path: root/arch/powerpc/platforms/iseries/pci.c

/*
 * Copyright (C) 2001 Allan Trautman, IBM Corporation
 * Copyright (C) 2005,2007  Stephen Rothwell, IBM Corp
 *
 * iSeries specific routines for PCI.
 *
 * Based on code from pci.c and iSeries_pci.c 32bit
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#undef DEBUG

#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/of.h>
#include <linux/ratelimit.h>

#include <asm/types.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/pci-bridge.h>
#include <asm/iommu.h>
#include <asm/abs_addr.h>
#include <asm/firmware.h>

#include <asm/iseries/hv_types.h>
#include <asm/iseries/hv_call_xm.h>
#include <asm/iseries/mf.h>
#include <asm/iseries/iommu.h>

#include <asm/ppc-pci.h>

#include "irq.h"
#include "pci.h"
#include "call_pci.h"

#define PCI_RETRY_MAX	3
static int limit_pci_retries = 1;	/* Set Retry Error on. */

/*
 * Table defines
 * Each Entry size is 4 MB * 1024 Entries = 4GB I/O address space.
 */
#define IOMM_TABLE_MAX_ENTRIES	1024
#define IOMM_TABLE_ENTRY_SIZE	0x0000000000400000UL
#define BASE_IO_MEMORY		0xE000000000000000UL
#define END_IO_MEMORY		0xEFFFFFFFFFFFFFFFUL

static unsigned long max_io_memory = BASE_IO_MEMORY;
static long current_iomm_table_entry;

/*
 * Lookup Tables.
 */
static struct device_node *iomm_table[IOMM_TABLE_MAX_ENTRIES];
static u64 ds_addr_table[IOMM_TABLE_MAX_ENTRIES];

static DEFINE_SPINLOCK(iomm_table_lock);

/*
 * Generate a Direct Select Address for the Hypervisor
 */
static inline u64 iseries_ds_addr(struct device_node *node)
{
	struct pci_dn *pdn = PCI_DN(node);
	const u32 *sbp = of_get_property(node, "linux,subbus", NULL);

	return ((u64)pdn->busno << 48) + ((u64)(sbp ? *sbp : 0) << 40)
			+ ((u64)0x10 << 32);
}

/*
 * Size of Bus VPD data
 */
#define BUS_VPDSIZE      1024

/*
 * Bus Vpd Tags
 */
#define VPD_END_OF_AREA		0x79
#define VPD_ID_STRING		0x82
#define VPD_VENDOR_AREA		0x84

/*
 * Mfg Area Tags
 */
#define VPD_FRU_FRAME_ID	0x4649	/* "FI" */
#define VPD_SLOT_MAP_FORMAT	0x4D46	/* "MF" */
#define VPD_SLOT_MAP		0x534D	/* "SM" */

/*
 * Structures of the areas
 */
struct mfg_vpd_area {
	u16	tag;
	u8	length;
	u8	data1;
	u8	data2;
};
#define MFG_ENTRY_SIZE   3

struct slot_map {
	u8	agent;
	u8	secondary_agent;
	u8	phb;
	char	card_location[3];
	char	parms[8];
	char	reserved[2];
};
#define SLOT_ENTRY_SIZE   16

/*
 * Parse the Slot Area
 */
static void __init iseries_parse_slot_area(struct slot_map *map, int len,
		HvAgentId agent, u8 *phb, char card[4])
{
	/*
	 * Parse Slot label until we find the one requested
	 */
	while (len > 0) {
		if (map->agent == agent) {
			/*
			 * If Phb wasn't found, grab the entry first one found.
			 */
			if (*phb == 0xff)
				*phb = map->phb;
			/* Found it, extract the data. */
			if (map->phb == *phb) {
				memcpy(card, &map->card_location, 3);
				card[3]  = 0;
				break;
			}
		}
		/* Point to the next Slot */
		map = (struct slot_map *)((char *)map + SLOT_ENTRY_SIZE);
		len -= SLOT_ENTRY_SIZE;
	}
}

