[PATCH 01/31] bitops: add parity functions

From	Zhaoxiu Zeng <zhaoxiu.zeng@gmail.com>
Newsgroups	linux.kernel
Subject	[PATCH 01/31] bitops: add parity functions
Date	2016-03-24 04:10 +0100
Message-ID	<rg3ON-4FE-7@gated-at.bofh.it> (permalink)
Organization	linux.* mail to news gateway

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From: Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com>

When I do "grep parity -r linux", I found many parity calculations distributed in many drivers.
These patches provide generic and architecture-specific parity calculations.

Signed-off-by: Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com>
---
 include/asm-generic/bitops.h              |  1 +
 include/asm-generic/bitops/arch_parity.h  | 39 +++++++++++++++++++++++++++++++
 include/asm-generic/bitops/const_parity.h | 36 ++++++++++++++++++++++++++++
 include/asm-generic/bitops/parity.h       |  7 ++++++
 include/linux/bitops.h                    |  5 ++++
 5 files changed, 88 insertions(+)
 create mode 100644 include/asm-generic/bitops/arch_parity.h
 create mode 100644 include/asm-generic/bitops/const_parity.h
 create mode 100644 include/asm-generic/bitops/parity.h

diff --git a/include/asm-generic/bitops.h b/include/asm-generic/bitops.h
index dcdcacf..d85722f 100644
--- a/include/asm-generic/bitops.h
+++ b/include/asm-generic/bitops.h
@@ -27,6 +27,7 @@
 #include <asm-generic/bitops/sched.h>
 #include <asm-generic/bitops/ffs.h>
 #include <asm-generic/bitops/hweight.h>
+#include <asm-generic/bitops/parity.h>
 #include <asm-generic/bitops/lock.h>
 
 #include <asm-generic/bitops/atomic.h>
diff --git a/include/asm-generic/bitops/arch_parity.h b/include/asm-generic/bitops/arch_parity.h
new file mode 100644
index 0000000..8d51eb3
--- /dev/null
+++ b/include/asm-generic/bitops/arch_parity.h
@@ -0,0 +1,39 @@
+#ifndef _ASM_GENERIC_BITOPS_ARCH_PARITY_H_
+#define _ASM_GENERIC_BITOPS_ARCH_PARITY_H_
+
+#include <asm/types.h>
+
+/*
+ * Refrence to 'https://graphics.stanford.edu/~seander/bithacks.html#ParityParallel'.
+ */
+
+static inline unsigned int __arch_parity4(unsigned int w)
+{
+	w &= 0xf;
+	return (0x6996 >> w) & 1;
+}
+
+static inline unsigned int __arch_parity8(unsigned int w)
+{
+	w ^= w >> 4;
+	return __arch_parity4(w);
+}
+
+static inline unsigned int __arch_parity16(unsigned int w)
+{
+	w ^= w >> 8;
+	return __arch_parity8(w);
+}
+
+static inline unsigned int __arch_parity32(unsigned int w)
+{
+	w ^= w >> 16;
+	return __arch_parity16(w);
+}
+
+static inline unsigned int __arch_parity64(__u64 w)
+{
+	return __arch_parity32((unsigned int)(w >> 32) ^ (unsigned int)w);
+}
+
+#endif /* _ASM_GENERIC_BITOPS_ARCH_PARITY_H_ */
diff --git a/include/asm-generic/bitops/const_parity.h b/include/asm-generic/bitops/const_parity.h
new file mode 100644
index 0000000..9590315
--- /dev/null
+++ b/include/asm-generic/bitops/const_parity.h
@@ -0,0 +1,36 @@
+#ifndef _ASM_GENERIC_BITOPS_CONST_PARITY_H_
+#define _ASM_GENERIC_BITOPS_CONST_PARITY_H_
+
+/*
+ * Compile time versions of __arch_parityN()
+ */
+#define __const_parity4(w)   ((0x6996 >> ((w) & 0xf)) & 1)
+#define __const_parity8(w)   (__const_parity4(w ^ (w >> 4)))
+#define __const_parity16(w)  (__const_parity8(w ^ (w >> 8)))
+#define __const_parity32(w)  (__const_parity16(w ^ (w >> 16)))
+#define __const_parity64(w)  (__const_parity32(w ^ (w >> 32)))
+
+/*
+ * Generic interface.
+ */
+#define parity4(w)   (__builtin_constant_p(w) ? __const_parity4(w)  : __arch_parity4(w))
+#define parity8(w)   (__builtin_constant_p(w) ? __const_parity8(w)  : __arch_parity8(w))
+#define parity16(w)  (__builtin_constant_p(w) ? __const_parity16(w) : __arch_parity16(w))
+#define parity32(w)  (__builtin_constant_p(w) ? __const_parity32(w) : __arch_parity32(w))
+#define parity64(w)  (__builtin_constant_p(w) ? __const_parity64(w) : __arch_parity64(w))
+
+/*
+ * Interface for known constant arguments
+ */
+#define PARITY4(w)   (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_parity4(w))
+#define PARITY8(w)   (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_parity8(w))
+#define PARITY16(w)  (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_parity16(w))
+#define PARITY32(w)  (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_parity32(w))
+#define PARITY64(w)  (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_parity64(w))
+
+/*
+ * Type invariant interface to the compile time constant parity functions.
+ */
+#define PARITY(w)    PARITY64((u64)w)
+
+#endif /* _ASM_GENERIC_BITOPS_CONST_PARITY_H_ */
diff --git a/include/asm-generic/bitops/parity.h b/include/asm-generic/bitops/parity.h
new file mode 100644
index 0000000..a91dce7
--- /dev/null
+++ b/include/asm-generic/bitops/parity.h
@@ -0,0 +1,7 @@
+#ifndef _ASM_GENERIC_BITOPS_PARITY_H_
+#define _ASM_GENERIC_BITOPS_PARITY_H_
+
+#include <asm-generic/bitops/arch_parity.h>
+#include <asm-generic/bitops/const_parity.h>
+
+#endif /* _ASM_GENERIC_BITOPS_PARITY_H_ */
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index defeaac..f91cb44 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -80,6 +80,11 @@ static __always_inline unsigned long hweight_long(unsigned long w)
 	return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
 }
 
