arch/ppc64/kernel/iSeries_irq.c - kernel/msm-4.19 - Gitiles

 /*
  * This module supports the iSeries PCI bus interrupt handling
  * Copyright (C) 20yy  <Robert L Holtorf> <IBM Corp>
  * Copyright (C) 2004-2005 IBM Corporation
  *
  * 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
  *
  * Change Activity:
  *   Created, December 13, 2000 by Wayne Holm
  * End Change Activity
  */
 #include <linux/config.h>
 #include <linux/pci.h>
 #include <linux/init.h>
 #include <linux/threads.h>
 #include <linux/smp.h>
 #include <linux/param.h>
 #include <linux/string.h>
 #include <linux/bootmem.h>
 #include <linux/ide.h>
 #include <linux/irq.h>
 #include <linux/spinlock.h>

 #include <asm/ppcdebug.h>
 #include <asm/iSeries/HvTypes.h>
 #include <asm/iSeries/HvLpEvent.h>
 #include <asm/iSeries/HvCallPci.h>
 #include <asm/iSeries/HvCallXm.h>
 #include <asm/iSeries/iSeries_irq.h>

 /* This maps virtual irq numbers to real irqs */
 unsigned int virt_irq_to_real_map[NR_IRQS];

 /* The next available virtual irq number */
 /* Note: the pcnet32 driver assumes irq numbers < 2 aren't valid. :( */
 static int next_virtual_irq = 2;

 static long Pci_Interrupt_Count;
 static long Pci_Event_Count;

 enum XmPciLpEvent_Subtype {
 	XmPciLpEvent_BusCreated		= 0,	// PHB has been created
 	XmPciLpEvent_BusError		= 1,	// PHB has failed
 	XmPciLpEvent_BusFailed		= 2,	// Msg to Secondary, Primary failed bus
 	XmPciLpEvent_NodeFailed		= 4,	// Multi-adapter bridge has failed
 	XmPciLpEvent_NodeRecovered	= 5,	// Multi-adapter bridge has recovered
 	XmPciLpEvent_BusRecovered	= 12,	// PHB has been recovered
 	XmPciLpEvent_UnQuiesceBus	= 18,	// Secondary bus unqiescing
 	XmPciLpEvent_BridgeError	= 21,	// Bridge Error
 	XmPciLpEvent_SlotInterrupt	= 22	// Slot interrupt
 };

 struct XmPciLpEvent_BusInterrupt {
 	HvBusNumber	busNumber;
 	HvSubBusNumber	subBusNumber;
 };

 struct XmPciLpEvent_NodeInterrupt {
 	HvBusNumber	busNumber;
 	HvSubBusNumber	subBusNumber;
 	HvAgentId	deviceId;
 };

 struct XmPciLpEvent {
 	struct HvLpEvent hvLpEvent;

 	union {
 		u64 alignData;			// Align on an 8-byte boundary

 		struct {
 			u32		fisr;
 			HvBusNumber	busNumber;
 			HvSubBusNumber	subBusNumber;
 			HvAgentId	deviceId;
 		} slotInterrupt;

 		struct XmPciLpEvent_BusInterrupt busFailed;
 		struct XmPciLpEvent_BusInterrupt busRecovered;
 		struct XmPciLpEvent_BusInterrupt busCreated;

 		struct XmPciLpEvent_NodeInterrupt nodeFailed;
 		struct XmPciLpEvent_NodeInterrupt nodeRecovered;

 	} eventData;

 };

 static void intReceived(struct XmPciLpEvent *eventParm,
 		struct pt_regs *regsParm)
 {
 	int irq;

