aboutsummaryrefslogtreecommitdiff
path: root/lib
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2011-03-16 16:29:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-16 16:29:25 -0700
commit7a6362800cb7d1d618a697a650c7aaed3eb39320 (patch)
tree087f9bc6c13ef1fad4b392c5cf9325cd28fa8523 /lib
parent6445ced8670f37cfc2c5e24a9de9b413dbfc788d (diff)
parentceda86a108671294052cbf51660097b6534672f5 (diff)
downloadlinux-7a6362800cb7d1d618a697a650c7aaed3eb39320.tar.gz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1480 commits) bonding: enable netpoll without checking link status xfrm: Refcount destination entry on xfrm_lookup net: introduce rx_handler results and logic around that bonding: get rid of IFF_SLAVE_INACTIVE netdev->priv_flag bonding: wrap slave state work net: get rid of multiple bond-related netdevice->priv_flags bonding: register slave pointer for rx_handler be2net: Bump up the version number be2net: Copyright notice change. Update to Emulex instead of ServerEngines e1000e: fix kconfig for crc32 dependency netfilter ebtables: fix xt_AUDIT to work with ebtables xen network backend driver bonding: Improve syslog message at device creation time bonding: Call netif_carrier_off after register_netdevice bonding: Incorrect TX queue offset net_sched: fix ip_tos2prio xfrm: fix __xfrm_route_forward() be2net: Fix UDP packet detected status in RX compl Phonet: fix aligned-mode pipe socket buffer header reserve netxen: support for GbE port settings ... Fix up conflicts in drivers/staging/brcm80211/brcmsmac/wl_mac80211.c with the staging updates.
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig13
-rw-r--r--lib/Makefile2
-rw-r--r--lib/cpu_rmap.c269
3 files changed, 283 insertions, 1 deletions
diff --git a/lib/Kconfig b/lib/Kconfig
index 0ee67e08ad3..3a55a43c43e 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -201,6 +201,10 @@ config DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
bool "Disable obsolete cpumask functions" if DEBUG_PER_CPU_MAPS
depends on EXPERIMENTAL && BROKEN
+config CPU_RMAP
+ bool
+ depends on SMP
+
#
# Netlink attribute parsing support is select'ed if needed
#
@@ -217,6 +221,13 @@ config LRU_CACHE
tristate
config AVERAGE
- bool
+ bool "Averaging functions"
+ help
+ This option is provided for the case where no in-kernel-tree
+ modules require averaging functions, but a module built outside
+ the kernel tree does. Such modules that use library averaging
+ functions require Y here.
+
+ If unsure, say N.
endmenu
diff --git a/lib/Makefile b/lib/Makefile
index cbb774f7d41..b73ba01a818 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -110,6 +110,8 @@ obj-$(CONFIG_ATOMIC64_SELFTEST) += atomic64_test.o
obj-$(CONFIG_AVERAGE) += average.o
+obj-$(CONFIG_CPU_RMAP) += cpu_rmap.o
+
hostprogs-y := gen_crc32table
clean-files := crc32table.h
diff --git a/lib/cpu_rmap.c b/lib/cpu_rmap.c
new file mode 100644
index 00000000000..987acfafeb8
--- /dev/null
+++ b/lib/cpu_rmap.c
@@ -0,0 +1,269 @@
+/*
+ * cpu_rmap.c: CPU affinity reverse-map support
+ * Copyright 2011 Solarflare Communications Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation, incorporated herein by reference.
+ */
+
+#include <linux/cpu_rmap.h>
+#ifdef CONFIG_GENERIC_HARDIRQS
+#include <linux/interrupt.h>
+#endif
+#include <linux/module.h>
+
+/*
+ * These functions maintain a mapping from CPUs to some ordered set of
+ * objects with CPU affinities. This can be seen as a reverse-map of
+ * CPU affinity. However, we do not assume that the object affinities
+ * cover all CPUs in the system. For those CPUs not directly covered
+ * by object affinities, we attempt to find a nearest object based on
+ * CPU topology.
