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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /lib/cpumask.c
Initial import
Diffstat (limited to 'lib/cpumask.c')
-rw-r--r--lib/cpumask.c179
1 files changed, 179 insertions, 0 deletions
diff --git a/lib/cpumask.c b/lib/cpumask.c
new file mode 100644
index 000000000..5a70f6196
--- /dev/null
+++ b/lib/cpumask.c
@@ -0,0 +1,179 @@
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/bitops.h>
+#include <linux/cpumask.h>
+#include <linux/export.h>
+#include <linux/bootmem.h>
+
+/**
+ * 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
+
+ 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_local_spread - select the i'th cpu with local numa cpu's first
+ * @i: index number
+ * @node: local numa_node
+ *
+ * This function selects an online CPU according to a numa aware policy;
+ * local cpus are returned first, followed by non-local ones, then it
+ * wraps around.
+ *
+ * It's not very efficient, but useful for setup.
+ */
+unsigned int cpumask_local_spread(unsigned int i, int node)
+{
+ int cpu;
+
+ /* Wrap: we always want a cpu. */
+ i %= num_online_cpus();
+
+ if (node == -1) {
+ for_each_cpu(cpu, cpu_online_mask)
+ if (i-- == 0)
+ return cpu;
+ } else {
+ /* NUMA first. */
+ for_each_cpu_and(cpu, cpumask_of_node(node), cpu_online_mask)
+ if (i-- == 0)
+ return cpu;
+
+ for_each_cpu(cpu, cpu_online_mask) {
+ /* Skip NUMA nodes, done above. */
+ if (cpumask_test_cpu(cpu, cpumask_of_node(node)))
+ continue;
+
+ if (i-- == 0)
+ return cpu;
+ }
+ }
+ BUG();
+}
+EXPORT_SYMBOL(cpumask_local_spread);