 	++Pci_Interrupt_Count;

 	switch (eventParm->hvLpEvent.xSubtype) {
 	case XmPciLpEvent_SlotInterrupt:
 		irq = eventParm->hvLpEvent.xCorrelationToken;
 		/* Dispatch the interrupt handlers for this irq */
 		ppc_irq_dispatch_handler(regsParm, irq);
 		HvCallPci_eoi(eventParm->eventData.slotInterrupt.busNumber,
 			eventParm->eventData.slotInterrupt.subBusNumber,
 			eventParm->eventData.slotInterrupt.deviceId);
 		break;
 		/* Ignore error recovery events for now */
 	case XmPciLpEvent_BusCreated:
 		printk(KERN_INFO "intReceived: system bus %d created\n",
 			eventParm->eventData.busCreated.busNumber);
 		break;
 	case XmPciLpEvent_BusError:
 	case XmPciLpEvent_BusFailed:
 		printk(KERN_INFO "intReceived: system bus %d failed\n",
 			eventParm->eventData.busFailed.busNumber);
 		break;
 	case XmPciLpEvent_BusRecovered:
 	case XmPciLpEvent_UnQuiesceBus:
 		printk(KERN_INFO "intReceived: system bus %d recovered\n",
 			eventParm->eventData.busRecovered.busNumber);
 		break;
 	case XmPciLpEvent_NodeFailed:
 	case XmPciLpEvent_BridgeError:
 		printk(KERN_INFO
 			"intReceived: multi-adapter bridge %d/%d/%d failed\n",
 			eventParm->eventData.nodeFailed.busNumber,
 			eventParm->eventData.nodeFailed.subBusNumber,
 			eventParm->eventData.nodeFailed.deviceId);
 		break;
 	case XmPciLpEvent_NodeRecovered:
 		printk(KERN_INFO
 			"intReceived: multi-adapter bridge %d/%d/%d recovered\n",
 			eventParm->eventData.nodeRecovered.busNumber,
 			eventParm->eventData.nodeRecovered.subBusNumber,
 			eventParm->eventData.nodeRecovered.deviceId);
 		break;
 	default:
 		printk(KERN_ERR
 			"intReceived: unrecognized event subtype 0x%x\n",
 			eventParm->hvLpEvent.xSubtype);
 		break;
 	}
 }

 static void XmPciLpEvent_handler(struct HvLpEvent *eventParm,
 		struct pt_regs *regsParm)
 {
 #ifdef CONFIG_PCI
 	++Pci_Event_Count;

 	if (eventParm && (eventParm->xType == HvLpEvent_Type_PciIo)) {
 		switch (eventParm->xFlags.xFunction) {
 		case HvLpEvent_Function_Int:
 			intReceived((struct XmPciLpEvent *)eventParm, regsParm);
 			break;
 		case HvLpEvent_Function_Ack:
 			printk(KERN_ERR
 				"XmPciLpEvent_handler: unexpected ack received\n");
 			break;
 		default:
 			printk(KERN_ERR
 				"XmPciLpEvent_handler: unexpected event function %d\n",
 				(int)eventParm->xFlags.xFunction);
 			break;
 		}
 	} else if (eventParm)
 		printk(KERN_ERR
 			"XmPciLpEvent_handler: Unrecognized PCI event type 0x%x\n",
 			(int)eventParm->xType);
 	else
 		printk(KERN_ERR "XmPciLpEvent_handler: NULL event received\n");
 #endif
 }

 /*
  * This is called by init_IRQ.  set in ppc_md.init_IRQ by iSeries_setup.c
  * It must be called before the bus walk.
  */
 void __init iSeries_init_IRQ(void)
 {
 	/* Register PCI event handler and open an event path */
 	int xRc;

 	xRc = HvLpEvent_registerHandler(HvLpEvent_Type_PciIo,
 			&XmPciLpEvent_handler);
 	if (xRc == 0) {
 		xRc = HvLpEvent_openPath(HvLpEvent_Type_PciIo, 0);
 		if (xRc != 0)
 			printk(KERN_ERR "iSeries_init_IRQ: open event path "
 					"failed with rc 0x%x\n", xRc);
 	} else
 		printk(KERN_ERR "iSeries_init_IRQ: register handler "
 				"failed with rc 0x%x\n", xRc);
 }