/*
 * Parse the Mfg Area
 */
static void __init iseries_parse_mfg_area(struct mfg_vpd_area *area, int len,
		HvAgentId agent, u8 *phb, u8 *frame, char card[4])
{
	u16 slot_map_fmt = 0;

	/* Parse Mfg Data */
	while (len > 0) {
		int mfg_tag_len = area->length;
		/* Frame ID         (FI 4649020310 ) */
		if (area->tag == VPD_FRU_FRAME_ID)
			*frame = area->data1;
		/* Slot Map Format  (MF 4D46020004 ) */
		else if (area->tag == VPD_SLOT_MAP_FORMAT)
			slot_map_fmt = (area->data1 * 256)
				+ area->data2;
		/* Slot Map         (SM 534D90 */
		else if (area->tag == VPD_SLOT_MAP) {
			struct slot_map *slot_map;

			if (slot_map_fmt == 0x1004)
				slot_map = (struct slot_map *)((char *)area
						+ MFG_ENTRY_SIZE + 1);
			else
				slot_map = (struct slot_map *)((char *)area
						+ MFG_ENTRY_SIZE);
			iseries_parse_slot_area(slot_map, mfg_tag_len,
					agent, phb, card);
		}
		/*
		 * Point to the next Mfg Area
		 * Use defined size, sizeof give wrong answer
		 */
		area = (struct mfg_vpd_area *)((char *)area + mfg_tag_len
				+ MFG_ENTRY_SIZE);
		len -= (mfg_tag_len + MFG_ENTRY_SIZE);
	}
}

/*
 * Look for "BUS".. Data is not Null terminated.
 * PHBID of 0xFF indicates PHB was not found in VPD Data.
 */
static u8 __init iseries_parse_phbid(u8 *area, int len)
{
	while (len > 0) {
		if ((*area == 'B') && (*(area + 1) == 'U')
				&& (*(area + 2) == 'S')) {
			area += 3;
			while (*area == ' ')
				area++;
			return *area & 0x0F;
		}
		area++;
		len--;
	}
	return 0xff;
}

/*
 * Parse out the VPD Areas
 */
static void __init iseries_parse_vpd(u8 *data, int data_len,
		HvAgentId agent, u8 *frame, char card[4])
{
	u8 phb = 0xff;

	while (data_len > 0) {
		int len;
		u8 tag = *data;

		if (tag == VPD_END_OF_AREA)
			break;
		len = *(data + 1) + (*(data + 2) * 256);
		data += 3;
		data_len -= 3;
		if (tag == VPD_ID_STRING)
			phb = iseries_parse_phbid(data, len);
		else if (tag == VPD_VENDOR_AREA)
			iseries_parse_mfg_area((struct mfg_vpd_area *)data, len,
					agent, &phb, frame, card);
		/* Point to next Area. */
		data += len;
		data_len -= len;
	}
}

static int __init iseries_get_location_code(u16 bus, HvAgentId agent,
		u8 *frame, char card[4])
{
	int status = 0;
	int bus_vpd_len = 0;
	u8 *bus_vpd = kmalloc(BUS_VPDSIZE, GFP_KERNEL);

	if (bus_vpd == NULL) {
		printk("PCI: Bus VPD Buffer allocation failure.\n");
		return 0;
	}
	bus_vpd_len = HvCallPci_getBusVpd(bus, iseries_hv_addr(bus_vpd),
					BUS_VPDSIZE);
	if (bus_vpd_len == 0) {
		printk("PCI: Bus VPD Buffer zero length.\n");
		goto out_free;
	}
	/* printk("PCI: bus_vpd: %p, %d\n",bus_vpd, bus_vpd_len); */
	/* Make sure this is what I think it is */
	if (*bus_vpd != VPD_ID_STRING) {
		printk("PCI: Bus VPD Buffer missing starting tag.\n");
		goto out_free;
	}
	iseries_parse_vpd(bus_vpd, bus_vpd_len, agent, frame, card);
	status = 1;
out_free:
	kfree(bus_vpd);
	return status;
}

