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Don't allow malloc() to wait for resource while holding a lock in ITS

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malloc() should not go to sleep in case of lack of resource while
the kernel thread is holding a non-sleepable lock.

- change malloc() flags to M_NOWAIT in such cases implement
  lpi_free_chunk() routine as it will be needed when ITT
  allocation fails in its_device_alloc_locked()
- do not increase verbosity of this code since upper layers will
  communicate an error if the interrupt setup fails

Obtained from: Semihalf
Sponsored by:  The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3121
This commit is contained in:
zbb 2015-07-21 15:28:07 +00:00
parent 5f08ac18d2
commit 34b957f11d
1 changed files with 30 additions and 2 deletions
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32
sys/arm64/arm64/gic_v3_its.c
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@ -813,6 +813,26 @@ lpi_alloc_chunk(struct gic_v3_its_softc *sc, struct lpi_chunk *lpic,
return (0);
}
static void
lpi_free_chunk(struct gic_v3_its_softc *sc, struct lpi_chunk *lpic)
{
int start, end;
uint8_t *bitmap;
bitmap = (uint8_t *)sc->its_lpi_bitmap;
KASSERT((lpic->lpi_free == lpic->lpi_num),
("Trying to free LPI chunk that is still in use.\n"));
/* First bit of this chunk in a global bitmap */
start = lpic->lpi_base - GIC_FIRST_LPI;
/* and last bit of this chunk... */
end = start + lpic->lpi_num - 1;
/* Finally free this chunk */
bit_nclear(bitmap, start, end);
}
static void
lpi_configure(struct gic_v3_its_softc *sc, struct its_dev *its_dev,
uint32_t lpinum, boolean_t unmask)
@ -1322,7 +1342,10 @@ its_device_alloc_locked(struct gic_v3_its_softc *sc, device_t pci_dev,
devid = its_get_devid(pci_dev);
/* There was no previously created device. Create one now */
newdev = malloc(sizeof(*newdev), M_GIC_V3_ITS, (M_WAITOK | M_ZERO));
newdev = malloc(sizeof(*newdev), M_GIC_V3_ITS, (M_NOWAIT | M_ZERO));
if (newdev == NULL)
return (NULL);
newdev->pci_dev = pci_dev;
newdev->devid = devid;
@ -1340,7 +1363,12 @@ its_device_alloc_locked(struct gic_v3_its_softc *sc, device_t pci_dev,
*/
newdev->itt = (vm_offset_t)contigmalloc(
roundup2(roundup2(nvecs, 2) * esize, 0x100), M_GIC_V3_ITS,
(M_WAITOK | M_ZERO), 0, ~0UL, 0x100, 0);
(M_NOWAIT | M_ZERO), 0, ~0UL, 0x100, 0);
if (newdev->itt == 0) {
lpi_free_chunk(sc, &newdev->lpis);
free(newdev, M_GIC_V3_ITS);
return (NULL);
}
/*
* XXX ARM64TODO: Currently all interrupts are going