From: Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com>
To: Sam Ravnborg <sam@ravnborg.org>, zengzhaoxiu@163.com
Cc: davem@davemloft.net, wim.coekaerts@oracle.com,
linux@roeck-us.net, julian.calaby@gmail.com,
sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 08/30] Add sparc-specific parity functions
Date: Thu, 7 Apr 2016 11:56:08 +0800 [thread overview]
Message-ID: <5705DA58.3040207@gmail.com> (raw)
In-Reply-To: <20160406184447.GA5963@ravnborg.org>
在 2016年04月07日 02:44, Sam Ravnborg 写道:
> Hi Zeng.
>
>> Use runtime patching for sparc64, lifted from hweight
> No errors found in patch - but a few comments.
> In general patch looks good.
Thanks. Sparc, powerpc, and x86 are all new to me.
>> +++ b/arch/sparc/include/asm/bitops_64.h
>> @@ -47,6 +47,24 @@ unsigned int __arch_hweight16(unsigned int w);
>> unsigned int __arch_hweight8(unsigned int w);
>>
>> #include <asm-generic/bitops/const_hweight.h>
>> +
>> +/*
>> + * parityN: returns the parity of a N-bit word,
>> + * i.e. the number of 1-bits in w modulo 2.
>> + */
>> +
>> +static inline unsigned int __arch_parity4(unsigned int w)
>> +{
>> + w &= 0xf;
>> + return (0x6996 >> w) & 1;
>> +}
> As Josef already said - this constant should have a name.
> PARITY_BIT
> ?
>
Maybe PARITY_MAGIC?
>> +++ b/arch/sparc/kernel/sparc_ksyms_64.c
>> @@ -45,6 +45,12 @@ EXPORT_SYMBOL(__arch_hweight16);
>> EXPORT_SYMBOL(__arch_hweight32);
>> EXPORT_SYMBOL(__arch_hweight64);
>>
>> +/* from parity.S */
>> +EXPORT_SYMBOL(__arch_parity8);
>> +EXPORT_SYMBOL(__arch_parity16);
>> +EXPORT_SYMBOL(__arch_parity32);
>> +EXPORT_SYMBOL(__arch_parity64);
> Did you compile this?
> I wonder if bitops_64.h is indirectly included.
Yes.
>> index 0000000..b1945e3
>> --- /dev/null
>> +++ b/arch/sparc/lib/parity.S
>> @@ -0,0 +1,93 @@
>> +#include <linux/linkage.h>
>> +
>> + .text
>> + .align 32
>> +
>> +ENTRY(__arch_parity8)
>> + srl %o0, 4, %g1
>> + xor %o0, %g1, %o0
>> + and %o0, 0xf, %o0
>> + sethi %hi(0x6996), %g1
>> + or %g1, %lo(0x6996), %g1
>> + srl %g1, %o0, %o0
>> + retl
>> + and %o0, 1, %o0
>> +ENDPROC(__arch_parity8)
> I know the level of comments in hweight is equal to none.
> But please do not follow this bad example.
> At least for each function a one-liner of the C code.
> And in the top of the file maybe two lines that the functions
> are patched at run-time if the processor has popc available.
>
>
> Sam
OK. I will try, but my english is very poor! :-)
next prev parent reply other threads:[~2016-04-07 3:56 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-05 2:06 [PATCH V2 01/30] bitops: add parity functions Zeng Zhaoxiu
2016-04-05 4:23 ` [PATCH V2 02/30] Include generic parity.h in some architectures' bitops.h Zeng Zhaoxiu
2016-04-06 8:41 ` [PATCH v2 " zengzhaoxiu
2016-04-05 19:04 ` [PATCH V2 01/30] bitops: add parity functions Sam Ravnborg
2016-04-06 5:33 ` Zeng Zhaoxiu
2016-04-06 8:24 ` Sam Ravnborg
2016-04-06 8:22 ` [PATCH v2 " zengzhaoxiu
2016-04-06 8:46 ` [PATCH v2 03/30] Add alpha-specific " zengzhaoxiu
2016-04-06 8:53 ` [PATCH v2 04/30] Add blackfin-specific " zengzhaoxiu
2016-04-06 8:57 ` [PATCH v2 05/30] Add ia64-specific " zengzhaoxiu
2016-04-06 8:59 ` [PATCH v2 06/30] Add mips-specific " zengzhaoxiu
2016-04-06 10:23 ` zengzhaoxiu
2016-04-06 9:03 ` [PATCH v2 07/30] Add powerpc-specific " zengzhaoxiu
2016-04-06 9:07 ` [PATCH v2 08/30] Add sparc-specific " zengzhaoxiu
2016-04-06 18:44 ` Sam Ravnborg
2016-04-07 3:56 ` Zeng Zhaoxiu [this message]