+ */
+
+/**
+ * alloc_cpu_rmap - allocate CPU affinity reverse-map
+ * @size: Number of objects to be mapped
+ * @flags: Allocation flags e.g. %GFP_KERNEL
+ */
+struct cpu_rmap *alloc_cpu_rmap(unsigned int size, gfp_t flags)
+{
+ struct cpu_rmap *rmap;
+ unsigned int cpu;
+ size_t obj_offset;
+
+ /* This is a silly number of objects, and we use u16 indices. */
+ if (size > 0xffff)
+ return NULL;
+
+ /* Offset of object pointer array from base structure */
+ obj_offset = ALIGN(offsetof(struct cpu_rmap, near[nr_cpu_ids]),
+ sizeof(void *));
+
+ rmap = kzalloc(obj_offset + size * sizeof(rmap->obj[0]), flags);
+ if (!rmap)
+ return NULL;
+
+ rmap->obj = (void **)((char *)rmap + obj_offset);
+
+ /* Initially assign CPUs to objects on a rota, since we have
+ * no idea where the objects are. Use infinite distance, so
+ * any object with known distance is preferable. Include the
+ * CPUs that are not present/online, since we definitely want
+ * any newly-hotplugged CPUs to have some object assigned.
+ */
+ for_each_possible_cpu(cpu) {
+ rmap->near[cpu].index = cpu % size;
+ rmap->near[cpu].dist = CPU_RMAP_DIST_INF;
+ }
+
+ rmap->size = size;
+ return rmap;
+}
+EXPORT_SYMBOL(alloc_cpu_rmap);
+
+/* Reevaluate nearest object for given CPU, comparing with the given
+ * neighbours at the given distance.
+ */
+static bool cpu_rmap_copy_neigh(struct cpu_rmap *rmap, unsigned int cpu,
+ const struct cpumask *mask, u16 dist)
+{
+ int neigh;
+
+ for_each_cpu(neigh, mask) {
+ if (rmap->near[cpu].dist > dist &&
+ rmap->near[neigh].dist <= dist) {
+ rmap->near[cpu].index = rmap->near[neigh].index;
+ rmap->near[cpu].dist = dist;
+ return true;
+ }
+ }
+ return false;
+}
+
+#ifdef DEBUG
+static void debug_print_rmap(const struct cpu_rmap *rmap, const char *prefix)
+{
+ unsigned index;
+ unsigned int cpu;
+
+ pr_info("cpu_rmap %p, %s:\n", rmap, prefix);
+
+ for_each_possible_cpu(cpu) {
+ index = rmap->near[cpu].index;
+ pr_info("cpu %d -> obj %u (distance %u)\n",
+ cpu, index, rmap->near[cpu].dist);
+ }
+}
+#else
+static inline void
+debug_print_rmap(const struct cpu_rmap *rmap, const char *prefix)
+{
+}
+#endif
+
+/**
+ * cpu_rmap_add - add object to a rmap
+ * @rmap: CPU rmap allocated with alloc_cpu_rmap()
+ * @obj: Object to add to rmap
+ *
+ * Return index of object.
+ */
+int cpu_rmap_add(struct cpu_rmap *rmap, void *obj)
+{
+ u16 index;
+
+ BUG_ON(rmap->used >= rmap->size);
+ index = rmap->used++;
+ rmap->obj[index] = obj;
+ return index;
+}
+EXPORT_SYMBOL(cpu_rmap_add);
+
+/**
+ * cpu_rmap_update - update CPU rmap following a change of object affinity
+ * @rmap: CPU rmap to update
+ * @index: Index of object whose affinity changed
+ * @affinity: New CPU affinity of object
+ */
+int cpu_rmap_update(struct cpu_rmap *rmap, u16 index,
+ const struct cpumask *affinity)
+{
+ cpumask_var_t update_mask;
+ unsigned int cpu;
+
+ if (unlikely(!zalloc_cpumask_var(&update_mask, GFP_KERNEL)))
+ return -ENOMEM;
+
+ /* Invalidate distance for all CPUs for which this used to be
+ * the nearest object. Mark those CPUs for update.
+ */
+ for_each_online_cpu(cpu) {
+ if (rmap->near[cpu].index == index) {
+ rmap->near[cpu].dist = CPU_RMAP_DIST_INF;
+ cpumask_set_cpu(cpu, update_mask);
+ }
+ }
+
+ debug_print_rmap(rmap, "after invalidating old distances");
+
+ /* Set distance to 0 for all CPUs in the new affinity mask.
