arch/s390/pci/pci_irq.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 #define KMSG_COMPONENT "zpci"
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

 #include <linux/kernel.h>
 #include <linux/irq.h>
 #include <linux/kernel_stat.h>
 #include <linux/pci.h>
 #include <linux/msi.h>
 #include <linux/smp.h>

 #include <asm/isc.h>
 #include <asm/airq.h>

 static enum {FLOATING, DIRECTED} irq_delivery;

 #define	SIC_IRQ_MODE_ALL		0
 #define	SIC_IRQ_MODE_SINGLE		1
 #define	SIC_IRQ_MODE_DIRECT		4
 #define	SIC_IRQ_MODE_D_ALL		16
 #define	SIC_IRQ_MODE_D_SINGLE		17
 #define	SIC_IRQ_MODE_SET_CPU		18

 /*
  * summary bit vector
  * FLOATING - summary bit per function
  * DIRECTED - summary bit per cpu (only used in fallback path)
  */
 static struct airq_iv *zpci_sbv;

 /*
  * interrupt bit vectors
  * FLOATING - interrupt bit vector per function
  * DIRECTED - interrupt bit vector per cpu
  */
 static struct airq_iv **zpci_ibv;

 /* Modify PCI: Register adapter interruptions */
 static int zpci_set_airq(struct zpci_dev *zdev)
 {
 	u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_REG_INT);
 	struct zpci_fib fib = {0};
 	u8 status;

 	fib.fmt0.isc = PCI_ISC;
 	fib.fmt0.sum = 1;	/* enable summary notifications */
 	fib.fmt0.noi = airq_iv_end(zdev->aibv);
 	fib.fmt0.aibv = (unsigned long) zdev->aibv->vector;
 	fib.fmt0.aibvo = 0;	/* each zdev has its own interrupt vector */
 	fib.fmt0.aisb = (unsigned long) zpci_sbv->vector + (zdev->aisb/64)*8;
 	fib.fmt0.aisbo = zdev->aisb & 63;

 	return zpci_mod_fc(req, &fib, &status) ? -EIO : 0;
 }

 /* Modify PCI: Unregister adapter interruptions */
 static int zpci_clear_airq(struct zpci_dev *zdev)
 {
 	u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_DEREG_INT);
 	struct zpci_fib fib = {0};
 	u8 cc, status;

 	cc = zpci_mod_fc(req, &fib, &status);
 	if (cc == 3 || (cc == 1 && status == 24))
 		/* Function already gone or IRQs already deregistered. */
 		cc = 0;

 	return cc ? -EIO : 0;
 }

 /* Modify PCI: Register CPU directed interruptions */
 static int zpci_set_directed_irq(struct zpci_dev *zdev)
 {
 	u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_REG_INT_D);
 	struct zpci_fib fib = {0};
 	u8 status;

 	fib.fmt = 1;
 	fib.fmt1.noi = zdev->msi_nr_irqs;
 	fib.fmt1.dibvo = zdev->msi_first_bit;

 	return zpci_mod_fc(req, &fib, &status) ? -EIO : 0;
 }

 /* Modify PCI: Unregister CPU directed interruptions */
 static int zpci_clear_directed_irq(struct zpci_dev *zdev)
 {
 	u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_DEREG_INT_D);
 	struct zpci_fib fib = {0};
 	u8 cc, status;

 	fib.fmt = 1;
 	cc = zpci_mod_fc(req, &fib, &status);
 	if (cc == 3 || (cc == 1 && status == 24))
 		/* Function already gone or IRQs already deregistered. */
 		cc = 0;

 	return cc ? -EIO : 0;
 }

 static int zpci_set_irq_affinity(struct irq_data *data, const struct cpumask *dest,
 				 bool force)
 {
 	struct msi_desc *entry = irq_get_msi_desc(data->irq);
 	struct msi_msg msg = entry->msg;

 	msg.address_lo &= 0xff0000ff;
 	msg.address_lo |= (cpumask_first(dest) << 8);
 	pci_write_msi_msg(data->irq, &msg);

 	return IRQ_SET_MASK_OK;
 }

 static struct irq_chip zpci_irq_chip = {
 	.name = "PCI-MSI",
 	.irq_unmask = pci_msi_unmask_irq,
 	.irq_mask = pci_msi_mask_irq,
 };