 #define REAL_IRQ_TO_BUS(irq)	((((irq) >> 6) & 0xff) + 1)
 #define REAL_IRQ_TO_IDSEL(irq)	((((irq) >> 3) & 7) + 1)
 #define REAL_IRQ_TO_FUNC(irq)	((irq) & 7)

 /*
  * This will be called by device drivers (via enable_IRQ)
  * to enable INTA in the bridge interrupt status register.
  */
 static void iSeries_enable_IRQ(unsigned int irq)
 {
 	u32 bus, deviceId, function, mask;
 	const u32 subBus = 0;
 	unsigned int rirq = virt_irq_to_real_map[irq];

 	/* The IRQ has already been locked by the caller */
 	bus = REAL_IRQ_TO_BUS(rirq);
 	function = REAL_IRQ_TO_FUNC(rirq);
 	deviceId = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;

 	/* Unmask secondary INTA */
 	mask = 0x80000000;
 	HvCallPci_unmaskInterrupts(bus, subBus, deviceId, mask);
 	PPCDBG(PPCDBG_BUSWALK, "iSeries_enable_IRQ 0x%02X.%02X.%02X 0x%04X\n",
 			bus, subBus, deviceId, irq);
 }

 /* This is called by iSeries_activate_IRQs */
 static unsigned int iSeries_startup_IRQ(unsigned int irq)
 {
 	u32 bus, deviceId, function, mask;
 	const u32 subBus = 0;
 	unsigned int rirq = virt_irq_to_real_map[irq];

 	bus = REAL_IRQ_TO_BUS(rirq);
 	function = REAL_IRQ_TO_FUNC(rirq);
 	deviceId = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;

 	/* Link the IRQ number to the bridge */
 	HvCallXm_connectBusUnit(bus, subBus, deviceId, irq);

 	/* Unmask bridge interrupts in the FISR */
 	mask = 0x01010000 << function;
 	HvCallPci_unmaskFisr(bus, subBus, deviceId, mask);
 	iSeries_enable_IRQ(irq);
 	return 0;
 }

 /*
  * This is called out of iSeries_fixup to activate interrupt
  * generation for usable slots
  */
 void __init iSeries_activate_IRQs()
 {
 	int irq;
 	unsigned long flags;

 	for_each_irq (irq) {
 		irq_desc_t *desc = get_irq_desc(irq);

 		if (desc && desc->handler && desc->handler->startup) {
 			spin_lock_irqsave(&desc->lock, flags);
 			desc->handler->startup(irq);
 			spin_unlock_irqrestore(&desc->lock, flags);
 		}
 	}
 }

 /*  this is not called anywhere currently */
 static void iSeries_shutdown_IRQ(unsigned int irq)
 {
 	u32 bus, deviceId, function, mask;
 	const u32 subBus = 0;
 	unsigned int rirq = virt_irq_to_real_map[irq];

 	/* irq should be locked by the caller */
 	bus = REAL_IRQ_TO_BUS(rirq);
 	function = REAL_IRQ_TO_FUNC(rirq);
 	deviceId = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;

 	/* Invalidate the IRQ number in the bridge */
 	HvCallXm_connectBusUnit(bus, subBus, deviceId, 0);

 	/* Mask bridge interrupts in the FISR */
 	mask = 0x01010000 << function;
 	HvCallPci_maskFisr(bus, subBus, deviceId, mask);
 }

 /*
  * This will be called by device drivers (via disable_IRQ)
  * to disable INTA in the bridge interrupt status register.
  */
 static void iSeries_disable_IRQ(unsigned int irq)
 {
 	u32 bus, deviceId, function, mask;
 	const u32 subBus = 0;
 	unsigned int rirq = virt_irq_to_real_map[irq];

