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s390/airq: allow for airq structure that uses an input vector

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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: Thomas Huth <thuth@redhat.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20220606203325.110625-7-mjrosato@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
This commit is contained in:
Matthew Rosato 2022-06-06 16:33:10 -04:00 committed by Christian Borntraeger
parent d2197485a1
commit 932b646727
4 changed files with 15 additions and 9 deletions
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4
arch/s390/include/asm/airq.h
View file

@ -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);

8
arch/s390/pci/pci_irq.c
View file

@ -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;

10
drivers/s390/cio/airq.c
View file

@ -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);

2
drivers/s390/virtio/virtio_ccw.c
View file

@ -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;