 static void zpci_handle_cpu_local_irq(bool rescan)
 {
 	struct airq_iv *dibv = zpci_ibv[smp_processor_id()];
 	unsigned long bit;
 	int irqs_on = 0;

 	for (bit = 0;;) {
 		/* Scan the directed IRQ bit vector */
 		bit = airq_iv_scan(dibv, bit, airq_iv_end(dibv));
 		if (bit == -1UL) {
 			if (!rescan || irqs_on++)
 				/* End of second scan with interrupts on. */
 				break;
 			/* First scan complete, reenable interrupts. */
 			if (zpci_set_irq_ctrl(SIC_IRQ_MODE_D_SINGLE, PCI_ISC))
 				break;
 			bit = 0;
 			continue;
 		}
 		inc_irq_stat(IRQIO_MSI);
 		generic_handle_irq(airq_iv_get_data(dibv, bit));
 	}
 }

 struct cpu_irq_data {
 	call_single_data_t csd;
 	atomic_t scheduled;
 };
 static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_irq_data, irq_data);

 static void zpci_handle_remote_irq(void *data)
 {
 	atomic_t *scheduled = data;

 	do {
 		zpci_handle_cpu_local_irq(false);
 	} while (atomic_dec_return(scheduled));
 }

 static void zpci_handle_fallback_irq(void)
 {
 	struct cpu_irq_data *cpu_data;
 	unsigned long cpu;
 	int irqs_on = 0;

 	for (cpu = 0;;) {
 		cpu = airq_iv_scan(zpci_sbv, cpu, airq_iv_end(zpci_sbv));
 		if (cpu == -1UL) {
 			if (irqs_on++)
 				/* End of second scan with interrupts on. */
 				break;
 			/* First scan complete, reenable interrupts. */
 			if (zpci_set_irq_ctrl(SIC_IRQ_MODE_SINGLE, PCI_ISC))
 				break;
 			cpu = 0;
 			continue;
 		}
 		cpu_data = &per_cpu(irq_data, cpu);
 		if (atomic_inc_return(&cpu_data->scheduled) > 1)
 			continue;

 		cpu_data->csd.func = zpci_handle_remote_irq;
 		cpu_data->csd.info = &cpu_data->scheduled;
 		cpu_data->csd.flags = 0;
 		smp_call_function_single_async(cpu, &cpu_data->csd);
 	}
 }

 static void zpci_directed_irq_handler(struct airq_struct *airq, bool floating)
 {
 	if (floating) {
 		inc_irq_stat(IRQIO_PCF);
 		zpci_handle_fallback_irq();
 	} else {
 		inc_irq_stat(IRQIO_PCD);
 		zpci_handle_cpu_local_irq(true);
 	}
 }

 static void zpci_floating_irq_handler(struct airq_struct *airq, bool floating)
 {
 	unsigned long si, ai;
 	struct airq_iv *aibv;
 	int irqs_on = 0;

 	inc_irq_stat(IRQIO_PCF);
 	for (si = 0;;) {
 		/* Scan adapter summary indicator bit vector */
 		si = airq_iv_scan(zpci_sbv, si, airq_iv_end(zpci_sbv));
 		if (si == -1UL) {
 			if (irqs_on++)
 				/* End of second scan with interrupts on. */
 				break;
 			/* First scan complete, reenable interrupts. */
 			if (zpci_set_irq_ctrl(SIC_IRQ_MODE_SINGLE, PCI_ISC))
 				break;
 			si = 0;
 			continue;
 		}

 		/* Scan the adapter interrupt vector for this device. */
 		aibv = zpci_ibv[si];
 		for (ai = 0;;) {
 			ai = airq_iv_scan(aibv, ai, airq_iv_end(aibv));
 			if (ai == -1UL)
 				break;
 			inc_irq_stat(IRQIO_MSI);
 			airq_iv_lock(aibv, ai);
 			generic_handle_irq(airq_iv_get_data(aibv, ai));
 			airq_iv_unlock(aibv, ai);
 		}
 	}
 }

 int arch_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 {
 	struct zpci_dev *zdev = to_zpci(pdev);
 	unsigned int hwirq, msi_vecs, cpu;
 	unsigned long bit;
 	struct msi_desc *msi;
 	struct msi_msg msg;
 	int rc, irq;