 	/* The IRQ has already been locked by the caller */
 	bus = REAL_IRQ_TO_BUS(rirq);
 	function = REAL_IRQ_TO_FUNC(rirq);
 	deviceId = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;

 	/* Mask secondary INTA   */
 	mask = 0x80000000;
 	HvCallPci_maskInterrupts(bus, subBus, deviceId, mask);
 	PPCDBG(PPCDBG_BUSWALK, "iSeries_disable_IRQ 0x%02X.%02X.%02X 0x%04X\n",
 			bus, subBus, deviceId, irq);
 }

 /*
  * Need to define this so ppc_irq_dispatch_handler will NOT call
  * enable_IRQ at the end of interrupt handling.  However, this does
  * nothing because there is not enough information provided to do
  * the EOI HvCall.  This is done by XmPciLpEvent.c
  */
 static void iSeries_end_IRQ(unsigned int irq)
 {
 }

 static hw_irq_controller iSeries_IRQ_handler = {
 	.typename = "iSeries irq controller",
 	.startup = iSeries_startup_IRQ,
 	.shutdown = iSeries_shutdown_IRQ,
 	.enable = iSeries_enable_IRQ,
 	.disable = iSeries_disable_IRQ,
 	.end = iSeries_end_IRQ
 };

 /*
  * This is called out of iSeries_scan_slot to allocate an IRQ for an EADS slot
  * It calculates the irq value for the slot.
  * Note that subBusNumber is always 0 (at the moment at least).
  */
 int __init iSeries_allocate_IRQ(HvBusNumber busNumber,
 		HvSubBusNumber subBusNumber, HvAgentId deviceId)
 {
 	unsigned int realirq, virtirq;
 	u8 idsel = (deviceId >> 4);
 	u8 function = deviceId & 7;

 	virtirq = next_virtual_irq++;
 	realirq = ((busNumber - 1) << 6) + ((idsel - 1) << 3) + function;
 	virt_irq_to_real_map[virtirq] = realirq;

 	irq_desc[virtirq].handler = &iSeries_IRQ_handler;
 	return virtirq;
 }

 int virt_irq_create_mapping(unsigned int real_irq)
 {
 	BUG(); /* Don't call this on iSeries, yet */

 	return 0;
 }

 void virt_irq_init(void)
 {
 	return;
 }
	/*
	* This module supports the iSeries PCI bus interrupt handling
	* Copyright (C) 20yy <Robert L Holtorf> <IBM Corp>
	* Copyright (C) 2004-2005 IBM Corporation
	*
	* 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
	*
	* Change Activity:
	* Created, December 13, 2000 by Wayne Holm
	* End Change Activity
	*/
	#include <linux/config.h>
	#include <linux/pci.h>
	#include <linux/init.h>
	#include <linux/threads.h>
	#include <linux/smp.h>
	#include <linux/param.h>
	#include <linux/string.h>
	#include <linux/bootmem.h>
	#include <linux/ide.h>
	#include <linux/irq.h>
	#include <linux/spinlock.h>

	#include <asm/ppcdebug.h>
	#include <asm/iSeries/HvTypes.h>
	#include <asm/iSeries/HvLpEvent.h>
	#include <asm/iSeries/HvCallPci.h>
	#include <asm/iSeries/HvCallXm.h>
	#include <asm/iSeries/iSeries_irq.h>

	/* This maps virtual irq numbers to real irqs */
	unsigned int virt_irq_to_real_map[NR_IRQS];

