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>

arch/mips/include/asm/arch_hweight.h

+/*
+ * 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 */

arch/mips/include/asm/bitops.h

@@ -700,7 +700,10 @@ static inline int ffs(int word)
 #ifdef __KERNEL__
 
 #include <asm-generic/bitops/sched.h>
-#include <asm-generic/bitops/hweight.h>
+
+#include <asm/arch_hweight.h>
+#include <asm-generic/bitops/const_hweight.h>
+
 #include <asm-generic/bitops/ext2-non-atomic.h>
 #include <asm-generic/bitops/ext2-atomic.h>
 #include <asm-generic/bitops/minix.h>