Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6da4b3ab authored by Jens Axboe's avatar Jens Axboe Committed by Thomas Gleixner
Browse files

genirq/affinity: Add support for allocating interrupt sets 



A driver may have a need to allocate multiple sets of MSI/MSI-X interrupts,
and have them appropriately affinitized.

Add support for defining a number of sets in the irq_affinity structure, of
varying sizes, and get each set affinitized correctly across the machine.

[ tglx: Minor changelog tweaks ]

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
Reviewed-by: default avatarKeith Busch <keith.busch@intel.com>
Reviewed-by: default avatarSagi Grimberg <sagi@grimberg.me>
Cc: linux-block@vger.kernel.org
Link: https://lkml.kernel.org/r/20181102145951.31979-5-ming.lei@redhat.com
parent 060746d9

drivers/pci/msi.c

+14 −0
Original line number Diff line number Diff line
@@ -1036,6 +1036,13 @@ static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec, 
	if (maxvec < minvec)

		return -ERANGE;



	/*

	 * If the caller is passing in sets, we can't support a range of

	 * vectors. The caller needs to handle that.

	 */

	if (affd && affd->nr_sets && minvec != maxvec)

		return -EINVAL;



	if (WARN_ON_ONCE(dev->msi_enabled))

		return -EINVAL;
@@ -1087,6 +1094,13 @@ static int __pci_enable_msix_range(struct pci_dev *dev, 
	if (maxvec < minvec)

		return -ERANGE;



	/*

	 * If the caller is passing in sets, we can't support a range of

	 * supported vectors. The caller needs to handle that.

	 */

	if (affd && affd->nr_sets && minvec != maxvec)

		return -EINVAL;



	if (WARN_ON_ONCE(dev->msix_enabled))

		return -EINVAL;

include/linux/interrupt.h

+4 −0
Original line number Diff line number Diff line
@@ -247,10 +247,14 @@ struct irq_affinity_notify { 
 *			the MSI(-X) vector space

 * @post_vectors:	Don't apply affinity to @post_vectors at end of

 *			the MSI(-X) vector space

 * @nr_sets:		Length of passed in *sets array

 * @sets:		Number of affinitized sets

 */

struct irq_affinity {

	int	pre_vectors;

	int	post_vectors;

	int	nr_sets;

	int	*sets;

};



#if defined(CONFIG_SMP)

kernel/irq/affinity.c

+54 −23
Original line number Diff line number Diff line
@@ -171,27 +171,28 @@ static int __irq_build_affinity_masks(const struct irq_affinity *affd, 
 *	2) spread other possible CPUs on these vectors

 */

static int irq_build_affinity_masks(const struct irq_affinity *affd,

				    int startvec, int numvecs,

				    int startvec, int numvecs, int firstvec,

				    cpumask_var_t *node_to_cpumask,

				    struct cpumask *masks)

{

	int curvec = startvec, usedvecs = -1;

	int curvec = startvec, nr_present, nr_others;

	int ret = -ENOMEM;

	cpumask_var_t nmsk, npresmsk;



	if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))

			return usedvecs;

			return ret;



	if (!zalloc_cpumask_var(&npresmsk, GFP_KERNEL))

			goto fail;



	ret = 0;

	/* Stabilize the cpumasks */

	get_online_cpus();

	build_node_to_cpumask(node_to_cpumask);



	/* Spread on present CPUs starting from affd->pre_vectors */

	usedvecs = __irq_build_affinity_masks(affd, curvec, numvecs,

					      affd->pre_vectors,

					      node_to_cpumask,

	nr_present = __irq_build_affinity_masks(affd, curvec, numvecs,

						firstvec, node_to_cpumask,

						cpu_present_mask, nmsk, masks);



	/*
@@ -200,23 +201,24 @@ static int irq_build_affinity_masks(const struct irq_affinity *affd, 
	 * vector space, assign the non present CPUs to the already spread

	 * out vectors.

	 */

	if (usedvecs >= numvecs)

		curvec = affd->pre_vectors;

	if (nr_present >= numvecs)

		curvec = firstvec;

	else

		curvec = affd->pre_vectors + usedvecs;

		curvec = firstvec + nr_present;

	cpumask_andnot(npresmsk, cpu_possible_mask, cpu_present_mask);

	usedvecs += __irq_build_affinity_masks(affd, curvec, numvecs,

					       affd->pre_vectors,

					       node_to_cpumask, npresmsk,

					       nmsk, masks);

	nr_others = __irq_build_affinity_masks(affd, curvec, numvecs,

					       firstvec, node_to_cpumask,

					       npresmsk, nmsk, masks);

	put_online_cpus();



	if (nr_present < numvecs)

			WARN_ON(nr_present + nr_others < numvecs);



	free_cpumask_var(npresmsk);



 fail:

	free_cpumask_var(nmsk);



	return usedvecs;

	return ret;

}



/**
@@ -233,6 +235,7 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd) 
	int curvec, usedvecs;

	cpumask_var_t *node_to_cpumask;

	struct cpumask *masks = NULL;

	int i, nr_sets;



	/*

	 * If there aren't any vectors left after applying the pre/post
@@ -253,8 +256,28 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd) 
	for (curvec = 0; curvec < affd->pre_vectors; curvec++)

		cpumask_copy(masks + curvec, irq_default_affinity);



	usedvecs = irq_build_affinity_masks(affd, curvec, affvecs,

					    node_to_cpumask, masks);

	/*

	 * Spread on present CPUs starting from affd->pre_vectors. If we

	 * have multiple sets, build each sets affinity mask separately.

	 */

	nr_sets = affd->nr_sets;

	if (!nr_sets)

		nr_sets = 1;



	for (i = 0, usedvecs = 0; i < nr_sets; i++) {

		int this_vecs = affd->sets ? affd->sets[i] : affvecs;

		int ret;



		ret = irq_build_affinity_masks(affd, curvec, this_vecs,

						curvec, node_to_cpumask, masks);

		if (ret) {

				kfree(masks);

				masks = NULL;

				goto outnodemsk;

		}

		curvec += this_vecs;

		usedvecs += this_vecs;

	}



	/* Fill out vectors at the end that don't need affinity */

	if (usedvecs >= affvecs)
@@ -279,13 +302,21 @@ int irq_calc_affinity_vectors(int minvec, int maxvec, const struct irq_affinity 
{

	int resv = affd->pre_vectors + affd->post_vectors;

	int vecs = maxvec - resv;

	int ret;

	int set_vecs;



	if (resv > minvec)

		return 0;



	if (affd->nr_sets) {

		int i;



		for (i = 0, set_vecs = 0;  i < affd->nr_sets; i++)

			set_vecs += affd->sets[i];

	} else {

		get_online_cpus();

	ret = min_t(int, cpumask_weight(cpu_possible_mask), vecs) + resv;

		set_vecs = cpumask_weight(cpu_possible_mask);

		put_online_cpus();

	return ret;

	}



	return resv + min(set_vecs, vecs);

}