	/* The next available virtual irq number */
	/* Note: the pcnet32 driver assumes irq numbers < 2 aren't valid. :( */
	static int next_virtual_irq = 2;

	static long Pci_Interrupt_Count;
	static long Pci_Event_Count;

	enum XmPciLpEvent_Subtype {
	XmPciLpEvent_BusCreated = 0, // PHB has been created
	XmPciLpEvent_BusError = 1, // PHB has failed
	XmPciLpEvent_BusFailed = 2, // Msg to Secondary, Primary failed bus
	XmPciLpEvent_NodeFailed = 4, // Multi-adapter bridge has failed
	XmPciLpEvent_NodeRecovered = 5, // Multi-adapter bridge has recovered
	XmPciLpEvent_BusRecovered = 12, // PHB has been recovered
	XmPciLpEvent_UnQuiesceBus = 18, // Secondary bus unqiescing
	XmPciLpEvent_BridgeError = 21, // Bridge Error
	XmPciLpEvent_SlotInterrupt = 22 // Slot interrupt
	};

	struct XmPciLpEvent_BusInterrupt {
	HvBusNumber busNumber;
	HvSubBusNumber subBusNumber;
	};

	struct XmPciLpEvent_NodeInterrupt {
	HvBusNumber busNumber;
	HvSubBusNumber subBusNumber;
	HvAgentId deviceId;
	};

	struct XmPciLpEvent {
	struct HvLpEvent hvLpEvent;

	union {
	u64 alignData; // Align on an 8-byte boundary

	struct {
	u32 fisr;
	HvBusNumber busNumber;
	HvSubBusNumber subBusNumber;
	HvAgentId deviceId;
	} slotInterrupt;

	struct XmPciLpEvent_BusInterrupt busFailed;
	struct XmPciLpEvent_BusInterrupt busRecovered;
	struct XmPciLpEvent_BusInterrupt busCreated;

	struct XmPciLpEvent_NodeInterrupt nodeFailed;
	struct XmPciLpEvent_NodeInterrupt nodeRecovered;

	} eventData;

	};

	static void intReceived(struct XmPciLpEvent *eventParm,
	struct pt_regs *regsParm)
	{
	int irq;

	++Pci_Interrupt_Count;

	switch (eventParm->hvLpEvent.xSubtype) {
	case XmPciLpEvent_SlotInterrupt:
	irq = eventParm->hvLpEvent.xCorrelationToken;
	/* Dispatch the interrupt handlers for this irq */
	ppc_irq_dispatch_handler(regsParm, irq);
	HvCallPci_eoi(eventParm->eventData.slotInterrupt.busNumber,
	eventParm->eventData.slotInterrupt.subBusNumber,
	eventParm->eventData.slotInterrupt.deviceId);
	break;
	/* Ignore error recovery events for now */
	case XmPciLpEvent_BusCreated:
	printk(KERN_INFO "intReceived: system bus %d created\n",
	eventParm->eventData.busCreated.busNumber);
	break;
	case XmPciLpEvent_BusError:
	case XmPciLpEvent_BusFailed:
	printk(KERN_INFO "intReceived: system bus %d failed\n",
	eventParm->eventData.busFailed.busNumber);
	break;
	case XmPciLpEvent_BusRecovered:
	case XmPciLpEvent_UnQuiesceBus:
	printk(KERN_INFO "intReceived: system bus %d recovered\n",
	eventParm->eventData.busRecovered.busNumber);
	break;
	case XmPciLpEvent_NodeFailed:
	case XmPciLpEvent_BridgeError:
	printk(KERN_INFO
	"intReceived: multi-adapter bridge %d/%d/%d failed\n",
	eventParm->eventData.nodeFailed.busNumber,
	eventParm->eventData.nodeFailed.subBusNumber,
	eventParm->eventData.nodeFailed.deviceId);
	break;
	case XmPciLpEvent_NodeRecovered:
	printk(KERN_INFO
	"intReceived: multi-adapter bridge %d/%d/%d recovered\n",
	eventParm->eventData.nodeRecovered.busNumber,
	eventParm->eventData.nodeRecovered.subBusNumber,
	eventParm->eventData.nodeRecovered.deviceId);
	break;
	default:
	printk(KERN_ERR
	"intReceived: unrecognized event subtype 0x%x\n",
	eventParm->hvLpEvent.xSubtype);
	break;
	}
	}