+static __always_inline unsigned int parity_long(unsigned long w)
+{
+	return sizeof(w) == 4 ? parity32(w) : parity64(w);
+}
+
 /**
  * rol64 - rotate a 64-bit value left
  * @word: value to rotate
-- 
2.5.0

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[PATCH 01/31] bitops: add parity functions Zhaoxiu Zeng <zhaoxiu.zeng@gmail.com> - 2016-03-24 04:10 +0100
  Re: [PATCH 01/31] bitops: add parity functions Denys Vlasenko <dvlasenk@redhat.com> - 2016-03-24 09:40 +0100
    Re: [PATCH 01/31] bitops: add parity functions Andrew Morton <akpm@linux-foundation.org> - 2016-03-24 23:30 +0100
      Re: [PATCH 01/31] bitops: add parity functions Martin Kepplinger <martink@posteo.de> - 2016-03-26 23:10 +0100
        Re: [PATCH 01/31] bitops: add parity functions "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 10:00 +0200
    Re: [PATCH 01/31] bitops: add parity functions "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 05:40 +0200
      Re: [PATCH 01/31] bitops: add parity functions Sam Ravnborg <sam@ravnborg.org> - 2016-03-27 14:50 +0200
        Re: [PATCH 01/31] bitops: add parity functions "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 15:40 +0200
          Re: [PATCH 01/31] bitops: add parity functions Sam Ravnborg <sam@ravnborg.org> - 2016-03-27 20:00 +0200
            Re: [PATCH 01/31] bitops: add parity functions Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com> - 2016-03-28 04:50 +0200
          Re: [PATCH 01/31] bitops: add parity functions Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com> - 2016-03-28 04:20 +0200
      Re: [PATCH 01/31] bitops: add parity functions Sam Ravnborg <sam@ravnborg.org> - 2016-03-28 09:00 +0200
        Re: [PATCH 01/31] bitops: add parity functions Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com> - 2016-03-29 04:30 +0200
          Re: [PATCH 01/31] bitops: add parity functions Joe Perches <joe@perches.com> - 2016-03-29 05:00 +0200
  [PATCH 02/31] Include generic parity.h in some architectures'  bitops.h "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 06:10 +0200
  [PATCH 03/31] Add alpha-specific parity functions "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 07:50 +0200
    Re: [PATCH 03/31] Add alpha-specific parity functions Richard Henderson <rth@twiddle.net> - 2016-03-28 20:40 +0200
  [PATCH 04/31] Add avr32-specific parity functions "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 07:50 +0200
    Re: [PATCH 04/31] Add avr32-specific parity functions Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> - 2016-03-28 22:10 +0200
  [PATCH 05/31] Add blackfin-specific parity functions "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 08:00 +0200
  [PATCH 07/31] Add mips-specific parity functions "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 08:10 +0200
    Re: [PATCH 07/31] Add mips-specific parity functions David Daney <ddaney.cavm@gmail.com> - 2016-03-28 19:30 +0200
      Re: [PATCH 07/31] Add mips-specific parity functions Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com> - 2016-03-29 04:20 +0200
  [PATCH 06/31] Add ia64-specific parity functions "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 08:10 +0200
  [PATCH 08/31] Add tile-specific parity functions "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 08:20 +0200
  [PATCH 09/31] Add powerpc-specific parity functions "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 08:40 +0200
  [PATCH 11/31] Add x86-specific parity functions "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 08:50 +0200
    Re: [PATCH 11/31] Add x86-specific parity functions One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> - 2016-03-29 14:20 +0200