 	zdev->aisb = -1UL;
 	zdev->msi_first_bit = -1U;
 	if (type == PCI_CAP_ID_MSI && nvec > 1)
 		return 1;
 	msi_vecs = min_t(unsigned int, nvec, zdev->max_msi);

 	if (irq_delivery == DIRECTED) {
 		/* Allocate cpu vector bits */
 		bit = airq_iv_alloc(zpci_ibv[0], msi_vecs);
 		if (bit == -1UL)
 			return -EIO;
 	} else {
 		/* Allocate adapter summary indicator bit */
 		bit = airq_iv_alloc_bit(zpci_sbv);
 		if (bit == -1UL)
 			return -EIO;
 		zdev->aisb = bit;

 		/* Create adapter interrupt vector */
 		zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA | AIRQ_IV_BITLOCK);
 		if (!zdev->aibv)
 			return -ENOMEM;

 		/* Wire up shortcut pointer */
 		zpci_ibv[bit] = zdev->aibv;
 		/* Each function has its own interrupt vector */
 		bit = 0;
 	}

 	/* Request MSI interrupts */
 	hwirq = bit;
 	for_each_pci_msi_entry(msi, pdev) {
 		rc = -EIO;
 		if (hwirq - bit >= msi_vecs)
 			break;
 		irq = __irq_alloc_descs(-1, 0, 1, 0, THIS_MODULE,
 				(irq_delivery == DIRECTED) ?
 				msi->affinity : NULL);
 		if (irq < 0)
 			return -ENOMEM;
 		rc = irq_set_msi_desc(irq, msi);
 		if (rc)
 			return rc;
 		irq_set_chip_and_handler(irq, &zpci_irq_chip,
 					 handle_percpu_irq);
 		msg.data = hwirq - bit;
 		if (irq_delivery == DIRECTED) {
 			msg.address_lo = zdev->msi_addr & 0xff0000ff;
 			msg.address_lo |= msi->affinity ?
 				(cpumask_first(&msi->affinity->mask) << 8) : 0;
 			for_each_possible_cpu(cpu) {
 				airq_iv_set_data(zpci_ibv[cpu], hwirq, irq);
 			}
 		} else {
 			msg.address_lo = zdev->msi_addr & 0xffffffff;
 			airq_iv_set_data(zdev->aibv, hwirq, irq);
 		}
 		msg.address_hi = zdev->msi_addr >> 32;
 		pci_write_msi_msg(irq, &msg);
 		hwirq++;
 	}

 	zdev->msi_first_bit = bit;
 	zdev->msi_nr_irqs = msi_vecs;

 	if (irq_delivery == DIRECTED)
 		rc = zpci_set_directed_irq(zdev);
 	else
 		rc = zpci_set_airq(zdev);
 	if (rc)
 		return rc;

 	return (msi_vecs == nvec) ? 0 : msi_vecs;
 }

 void arch_teardown_msi_irqs(struct pci_dev *pdev)
 {
 	struct zpci_dev *zdev = to_zpci(pdev);
 	struct msi_desc *msi;
 	int rc;

 	/* Disable interrupts */
 	if (irq_delivery == DIRECTED)
 		rc = zpci_clear_directed_irq(zdev);
 	else
 		rc = zpci_clear_airq(zdev);
 	if (rc)
 		return;

 	/* Release MSI interrupts */
 	for_each_pci_msi_entry(msi, pdev) {
 		if (!msi->irq)
 			continue;
 		if (msi->msi_attrib.is_msix)
 			__pci_msix_desc_mask_irq(msi, 1);
 		else
 			__pci_msi_desc_mask_irq(msi, 1, 1);
 		irq_set_msi_desc(msi->irq, NULL);
 		irq_free_desc(msi->irq);
 		msi->msg.address_lo = 0;
 		msi->msg.address_hi = 0;
 		msi->msg.data = 0;
 		msi->irq = 0;
 	}

 	if (zdev->aisb != -1UL) {
 		zpci_ibv[zdev->aisb] = NULL;
 		airq_iv_free_bit(zpci_sbv, zdev->aisb);
 		zdev->aisb = -1UL;
 	}
 	if (zdev->aibv) {
 		airq_iv_release(zdev->aibv);
 		zdev->aibv = NULL;
 	}

