From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7E7A3ECE58C for ; Wed, 9 Oct 2019 16:28:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4E55820B7C for ; Wed, 9 Oct 2019 16:28:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nifty.com header.i=@nifty.com header.b="SQPud2h0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731829AbfJIQ2x (ORCPT ); Wed, 9 Oct 2019 12:28:53 -0400 Received: from conssluserg-02.nifty.com ([210.131.2.81]:53370 "EHLO conssluserg-02.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729644AbfJIQ2x (ORCPT ); Wed, 9 Oct 2019 12:28:53 -0400 Received: from mail-vs1-f51.google.com (mail-vs1-f51.google.com [209.85.217.51]) (authenticated) by conssluserg-02.nifty.com with ESMTP id x99GSjFp013815; Thu, 10 Oct 2019 01:28:46 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-02.nifty.com x99GSjFp013815 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1570638527; bh=zM7dxD3GmLuJA27n7tj6vmU9wclV7umhFu5rYXOd+6c=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=SQPud2h0OWu0HF3XYWYxty13tni/EzU9iRFSRy6Ulcx1nol+bNQtyk6jfN+yVAkj9 h+1IgrHE8gA9JeygREhqo4gg9/wYVIGeKZhCmqsSUE6VXOrLL+ACe9eQZsn4NawO2s AlEmlOyZcmN613ziPcn6hFKqxpPkhCRc6qGmrQYUaN/7OF+NQB9oJIHQnk0EW9ucMD Az87WvdwWY3kelGhzYJoMQobsQcGwf1gRZkrRUmeb6p+B7GF/l92EYD0vsO7aPfvCC 5WvOZTmb6JWM+lY+xsEmT7fmfk1tXwa/EMz5qmVGOJZMNHXRwJd28CPdhWITzNvYTB jKj3Q/x9Dcqlw== X-Nifty-SrcIP: [209.85.217.51] Received: by mail-vs1-f51.google.com with SMTP id m22so1910937vsl.9; Wed, 09 Oct 2019 09:28:46 -0700 (PDT) X-Gm-Message-State: APjAAAV9TeKYg9gLswCJwGEiVSqpbtKjisMiA2+QcRscDA7Wd1+OiVTF cLef8Vw7m7fhqQgzglAeGVjFnzeKVDTafYuOWIE= X-Google-Smtp-Source: APXvYqzH0lno0Jfiz/rFQhtYHfui45CzQbPKiMY0yhhlnjAVEgFdHdM9+zJ7EOc9vXnfVbLZJAT9ZLaAw0J1HbDFjmA= X-Received: by 2002:a67:2e81:: with SMTP id u123mr1224042vsu.155.1570638525039; Wed, 09 Oct 2019 09:28:45 -0700 (PDT) MIME-Version: 1.0 References: <893c3b4f03266c9496137cc98ac2b1bd27f92c73.1570633189.git.vilhelm.gray@gmail.com> In-Reply-To: <893c3b4f03266c9496137cc98ac2b1bd27f92c73.1570633189.git.vilhelm.gray@gmail.com> From: Masahiro Yamada Date: Thu, 10 Oct 2019 01:28:08 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v17 01/14] bitops: Introduce the for_each_set_clump8 macro To: William Breathitt Gray Cc: Linus Walleij , Bartosz Golaszewski , Andrew Morton , "open list:GPIO SUBSYSTEM" , Linux Kernel Mailing List , linux-arch , Andy Shevchenko , Rasmus Villemoes , linux-arm-kernel , Linux PM mailing list , Geert Uytterhoeven , preid@electromag.com.au, Lukas Wunner , sean.nyekjaer@prevas.dk, morten.tiljeset@prevas.dk, Andy Shevchenko , Arnd Bergmann Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 10, 2019 at 12:27 AM William Breathitt Gray wrote: > > This macro iterates for each 8-bit group of bits (clump) with set bits, > within a bitmap memory region. For each iteration, "start" is set to the > bit offset of the found clump, while the respective clump value is > stored to the location pointed by "clump". Additionally, the > bitmap_get_value8 and bitmap_set_value8 functions are introduced to > respectively get and set an 8-bit value in a bitmap memory region. > > Suggested-by: Andy Shevchenko > Suggested-by: Rasmus Villemoes > Suggested-by: Lukas Wunner > Cc: Arnd Bergmann > Cc: Andrew Morton > Cc: Andy Shevchenko > Cc: Linus Walleij > Signed-off-by: William Breathitt Gray > --- > include/asm-generic/bitops/find.h | 17 +++++++++++++++ > include/linux/bitmap.h | 35 +++++++++++++++++++++++++++++++ > include/linux/bitops.h | 5 +++++ > lib/find_bit.c | 14 +++++++++++++ > 4 files changed, 71 insertions(+) > > diff --git a/include/asm-generic/bitops/find.h b/include/asm-generic/bitops/find.h > index 8a1ee10014de..9fdf21302fdf 100644 > --- a/include/asm-generic/bitops/find.h > +++ b/include/asm-generic/bitops/find.h > @@ -80,4 +80,21 @@ extern unsigned long find_first_zero_bit(const unsigned long *addr, > > #endif /* CONFIG_GENERIC_FIND_FIRST_BIT */ > > +/** > + * find_next_clump8 - find next 8-bit clump with set bits in a memory