MIPS: Create and use asm/arch_hweight.h

Some MIPS ISA processor varients can do hweight operations
efficiently.

Split arch_hweight.h into a seperate file, and implement the
operations with __builtin_popcount{,ll} if supported.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Cc: David Daney <ddaney@caviumnetworks.com>
Patchwork: https://patchwork.linux-mips.org/patch/1430/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 38 insertions, 0 deletions

diff --git a/arch/mips/include/asm/arch_hweight.h b/arch/mips/include/asm/arch_hweight.h
new file mode 100644
index 000000000000..712a7445ee93
--- /dev/null
+++ b/arch/mips/include/asm/arch_hweight.h
@@ -0,0 +1,38 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ */
+#ifndef _ASM_ARCH_HWEIGHT_H
+#define _ASM_ARCH_HWEIGHT_H
+
+#ifdef ARCH_HAS_USABLE_BUILTIN_POPCOUNT
+
+#include <asm/types.h>
+
+static inline unsigned int __arch_hweight32(unsigned int w)
+{
+	return __builtin_popcount(w);
+}
+
+static inline unsigned int __arch_hweight16(unsigned int w)
+{
+	return __builtin_popcount(w & 0xffff);
+}
+
+static inline unsigned int __arch_hweight8(unsigned int w)
+{
+	return __builtin_popcount(w & 0xff);
+}
+
+static inline unsigned long __arch_hweight64(__u64 w)
+{
+	return __builtin_popcountll(w);
+}
+
+#else
+#include <asm-generic/bitops/arch_hweight.h>
+#endif
+
+#endif /* _ASM_ARCH_HWEIGHT_H */