  [PATCH 10/31] Add sparc-specific parity functions "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 08:50 +0200
    Re: [PATCH 10/31] Add sparc-specific parity functions David Miller <davem@davemloft.net> - 2016-03-28 04:50 +0200
      Re: [PATCH 10/31] Add sparc-specific parity functions Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com> - 2016-03-28 07:50 +0200
        Re: [PATCH 10/31] Add sparc-specific parity functions David Miller <davem@davemloft.net> - 2016-03-28 17:30 +0200
          Re: [PATCH 10/31] Add sparc-specific parity functions Sam Ravnborg <sam@ravnborg.org> - 2016-03-28 17:40 +0200
            Re: [PATCH 10/31] Add sparc-specific parity functions David Miller <davem@davemloft.net> - 2016-03-28 17:50 +0200
  [PATCH 12/31] sunrpc: auth_gss: use parity8 "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:00 +0200
  [PATCH 13/31] mips: use parity functions in cerr-sb1.c "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:00 +0200
  [PATCH 15/31] media: use parity8 in vivid-vbi-gen.c "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:10 +0200
  [PATCH 14/31] lib: bch: use parity32 "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:10 +0200
  [PATCH 17/31] input: joystick: use parity32 in grip_mp.c "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:20 +0200
  [PATCH 18/31] input: joystick: use parity64 in sidewinder.c "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:20 +0200
  [PATCH 16/31] media: saa7115: use parity functions "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:20 +0200
  [PATCH 19/31] input: serio: use parity16 in ams_delta_serio.c "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:20 +0200
  [PATCH 22/31] mtd: use parity functions in inftlcore.c "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:30 +0200
  [PATCH 21/31] mtd: use parity16 in ssfdc.c "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:30 +0200
    Re: [PATCH 21/31] mtd: use parity16 in ssfdc.c Brian Norris <computersforpeace@gmail.com> - 2016-04-02 01:50 +0200
  [PATCH 20/31] scsi: use parity32 in isci/phy.c "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:30 +0200
  [PATCH 26/31] input: serio: use parity8 in pcips2.c "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:40 +0200
  [PATCH 25/31] ethernet: use parity8 in sun/niu.c "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:40 +0200
    Re: [PATCH 25/31] ethernet: use parity8 in sun/niu.c Michal Nazarewicz <mina86@mina86.com> - 2016-03-28 16:40 +0200
  [PATCH 24/31] mtd: use parity16 in sm_ftl.c "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:40 +0200
  [PATCH 23/31] crypto: qat: use parity functions in qat_hal.c "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:40 +0200
  [PATCH 28/31] iio: gyro: use parity32 in adxrs450.c "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:50 +0200
    Re: [PATCH 28/31] iio: gyro: use parity32 in adxrs450.c Jonathan Cameron <jic23@kernel.org> - 2016-03-28 10:40 +0200
      Re: [PATCH 28/31] iio: gyro: use parity32 in adxrs450.c Lars-Peter Clausen <lars@metafoo.de> - 2016-03-28 11:30 +0200
  [PATCH 29/31] serial: use parity32 in max3100.c "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:50 +0200
  [PATCH 30/31] input: mouse: use parity8 in elantech "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:50 +0200
  [PATCH 27/31] input: serio: use parity8 in sa1111ps2.c "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 09:50 +0200
  [PATCH 31/31] ethernet: broadcom: use parity8 in tg3.c "zhaoxiu.zeng" <zhaoxiu.zeng@gmail.com> - 2016-03-27 10:00 +0200

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