/*
 * Prints the device information.
 * - Pass in pci_dev* pointer to the device.
 * - Pass in the device count
 *
 * Format:
 * PCI: Bus  0, Device 26, Vendor 0x12AE  Frame  1, Card  C10  Ethernet
 * controller
 */
static void __init iseries_device_information(struct pci_dev *pdev,
					      u16 bus, HvSubBusNumber subbus)
{
	u8 frame = 0;
	char card[4];
	HvAgentId agent;

	agent = ISERIES_PCI_AGENTID(ISERIES_GET_DEVICE_FROM_SUBBUS(subbus),
			ISERIES_GET_FUNCTION_FROM_SUBBUS(subbus));

	if (iseries_get_location_code(bus, agent, &frame, card)) {
		printk(KERN_INFO "PCI: %s, Vendor %04X Frame%3d, "
		       "Card %4s  0x%04X\n", pci_name(pdev), pdev->vendor,
		       frame, card, (int)(pdev->class >> 8));
	}
}

/*
 * iomm_table_allocate_entry
 *
 * Adds pci_dev entry in address translation table
 *
 * - Allocates the number of entries required in table base on BAR
 *   size.
 * - Allocates starting at BASE_IO_MEMORY and increases.
 * - The size is round up to be a multiple of entry size.
 * - CurrentIndex is incremented to keep track of the last entry.
 * - Builds the resource entry for allocated BARs.
 */
static void __init iomm_table_allocate_entry(struct pci_dev *dev, int bar_num)
{
	struct resource *bar_res = &dev->resource[bar_num];
	long bar_size = pci_resource_len(dev, bar_num);
	struct device_node *dn = pci_device_to_OF_node(dev);

	/*
	 * No space to allocate, quick exit, skip Allocation.
	 */
	if (bar_size == 0)
		return;
	/*
	 * Set Resource values.
	 */
	spin_lock(&iomm_table_lock);
	bar_res->start = BASE_IO_MEMORY +
		IOMM_TABLE_ENTRY_SIZE * current_iomm_table_entry;
	bar_res->end = bar_res->start + bar_size - 1;
	/*
	 * Allocate the number of table entries needed for BAR.
	 */
	while (bar_size > 0 ) {
		iomm_table[current_iomm_table_entry] = dn;
		ds_addr_table[current_iomm_table_entry] =
			iseries_ds_addr(dn) | (bar_num << 24);
		bar_size -= IOMM_TABLE_ENTRY_SIZE;
		++current_iomm_table_entry;
	}
	max_io_memory = BASE_IO_MEMORY +
		IOMM_TABLE_ENTRY_SIZE * current_iomm_table_entry;
	spin_unlock(&iomm_table_lock);
}

/*
 * allocate_device_bars
 *
 * - Allocates ALL pci_dev BAR's and updates the resources with the
 *   BAR value.  BARS with zero length will have the resources
 *   The HvCallPci_getBarParms is used to get the size of the BAR
 *   space.  It calls iomm_table_allocate_entry to allocate
 *   each entry.
 * - Loops through The Bar resources(0 - 5) including the ROM
 *   is resource(6).
 */
static void __init allocate_device_bars(struct pci_dev *dev)
{
	int bar_num;

	for (bar_num = 0; bar_num <= PCI_ROM_RESOURCE; ++bar_num)
		iomm_table_allocate_entry(dev, bar_num);
}

/*
 * Log error information to system console.
 * Filter out the device not there errors.
 * PCI: EADs Connect Failed 0x18.58.10 Rc: 0x00xx
 * PCI: Read Vendor Failed 0x18.58.10 Rc: 0x00xx
 * PCI: Connect Bus Unit Failed 0x18.58.10 Rc: 0x00xx
 */
static void pci_log_error(char *error, int bus, int subbus,
		int agent, int hv_res)
{
	if (hv_res == 0x0302)
		return;
	printk(KERN_ERR "PCI: %s Failed: 0x%02X.%02X.%02X Rc: 0x%04X",
	       error, bus, subbus, agent, hv_res);
}

/*
 * Look down the chain to find the matching Device Device
 */
static struct device_node *find_device_node(int bus, int devfn)
{
	struct device_node *node;

	for (node = NULL; (node = of_find_all_nodes(node)); ) {
		struct pci_dn *pdn = PCI_DN(node);

		if (pdn && (bus == pdn->busno) && (devfn == pdn->devfn))
			return node;
	}
	return NULL;
}