2016-04-06 9:08 ` [PATCH v2 09/30] Add tile-specific " zengzhaoxiu
2016-04-06 13:27 ` Chris Metcalf
2016-04-07 3:55 ` Zeng Zhaoxiu
2016-04-06 9:14 ` [PATCH v2 10/30] Add x86-specific " zengzhaoxiu
2016-04-06 10:13 ` Borislav Petkov
2016-04-06 10:37 ` One Thousand Gnomes
2016-04-06 10:53 ` Borislav Petkov
2016-04-07 3:55 ` Zeng Zhaoxiu
2016-04-07 9:39 ` Borislav Petkov
2016-04-11 2:43 ` Zeng Zhaoxiu
2016-04-15 2:11 ` Borislav Petkov
2016-04-07 3:55 ` Zeng Zhaoxiu
2016-04-07 9:41 ` Borislav Petkov
2016-04-06 19:45 ` Andi Kleen
2016-04-07 3:56 ` Zeng Zhaoxiu
2016-04-07 6:31 ` Dmitry Vyukov
2016-04-07 9:43 ` Borislav Petkov
2016-05-04 18:46 ` [RFC PATCH] x86/hweight: Get rid of the special calling convention Borislav Petkov
2016-05-04 19:31 ` Brian Gerst
2016-05-04 19:33 ` H. Peter Anvin
2016-05-04 19:41 ` Borislav Petkov
2016-05-04 19:49 ` H. Peter Anvin
2016-05-04 20:22 ` Borislav Petkov
2016-05-04 20:51 ` H. Peter Anvin
2016-05-04 21:09 ` Andi Kleen
2016-05-05 13:02 ` Denys Vlasenko
2016-05-05 14:04 ` Borislav Petkov
2016-05-10 16:53 ` [PATCH -v2] " Borislav Petkov
2016-05-10 17:23 ` Peter Zijlstra
2016-05-10 19:02 ` Borislav Petkov
2016-05-10 19:03 ` H. Peter Anvin
2016-05-10 19:10 ` Borislav Petkov
2016-05-10 22:30 ` H. Peter Anvin
2016-05-11 4:11 ` Borislav Petkov
2016-05-11 11:15 ` Brian Gerst
2016-05-11 11:24 ` Peter Zijlstra
2016-05-11 12:47 ` Borislav Petkov
2016-05-12 4:54 ` H. Peter Anvin
2016-05-12 11:57 ` Borislav Petkov
2016-05-12 12:14 ` Peter Zijlstra
2016-05-12 13:09 ` Borislav Petkov
2016-05-18 10:38 ` Borislav Petkov
2016-04-07 14:10 ` [PATCH v2 10/30] Add x86-specific parity functions One Thousand Gnomes
2016-04-06 9:27 ` [PATCH v2 11/30] sunrpc: use parity8 zengzhaoxiu
2016-04-06 9:30 ` [PATCH v2 12/30] mips: use parity functions in cerr-sb1.c zengzhaoxiu
2016-04-06 9:36 ` [PATCH v2 13/30] bch: use parity32 zengzhaoxiu
2016-04-06 9:39 ` [PATCH v2 14/30] media: use parity8 in vivid-vbi-gen.c zengzhaoxiu
2016-04-06 9:41 ` [PATCH v2 15/30] media: use parity functions in saa7115 zengzhaoxiu
2016-04-06 9:43 ` [PATCH v2 16/30] input: use parity32 in grip_mp zengzhaoxiu
2016-04-06 9:44 ` [PATCH v2 17/30] input: use parity64 in sidewinder zengzhaoxiu
2016-04-06 9:45 ` [PATCH v2 18/30] input: use parity16 in ams_delta_serio zengzhaoxiu
2016-04-06 9:47 ` [PATCH v2 19/30] scsi: use parity32 in isci's phy zengzhaoxiu
2016-04-06 9:52 ` [PATCH v2 20/30] mtd: use parity16 in ssfdc zengzhaoxiu
2016-04-06 9:53 ` [PATCH v2 21/30] mtd: use parity functions in inftlcore zengzhaoxiu
2016-04-06 9:58 ` [PATCH v2 22/30] crypto: use parity functions in qat_hal zengzhaoxiu
2016-04-06 10:05 ` [PATCH v2 23/30] mtd: use parity16 in sm_ftl zengzhaoxiu
2016-04-06 10:11 ` [PATCH v2 24/30] ethernet: use parity8 in sun/niu.c zengzhaoxiu
2016-04-06 10:14 ` [PATCH v2 25/30] input: use parity8 in pcips2 zengzhaoxiu
2016-04-06 10:15 ` [PATCH v2 26/30] input: use parity8 in sa1111ps2 zengzhaoxiu
2016-04-06 10:16 ` [PATCH v2 27/30] iio: use parity32 in adxrs450 zengzhaoxiu
2016-04-10 14:37 ` Jonathan Cameron
2016-04-10 14:41 ` Lars-Peter Clausen
2016-04-10 15:13 ` Jonathan Cameron
2016-04-10 15:14 ` Jonathan Cameron
2016-04-06 10:18 ` [PATCH v2 28/30] serial: use parity32 in max3100 zengzhaoxiu
2016-04-06 10:25 ` Greg KH
2016-04-06 10:20 ` [PATCH v2 29/30] input: use parity8 in elantech zengzhaoxiu
2016-04-06 10:21 ` [PATCH v2 30/30] ethernet: use parity8 in broadcom/tg3.c zengzhaoxiu
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