	static void XmPciLpEvent_handler(struct HvLpEvent *eventParm,
	struct pt_regs *regsParm)
	{
	#ifdef CONFIG_PCI
	++Pci_Event_Count;

	if (eventParm && (eventParm->xType == HvLpEvent_Type_PciIo)) {
	switch (eventParm->xFlags.xFunction) {
	case HvLpEvent_Function_Int:
	intReceived((struct XmPciLpEvent *)eventParm, regsParm);
	break;
	case HvLpEvent_Function_Ack:
	printk(KERN_ERR
	"XmPciLpEvent_handler: unexpected ack received\n");
	break;
	default:
	printk(KERN_ERR
	"XmPciLpEvent_handler: unexpected event function %d\n",
	(int)eventParm->xFlags.xFunction);
	break;
	}
	} else if (eventParm)
	printk(KERN_ERR
	"XmPciLpEvent_handler: Unrecognized PCI event type 0x%x\n",
	(int)eventParm->xType);
	else
	printk(KERN_ERR "XmPciLpEvent_handler: NULL event received\n");
	#endif
	}

	/*
	* This is called by init_IRQ. set in ppc_md.init_IRQ by iSeries_setup.c
	* It must be called before the bus walk.
	*/
	void __init iSeries_init_IRQ(void)
	{
	/* Register PCI event handler and open an event path */
	int xRc;

	xRc = HvLpEvent_registerHandler(HvLpEvent_Type_PciIo,
	&XmPciLpEvent_handler);
	if (xRc == 0) {
	xRc = HvLpEvent_openPath(HvLpEvent_Type_PciIo, 0);
	if (xRc != 0)
	printk(KERN_ERR "iSeries_init_IRQ: open event path "
	"failed with rc 0x%x\n", xRc);
	} else
	printk(KERN_ERR "iSeries_init_IRQ: register handler "
	"failed with rc 0x%x\n", xRc);
	}

	#define REAL_IRQ_TO_BUS(irq) ((((irq) >> 6) & 0xff) + 1)
	#define REAL_IRQ_TO_IDSEL(irq) ((((irq) >> 3) & 7) + 1)
	#define REAL_IRQ_TO_FUNC(irq) ((irq) & 7)

	/*
	* This will be called by device drivers (via enable_IRQ)
	* to enable INTA in the bridge interrupt status register.
	*/
	static void iSeries_enable_IRQ(unsigned int irq)
	{
	u32 bus, deviceId, function, mask;
	const u32 subBus = 0;
	unsigned int rirq = virt_irq_to_real_map[irq];

	/* The IRQ has already been locked by the caller */
	bus = REAL_IRQ_TO_BUS(rirq);
	function = REAL_IRQ_TO_FUNC(rirq);
	deviceId = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;

	/* Unmask secondary INTA */
	mask = 0x80000000;
	HvCallPci_unmaskInterrupts(bus, subBus, deviceId, mask);
	PPCDBG(PPCDBG_BUSWALK, "iSeries_enable_IRQ 0x%02X.%02X.%02X 0x%04X\n",
	bus, subBus, deviceId, irq);
	}

	/* This is called by iSeries_activate_IRQs */
	static unsigned int iSeries_startup_IRQ(unsigned int irq)
	{
	u32 bus, deviceId, function, mask;
	const u32 subBus = 0;
	unsigned int rirq = virt_irq_to_real_map[irq];

	bus = REAL_IRQ_TO_BUS(rirq);
	function = REAL_IRQ_TO_FUNC(rirq);
	deviceId = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;

	/* Link the IRQ number to the bridge */
	HvCallXm_connectBusUnit(bus, subBus, deviceId, irq);

	/* Unmask bridge interrupts in the FISR */
	mask = 0x01010000 << function;
	HvCallPci_unmaskFisr(bus, subBus, deviceId, mask);
	iSeries_enable_IRQ(irq);
	return 0;
	}