 	if ((irq_delivery == DIRECTED) && zdev->msi_first_bit != -1U)
 		airq_iv_free(zpci_ibv[0], zdev->msi_first_bit, zdev->msi_nr_irqs);
 }

 static struct airq_struct zpci_airq = {
 	.handler = zpci_floating_irq_handler,
 	.isc = PCI_ISC,
 };

 static void __init cpu_enable_directed_irq(void *unused)
 {
 	union zpci_sic_iib iib = {{0}};

 	iib.cdiib.dibv_addr = (u64) zpci_ibv[smp_processor_id()]->vector;

 	__zpci_set_irq_ctrl(SIC_IRQ_MODE_SET_CPU, 0, &iib);
 	zpci_set_irq_ctrl(SIC_IRQ_MODE_D_SINGLE, PCI_ISC);
 }

 static int __init zpci_directed_irq_init(void)
 {
 	union zpci_sic_iib iib = {{0}};
 	unsigned int cpu;

 	zpci_sbv = airq_iv_create(num_possible_cpus(), 0);
 	if (!zpci_sbv)
 		return -ENOMEM;

 	iib.diib.isc = PCI_ISC;
 	iib.diib.nr_cpus = num_possible_cpus();
 	iib.diib.disb_addr = (u64) zpci_sbv->vector;
 	__zpci_set_irq_ctrl(SIC_IRQ_MODE_DIRECT, 0, &iib);

 	zpci_ibv = kcalloc(num_possible_cpus(), sizeof(*zpci_ibv),
 			   GFP_KERNEL);
 	if (!zpci_ibv)
 		return -ENOMEM;

 	for_each_possible_cpu(cpu) {
 		/*
 		 * Per CPU IRQ vectors look the same but bit-allocation
 		 * is only done on the first vector.
 		 */
 		zpci_ibv[cpu] = airq_iv_create(cache_line_size() * BITS_PER_BYTE,
 					       AIRQ_IV_DATA |
 					       AIRQ_IV_CACHELINE |
 					       (!cpu ? AIRQ_IV_ALLOC : 0));
 		if (!zpci_ibv[cpu])
 			return -ENOMEM;
 	}
 	on_each_cpu(cpu_enable_directed_irq, NULL, 1);

 	zpci_irq_chip.irq_set_affinity = zpci_set_irq_affinity;

 	return 0;
 }

 static int __init zpci_floating_irq_init(void)
 {
 	zpci_ibv = kcalloc(ZPCI_NR_DEVICES, sizeof(*zpci_ibv), GFP_KERNEL);
 	if (!zpci_ibv)
 		return -ENOMEM;

 	zpci_sbv = airq_iv_create(ZPCI_NR_DEVICES, AIRQ_IV_ALLOC);
 	if (!zpci_sbv)
 		goto out_free;

 	return 0;

 out_free:
 	kfree(zpci_ibv);
 	return -ENOMEM;
 }

 int __init zpci_irq_init(void)
 {
 	int rc;

 	irq_delivery = sclp.has_dirq ? DIRECTED : FLOATING;
 	if (s390_pci_force_floating)
 		irq_delivery = FLOATING;

 	if (irq_delivery == DIRECTED)
 		zpci_airq.handler = zpci_directed_irq_handler;

 	rc = register_adapter_interrupt(&zpci_airq);
 	if (rc)
 		goto out;
 	/* Set summary to 1 to be called every time for the ISC. */
 	*zpci_airq.lsi_ptr = 1;

 	switch (irq_delivery) {
 	case FLOATING:
 		rc = zpci_floating_irq_init();
 		break;
 	case DIRECTED:
 		rc = zpci_directed_irq_init();
 		break;
 	}

 	if (rc)
 		goto out_airq;

