Commit 932b6467 authored by Matthew Rosato's avatar Matthew Rosato Committed by Christian Borntraeger
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s390/airq: allow for airq structure that uses an input vector 



When doing device passthrough where interrupts are being forwarded from
host to guest, we wish to use a pinned section of guest memory as the
vector (the same memory used by the guest as the vector). To accomplish
this, add a new parameter for airq_iv_create which allows passing an
existing vector to be used instead of allocating a new one. The caller
is responsible for ensuring the vector is pinned in memory as well as for
unpinning the memory when the vector is no longer needed.

A subsequent patch will use this new parameter for zPCI interpretation.

Reviewed-by: default avatarThomas Huth <thuth@redhat.com>
Reviewed-by: default avatarPierre Morel <pmorel@linux.ibm.com>
Reviewed-by: default avatarClaudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: default avatarCornelia Huck <cohuck@redhat.com>
Signed-off-by: default avatarMatthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20220606203325.110625-7-mjrosato@linux.ibm.com


Signed-off-by: default avatarChristian Borntraeger <borntraeger@linux.ibm.com>
parent d2197485

arch/s390/include/asm/airq.h

+3 −1
Original line number Diff line number Diff line
@@ -47,8 +47,10 @@ struct airq_iv { 
#define AIRQ_IV_PTR		4	/* Allocate the ptr array */

#define AIRQ_IV_DATA		8	/* Allocate the data array */

#define AIRQ_IV_CACHELINE	16	/* Cacheline alignment for the vector */

#define AIRQ_IV_GUESTVEC	32	/* Vector is a pinned guest page */



struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags);

struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags,

			       unsigned long *vec);

void airq_iv_release(struct airq_iv *iv);

unsigned long airq_iv_alloc(struct airq_iv *iv, unsigned long num);

void airq_iv_free(struct airq_iv *iv, unsigned long bit, unsigned long num);

arch/s390/pci/pci_irq.c

+4 −4
Original line number Diff line number Diff line
@@ -296,7 +296,7 @@ int arch_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type) 
		zdev->aisb = bit;



		/* Create adapter interrupt vector */

		zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA | AIRQ_IV_BITLOCK);

		zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA | AIRQ_IV_BITLOCK, NULL);

		if (!zdev->aibv)

			return -ENOMEM;
@@ -419,7 +419,7 @@ 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);

	zpci_sbv = airq_iv_create(num_possible_cpus(), 0, NULL);

	if (!zpci_sbv)

		return -ENOMEM;
@@ -441,7 +441,7 @@ static int __init zpci_directed_irq_init(void) 
		zpci_ibv[cpu] = airq_iv_create(cache_line_size() * BITS_PER_BYTE,

					       AIRQ_IV_DATA |

					       AIRQ_IV_CACHELINE |

					       (!cpu ? AIRQ_IV_ALLOC : 0));

					       (!cpu ? AIRQ_IV_ALLOC : 0), NULL);

		if (!zpci_ibv[cpu])

			return -ENOMEM;

	}
@@ -458,7 +458,7 @@ static int __init zpci_floating_irq_init(void) 
	if (!zpci_ibv)

		return -ENOMEM;



	zpci_sbv = airq_iv_create(ZPCI_NR_DEVICES, AIRQ_IV_ALLOC);

	zpci_sbv = airq_iv_create(ZPCI_NR_DEVICES, AIRQ_IV_ALLOC, NULL);

	if (!zpci_sbv)

		goto out_free;

drivers/s390/cio/airq.c

+7 −3
Original line number Diff line number Diff line
@@ -122,10 +122,12 @@ static inline unsigned long iv_size(unsigned long bits) 
 * airq_iv_create - create an interrupt vector

 * @bits: number of bits in the interrupt vector

 * @flags: allocation flags

 * @vec: pointer to pinned guest memory if AIRQ_IV_GUESTVEC

 *

 * Returns a pointer to an interrupt vector structure

 */

struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags)

struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags,

			       unsigned long *vec)

{

	struct airq_iv *iv;

	unsigned long size;
@@ -146,6 +148,8 @@ struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags) 
					     &iv->vector_dma);

		if (!iv->vector)

			goto out_free;

	} else if (flags & AIRQ_IV_GUESTVEC) {

		iv->vector = vec;

	} else {

		iv->vector = cio_dma_zalloc(size);

		if (!iv->vector)
@@ -185,7 +189,7 @@ struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags) 
	kfree(iv->avail);

	if (iv->flags & AIRQ_IV_CACHELINE && iv->vector)

		dma_pool_free(airq_iv_cache, iv->vector, iv->vector_dma);

	else

	else if (!(iv->flags & AIRQ_IV_GUESTVEC))

		cio_dma_free(iv->vector, size);

	kfree(iv);

out:
@@ -204,7 +208,7 @@ void airq_iv_release(struct airq_iv *iv) 
	kfree(iv->bitlock);

	if (iv->flags & AIRQ_IV_CACHELINE)

		dma_pool_free(airq_iv_cache, iv->vector, iv->vector_dma);

	else

	else if (!(iv->flags & AIRQ_IV_GUESTVEC))

		cio_dma_free(iv->vector, iv_size(iv->bits));

	kfree(iv->avail);

	kfree(iv);

drivers/s390/virtio/virtio_ccw.c

+1 −1
Original line number Diff line number Diff line
@@ -242,7 +242,7 @@ static struct airq_info *new_airq_info(int index) 
		return NULL;

	rwlock_init(&info->lock);

	info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR

				   | AIRQ_IV_CACHELINE);

				   | AIRQ_IV_CACHELINE, NULL);

	if (!info->aiv) {

		kfree(info);

		return NULL;