From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 arch/powerpc/include/asm/cputhreads.h | 97 +++++++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 arch/powerpc/include/asm/cputhreads.h

(limited to 'arch/powerpc/include/asm/cputhreads.h')

diff --git a/arch/powerpc/include/asm/cputhreads.h b/arch/powerpc/include/asm/cputhreads.h
new file mode 100644
index 000000000..5be6c4753
--- /dev/null
+++ b/arch/powerpc/include/asm/cputhreads.h
@@ -0,0 +1,97 @@
+#ifndef _ASM_POWERPC_CPUTHREADS_H
+#define _ASM_POWERPC_CPUTHREADS_H
+
+#include <linux/cpumask.h>
+
+/*
+ * Mapping of threads to cores
+ *
+ * Note: This implementation is limited to a power of 2 number of
+ * threads per core and the same number for each core in the system
+ * (though it would work if some processors had less threads as long
+ * as the CPU numbers are still allocated, just not brought online).
+ *
+ * However, the API allows for a different implementation in the future
+ * if needed, as long as you only use the functions and not the variables
+ * directly.
+ */
+
+#ifdef CONFIG_SMP
+extern int threads_per_core;
+extern int threads_per_subcore;
+extern int threads_shift;
+extern cpumask_t threads_core_mask;
+#else
+#define threads_per_core	1
+#define threads_per_subcore	1
+#define threads_shift		0
+#define threads_core_mask	(*get_cpu_mask(0))
+#endif
+
+/* cpu_thread_mask_to_cores - Return a cpumask of one per cores
+ *                            hit by the argument
+ *
+ * @threads:	a cpumask of threads
+ *
+ * This function returns a cpumask which will have one "cpu" (or thread)
+ * bit set for each core that has at least one thread set in the argument.
+ *
+ * This can typically be used for things like IPI for tlb invalidations
+ * since those need to be done only once per core/TLB
+ */
+static inline cpumask_t cpu_thread_mask_to_cores(const struct cpumask *threads)
+{
+	cpumask_t	tmp, res;
+	int		i;
+
+	cpumask_clear(&res);
+	for (i = 0; i < NR_CPUS; i += threads_per_core) {
+		cpumask_shift_left(&tmp, &threads_core_mask, i);
+		if (cpumask_intersects(threads, &tmp))
+			cpumask_set_cpu(i, &res);
+	}
+	return res;
+}
+
+static inline int cpu_nr_cores(void)
+{
+	return nr_cpu_ids >> threads_shift;
+}
+
+static inline cpumask_t cpu_online_cores_map(void)
+{
+	return cpu_thread_mask_to_cores(cpu_online_mask);
+}
+
+#ifdef CONFIG_SMP
+int cpu_core_index_of_thread(int cpu);
+int cpu_first_thread_of_core(int core);
+#else
+static inline int cpu_core_index_of_thread(int cpu) { return cpu; }
+static inline int cpu_first_thread_of_core(int core) { return core; }
+#endif
+
+static inline int cpu_thread_in_core(int cpu)
+{
+	return cpu & (threads_per_core - 1);
+}
+
+static inline int cpu_thread_in_subcore(int cpu)
+{
+	return cpu & (threads_per_subcore - 1);
+}
+
+static inline int cpu_first_thread_sibling(int cpu)
+{
+	return cpu & ~(threads_per_core - 1);
+}
+
+static inline int cpu_last_thread_sibling(int cpu)
+{
+	return cpu | (threads_per_core - 1);
+}
+
+
+
+#endif /* _ASM_POWERPC_CPUTHREADS_H */
+
-- 
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