 	/*
 	 * Enable floating IRQs (with suppression after one IRQ). When using
 	 * directed IRQs this enables the fallback path.
 	 */
 	zpci_set_irq_ctrl(SIC_IRQ_MODE_SINGLE, PCI_ISC);

 	return 0;
 out_airq:
 	unregister_adapter_interrupt(&zpci_airq);
 out:
 	return rc;
 }

 void __init zpci_irq_exit(void)
 {
 	unsigned int cpu;

 	if (irq_delivery == DIRECTED) {
 		for_each_possible_cpu(cpu) {
 			airq_iv_release(zpci_ibv[cpu]);
 		}
 	}
 	kfree(zpci_ibv);
 	if (zpci_sbv)
 		airq_iv_release(zpci_sbv);
 	unregister_adapter_interrupt(&zpci_airq);
 }
	// SPDX-License-Identifier: GPL-2.0
	#define KMSG_COMPONENT "zpci"
	#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

	#include <linux/kernel.h>
	#include <linux/irq.h>
	#include <linux/kernel_stat.h>
	#include <linux/pci.h>
	#include <linux/msi.h>
	#include <linux/smp.h>

	#include <asm/isc.h>
	#include <asm/airq.h>

	static enum {FLOATING, DIRECTED} irq_delivery;

	#define SIC_IRQ_MODE_ALL 0
	#define SIC_IRQ_MODE_SINGLE 1
	#define SIC_IRQ_MODE_DIRECT 4
	#define SIC_IRQ_MODE_D_ALL 16
	#define SIC_IRQ_MODE_D_SINGLE 17
	#define SIC_IRQ_MODE_SET_CPU 18

	/*
	* summary bit vector
	* FLOATING - summary bit per function
	* DIRECTED - summary bit per cpu (only used in fallback path)
	*/
	static struct airq_iv *zpci_sbv;

	/*
	* interrupt bit vectors
	* FLOATING - interrupt bit vector per function
	* DIRECTED - interrupt bit vector per cpu
	*/
	static struct airq_iv **zpci_ibv;

	/* Modify PCI: Register adapter interruptions */
	static int zpci_set_airq(struct zpci_dev *zdev)
	{
	u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_REG_INT);
	struct zpci_fib fib = {0};
	u8 status;

	fib.fmt0.isc = PCI_ISC;
	fib.fmt0.sum = 1; /* enable summary notifications */
	fib.fmt0.noi = airq_iv_end(zdev->aibv);
	fib.fmt0.aibv = (unsigned long) zdev->aibv->vector;
	fib.fmt0.aibvo = 0; /* each zdev has its own interrupt vector */
	fib.fmt0.aisb = (unsigned long) zpci_sbv->vector + (zdev->aisb/64)*8;
	fib.fmt0.aisbo = zdev->aisb & 63;

	return zpci_mod_fc(req, &fib, &status) ? -EIO : 0;
	}

	/* Modify PCI: Unregister adapter interruptions */
	static int zpci_clear_airq(struct zpci_dev *zdev)
	{
	u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_DEREG_INT);
	struct zpci_fib fib = {0};
	u8 cc, status;

	cc = zpci_mod_fc(req, &fib, &status);
	if (cc == 3 \|\| (cc == 1 && status == 24))
	/* Function already gone or IRQs already deregistered. */
	cc = 0;

	return cc ? -EIO : 0;
	}

	/* Modify PCI: Register CPU directed interruptions */
	static int zpci_set_directed_irq(struct zpci_dev *zdev)
	{
	u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_REG_INT_D);
	struct zpci_fib fib = {0};
	u8 status;

	fib.fmt = 1;
	fib.fmt1.noi = zdev->msi_nr_irqs;
	fib.fmt1.dibvo = zdev->msi_first_bit;

	return zpci_mod_fc(req, &fib, &status) ? -EIO : 0;
	}

	/* Modify PCI: Unregister CPU directed interruptions */
	static int zpci_clear_directed_irq(struct zpci_dev *zdev)
	{
	u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_DEREG_INT_D);
	struct zpci_fib fib = {0};
	u8 cc, status;

	fib.fmt = 1;
	cc = zpci_mod_fc(req, &fib, &status);
	if (cc == 3 \|\| (cc == 1 && status == 24))
	/* Function already gone or IRQs already deregistered. */
	cc = 0;

	return cc ? -EIO : 0;
	}

	static int zpci_set_irq_affinity(struct irq_data data, const struct cpumask dest,
	bool force)
	{
	struct msi_desc *entry = irq_get_msi_desc(data->irq);
	struct msi_msg msg = entry->msg;

