Avoid looking for an existing mapping twice when creating a new mapping using irq_create_fwspec_mapping() by factoring out the actual allocation which is shared with irq_create_mapping_affinity().

The new helper function will also be used to fix a shared-interrupt mapping race, hence the Fixes tag.

Fixes: b62b2cf5759b ("irqdomain: Fix handling of type settings for existing mappings") Cc: stable@vger.kernel.org # 4.8 Tested-by: Hsin-Yi Wang hsinyi@chromium.org Tested-by: Mark-PK Tsai mark-pk.tsai@mediatek.com Signed-off-by: Johan Hovold johan+linaro@kernel.org --- kernel/irq/irqdomain.c | 60 +++++++++++++++++++++++------------------- 1 file changed, 33 insertions(+), 27 deletions(-)

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index b4326c364ae7..3d6a14efae62 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -682,6 +682,34 @@ unsigned int irq_create_direct_mapping(struct irq_domain *domain) EXPORT_SYMBOL_GPL(irq_create_direct_mapping); #endif

+static unsigned int __irq_create_mapping_affinity(struct irq_domain *domain, + irq_hw_number_t hwirq, + const struct irq_affinity_desc *affinity) +{ + struct device_node *of_node = irq_domain_get_of_node(domain); + int virq; + + pr_debug("irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq); + + /* Allocate a virtual interrupt number */ + virq = irq_domain_alloc_descs(-1, 1, hwirq, of_node_to_nid(of_node), + affinity); + if (virq <= 0) { + pr_debug("-> virq allocation failed\n"); + return 0; + } + + if (irq_domain_associate(domain, virq, hwirq)) { + irq_free_desc(virq); + return 0; + } + + pr_debug("irq %lu on domain %s mapped to virtual irq %u\n", + hwirq, of_node_full_name(of_node), virq); + + return virq; +} + /** * irq_create_mapping_affinity() - Map a hardware interrupt into linux irq space * @domain: domain owning this hardware interrupt or NULL for default domain @@ -694,14 +722,11 @@ EXPORT_SYMBOL_GPL(irq_create_direct_mapping); * on the number returned from that call. */ unsigned int irq_create_mapping_affinity(struct irq_domain *domain, - irq_hw_number_t hwirq, - const struct irq_affinity_desc *affinity) + irq_hw_number_t hwirq, + const struct irq_affinity_desc *affinity) { - struct device_node *of_node; int virq;

- pr_debug("irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq); - /* Look for default domain if necessary */ if (domain == NULL) domain = irq_default_domain; @@ -709,34 +734,15 @@ unsigned int irq_create_mapping_affinity(struct irq_domain *domain, WARN(1, "%s(, %lx) called with NULL domain\n", __func__, hwirq); return 0; } - pr_debug("-> using domain @%p\n", domain); - - of_node = irq_domain_get_of_node(domain);

/* Check if mapping already exists */ virq = irq_find_mapping(domain, hwirq); if (virq) { - pr_debug("-> existing mapping on virq %d\n", virq); + pr_debug("existing mapping on virq %d\n", virq); return virq; }

- /* Allocate a virtual interrupt number */ - virq = irq_domain_alloc_descs(-1, 1, hwirq, of_node_to_nid(of_node), - affinity); - if (virq <= 0) { - pr_debug("-> virq allocation failed\n"); - return 0; - } - - if (irq_domain_associate(domain, virq, hwirq)) { - irq_free_desc(virq); - return 0; - } - - pr_debug("irq %lu on domain %s mapped to virtual irq %u\n", - hwirq, of_node_full_name(of_node), virq); - - return virq; + return __irq_create_mapping_affinity(domain, hwirq, affinity); } EXPORT_SYMBOL_GPL(irq_create_mapping_affinity);

@@ -841,7 +847,7 @@ unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec) return 0; } else { /* Create mapping */ - virq = irq_create_mapping(domain, hwirq); + virq = __irq_create_mapping_affinity(domain, hwirq, NULL); if (!virq) return virq; }