在 2016年03月29日 01:25, David Daney 写道:
On 03/26/2016 11:06 PM, zhaoxiu.zeng wrote:
From: Zeng Zhaoxiu <zhaoxiu.zeng@xxxxxxxxx>
There is nothing MIPS specific here. Why not put it in asm-generic or
some similar place where it can be shared by all architectures?
Also, are you sure __builtin_popcount() is available on all GCC
versions that are supported for building the kernel?
David Daney
Refrence to arch_hweight.h.
In the 68th line of
arch/mips/include/asm/mach-cavium-octeon/cpu-feature-overrides.h, we can
see:
#ifdef __OCTEON__
/*
* All gcc versions that have OCTEON support define __OCTEON__ and have the
* __builtin_popcount support.
*/
#define ARCH_HAS_USABLE_BUILTIN_POPCOUNT 1
#endif
/*
* All gcc versions that have OCTEON support define __OCTEON__ and have the
* __builtin_popcount support.
*/
Signed-off-by: Zeng Zhaoxiu <zhaoxiu.zeng@xxxxxxxxx>
---
arch/mips/include/asm/arch_parity.h | 44
+++++++++++++++++++++++++++++++++++++
arch/mips/include/asm/bitops.h | 3 +++
2 files changed, 47 insertions(+)
create mode 100644 arch/mips/include/asm/arch_parity.h
diff --git a/arch/mips/include/asm/arch_parity.h
b/arch/mips/include/asm/arch_parity.h
new file mode 100644
index 0000000..23b3c23
--- /dev/null
+++ b/arch/mips/include/asm/arch_parity.h
@@ -0,0 +1,44 @@
+/*
+ * 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_PARITY_H
+#define _ASM_ARCH_PARITY_H
+
+#ifdef ARCH_HAS_USABLE_BUILTIN_POPCOUNT
+
+#include <asm/types.h>
+
+static inline unsigned int __arch_parity32(unsigned int w)
+{
+ return __builtin_popcount(w) & 1;
+}
+
+static inline unsigned int __arch_parity16(unsigned int w)
+{
+ return __arch_parity32(w & 0xffff);
+}
+
+static inline unsigned int __arch_parity8(unsigned int w)
+{
+ return __arch_parity32(w & 0xff);
+}
+
+static inline unsigned int __arch_parity4(unsigned int w)
+{
+ return __arch_parity32(w & 0xf);
+}
+
+static inline unsigned int __arch_parity64(__u64 w)
+{
+ return (unsigned int)__builtin_popcountll(w) & 1;
+}
+
+#else
+#include <asm-generic/bitops/arch_hweight.h>
+#include <asm-generic/bitops/arch_parity.h>
+#endif
+
+#endif /* _ASM_ARCH_PARITY_H */
diff --git a/arch/mips/include/asm/bitops.h
b/arch/mips/include/asm/bitops.h
index ce9666c..0b87734 100644
--- a/arch/mips/include/asm/bitops.h
+++ b/arch/mips/include/asm/bitops.h
@@ -626,6 +626,9 @@ static inline int ffs(int word)
#include <asm/arch_hweight.h>
#include <asm-generic/bitops/const_hweight.h>
+#include <asm/arch_parity.h>
+#include <asm-generic/bitops/const_parity.h>
+
#include <asm-generic/bitops/le.h>
#include <asm-generic/bitops/ext2-atomic.h>