	msg.address_lo &= 0xff0000ff;
	msg.address_lo \|= (cpumask_first(dest) << 8);
	pci_write_msi_msg(data->irq, &msg);

	return IRQ_SET_MASK_OK;
	}

	static struct irq_chip zpci_irq_chip = {
	.name = "PCI-MSI",
	.irq_unmask = pci_msi_unmask_irq,
	.irq_mask = pci_msi_mask_irq,
	};

	static void zpci_handle_cpu_local_irq(bool rescan)
	{
	struct airq_iv *dibv = zpci_ibv[smp_processor_id()];
	unsigned long bit;
	int irqs_on = 0;

	for (bit = 0;;) {
	/* Scan the directed IRQ bit vector */
	bit = airq_iv_scan(dibv, bit, airq_iv_end(dibv));
	if (bit == -1UL) {
	if (!rescan \|\| irqs_on++)
	/* End of second scan with interrupts on. */
	break;
	/* First scan complete, reenable interrupts. */
	if (zpci_set_irq_ctrl(SIC_IRQ_MODE_D_SINGLE, PCI_ISC))
	break;
	bit = 0;
	continue;
	}
	inc_irq_stat(IRQIO_MSI);
	generic_handle_irq(airq_iv_get_data(dibv, bit));
	}
	}

	struct cpu_irq_data {
	call_single_data_t csd;
	atomic_t scheduled;
	};
	static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_irq_data, irq_data);

	static void zpci_handle_remote_irq(void *data)
	{
	atomic_t *scheduled = data;

	do {
	zpci_handle_cpu_local_irq(false);
	} while (atomic_dec_return(scheduled));
	}

	static void zpci_handle_fallback_irq(void)
	{
	struct cpu_irq_data *cpu_data;
	unsigned long cpu;
	int irqs_on = 0;

	for (cpu = 0;;) {
	cpu = airq_iv_scan(zpci_sbv, cpu, airq_iv_end(zpci_sbv));
	if (cpu == -1UL) {
	if (irqs_on++)
	/* End of second scan with interrupts on. */
	break;
	/* First scan complete, reenable interrupts. */
	if (zpci_set_irq_ctrl(SIC_IRQ_MODE_SINGLE, PCI_ISC))
	break;
	cpu = 0;
	continue;
	}
	cpu_data = &per_cpu(irq_data, cpu);
	if (atomic_inc_return(&cpu_data->scheduled) > 1)
	continue;

	cpu_data->csd.func = zpci_handle_remote_irq;
	cpu_data->csd.info = &cpu_data->scheduled;
	cpu_data->csd.flags = 0;
	smp_call_function_single_async(cpu, &cpu_data->csd);
	}
	}

	static void zpci_directed_irq_handler(struct airq_struct *airq, bool floating)
	{
	if (floating) {
	inc_irq_stat(IRQIO_PCF);
	zpci_handle_fallback_irq();
	} else {
	inc_irq_stat(IRQIO_PCD);
	zpci_handle_cpu_local_irq(true);
	}
	}

	static void zpci_floating_irq_handler(struct airq_struct *airq, bool floating)
	{
	unsigned long si, ai;
	struct airq_iv *aibv;
	int irqs_on = 0;

	inc_irq_stat(IRQIO_PCF);
	for (si = 0;;) {
	/* Scan adapter summary indicator bit vector */
	si = airq_iv_scan(zpci_sbv, si, airq_iv_end(zpci_sbv));
	if (si == -1UL) {
	if (irqs_on++)
	/* End of second scan with interrupts on. */
	break;
	/* First scan complete, reenable interrupts. */
	if (zpci_set_irq_ctrl(SIC_IRQ_MODE_SINGLE, PCI_ISC))
	break;
	si = 0;
	continue;
	}