/*
 * iSeries_pcibios_fixup_resources
 *
 * Fixes up all resources for devices
 */
void __init iSeries_pcibios_fixup_resources(struct pci_dev *pdev)
{
	const u32 *agent;
	const u32 *sub_bus;
	unsigned char bus = pdev->bus->number;
	struct device_node *node;
	int i;

	node = pci_device_to_OF_node(pdev);
	pr_debug("PCI: iSeries %s, pdev %p, node %p\n",
		 pci_name(pdev), pdev, node);
	if (!node) {
		printk("PCI: %s disabled, device tree entry not found !\n",
		       pci_name(pdev));
		for (i = 0; i <= PCI_ROM_RESOURCE; i++)
			pdev->resource[i].flags = 0;
		return;
	}
	sub_bus = of_get_property(node, "linux,subbus", NULL);
	agent = of_get_property(node, "linux,agent-id", NULL);
	if (agent && sub_bus) {
		u8 irq = iSeries_allocate_IRQ(bus, 0, *sub_bus);
		int err;

		err = HvCallXm_connectBusUnit(bus, *sub_bus, *agent, irq);
		if (err)
			pci_log_error("Connect Bus Unit",
				      bus, *sub_bus, *agent, err);
		else {
			err = HvCallPci_configStore8(bus, *sub_bus,
					*agent, PCI_INTERRUPT_LINE, irq);
			if (err)
				pci_log_error("PciCfgStore Irq Failed!",
						bus, *sub_bus, *agent, err);
			else
				pdev->irq = irq;
		}
	}

	allocate_device_bars(pdev);
	iseries_device_information(pdev, bus, *sub_bus);
}

/*
 * iSeries_pci_final_fixup(void)
 */
void __init iSeries_pci_final_fixup(void)
{
	/* Fix up at the device node and pci_dev relationship */
	mf_display_src(0xC9000100);
	iSeries_activate_IRQs();
	mf_display_src(0xC9000200);
}

/*
 * Config space read and write functions.
 * For now at least, we look for the device node for the bus and devfn
 * that we are asked to access.  It may be possible to translate the devfn
 * to a subbus and deviceid more directly.
 */
static u64 hv_cfg_read_func[4]  = {
	HvCallPciConfigLoad8, HvCallPciConfigLoad16,
	HvCallPciConfigLoad32, HvCallPciConfigLoad32
};

static u64 hv_cfg_write_func[4] = {
	HvCallPciConfigStore8, HvCallPciConfigStore16,
	HvCallPciConfigStore32, HvCallPciConfigStore32
};

/*
 * Read PCI config space
 */
static int iSeries_pci_read_config(struct pci_bus *bus, unsigned int devfn,
		int offset, int size, u32 *val)
{
	struct device_node *node = find_device_node(bus->number, devfn);
	u64 fn;
	struct HvCallPci_LoadReturn ret;

	if (node == NULL)
		return PCIBIOS_DEVICE_NOT_FOUND;
	if (offset > 255) {
		*val = ~0;
		return PCIBIOS_BAD_REGISTER_NUMBER;
	}

	fn = hv_cfg_read_func[(size - 1) & 3];
	HvCall3Ret16(fn, &ret, iseries_ds_addr(node), offset, 0);

	if (ret.rc != 0) {
		*val = ~0;
		return PCIBIOS_DEVICE_NOT_FOUND;	/* or something */
	}

	*val = ret.value;
	return 0;
}

/*
 * Write PCI config space
 */

static int iSeries_pci_write_config(struct pci_bus *bus, unsigned int devfn,
		int offset, int size, u32 val)
{
	struct device_node *node = find_device_node(bus->number, devfn);
	u64 fn;
	u64 ret;

	if (node == NULL)
		return PCIBIOS_DEVICE_NOT_FOUND;
	if (offset > 255)
		return PCIBIOS_BAD_REGISTER_NUMBER;

	fn = hv_cfg_write_func[(size - 1) & 3];
	ret = HvCall4(fn, iseries_ds_addr(node), offset, val, 0);

	if (ret != 0)
		return PCIBIOS_DEVICE_NOT_FOUND;

	return 0;
}

static struct pci_ops iSeries_pci_ops = {
	.read = iSeries_pci_read_config,
	.write = iSeries_pci_write_config
};

