aboutsummaryrefslogtreecommitdiff
path: root/lib/cpumask.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/cpumask.c')
-rw-r--r--lib/cpumask.c215
1 files changed, 208 insertions, 7 deletions
diff --git a/lib/cpumask.c b/lib/cpumask.c
index bb4f76d3c3e..b6513a9f289 100644
--- a/lib/cpumask.c
+++ b/lib/cpumask.c
@@ -1,7 +1,9 @@
+#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/bitops.h>
#include <linux/cpumask.h>
-#include <linux/module.h>
+#include <linux/export.h>
+#include <linux/bootmem.h>
int __first_cpu(const cpumask_t *srcp)
{
@@ -15,14 +17,213 @@ int __next_cpu(int n, const cpumask_t *srcp)
}
EXPORT_SYMBOL(__next_cpu);
-int __any_online_cpu(const cpumask_t *mask)
+#if NR_CPUS > 64
+int __next_cpu_nr(int n, const cpumask_t *srcp)
{
- int cpu;
+ return min_t(int, nr_cpu_ids,
+ find_next_bit(srcp->bits, nr_cpu_ids, n+1));
+}
+EXPORT_SYMBOL(__next_cpu_nr);
+#endif
- for_each_cpu_mask(cpu, *mask) {
- if (cpu_online(cpu))
+/**
+ * cpumask_next_and - get the next cpu in *src1p & *src2p
+ * @n: the cpu prior to the place to search (ie. return will be > @n)
+ * @src1p: the first cpumask pointer
+ * @src2p: the second cpumask pointer
+ *
+ * Returns >= nr_cpu_ids if no further cpus set in both.
+ */
+int cpumask_next_and(int n, const struct cpumask *src1p,
+ const struct cpumask *src2p)
+{
+ while ((n = cpumask_next(n, src1p)) < nr_cpu_ids)
+ if (cpumask_test_cpu(n, src2p))
break;
+ return n;
+}
+EXPORT_SYMBOL(cpumask_next_and);
+
+/**
+ * cpumask_any_but - return a "random" in a cpumask, but not this one.
+ * @mask: the cpumask to search
+ * @cpu: the cpu to ignore.
+ *
+ * Often used to find any cpu but smp_processor_id() in a mask.
+ * Returns >= nr_cpu_ids if no cpus set.
+ */
+int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
+{
+ unsigned int i;
+
+ cpumask_check(cpu);
+ for_each_cpu(i, mask)
+ if (i != cpu)
+ break;
+ return i;
+}
+
+/* These are not inline because of header tangles. */
+#ifdef CONFIG_CPUMASK_OFFSTACK
+/**
+ * alloc_cpumask_var_node - allocate a struct cpumask on a given node
+ * @mask: pointer to cpumask_var_t where the cpumask is returned
+ * @flags: GFP_ flags
+ *
+ * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
+ * a nop returning a constant 1 (in <linux/cpumask.h>)
+ * Returns TRUE if memory allocation succeeded, FALSE otherwise.
+ *
+ * In addition, mask will be NULL if this fails. Note that gcc is
+ * usually smart enough to know that mask can never be NULL if
+ * CONFIG_CPUMASK_OFFSTACK=n, so does code elimination in that case
+ * too.
+ */
+bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
+{
+ *mask = kmalloc_node(cpumask_size(), flags, node);
+
+#ifdef CONFIG_DEBUG_PER_CPU_MAPS
+ if (!*mask) {
+ printk(KERN_ERR "=> alloc_cpumask_var: failed!\n");
+ dump_stack();
+ }
+#endif
+ /* FIXME: Bandaid to save us from old primitives which go to NR_CPUS. */
+ if (*mask) {
+ unsigned char *ptr = (unsigned char *)cpumask_bits(*mask);
+ unsigned int tail;
+ tail = BITS_TO_LONGS(NR_CPUS - nr_cpumask_bits) * sizeof(long);
+ memset(ptr + cpumask_size() - tail, 0, tail);
}
- return cpu;
+
+ return *mask != NULL;
+}
+EXPORT_SYMBOL(alloc_cpumask_var_node);
+
+bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
+{
+ return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node);
+}
+EXPORT_SYMBOL(zalloc_cpumask_var_node);
+
+/**
+ * alloc_cpumask_var - allocate a struct cpumask
+ * @mask: pointer to cpumask_var_t where the cpumask is returned
+ * @flags: GFP_ flags
+ *
+ * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
+ * a nop returning a constant 1 (in <linux/cpumask.h>).
