From ff762cdbf0c8c9bf0b97684f39af13b3332e77e8 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 13 Feb 2023 11:42:46 +0100 Subject: [PATCH] irqdomain: Look for existing mapping only once [ Upstream commit 6e6f75c9c98d2d246d90411ff2b6f0cd271f4cba ] 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 Tested-by: Mark-PK Tsai Signed-off-by: Johan Hovold Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20230213104302.17307-5-johan+linaro@kernel.org Signed-off-by: Sasha Levin --- kernel/irq/irqdomain.c | 74 +++++++++++++++++++++++------------------- 1 file changed, 40 insertions(+), 34 deletions(-) diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index fe07888a7d96..d18c25a41673 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -637,44 +637,15 @@ unsigned int irq_create_direct_mapping(struct irq_domain *domain) } EXPORT_SYMBOL_GPL(irq_create_direct_mapping); -/** - * irq_create_mapping_affinity() - Map a hardware interrupt into linux irq space - * @domain: domain owning this hardware interrupt or NULL for default domain - * @hwirq: hardware irq number in that domain space - * @affinity: irq affinity - * - * Only one mapping per hardware interrupt is permitted. Returns a linux - * irq number. - * If the sense/trigger is to be specified, set_irq_type() should be called - * 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) +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; + 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); - /* Look for default domain if necessary */ - if (domain == NULL) - domain = irq_default_domain; - if (domain == NULL) { - 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); - return virq; - } - /* Allocate a virtual interrupt number */ virq = irq_domain_alloc_descs(-1, 1, hwirq, of_node_to_nid(of_node), affinity); @@ -693,6 +664,41 @@ unsigned int irq_create_mapping_affinity(struct irq_domain *domain, 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 + * @hwirq: hardware irq number in that domain space + * @affinity: irq affinity + * + * Only one mapping per hardware interrupt is permitted. Returns a linux + * irq number. + * If the sense/trigger is to be specified, set_irq_type() should be called + * 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) +{ + int virq; + + /* Look for default domain if necessary */ + if (domain == NULL) + domain = irq_default_domain; + if (domain == NULL) { + WARN(1, "%s(, %lx) called with NULL domain\n", __func__, hwirq); + return 0; + } + + /* Check if mapping already exists */ + virq = irq_find_mapping(domain, hwirq); + if (virq) { + pr_debug("existing mapping on virq %d\n", virq); + return virq; + } + + return __irq_create_mapping_affinity(domain, hwirq, affinity); +} EXPORT_SYMBOL_GPL(irq_create_mapping_affinity); /** @@ -831,7 +837,7 @@ 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; }