+ * Mark all CPUs within their NUMA nodes for update.
+ */
+ for_each_cpu(cpu, affinity) {
+ rmap->near[cpu].index = index;
+ rmap->near[cpu].dist = 0;
+ cpumask_or(update_mask, update_mask,
+ cpumask_of_node(cpu_to_node(cpu)));
+ }
+
+ debug_print_rmap(rmap, "after updating neighbours");
+
+ /* Update distances based on topology */
+ for_each_cpu(cpu, update_mask) {
+ if (cpu_rmap_copy_neigh(rmap, cpu,
+ topology_thread_cpumask(cpu), 1))
+ continue;
+ if (cpu_rmap_copy_neigh(rmap, cpu,
+ topology_core_cpumask(cpu), 2))
+ continue;
+ if (cpu_rmap_copy_neigh(rmap, cpu,
+ cpumask_of_node(cpu_to_node(cpu)), 3))
+ continue;
+ /* We could continue into NUMA node distances, but for now
+ * we give up.
+ */
+ }
+
+ debug_print_rmap(rmap, "after copying neighbours");
+
+ free_cpumask_var(update_mask);
+ return 0;
+}
+EXPORT_SYMBOL(cpu_rmap_update);
+
+#ifdef CONFIG_GENERIC_HARDIRQS
+
+/* Glue between IRQ affinity notifiers and CPU rmaps */
+
+struct irq_glue {
+ struct irq_affinity_notify notify;
+ struct cpu_rmap *rmap;
+ u16 index;
+};
+
+/**
+ * free_irq_cpu_rmap - free a CPU affinity reverse-map used for IRQs
+ * @rmap: Reverse-map allocated with alloc_irq_cpu_map(), or %NULL
+ *
+ * Must be called in process context, before freeing the IRQs, and
+ * without holding any locks required by global workqueue items.
+ */
+void free_irq_cpu_rmap(struct cpu_rmap *rmap)
+{
+ struct irq_glue *glue;
+ u16 index;
+
+ if (!rmap)
+ return;
+
+ for (index = 0; index < rmap->used; index++) {
+ glue = rmap->obj[index];
+ irq_set_affinity_notifier(glue->notify.irq, NULL);
+ }
+ irq_run_affinity_notifiers();
+
+ kfree(rmap);
+}
+EXPORT_SYMBOL(free_irq_cpu_rmap);
+
+static void
+irq_cpu_rmap_notify(struct irq_affinity_notify *notify, const cpumask_t *mask)
+{
+ struct irq_glue *glue =
+ container_of(notify, struct irq_glue, notify);
+ int rc;
+
+ rc = cpu_rmap_update(glue->rmap, glue->index, mask);
+ if (rc)
+ pr_warning("irq_cpu_rmap_notify: update failed: %d\n", rc);
+}
+
+static void irq_cpu_rmap_release(struct kref *ref)
+{
+ struct irq_glue *glue =
+ container_of(ref, struct irq_glue, notify.kref);
+ kfree(glue);
+}
+
+/**
+ * irq_cpu_rmap_add - add an IRQ to a CPU affinity reverse-map
+ * @rmap: The reverse-map
+ * @irq: The IRQ number
+ *
+ * This adds an IRQ affinity notifier that will update the reverse-map
+ * automatically.
+ *
+ * Must be called in process context, after the IRQ is allocated but
+ * before it is bound with request_irq().
+ */
+int irq_cpu_rmap_add(struct cpu_rmap *rmap, int irq)
+{
+ struct irq_glue *glue = kzalloc(sizeof(*glue), GFP_KERNEL);
+ int rc;
+
+ if (!glue)
+ return -ENOMEM;
+ glue->notify.notify = irq_cpu_rmap_notify;
+ glue->notify.release = irq_cpu_rmap_release;
+ glue->rmap = rmap;
+ glue->index = cpu_rmap_add(rmap, glue);
+ rc = irq_set_affinity_notifier(irq, &glue->notify);
+ if (rc)
+ kfree(glue);
+ return rc;
+}
+EXPORT_SYMBOL(irq_cpu_rmap_add);
+
+#endif /* CONFIG_GENERIC_HARDIRQS */