From 5cad61a6ba6f4956a218ffbb64cafcc1daefaca0 Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Fri, 18 Feb 2011 16:43:31 +0000 Subject: [PATCH] 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 Signed-off-by: Konrad Rzeszutek Wilk --- drivers/xen/events.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/drivers/xen/events.c b/drivers/xen/events.c index ed3420df093..c21066fc30b 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) -- 2.39.2