: allow IXP4XX to
	* respond to PCI configuration cycles. Specify that the AHB bus is
	* operating in big endian mode. Set up byte lane swapping between
	* little-endian PCI and the big-endian AHB bus
	*/
	#ifdef __ARMEB__
	*PCI_CSR = PCI_CSR_IC \| PCI_CSR_ABE \| PCI_CSR_PDS \| PCI_CSR_ADS;
	#else
	*PCI_CSR = PCI_CSR_IC;
	#endif

	pr_debug("DONE\n");
	}

	int ixp4xx_setup(int nr, struct pci_sys_data *sys)
	{
	struct resource *res;

	if (nr >= 1)
	return 0;

	res = kmalloc(sizeof(res) 2, GFP_KERNEL);
	if (res == NULL) {
	/*
	* If we're out of memory this early, something is wrong,
	* so we might as well catch it here.
	*/
	panic("PCI: unable to allocate resources?\n");
	}
	memset(res, 0, sizeof(res) 2);

	local_write_config(PCI_COMMAND, 2, PCI_COMMAND_MASTER \| PCI_COMMAND_MEMORY);

	res[0].name = "PCI I/O Space";
	res[0].start = 0x00001000;
	res[0].end = 0xffff0000;
	res[0].flags = IORESOURCE_IO;

	res[1].name = "PCI Memory Space";
	res[1].start = 0x48000000;
	#ifndef CONFIG_IXP4XX_INDIRECT_PCI
	res[1].end = 0x4bffffff;
	#else
	res[1].end = 0x4fffffff;
	#endif
	res[1].flags = IORESOURCE_MEM;

	request_resource(&ioport_resource, &res[0]);
	request_resource(&iomem_resource, &res[1]);

	sys->resource[0] = &res[0];
	sys->resource[1] = &res[1];
	sys->resource[2] = NULL;

	platform_notify = ixp4xx_pci_platform_notify;
	platform_notify_remove = ixp4xx_pci_platform_notify_remove;

	return 1;
	}

	struct pci_bus ixp4xx_scan_bus(int nr, struct pci_sys_data sys)
	{
	return pci_scan_bus(sys->busnr, &ixp4xx_ops, sys);
	}

	/*
	* We override these so we properly do dmabounce otherwise drivers
	* are able to set the dma_mask to 0xffffffff and we can no longer
	* trap bounces. :(
	*
	* We just return true on everyhing except for < 64MB in which case
	* we will fail miseralby and die since we can't handle that case.
	*/
	int
	pci_set_dma_mask(struct pci_dev *dev, u64 mask)
	{
	if (mask >= SZ_64M - 1 )
	return 0;

	return -EIO;
	}

	int
	pci_dac_set_dma_mask(struct pci_dev *dev, u64 mask)
	{
	if (mask >= SZ_64M - 1 )
	return 0;

	return -EIO;
	}

	int
	pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
	{
	if (mask >= SZ_64M - 1 )
	return 0;

	return -EIO;
	}

	EXPORT_SYMBOL(pci_set_dma_mask);
	EXPORT_SYMBOL(pci_dac_set_dma_mask);
	EXPORT_SYMBOL(pci_set_consistent_dma_mask);
	EXPORT_SYMBOL(ixp4xx_pci_read);
	EXPORT_SYMBOL(ixp4xx_pci_write);