	/*
	* This is called out of iSeries_fixup to activate interrupt
	* generation for usable slots
	*/
	void __init iSeries_activate_IRQs()
	{
	int irq;
	unsigned long flags;

	for_each_irq (irq) {
	irq_desc_t *desc = get_irq_desc(irq);

	if (desc && desc->handler && desc->handler->startup) {
	spin_lock_irqsave(&desc->lock, flags);
	desc->handler->startup(irq);
	spin_unlock_irqrestore(&desc->lock, flags);
	}
	}
	}

	/* this is not called anywhere currently */
	static void iSeries_shutdown_IRQ(unsigned int irq)
	{
	u32 bus, deviceId, function, mask;
	const u32 subBus = 0;
	unsigned int rirq = virt_irq_to_real_map[irq];

	/* irq should be locked by the caller */
	bus = REAL_IRQ_TO_BUS(rirq);
	function = REAL_IRQ_TO_FUNC(rirq);
	deviceId = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;

	/* Invalidate the IRQ number in the bridge */
	HvCallXm_connectBusUnit(bus, subBus, deviceId, 0);

	/* Mask bridge interrupts in the FISR */
	mask = 0x01010000 << function;
	HvCallPci_maskFisr(bus, subBus, deviceId, mask);
	}

	/*
	* This will be called by device drivers (via disable_IRQ)
	* to disable INTA in the bridge interrupt status register.
	*/
	static void iSeries_disable_IRQ(unsigned int irq)
	{
	u32 bus, deviceId, function, mask;
	const u32 subBus = 0;
	unsigned int rirq = virt_irq_to_real_map[irq];

	/* The IRQ has already been locked by the caller */
	bus = REAL_IRQ_TO_BUS(rirq);
	function = REAL_IRQ_TO_FUNC(rirq);
	deviceId = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;

	/* Mask secondary INTA */
	mask = 0x80000000;
	HvCallPci_maskInterrupts(bus, subBus, deviceId, mask);
	PPCDBG(PPCDBG_BUSWALK, "iSeries_disable_IRQ 0x%02X.%02X.%02X 0x%04X\n",
	bus, subBus, deviceId, irq);
	}

	/*
	* Need to define this so ppc_irq_dispatch_handler will NOT call
	* enable_IRQ at the end of interrupt handling. However, this does
	* nothing because there is not enough information provided to do
	* the EOI HvCall. This is done by XmPciLpEvent.c
	*/
	static void iSeries_end_IRQ(unsigned int irq)
	{
	}

	static hw_irq_controller iSeries_IRQ_handler = {
	.typename = "iSeries irq controller",
	.startup = iSeries_startup_IRQ,
	.shutdown = iSeries_shutdown_IRQ,
	.enable = iSeries_enable_IRQ,
	.disable = iSeries_disable_IRQ,
	.end = iSeries_end_IRQ
	};

	/*
	* This is called out of iSeries_scan_slot to allocate an IRQ for an EADS slot
	* It calculates the irq value for the slot.
	* Note that subBusNumber is always 0 (at the moment at least).
	*/
	int __init iSeries_allocate_IRQ(HvBusNumber busNumber,
	HvSubBusNumber subBusNumber, HvAgentId deviceId)
	{
	unsigned int realirq, virtirq;
	u8 idsel = (deviceId >> 4);
	u8 function = deviceId & 7;

	virtirq = next_virtual_irq++;
	realirq = ((busNumber - 1) << 6) + ((idsel - 1) << 3) + function;
	virt_irq_to_real_map[virtirq] = realirq;

	irq_desc[virtirq].handler = &iSeries_IRQ_handler;
	return virtirq;
	}

	int virt_irq_create_mapping(unsigned int real_irq)
	{
	BUG(); /* Don't call this on iSeries, yet */

	return 0;
	}

	void virt_irq_init(void)
	{
	return;
	}