Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq updates from Thomas Gleixner:
 "The irq departement proudly presents:

   - A rework of the core infrastructure to optimally spread interrupt
     for multiqueue devices. The first version was a bit naive and
     failed to take thread siblings and other details into account.
     Developed in cooperation with Christoph and Keith.

   - Proper delegation of softirqs to ksoftirqd, so if ksoftirqd is
     active then no further softirq processsing on interrupt return
     happens. Otherwise we try to delegate and still run another batch
     of network packets in the irq return path, which then tries to
     delegate to ksoftirqd .....

   - A proper machine parseable sysfs based alternative for
     /proc/interrupts.

   - ACPI support for the GICV3-ITS and ARM interrupt remapping

   - Two new irq chips from the ARM SoC zoo: STM32-EXTI and MVEBU-PIC

   - A new irq chip for the JCore (SuperH)

   - The usual pile of small fixlets in core and irqchip drivers"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits)
  softirq: Let ksoftirqd do its job
  genirq: Make function __irq_do_set_handler() static
  ARM/dts: Add EXTI controller node to stm32f429
  ARM/STM32: Select external interrupts controller
  drivers/irqchip: Add STM32 external interrupts support
  Documentation/dt-bindings: Document STM32 EXTI controller bindings
  irqchip/mips-gic: Use for_each_set_bit to iterate over local IRQs
  pci/msi: Retrieve affinity for a vector
  genirq/affinity: Remove old irq spread infrastructure
  genirq/msi: Switch to new irq spreading infrastructure
  genirq/affinity: Provide smarter irq spreading infrastructure
  genirq/msi: Add cpumask allocation to alloc_msi_entry
  genirq: Expose interrupt information through sysfs
  irqchip/gicv3-its: Use MADT ITS subtable to do PCI/MSI domain initialization
  irqchip/gicv3-its: Factor out PCI-MSI part that might be reused for ACPI
  irqchip/gicv3-its: Probe ITS in the ACPI way
  irqchip/gicv3-its: Refactor ITS DT init code to prepare for ACPI
  irqchip/gicv3-its: Cleanup for ITS domain initialization
  PCI/MSI: Setup MSI domain on a per-device basis using IORT ACPI table
  ACPI: Add new IORT functions to support MSI domain handling
  ...

1 files changed, 129 insertions, 38 deletions

diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index 32f6cfcff212..17f51d63da56 100644
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -4,60 +4,151 @@
 #include <linux/slab.h>
 #include <linux/cpu.h>
 
-static int get_first_sibling(unsigned int cpu)
+static void irq_spread_init_one(struct cpumask *irqmsk, struct cpumask *nmsk,
+				int cpus_per_vec)
 {
-	unsigned int ret;
+	const struct cpumask *siblmsk;
+	int cpu, sibl;
 
-	ret = cpumask_first(topology_sibling_cpumask(cpu));
-	if (ret < nr_cpu_ids)
-		return ret;
-	return cpu;
+	for ( ; cpus_per_vec > 0; ) {
+		cpu = cpumask_first(nmsk);
+
+		/* Should not happen, but I'm too lazy to think about it */
+		if (cpu >= nr_cpu_ids)
+			return;
+
+		cpumask_clear_cpu(cpu, nmsk);
+		cpumask_set_cpu(cpu, irqmsk);
+		cpus_per_vec--;
+
+		/* If the cpu has siblings, use them first */
+		siblmsk = topology_sibling_cpumask(cpu);
+		for (sibl = -1; cpus_per_vec > 0; ) {
+			sibl = cpumask_next(sibl, siblmsk);
+			if (sibl >= nr_cpu_ids)
+				break;
+			if (!cpumask_test_and_clear_cpu(sibl, nmsk))
+				continue;
+			cpumask_set_cpu(sibl, irqmsk);
+			cpus_per_vec--;
+		}
+	}
+}
+
+static int get_nodes_in_cpumask(const struct cpumask *mask, nodemask_t *nodemsk)
+{
+	int n, nodes;
+
+	/* Calculate the number of nodes in the supplied affinity mask */
+	for (n = 0, nodes = 0; n < num_online_nodes(); n++) {
+		if (cpumask_intersects(mask, cpumask_of_node(n))) {
+			node_set(n, *nodemsk);
+			nodes++;
+		}
+	}
+	return nodes;
 }
 
