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authorDou Liyang <douliyangs@gmail.com>2018-12-04 18:51:20 +0300
committerThomas Gleixner <tglx@linutronix.de>2018-12-19 13:32:08 +0300
commitbec04037e4e484f41ee4d9409e40616874169d20 (patch)
tree5fde4bc9e597250dbdac3a4c0741b13766da8d4e /include/linux/irqdomain.h
parentc2899c3470de04823870b28646981695c0046efe (diff)
downloadlinux-bec04037e4e484f41ee4d9409e40616874169d20.tar.xz
genirq/core: Introduce struct irq_affinity_desc
The interrupt affinity management uses straight cpumask pointers to convey the automatically assigned affinity masks for managed interrupts. The core interrupt descriptor allocation also decides based on the pointer being non NULL whether an interrupt is managed or not. Devices which use managed interrupts usually have two classes of interrupts: - Interrupts for multiple device queues - Interrupts for general device management Currently both classes are treated the same way, i.e. as managed interrupts. The general interrupts get the default affinity mask assigned while the device queue interrupts are spread out over the possible CPUs. Treating the general interrupts as managed is both a limitation and under certain circumstances a bug. Assume the following situation: default_irq_affinity = 4..7 So if CPUs 4-7 are offlined, then the core code will shut down the device management interrupts because the last CPU in their affinity mask went offline. It's also a limitation because it's desired to allow manual placement of the general device interrupts for various reasons. If they are marked managed then the interrupt affinity setting from both user and kernel space is disabled. To remedy that situation it's required to convey more information than the cpumasks through various interfaces related to interrupt descriptor allocation. Instead of adding yet another argument, create a new data structure 'irq_affinity_desc' which for now just contains the cpumask. This struct can be expanded to convey auxilliary information in the next step. No functional change, just preparatory work. [ tglx: Simplified logic and clarified changelog ] Suggested-by: Thomas Gleixner <tglx@linutronix.de> Suggested-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Dou Liyang <douliyangs@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-pci@vger.kernel.org Cc: kashyap.desai@broadcom.com Cc: shivasharan.srikanteshwara@broadcom.com Cc: sumit.saxena@broadcom.com Cc: ming.lei@redhat.com Cc: hch@lst.de Cc: douliyang1@huawei.com Link: https://lkml.kernel.org/r/20181204155122.6327-2-douliyangs@gmail.com
Diffstat (limited to 'include/linux/irqdomain.h')
-rw-r--r--include/linux/irqdomain.h6
1 files changed, 4 insertions, 2 deletions
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 068aa46f0d55..35965f41d7be 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -43,6 +43,7 @@ struct irq_chip;
struct irq_data;
struct cpumask;
struct seq_file;
+struct irq_affinity_desc;
/* Number of irqs reserved for a legacy isa controller */
#define NUM_ISA_INTERRUPTS 16
@@ -266,7 +267,7 @@ extern bool irq_domain_check_msi_remap(void);
extern void irq_set_default_host(struct irq_domain *host);
extern int irq_domain_alloc_descs(int virq, unsigned int nr_irqs,
irq_hw_number_t hwirq, int node,
- const struct cpumask *affinity);
+ const struct irq_affinity_desc *affinity);
static inline struct fwnode_handle *of_node_to_fwnode(struct device_node *node)
{
@@ -449,7 +450,8 @@ static inline struct irq_domain *irq_domain_add_hierarchy(struct irq_domain *par
extern int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base,
unsigned int nr_irqs, int node, void *arg,
- bool realloc, const struct cpumask *affinity);
+ bool realloc,
+ const struct irq_affinity_desc *affinity);
extern void irq_domain_free_irqs(unsigned int virq, unsigned int nr_irqs);
extern int irq_domain_activate_irq(struct irq_data *irq_data, bool early);
extern void irq_domain_deactivate_irq(struct irq_data *irq_data);