/*
 * Check Return Code
 * -> On Failure, print and log information.
 *    Increment Retry Count, if exceeds max, panic partition.
 *
 * PCI: Device 23.90 ReadL I/O Error( 0): 0x1234
 * PCI: Device 23.90 ReadL Retry( 1)
 * PCI: Device 23.90 ReadL Retry Successful(1)
 */
static int check_return_code(char *type, struct device_node *dn,
		int *retry, u64 ret)
{
	if (ret != 0)  {
		struct pci_dn *pdn = PCI_DN(dn);

		(*retry)++;
		printk("PCI: %s: Device 0x%04X:%02X  I/O Error(%2d): 0x%04X\n",
				type, pdn->busno, pdn->devfn,
				*retry, (int)ret);
		/*
		 * Bump the retry and check for retry count exceeded.
		 * If, Exceeded, panic the system.
		 */
		if (((*retry) > PCI_RETRY_MAX) &&
				(limit_pci_retries > 0)) {
			mf_display_src(0xB6000103);
			panic_timeout = 0;
			panic("PCI: Hardware I/O Error, SRC B6000103, "
					"Automatic Reboot Disabled.\n");
		}
		return -1;	/* Retry Try */
	}
	return 0;
}

/*
 * Translate the I/O Address into a device node, bar, and bar offset.
 * Note: Make sure the passed variable end up on the stack to avoid
 * the exposure of being device global.
 */
static inline struct device_node *xlate_iomm_address(
		const volatile void __iomem *addr,
		u64 *dsaptr, u64 *bar_offset, const char *func)
{
	unsigned long orig_addr;
	unsigned long base_addr;
	unsigned long ind;
	struct device_node *dn;

	orig_addr = (unsigned long __force)addr;
	if ((orig_addr < BASE_IO_MEMORY) || (orig_addr >= max_io_memory)) {
		static DEFINE_RATELIMIT_STATE(ratelimit, 60 * HZ, 10);

		if (__ratelimit(&ratelimit))
			printk(KERN_ERR
				"iSeries_%s: invalid access at IO address %p\n",
				func, addr);
		return NULL;
	}
	base_addr = orig_addr - BASE_IO_MEMORY;
	ind = base_addr / IOMM_TABLE_ENTRY_SIZE;
	dn = iomm_table[ind];

	if (dn != NULL) {
		*dsaptr = ds_addr_table[ind];
		*bar_offset = base_addr % IOMM_TABLE_ENTRY_SIZE;
	} else
		panic("PCI: Invalid PCI IO address detected!\n");
	return dn;
}

/*
 * Read MM I/O Instructions for the iSeries
 * On MM I/O error, all ones are returned and iSeries_pci_IoError is cal
 * else, data is returned in Big Endian format.
 */
static u8 iseries_readb(const volatile void __iomem *addr)
{
	u64 bar_offset;
	u64 dsa;
	int retry = 0;
	struct HvCallPci_LoadReturn ret;
	struct device_node *dn =
		xlate_iomm_address(addr, &dsa, &bar_offset, "read_byte");

	if (dn == NULL)
		return 0xff;
	do {
		HvCall3Ret16(HvCallPciBarLoad8, &ret, dsa, bar_offset, 0);
	} while (check_return_code("RDB", dn, &retry, ret.rc) != 0);

	return ret.value;
}

static u16 iseries_readw_be(const volatile void __iomem *addr)
{
	u64 bar_offset;
	u64 dsa;
	int retry = 0;
	struct HvCallPci_LoadReturn ret;
	struct device_node *dn =
		xlate_iomm_address(addr, &dsa, &bar_offset, "read_word");

	if (dn == NULL)
		return 0xffff;
	do {
		HvCall3Ret16(HvCallPciBarLoad16, &ret, dsa,
				bar_offset, 0);
	} while (check_return_code("RDW", dn, &retry, ret.rc) != 0);