-/*
- * Take a map of online CPUs and the number of available interrupt vectors
- * and generate an output cpumask suitable for spreading MSI/MSI-X vectors
- * so that they are distributed as good as possible around the CPUs.  If
- * more vectors than CPUs are available we'll map one to each CPU,
- * otherwise we map one to the first sibling of each socket.
+/**
+ * irq_create_affinity_masks - Create affinity masks for multiqueue spreading
+ * @affinity:		The affinity mask to spread. If NULL cpu_online_mask
+ *			is used
+ * @nvecs:		The number of vectors
  *
- * If there are more vectors than CPUs we will still only have one bit
- * set per CPU, but interrupt code will keep on assigning the vectors from
- * the start of the bitmap until we run out of vectors.
+ * Returns the masks pointer or NULL if allocation failed.
  */
-struct cpumask *irq_create_affinity_mask(unsigned int *nr_vecs)
+struct cpumask *irq_create_affinity_masks(const struct cpumask *affinity,
+					  int nvec)
 {
-	struct cpumask *affinity_mask;
-	unsigned int max_vecs = *nr_vecs;
+	int n, nodes, vecs_per_node, cpus_per_vec, extra_vecs, curvec = 0;
+	nodemask_t nodemsk = NODE_MASK_NONE;
+	struct cpumask *masks;
+	cpumask_var_t nmsk;
 
-	if (max_vecs == 1)
+	if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
 		return NULL;
 
-	affinity_mask = kzalloc(cpumask_size(), GFP_KERNEL);
-	if (!affinity_mask) {
-		*nr_vecs = 1;
-		return NULL;
-	}
+	masks = kzalloc(nvec * sizeof(*masks), GFP_KERNEL);
+	if (!masks)
+		goto out;
 
+	/* Stabilize the cpumasks */
 	get_online_cpus();
-	if (max_vecs >= num_online_cpus()) {
-		cpumask_copy(affinity_mask, cpu_online_mask);
-		*nr_vecs = num_online_cpus();
-	} else {
-		unsigned int vecs = 0, cpu;
-
-		for_each_online_cpu(cpu) {
-			if (cpu == get_first_sibling(cpu)) {
-				cpumask_set_cpu(cpu, affinity_mask);
-				vecs++;
-			}
+	/* If the supplied affinity mask is NULL, use cpu online mask */
+	if (!affinity)
+		affinity = cpu_online_mask;
+
+	nodes = get_nodes_in_cpumask(affinity, &nodemsk);
 
-			if (--max_vecs == 0)
+	/*
+	 * If the number of nodes in the mask is less than or equal the
+	 * number of vectors we just spread the vectors across the nodes.
+	 */
+	if (nvec <= nodes) {
+		for_each_node_mask(n, nodemsk) {
+			cpumask_copy(masks + curvec, cpumask_of_node(n));
+			if (++curvec == nvec)
 				break;
 		}
-		*nr_vecs = vecs;
+		goto outonl;
 	}
+
+	/* Spread the vectors per node */
+	vecs_per_node = nvec / nodes;
+	/* Account for rounding errors */
+	extra_vecs = nvec - (nodes * vecs_per_node);
+
+	for_each_node_mask(n, nodemsk) {
+		int ncpus, v, vecs_to_assign = vecs_per_node;
+
+		/* Get the cpus on this node which are in the mask */
+		cpumask_and(nmsk, affinity, cpumask_of_node(n));
+
+		/* Calculate the number of cpus per vector */
+		ncpus = cpumask_weight(nmsk);
+
+		for (v = 0; curvec < nvec && v < vecs_to_assign; curvec++, v++) {
+			cpus_per_vec = ncpus / vecs_to_assign;
+
+			/* Account for extra vectors to compensate rounding errors */
+			if (extra_vecs) {
+				cpus_per_vec++;
+				if (!--extra_vecs)
+					vecs_per_node++;
+			}
+			irq_spread_init_one(masks + curvec, nmsk, cpus_per_vec);
+		}
+
+		if (curvec >= nvec)
+			break;
+	}
+
+outonl:
 	put_online_cpus();
+out:
+	free_cpumask_var(nmsk);
+	return masks;
+}
+
+/**
+ * irq_calc_affinity_vectors - Calculate to optimal number of vectors for a given affinity mask
+ * @affinity:		The affinity mask to spread. If NULL cpu_online_mask
+ *			is used
+ * @maxvec:		The maximum number of vectors available
+ */
+int irq_calc_affinity_vectors(const struct cpumask *affinity, int maxvec)
+{
+	int cpus, ret;
 
-	return affinity_mask;
+	/* Stabilize the cpumasks */
+	get_online_cpus();
+	/* If the supplied affinity mask is NULL, use cpu online mask */
+	if (!affinity)
+		affinity = cpu_online_mask;
+
+	cpus = cpumask_weight(affinity);
+	ret = (cpus < maxvec) ? cpus : maxvec;
+
+	put_online_cpus();
+	return ret;
 }