From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Shevchenko Subject: Re: [PATCH v16 01/14] bitops: Introduce the for_each_set_clump8 macro Date: Mon, 7 Oct 2019 11:21:56 +0300 Message-ID: <20191007082156.GL32742@smile.fi.intel.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: William Breathitt Gray Cc: linus.walleij@linaro.org, bgolaszewski@baylibre.com, akpm@linux-foundation.org, linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux@rasmusvillemoes.dk, yamada.masahiro@socionext.com, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, geert@linux-m68k.org, preid@electromag.com.au, lukas@wunner.de, sean.nyekjaer@prevas.dk, morten.tiljeset@prevas.dk, Arnd Bergmann List-Id: linux-arch.vger.kernel.org On Sun, Oct 06, 2019 at 11:10:58AM -0400, 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. Very much thank you for an update! I have comments below. > +/** > + * bitmap_get_value8 - get an 8-bit value within a memory region Since it's in find.h I would not collide with bitmap namespace. How about find_and_get_value8() > + * @addr: 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 @addr > + * memory region. > + */ > +static inline unsigned long bitmap_get_value8(const unsigned long *addr, > + unsigned long start) > +{ > + const size_t index = BIT_WORD(start); > + const unsigned long offset = start % BITS_PER_LONG; > + > + return (addr[index] >> offset) & 0xFF; > +} > + > +/** > + * bitmap_set_value8 - set an 8-bit value within a memory region find_and_set_value8() ? > + * @addr: 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 *addr, unsigned long value, > + unsigned long start) > +{ > + const size_t index = BIT_WORD(start); > + const unsigned long offset = start % BITS_PER_LONG; > + > + addr[index] &= ~(0xFF << offset); > + addr[index] |= value << offset; > +} -- With Best Regards, Andy Shevchenko From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga07.intel.com ([134.134.136.100]:26049 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727028AbfJGIWD (ORCPT ); Mon, 7 Oct 2019 04:22:03 -0400 Date: Mon, 7 Oct 2019 11:21:56 +0300 From: Andy Shevchenko Subject: Re: [PATCH v16 01/14] bitops: Introduce the for_each_set_clump8 macro Message-ID: <20191007082156.GL32742@smile.fi.intel.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-arch-owner@vger.kernel.org List-ID: To: William Breathitt Gray Cc: linus.walleij@linaro.org, bgolaszewski@baylibre.com, akpm@linux-foundation.org, linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux@rasmusvillemoes.dk, yamada.masahiro@socionext.com, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, geert@linux-m68k.org, preid@electromag.com.au, lukas@wunner.de, sean.nyekjaer@prevas.dk, morten.tiljeset@prevas.dk, Arnd Bergmann Message-ID: <20191007082156.KmfzIgVv_VLYQszp7Iof-IV4X1FK2Fr7TvrQpU4fVDg@z> On Sun, Oct 06, 2019 at 11:10:58AM -0400, 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. Very much thank you for an update! I have comments below. > +/** > + * bitmap_get_value8 - get an 8-bit value within a memory region Since it's in find.h I would not collide with bitmap namespace. How about find_and_get_value8() > + * @addr: 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 @addr > + * memory region. > + */ > +static inline unsigned long bitmap_get_value8(const unsigned long *addr, > + unsigned long start) > +{ > + const size_t index = BIT_WORD(start); > + const unsigned long offset = start % BITS_PER_LONG; > + > + return (addr[index] >> offset) & 0xFF; > +} > + > +/** > + * bitmap_set_value8 - set an 8-bit value within a memory region find_and_set_value8() ? > + * @addr: 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 *addr, unsigned long value, > + unsigned long start) > +{ > + const size_t index = BIT_WORD(start); > + const unsigned long offset = start % BITS_PER_LONG; > + > + addr[index] &= ~(0xFF << offset); > + addr[index] |= value << offset; > +} -- With Best Regards, Andy Shevchenko