From 7cec18a3906b52e855c9386650c0226bbe594a4c Mon Sep 17 00:00:00 2001 From: Matt Redfearn Date: Mon, 25 Apr 2016 08:14:24 +0100 Subject: [PATCH] genirq: Add error code reporting to irq_{reserve,destroy}_ipi Make these functions return appropriate error codes when something goes wrong. Previously irq_destroy_ipi returned void making it impossible to notify the caller if the request could not be fulfilled. Patch 1 in the series added another condition in which this could fail in addition to the existing ones. irq_reserve_ipi returned an unsigned int meaning it could only return 0 on failure and give the caller no indication as to why the request failed. As time goes on there are likely to be further conditions added in which these functions can fail. These APIs and the IPI IRQ domain are new in 4.6 and the number of existing call sites are low, changing the API now has little impact on the code, while making it easier for these functions to grow over time. Signed-off-by: Matt Redfearn Cc: linux-mips@linux-mips.org Cc: jason@lakedaemon.net Cc: marc.zyngier@arm.com Cc: ralf@linux-mips.org Cc: Qais Yousef Cc: lisa.parratt@imgtec.com Cc: jiang.liu@linux.intel.com Link: http://lkml.kernel.org/r/1461568464-31701-2-git-send-email-matt.redfearn@imgtec.com Signed-off-by: Thomas Gleixner --- include/linux/irqdomain.h | 5 ++--- kernel/irq/ipi.c | 31 +++++++++++++++++-------------- 2 files changed, 19 insertions(+), 17 deletions(-) diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h index e1b81d35e7a3..736abd74c135 100644 --- a/include/linux/irqdomain.h +++ b/include/linux/irqdomain.h @@ -346,9 +346,8 @@ int irq_domain_xlate_onetwocell(struct irq_domain *d, struct device_node *ctrlr, irq_hw_number_t *out_hwirq, unsigned int *out_type); /* IPI functions */ -unsigned int irq_reserve_ipi(struct irq_domain *domain, - const struct cpumask *dest); -void irq_destroy_ipi(unsigned int irq, const struct cpumask *dest); +int irq_reserve_ipi(struct irq_domain *domain, const struct cpumask *dest); +int irq_destroy_ipi(unsigned int irq, const struct cpumask *dest); /* V2 interfaces to support hierarchy IRQ domains. */ extern struct irq_data *irq_domain_get_irq_data(struct irq_domain *domain, diff --git a/kernel/irq/ipi.c b/kernel/irq/ipi.c index bedc995ae214..c42742208e5e 100644 --- a/kernel/irq/ipi.c +++ b/kernel/irq/ipi.c @@ -19,9 +19,9 @@ * * Allocate a virq that can be used to send IPI to any CPU in dest mask. * - * On success it'll return linux irq number and 0 on failure + * On success it'll return linux irq number and error code on failure */ -unsigned int irq_reserve_ipi(struct irq_domain *domain, +int irq_reserve_ipi(struct irq_domain *domain, const struct cpumask *dest) { unsigned int nr_irqs, offset; @@ -30,18 +30,18 @@ unsigned int irq_reserve_ipi(struct irq_domain *domain, if (!domain ||!irq_domain_is_ipi(domain)) { pr_warn("Reservation on a non IPI domain\n"); - return 0; + return -EINVAL; } if (!cpumask_subset(dest, cpu_possible_mask)) { pr_warn("Reservation is not in possible_cpu_mask\n"); - return 0; + return -EINVAL; } nr_irqs = cpumask_weight(dest); if (!nr_irqs) { pr_warn("Reservation for empty destination mask\n"); - return 0; + return -EINVAL; } if (irq_domain_is_ipi_single(domain)) { @@ -72,14 +72,14 @@ unsigned int irq_reserve_ipi(struct irq_domain *domain, next = cpumask_next(next, dest); if (next < nr_cpu_ids) { pr_warn("Destination mask has holes\n"); - return 0; + return -EINVAL; } } virq = irq_domain_alloc_descs(-1, nr_irqs, 0, NUMA_NO_NODE); if (virq <= 0) { pr_warn("Can't reserve IPI, failed to alloc descs\n"); - return 0; + return -ENOMEM; } virq = __irq_domain_alloc_irqs(domain, virq, nr_irqs, NUMA_NO_NODE, @@ -100,7 +100,7 @@ unsigned int irq_reserve_ipi(struct irq_domain *domain, free_descs: irq_free_descs(virq, nr_irqs); - return 0; + return -EBUSY; } /** @@ -108,10 +108,12 @@ free_descs: * @irq: linux irq number to be destroyed * @dest: cpumask of cpus which should have the IPI removed * - * Return the IPIs allocated with irq_reserve_ipi() to the system destroying - * all virqs associated with them. + * The IPIs allocated with irq_reserve_ipi() are retuerned to the system + * destroying all virqs associated with them. + * + * Return 0 on success or error code on failure. */ -void irq_destroy_ipi(unsigned int irq, const struct cpumask *dest) +int irq_destroy_ipi(unsigned int irq, const struct cpumask *dest) { struct irq_data *data = irq_get_irq_data(irq); struct cpumask *ipimask = data ? irq_data_get_affinity_mask(data) : NULL; @@ -119,7 +121,7 @@ void irq_destroy_ipi(unsigned int irq, const struct cpumask *dest) unsigned int nr_irqs; if (!irq || !data || !ipimask) - return; + return -EINVAL; domain = data->domain; if (WARN_ON(domain == NULL)) @@ -127,7 +129,7 @@ void irq_destroy_ipi(unsigned int irq, const struct cpumask *dest) if (!irq_domain_is_ipi(domain)) { pr_warn("Trying to destroy a non IPI domain!\n"); - return; + return -EINVAL; } if (WARN_ON(!cpumask_subset(dest, ipimask))) @@ -135,7 +137,7 @@ void irq_destroy_ipi(unsigned int irq, const struct cpumask *dest) * Must be destroying a subset of CPUs to which this IPI * was set up to target */ - return; + return -EINVAL; if (irq_domain_is_ipi_per_cpu(domain)) { irq = irq + cpumask_first(dest) - data->common->ipi_offset; @@ -145,6 +147,7 @@ void irq_destroy_ipi(unsigned int irq, const struct cpumask *dest) } irq_domain_free_irqs(irq, nr_irqs); + return 0; } /** -- 2.20.1