Drivers may use this API to build customized irq affinity, one example is NVMe, which needs to build multiple irq sets, on each of which all CPUs are spread.
Signed-off-by: Ming Lei <[email protected]> --- include/linux/interrupt.h | 12 ++++++++++++ kernel/irq/affinity.c | 27 +++++++++++++++++++++++++++ 2 files changed, 39 insertions(+) diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index f6cea778cf50..b820b07f3b55 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -323,6 +323,10 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify); struct irq_affinity_desc * irq_create_affinity_masks(int nvec, const struct irq_affinity *affd); +int irq_build_affinity(const struct irq_affinity *affd, int startvec, + int numvecs, int firstvec, + struct irq_affinity_desc *masks, int nmasks); + int irq_calc_affinity_vectors(int minvec, int maxvec, const struct irq_affinity *affd); #else /* CONFIG_SMP */ @@ -368,6 +372,14 @@ irq_calc_affinity_vectors(int minvec, int maxvec, const struct irq_affinity *aff return maxvec; } +static inline int +irq_build_affinity(const struct irq_affinity *affd, int startvec, + int numvecs, int firstvec, + struct irq_affinity_desc *masks, int nmasks) +{ + return 0; +} + #endif /* CONFIG_SMP */ /* diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c index 7b77cbdf739c..524fdcda9f85 100644 --- a/kernel/irq/affinity.c +++ b/kernel/irq/affinity.c @@ -232,6 +232,33 @@ static int irq_build_affinity_masks(const struct irq_affinity *affd, } /** + * irq_build_affinity - build affinity masks for multiqueue spreading + * @affd: Description of the affinity requirements + * @startvec: The start vector for building affinity masks + * @numvec: The number of vectors is needed for building affinity + * @firstvec: It is the IRQ vector which we jump to for continue spread + * after the last vector(@startvec + @numvec - 1) is built. + * @masks: The mask array for storing the affinity masks + * @nmasks: The total number of @masks + * + * Both @startvec and @firstvec are relative to the 1st irq vectorc + * allocated to the device. + * + * Returns 0 if affinty masks is built successfully. + */ +int irq_build_affinity(const struct irq_affinity *affd, int startvec, + int numvecs, int firstvec, + struct irq_affinity_desc *masks, int nmasks) +{ + if (startvec >= nmasks || firstvec >= nmasks || numvecs > nmasks) + return -EINVAL; + + return irq_build_affinity_masks(affd, startvec, numvecs, firstvec, + masks); +} +EXPORT_SYMBOL_GPL(irq_build_affinity); + +/** * irq_create_affinity_masks - Create affinity masks for multiqueue spreading * @nvecs: The total number of vectors * @affd: Description of the affinity requirements -- 2.9.5