	/* Scan the adapter interrupt vector for this device. */
	aibv = zpci_ibv[si];
	for (ai = 0;;) {
	ai = airq_iv_scan(aibv, ai, airq_iv_end(aibv));
	if (ai == -1UL)
	break;
	inc_irq_stat(IRQIO_MSI);
	airq_iv_lock(aibv, ai);
	generic_handle_irq(airq_iv_get_data(aibv, ai));
	airq_iv_unlock(aibv, ai);
	}
	}
	}

	int arch_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
	{
	struct zpci_dev *zdev = to_zpci(pdev);
	unsigned int hwirq, msi_vecs, cpu;
	unsigned long bit;
	struct msi_desc *msi;
	struct msi_msg msg;
	int rc, irq;

	zdev->aisb = -1UL;
	zdev->msi_first_bit = -1U;
	if (type == PCI_CAP_ID_MSI && nvec > 1)
	return 1;
	msi_vecs = min_t(unsigned int, nvec, zdev->max_msi);

	if (irq_delivery == DIRECTED) {
	/* Allocate cpu vector bits */
	bit = airq_iv_alloc(zpci_ibv[0], msi_vecs);
	if (bit == -1UL)
	return -EIO;
	} else {
	/* Allocate adapter summary indicator bit */
	bit = airq_iv_alloc_bit(zpci_sbv);
	if (bit == -1UL)
	return -EIO;
	zdev->aisb = bit;

	/* Create adapter interrupt vector */
	zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA \| AIRQ_IV_BITLOCK);
	if (!zdev->aibv)
	return -ENOMEM;

	/* Wire up shortcut pointer */
	zpci_ibv[bit] = zdev->aibv;
	/* Each function has its own interrupt vector */
	bit = 0;
	}

	/* Request MSI interrupts */
	hwirq = bit;
	for_each_pci_msi_entry(msi, pdev) {
	rc = -EIO;
	if (hwirq - bit >= msi_vecs)
	break;
	irq = __irq_alloc_descs(-1, 0, 1, 0, THIS_MODULE,
	(irq_delivery == DIRECTED) ?
	msi->affinity : NULL);
	if (irq < 0)
	return -ENOMEM;
	rc = irq_set_msi_desc(irq, msi);
	if (rc)
	return rc;
	irq_set_chip_and_handler(irq, &zpci_irq_chip,
	handle_percpu_irq);
	msg.data = hwirq - bit;
	if (irq_delivery == DIRECTED) {
	msg.address_lo = zdev->msi_addr & 0xff0000ff;
	msg.address_lo \|= msi->affinity ?
	(cpumask_first(&msi->affinity->mask) << 8) : 0;
	for_each_possible_cpu(cpu) {
	airq_iv_set_data(zpci_ibv[cpu], hwirq, irq);
	}
	} else {
	msg.address_lo = zdev->msi_addr & 0xffffffff;
	airq_iv_set_data(zdev->aibv, hwirq, irq);
	}
	msg.address_hi = zdev->msi_addr >> 32;
	pci_write_msi_msg(irq, &msg);
	hwirq++;
	}

	zdev->msi_first_bit = bit;
	zdev->msi_nr_irqs = msi_vecs;

	if (irq_delivery == DIRECTED)
	rc = zpci_set_directed_irq(zdev);
	else
	rc = zpci_set_airq(zdev);
	if (rc)
	return rc;

	return (msi_vecs == nvec) ? 0 : msi_vecs;
	}

	void arch_teardown_msi_irqs(struct pci_dev *pdev)
	{
	struct zpci_dev *zdev = to_zpci(pdev);
	struct msi_desc *msi;
	int rc;

	/* Disable interrupts */
	if (irq_delivery == DIRECTED)
	rc = zpci_clear_directed_irq(zdev);
	else
	rc = zpci_clear_airq(zdev);
	if (rc)
	return;

	/* Release MSI interrupts */
	for_each_pci_msi_entry(msi, pdev) {
	if (!msi->irq)
	continue;
	if (msi->msi_attrib.is_msix)
	__pci_msix_desc_mask_irq(msi, 1);
	else
	__pci_msi_desc_mask_irq(msi, 1, 1);
	irq_set_msi_desc(msi->irq, NULL);
	irq_free_desc(msi->irq);
	msi->msg.address_lo = 0;
	msi->msg.address_hi = 0;
	msi->msg.data = 0;
	msi->irq = 0;
	}

	if (zdev->aisb != -1UL) {
	zpci_ibv[zdev->aisb] = NULL;
	airq_iv_free_bit(zpci_sbv, zdev->aisb);
	zdev->aisb = -1UL;
	}
	if (zdev->aibv) {
	airq_iv_release(zdev->aibv);
	zdev->aibv = NULL;
	}

	if ((irq_delivery == DIRECTED) && zdev->msi_first_bit != -1U)
	airq_iv_free(zpci_ibv[0], zdev->msi_first_bit, zdev->msi_nr_irqs);
	}

	static struct airq_struct zpci_airq = {
	.handler = zpci_floating_irq_handler,
	.isc = PCI_ISC,
	};

	static void __init cpu_enable_directed_irq(void *unused)
	{
	union zpci_sic_iib iib = {{0}};

	iib.cdiib.dibv_addr = (u64) zpci_ibv[smp_processor_id()]->vector;