	return ret.value;
}

static u32 iseries_readl_be(const volatile void __iomem *addr)
{
	u64 bar_offset;
	u64 dsa;
	int retry = 0;
	struct HvCallPci_LoadReturn ret;
	struct device_node *dn =
		xlate_iomm_address(addr, &dsa, &bar_offset, "read_long");

	if (dn == NULL)
		return 0xffffffff;
	do {
		HvCall3Ret16(HvCallPciBarLoad32, &ret, dsa,
				bar_offset, 0);
	} while (check_return_code("RDL", dn, &retry, ret.rc) != 0);

	return ret.value;
}

/*
 * Write MM I/O Instructions for the iSeries
 *
 */
static void iseries_writeb(u8 data, volatile void __iomem *addr)
{
	u64 bar_offset;
	u64 dsa;
	int retry = 0;
	u64 rc;
	struct device_node *dn =
		xlate_iomm_address(addr, &dsa, &bar_offset, "write_byte");

	if (dn == NULL)
		return;
	do {
		rc = HvCall4(HvCallPciBarStore8, dsa, bar_offset, data, 0);
	} while (check_return_code("WWB", dn, &retry, rc) != 0);
}

static void iseries_writew_be(u16 data, volatile void __iomem *addr)
{
	u64 bar_offset;
	u64 dsa;
	int retry = 0;
	u64 rc;
	struct device_node *dn =
		xlate_iomm_address(addr, &dsa, &bar_offset, "write_word");

	if (dn == NULL)
		return;
	do {
		rc = HvCall4(HvCallPciBarStore16, dsa, bar_offset, data, 0);
	} while (check_return_code("WWW", dn, &retry, rc) != 0);
}

static void iseries_writel_be(u32 data, volatile void __iomem *addr)
{
	u64 bar_offset;
	u64 dsa;
	int retry = 0;
	u64 rc;
	struct device_node *dn =
		xlate_iomm_address(addr, &dsa, &bar_offset, "write_long");

	if (dn == NULL)
		return;
	do {
		rc = HvCall4(HvCallPciBarStore32, dsa, bar_offset, data, 0);
	} while (check_return_code("WWL", dn, &retry, rc) != 0);
}

static u16 iseries_readw(const volatile void __iomem *addr)
{
	return le16_to_cpu(iseries_readw_be(addr));
}

static u32 iseries_readl(const volatile void __iomem *addr)
{
	return le32_to_cpu(iseries_readl_be(addr));
}

static void iseries_writew(u16 data, volatile void __iomem *addr)
{
	iseries_writew_be(cpu_to_le16(data), addr);
}

static void iseries_writel(u32 data, volatile void __iomem *addr)
{
	iseries_writel(cpu_to_le32(data), addr);
}

static void iseries_readsb(const volatile void __iomem *addr, void *buf,
			   unsigned long count)
{
	u8 *dst = buf;
	while(count-- > 0)
		*(dst++) = iseries_readb(addr);
}

static void iseries_readsw(const volatile void __iomem *addr, void *buf,
			   unsigned long count)
{
	u16 *dst = buf;
	while(count-- > 0)
		*(dst++) = iseries_readw_be(addr);
}

static void iseries_readsl(const volatile void __iomem *addr, void *buf,
			   unsigned long count)
{
	u32 *dst = buf;
	while(count-- > 0)
		*(dst++) = iseries_readl_be(addr);
}

static void iseries_writesb(volatile void __iomem *addr, const void *buf,
			    unsigned long count)
{
	const u8 *src = buf;
	while(count-- > 0)
		iseries_writeb(*(src++), addr);
}

static void iseries_writesw(volatile void __iomem *addr, const void *buf,
			    unsigned long count)
{
	const u16 *src = buf;
	while(count-- > 0)
		iseries_writew_be(*(src++), addr);
}

static void iseries_writesl(volatile void __iomem *addr, const void *buf,
			    unsigned long count)
{
	const u32 *src = buf;
	while(count-- > 0)
		iseries_writel_be(*(src++), addr);
}