region > + * @clump: location to store copy of found clump > + * @addr: address to base the search on > + * @size: bitmap size in number of bits > + * @offset: bit offset at which to start searching > + * > + * Returns the bit offset for the next set clump; the found clump value is > + * copied to the location pointed by @clump. If no bits are set, returns @size. > + */ > +extern unsigned long find_next_clump8(unsigned long *clump, > + const unsigned long *addr, > + unsigned long size, unsigned long offset); > + > +#define find_first_clump8(clump, bits, size) \ > + find_next_clump8((clump), (bits), (size), 0) > + > #endif /*_ASM_GENERIC_BITOPS_FIND_H_ */ > diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h > index 90528f12bdfa..761fab5b60a7 100644 > --- a/include/linux/bitmap.h > +++ b/include/linux/bitmap.h > @@ -66,6 +66,8 @@ > * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region > * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst > * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst > + * bitmap_get_value8(map, start) Get 8bit value from map at start > + * bitmap_set_value8(map, value, start) Set 8bit value to map at start > * > * Note, bitmap_zero() and bitmap_fill() operate over the region of > * unsigned longs, that is, bits behind bitmap till the unsigned long > @@ -488,6 +490,39 @@ static inline void bitmap_from_u64(unsigned long *dst, u64 mask) > dst[1] = mask >> 32; > } > > +/** > + * bitmap_get_value8 - get an 8-bit value within a memory region > + * @map: address to the bitmap memory region > + * @start: bit offset of the 8-bit value; must be a multiple of 8 > + * > + * Returns the 8-bit value located at the @start bit offset within the @src > + * memory region. > + */ > +static inline unsigned long bitmap_get_value8(const unsigned long *map, > + unsigned long start) Why is the return type "unsigned long" where you know it return the 8-bit value ? u8? > +{ > + const size_t index = BIT_WORD(start); > + const unsigned long offset = start % BITS_PER_LONG; > + > + return (map[index] >> offset) & 0xFF; > +} > + > +/** > + * bitmap_set_value8 - set an 8-bit value within a memory region > + * @map: address to the bitmap memory region > + * @value: the 8-bit value; values wider than 8 bits may clobber bitmap > + * @start: bit offset of the 8-bit value; must be a multiple of 8 > + */ > +static inline void bitmap_set_value8(unsigned long *map, unsigned long value, Same here, "u8 value" > + unsigned long start) > +{ > + const size_t index = BIT_WORD(start); > + const unsigned long offset = start % BITS_PER_LONG; > + > + map[index] &= ~(0xFF << offset); > + map[index] |= value << offset; > +} > + > #endif /* __ASSEMBLY__ */ > > #endif /* __LINUX_BITMAP_H */ > diff --git a/include/linux/bitops.h b/include/linux/bitops.h > index cf074bce3eb3..fb94a10f7853 100644 > --- a/include/linux/bitops.h > +++ b/include/linux/bitops.h > @@ -40,6 +40,11 @@ extern unsigned long __sw_hweight64(__u64 w); > (bit) < (size); \ > (bit) = find_next_zero_bit((addr), (size), (bit) + 1)) > > +#define for_each_set_clump8(start, clump, bits, size) \ > + for ((start) = find_first_clump8(&(clump), (bits), (size)); \ > + (start) < (size); \ > + (start) = find_next_clump8(&(clump), (bits), (size), (start) + 8)) > + > static inline int get_bitmask_order(unsigned int count) > { > int order; > diff --git a/lib/find_bit.c b/lib/find_bit.c > index 5c51eb45178a..e35a76b291e6 100644 > --- a/lib/find_bit.c > +++ b/lib/find_bit.c > @@ -214,3 +214,17 @@ EXPORT_SYMBOL(find_next_bit_le); > #endif > > #endif /* __BIG_ENDIAN */ > + > +unsigned long find_next_clump8(unsigned long *clump, const unsigned long *addr, Ditto. "u8 *clump" > + unsigned long size, unsigned long offset) > +{ > + offset = find_next_bit(addr, size, offset); > + if (offset == size) > + return size; > + > + offset = round_down(offset, 8); > + *clump = bitmap_get_value8(addr, offset); > + > + return offset; > +} > +EXPORT_SYMBOL(find_next_clump8); > -- > 2.23.0 > -- Best Regards Masahiro Yamada