	__zpci_set_irq_ctrl(SIC_IRQ_MODE_SET_CPU, 0, &iib);
	zpci_set_irq_ctrl(SIC_IRQ_MODE_D_SINGLE, PCI_ISC);
	}

	static int __init zpci_directed_irq_init(void)
	{
	union zpci_sic_iib iib = {{0}};
	unsigned int cpu;

	zpci_sbv = airq_iv_create(num_possible_cpus(), 0);
	if (!zpci_sbv)
	return -ENOMEM;

	iib.diib.isc = PCI_ISC;
	iib.diib.nr_cpus = num_possible_cpus();
	iib.diib.disb_addr = (u64) zpci_sbv->vector;
	__zpci_set_irq_ctrl(SIC_IRQ_MODE_DIRECT, 0, &iib);

	zpci_ibv = kcalloc(num_possible_cpus(), sizeof(*zpci_ibv),
	GFP_KERNEL);
	if (!zpci_ibv)
	return -ENOMEM;

	for_each_possible_cpu(cpu) {
	/*
	* Per CPU IRQ vectors look the same but bit-allocation
	* is only done on the first vector.
	*/
	zpci_ibv[cpu] = airq_iv_create(cache_line_size() * BITS_PER_BYTE,
	AIRQ_IV_DATA \|
	AIRQ_IV_CACHELINE \|
	(!cpu ? AIRQ_IV_ALLOC : 0));
	if (!zpci_ibv[cpu])
	return -ENOMEM;
	}
	on_each_cpu(cpu_enable_directed_irq, NULL, 1);

	zpci_irq_chip.irq_set_affinity = zpci_set_irq_affinity;

	return 0;
	}

	static int __init zpci_floating_irq_init(void)
	{
	zpci_ibv = kcalloc(ZPCI_NR_DEVICES, sizeof(*zpci_ibv), GFP_KERNEL);
	if (!zpci_ibv)
	return -ENOMEM;

	zpci_sbv = airq_iv_create(ZPCI_NR_DEVICES, AIRQ_IV_ALLOC);
	if (!zpci_sbv)
	goto out_free;

	return 0;

	out_free:
	kfree(zpci_ibv);
	return -ENOMEM;
	}

	int __init zpci_irq_init(void)
	{
	int rc;

	irq_delivery = sclp.has_dirq ? DIRECTED : FLOATING;
	if (s390_pci_force_floating)
	irq_delivery = FLOATING;

	if (irq_delivery == DIRECTED)
	zpci_airq.handler = zpci_directed_irq_handler;

	rc = register_adapter_interrupt(&zpci_airq);
	if (rc)
	goto out;
	/* Set summary to 1 to be called every time for the ISC. */
	*zpci_airq.lsi_ptr = 1;

	switch (irq_delivery) {
	case FLOATING:
	rc = zpci_floating_irq_init();
	break;
	case DIRECTED:
	rc = zpci_directed_irq_init();
	break;
	}

	if (rc)
	goto out_airq;

	/*
	* Enable floating IRQs (with suppression after one IRQ). When using
	* directed IRQs this enables the fallback path.
	*/
	zpci_set_irq_ctrl(SIC_IRQ_MODE_SINGLE, PCI_ISC);

	return 0;
	out_airq:
	unregister_adapter_interrupt(&zpci_airq);
	out:
	return rc;
	}

	void __init zpci_irq_exit(void)
	{
	unsigned int cpu;

	if (irq_delivery == DIRECTED) {
	for_each_possible_cpu(cpu) {
	airq_iv_release(zpci_ibv[cpu]);
	}
	}
	kfree(zpci_ibv);
	if (zpci_sbv)
	airq_iv_release(zpci_sbv);
	unregister_adapter_interrupt(&zpci_airq);
	}