static void iseries_memset_io(volatile void __iomem *addr, int c,
			      unsigned long n)
{
	volatile char __iomem *d = addr;

	while (n-- > 0)
		iseries_writeb(c, d++);
}

static void iseries_memcpy_fromio(void *dest, const volatile void __iomem *src,
				  unsigned long n)
{
	char *d = dest;
	const volatile char __iomem *s = src;

	while (n-- > 0)
		*d++ = iseries_readb(s++);
}

static void iseries_memcpy_toio(volatile void __iomem *dest, const void *src,
				unsigned long n)
{
	const char *s = src;
	volatile char __iomem *d = dest;

	while (n-- > 0)
		iseries_writeb(*s++, d++);
}

/* We only set MMIO ops. The default PIO ops will be default
 * to the MMIO ops + pci_io_base which is 0 on iSeries as
 * expected so both should work.
 *
 * Note that we don't implement the readq/writeq versions as
 * I don't know of an HV call for doing so. Thus, the default
 * operation will be used instead, which will fault a the value
 * return by iSeries for MMIO addresses always hits a non mapped
 * area. This is as good as the BUG() we used to have there.
 */
static struct ppc_pci_io __initdata iseries_pci_io = {
	.readb = iseries_readb,
	.readw = iseries_readw,
	.readl = iseries_readl,
	.readw_be = iseries_readw_be,
	.readl_be = iseries_readl_be,
	.writeb = iseries_writeb,
	.writew = iseries_writew,
	.writel = iseries_writel,
	.writew_be = iseries_writew_be,
	.writel_be = iseries_writel_be,
	.readsb = iseries_readsb,
	.readsw = iseries_readsw,
	.readsl = iseries_readsl,
	.writesb = iseries_writesb,
	.writesw = iseries_writesw,
	.writesl = iseries_writesl,
	.memset_io = iseries_memset_io,
	.memcpy_fromio = iseries_memcpy_fromio,
	.memcpy_toio = iseries_memcpy_toio,
};

/*
 * iSeries_pcibios_init
 *
 * Description:
 *   This function checks for all possible system PCI host bridges that connect
 *   PCI buses.  The system hypervisor is queried as to the guest partition
 *   ownership status.  A pci_controller is built for any bus which is partially
 *   owned or fully owned by this guest partition.
 */
void __init iSeries_pcibios_init(void)
{
	struct pci_controller *phb;
	struct device_node *root = of_find_node_by_path("/");
	struct device_node *node = NULL;

	/* Install IO hooks */
	ppc_pci_io = iseries_pci_io;

	pci_probe_only = 1;

	/* iSeries has no IO space in the common sense, it needs to set
	 * the IO base to 0
	 */
	pci_io_base = 0;

	if (root == NULL) {
		printk(KERN_CRIT "iSeries_pcibios_init: can't find root "
				"of device tree\n");
		return;
	}
	while ((node = of_get_next_child(root, node)) != NULL) {
		HvBusNumber bus;
		const u32 *busp;

		if ((node->type == NULL) || (strcmp(node->type, "pci") != 0))
			continue;

		busp = of_get_property(node, "bus-range", NULL);
		if (busp == NULL)
			continue;
		bus = *busp;
		printk("bus %d appears to exist\n", bus);
		phb = pcibios_alloc_controller(node);
		if (phb == NULL)
			continue;
		/* All legacy iSeries PHBs are in domain zero */
		phb->global_number = 0;

		phb->first_busno = bus;
		phb->last_busno = bus;
		phb->ops = &iSeries_pci_ops;
		phb->io_base_virt = (void __iomem *)_IO_BASE;
		phb->io_resource.flags = IORESOURCE_IO;
		phb->io_resource.start = BASE_IO_MEMORY;
		phb->io_resource.end = END_IO_MEMORY;
		phb->io_resource.name = "iSeries PCI IO";
		phb->mem_resources[0].flags = IORESOURCE_MEM;
		phb->mem_resources[0].start = BASE_IO_MEMORY;
		phb->mem_resources[0].end = END_IO_MEMORY;
		phb->mem_resources[0].name = "Series PCI MEM";
	}

	of_node_put(root);

	pci_devs_phb_init();
}