4.12-stable review patch. If anyone has any objections, please let me know.
------------------ From: Michael Hernandez <[email protected]> commit 6f9a22bc5775d231ab8fbe2c2f3c88e45e3e7c28 upstream. min_vecs is the minimum amount of vectors needed to operate in MSI-X mode which may just include the vectors that don't need affinity. Disabling affinity settings causes the qla2xxx driver scsi_add_host() to fail when blk_mq is enabled as the blk_mq_pci_map_queues() expects affinity masks on each vector. Fixes: dfef358bd1be ("PCI/MSI: Don't apply affinity if there aren't enough vectors left") Signed-off-by: Michael Hernandez <[email protected]> Signed-off-by: Himanshu Madhani <[email protected]> Signed-off-by: Bjorn Helgaas <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/pci/msi.c | 14 ++------------ include/linux/interrupt.h | 4 ++-- kernel/irq/affinity.c | 13 ++++++++++++- 3 files changed, 16 insertions(+), 15 deletions(-) --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -1058,7 +1058,7 @@ static int __pci_enable_msi_range(struct for (;;) { if (affd) { - nvec = irq_calc_affinity_vectors(nvec, affd); + nvec = irq_calc_affinity_vectors(minvec, nvec, affd); if (nvec < minvec) return -ENOSPC; } @@ -1097,7 +1097,7 @@ static int __pci_enable_msix_range(struc for (;;) { if (affd) { - nvec = irq_calc_affinity_vectors(nvec, affd); + nvec = irq_calc_affinity_vectors(minvec, nvec, affd); if (nvec < minvec) return -ENOSPC; } @@ -1165,16 +1165,6 @@ int pci_alloc_irq_vectors_affinity(struc if (flags & PCI_IRQ_AFFINITY) { if (!affd) affd = &msi_default_affd; - - if (affd->pre_vectors + affd->post_vectors > min_vecs) - return -EINVAL; - - /* - * If there aren't any vectors left after applying the pre/post - * vectors don't bother with assigning affinity. - */ - if (affd->pre_vectors + affd->post_vectors == min_vecs) - affd = NULL; } else { if (WARN_ON(affd)) affd = NULL; --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -291,7 +291,7 @@ extern int irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify); struct cpumask *irq_create_affinity_masks(int nvec, const struct irq_affinity *affd); -int irq_calc_affinity_vectors(int maxvec, const struct irq_affinity *affd); +int irq_calc_affinity_vectors(int minvec, int maxvec, const struct irq_affinity *affd); #else /* CONFIG_SMP */ @@ -331,7 +331,7 @@ irq_create_affinity_masks(int nvec, cons } static inline int -irq_calc_affinity_vectors(int maxvec, const struct irq_affinity *affd) +irq_calc_affinity_vectors(int minvec, int maxvec, const struct irq_affinity *affd) { return maxvec; } --- a/kernel/irq/affinity.c +++ b/kernel/irq/affinity.c @@ -66,6 +66,13 @@ irq_create_affinity_masks(int nvecs, con struct cpumask *masks; cpumask_var_t nmsk; + /* + * If there aren't any vectors left after applying the pre/post + * vectors don't bother with assigning affinity. + */ + if (!affv) + return NULL; + if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL)) return NULL; @@ -140,15 +147,19 @@ out: /** * irq_calc_affinity_vectors - Calculate the optimal number of vectors + * @minvec: The minimum number of vectors available * @maxvec: The maximum number of vectors available * @affd: Description of the affinity requirements */ -int irq_calc_affinity_vectors(int maxvec, const struct irq_affinity *affd) +int irq_calc_affinity_vectors(int minvec, int maxvec, const struct irq_affinity *affd) { int resv = affd->pre_vectors + affd->post_vectors; int vecs = maxvec - resv; int cpus; + if (resv > minvec) + return 0; + /* Stabilize the cpumasks */ get_online_cpus(); cpus = cpumask_weight(cpu_online_mask);
