Add a generic mechanism to dynamically allocate an IPI. With this change the user can call irq_reserve_ipi() to dynamically allocate an IPI and use the associate virq to send one to 1 or more cpus.
Signed-off-by: Qais Yousef <[email protected]> --- include/linux/irqdomain.h | 6 ++++ kernel/irq/irqdomain.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 90 insertions(+) diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h index 9b3dc6c2a3cc..f5003f5fd530 100644 --- a/include/linux/irqdomain.h +++ b/include/linux/irqdomain.h @@ -41,6 +41,7 @@ struct irq_domain; struct of_device_id; struct irq_chip; struct irq_data; +struct ipi_mask; /* Number of irqs reserved for a legacy isa controller */ #define NUM_ISA_INTERRUPTS 16 @@ -280,6 +281,11 @@ int irq_domain_xlate_onetwocell(struct irq_domain *d, struct device_node *ctrlr, const u32 *intspec, unsigned int intsize, irq_hw_number_t *out_hwirq, unsigned int *out_type); +/* IPI functions */ +unsigned int irq_reserve_ipi(struct irq_domain *domain, + const struct ipi_mask *dest); +void irq_destroy_ipi(unsigned int irq); + /* V2 interfaces to support hierarchy IRQ domains. */ extern struct irq_data *irq_domain_get_irq_data(struct irq_domain *domain, unsigned int virq); diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index dc9d27c0c158..781407f7d692 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -749,6 +749,90 @@ static int irq_domain_alloc_descs(int virq, unsigned int cnt, return virq; } +/** + * irq_reserve_ipi() - setup an IPI to destination cpumask + * @domain: IPI domain + * @dest: cpumask of cpus to receive the IPI + * + * 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 + */ +unsigned int irq_reserve_ipi(struct irq_domain *domain, + const struct ipi_mask *dest) +{ + struct irq_data *data; + int virq; + unsigned int nr_irqs; + + if (domain == NULL) + domain = irq_default_domain; /* need a separate ipi_default_domain? */ + + if (domain == NULL) { + pr_warn("Must provide a valid IPI domain!\n"); + return 0; + } + + if (!irq_domain_is_ipi(domain)) { + pr_warn("Not an IPI domain!\n"); + return 0; + } + + /* always allocate a virq per cpu */ + nr_irqs = bitmap_weight(dest->cpumask, dest->nbits);; + + 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; + } + + /* we are reusing hierarchy alloc function, should we create another one? */ + virq = __irq_domain_alloc_irqs(domain, virq, nr_irqs, NUMA_NO_NODE, + (void *) dest, true); + if (virq <= 0) { + pr_warn("Can't reserve IPI, failed to alloc irqs\n"); + goto free_descs; + } + + data = irq_get_irq_data(virq); + bitmap_copy(data->ipi_mask.cpumask, dest->cpumask, dest->nbits); + data->ipi_mask.nbits = dest->nbits; + + return virq; + +free_descs: + irq_free_descs(virq, nr_irqs); + return 0; +} + +/** + * irq_destroy_ipi() - unreserve an IPI that was previously allocated + * @irq: linux irq number to be destroyed + * + * Return an IPI allocated with irq_reserve_ipi() to the system. + */ +void irq_destroy_ipi(unsigned int irq) +{ + struct irq_data *data = irq_get_irq_data(irq); + struct irq_domain *domain; + + if (!irq || !data) + return; + + domain = data->domain; + if (WARN_ON(domain == NULL)) + return; + + if (!irq_domain_is_ipi(domain)) { + pr_warn("Not an IPI domain!\n"); + return; + } + + irq_domain_free_irqs(irq, + bitmap_weight(data->ipi_mask.cpumask, data->ipi_mask.nbits)); +} + #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY /** * irq_domain_add_hierarchy - Add a irqdomain into the hierarchy -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
