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| author | Ian Campbell <ian.campbell@citrix.com> | 2011-02-18 16:43:31 +0000 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2011-03-10 14:44:39 -0500 |
| commit | 5cad61a6ba6f4956a218ffbb64cafcc1daefaca0 (patch) | |
| tree | 96b25ef58b3bba37808fe3cd7bbb37a444187260 /drivers | |
| parent | 9a626612c2010699d9909a4c3141d3a38660f3b3 (diff) | |
| download | kernel-common-5cad61a6ba6f4956a218ffbb64cafcc1daefaca0.tar.gz kernel-common-5cad61a6ba6f4956a218ffbb64cafcc1daefaca0.tar.bz2 kernel-common-5cad61a6ba6f4956a218ffbb64cafcc1daefaca0.zip | |
xen: events: assume PHYSDEVOP_get_free_pirq exists
The find_unbound_pirq is called only from xen_allocate_pirq_msi and
only if alloc_pirq is true. The only caller which does this is
xen_hvm_setup_msi_irqs. The use of this function is gated, in
pci_xen_hvm_init, on XENFEAT_hvm_pirqs.
The PHYSDEVOP_get_free_pirq interfaces was added to the hypervisor in
22410:be96f6058c05 while XENFEAT_hvm_pirqs was added a couple of
minutes prior in 22409:6663214f06ac. Therefore we do not need to
concern ourselves with hypervisors which support XENFEAT_hvm_pirqs but
not PHYSDEVOP_get_free_pirq.
This eliminates the fallback path in find_unbound_pirq which walks to
pirq_to_irq array looking for a free pirq. Unlike the
PHYSDEVOP_get_free_pirq interface this fallback only looks up a free
pirq but does not reserve it. Removing this fallback will simplify
locking in the future.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/xen/events.c | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/drivers/xen/events.c b/drivers/xen/events.c index ed3420df0937..c21066fc30be 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -649,19 +649,16 @@ out: static int find_unbound_pirq(int type) { - int rc, i; + int rc; struct physdev_get_free_pirq op_get_free_pirq; - op_get_free_pirq.type = type; + op_get_free_pirq.type = type; rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq); - if (!rc) - return op_get_free_pirq.pirq; - for (i = 0; i < nr_irqs; i++) { - if (pirq_to_irq[i] < 0) - return i; - } - return -1; + WARN_ONCE(rc == -ENOSYS, + "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n"); + + return rc ? -1 : op_get_free_pirq.pirq; } int xen_allocate_pirq_msi(char *name, int *pirq, int alloc_pirq) |