+ *
+ * See alloc_cpumask_var_node.
+ */
+bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
+{
+ return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE);
+}
+EXPORT_SYMBOL(alloc_cpumask_var);
+
+bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
+{
+ return alloc_cpumask_var(mask, flags | __GFP_ZERO);
+}
+EXPORT_SYMBOL(zalloc_cpumask_var);
+
+/**
+ * alloc_bootmem_cpumask_var - allocate a struct cpumask from the bootmem arena.
+ * @mask: pointer to cpumask_var_t where the cpumask is returned
+ *
+ * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
+ * a nop (in <linux/cpumask.h>).
+ * Either returns an allocated (zero-filled) cpumask, or causes the
+ * system to panic.
+ */
+void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask)
+{
+ *mask = memblock_virt_alloc(cpumask_size(), 0);
+}
+
+/**
+ * free_cpumask_var - frees memory allocated for a struct cpumask.
+ * @mask: cpumask to free
+ *
+ * This is safe on a NULL mask.
+ */
+void free_cpumask_var(cpumask_var_t mask)
+{
+ kfree(mask);
+}
+EXPORT_SYMBOL(free_cpumask_var);
+
+/**
+ * free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var
+ * @mask: cpumask to free
+ */
+void __init free_bootmem_cpumask_var(cpumask_var_t mask)
+{
+ memblock_free_early(__pa(mask), cpumask_size());
+}
+#endif
+
+/**
+ * cpumask_set_cpu_local_first - set i'th cpu with local numa cpu's first
+ *
+ * @i: index number
+ * @numa_node: local numa_node
+ * @dstp: cpumask with the relevant cpu bit set according to the policy
+ *
+ * This function sets the cpumask according to a numa aware policy.
+ * cpumask could be used as an affinity hint for the IRQ related to a
+ * queue. When the policy is to spread queues across cores - local cores
+ * first.
+ *
+ * Returns 0 on success, -ENOMEM for no memory, and -EAGAIN when failed to set
+ * the cpu bit and need to re-call the function.
+ */
+int cpumask_set_cpu_local_first(int i, int numa_node, cpumask_t *dstp)
+{
+ cpumask_var_t mask;
+ int cpu;
+ int ret = 0;
+
+ if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
+ return -ENOMEM;
+
+ i %= num_online_cpus();
+
+ if (numa_node == -1 || !cpumask_of_node(numa_node)) {
+ /* Use all online cpu's for non numa aware system */
+ cpumask_copy(mask, cpu_online_mask);
+ } else {
+ int n;
+
+ cpumask_and(mask,
+ cpumask_of_node(numa_node), cpu_online_mask);
+
+ n = cpumask_weight(mask);
+ if (i >= n) {
+ i -= n;
+
+ /* If index > number of local cpu's, mask out local
+ * cpu's
+ */
+ cpumask_andnot(mask, cpu_online_mask, mask);
+ }
+ }
+
+ for_each_cpu(cpu, mask) {
+ if (--i < 0)
+ goto out;
+ }
+
+ ret = -EAGAIN;
+
+out:
+ free_cpumask_var(mask);
+
+ if (!ret)
+ cpumask_set_cpu(cpu, dstp);
+
+ return ret;
}
-EXPORT_SYMBOL(__any_online_cpu);
+EXPORT_SYMBOL(cpumask_set_cpu_local_first);