From: Geert Uytterhoeven <geert+renesas@glider.be> To: Tony Lindgren <tony@atomide.com>, Russell King <linux@armlinux.org.uk>, Rajendra Nayak <rnayak@codeaurora.org>, Paul Walmsley <paul@pwsan.com>, Michael Turquette <mturquette@baylibre.com>, Stephen Boyd <sboyd@kernel.org>, Nicolas Ferre <nicolas.ferre@microchip.com>, Alexandre Belloni <alexandre.belloni@bootlin.com>, Ludovic Desroches <ludovic.desroches@microchip.com>, Tero Kristo <kristo@kernel.org>, Jonathan Cameron <jic23@kernel.org>, Lars-Peter Clausen <lars@metafoo.de>, Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>, Benoit Parrot <bparrot@ti.com>, Mauro Carvalho Chehab <mchehab@kernel.org>, Adrian Hunter <adrian.hunter@intel.com>, Andrew Jeffery <andrew@aj.id.au>, Ulf Hansson <ulf.hansson@linaro.org>, Joel Stanley <joel@jms.id.au>, Ping-Ke Shih <pkshih@realtek.com>, Kalle Valo <kvalo@codeaurora.org>, "David S . Miller" <davem@davemloft.net>, Jakub Kicinski <kuba@kernel.org>, Linus Walleij <linus.walleij@linaro.org>, Liam Girdwood <lgirdwood@gmail.com>, Mark Brown <broonie@kernel.org>, Magnus Damm <magnus.damm@gmail.com>, Eduardo Valentin <edubezval@gmail.com>, Keerthy <j-keerthy@ti.com>, "Rafael J . Wysocki" <rafael@kernel.org>, Daniel Lezcano <daniel.lezcano@linaro.org>, Amit Kucheria <amitk@kernel.org>, Zhang Rui <rui.zhang@intel.com>, Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com> Cc: linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-iio@vger.kernel.org, linux-media@vger.kernel.org, linux-mmc@vger.kernel.org, linux-aspeed@lists.ozlabs.org, openbmc@lists.ozlabs.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-gpio@vger.kernel.org, linux-pm@vger.kernel.org, alsa-devel@alsa-project.org, Geert Uytterhoeven <geert+renesas@glider.be> Subject: [PATCH 01/17] bitfield: Add non-constant field_{prep,get}() helpers Date: Mon, 22 Nov 2021 16:53:54 +0100 [thread overview] Message-ID: <3a54a6703879d10f08cf0275a2a69297ebd2b1d4.1637592133.git.geert+renesas@glider.be> (raw) In-Reply-To: <cover.1637592133.git.geert+renesas@glider.be> The existing FIELD_{GET,PREP}() macros are limited to compile-time constants. However, it is very common to prepare or extract bitfield elements where the bitfield mask is not a compile-time constant. To avoid this limitation, the AT91 clock driver already has its own field_{prep,get}() macros. Make them available for general use by moving them to <linux/bitfield.h>, and improve them slightly: 1. Avoid evaluating macro parameters more than once, 2. Replace "ffs() - 1" by "__ffs()", as the latter operates on "unsigned long", just like BIT() and GENMASK(). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> --- Using __ffs() actually reduces code size (16 bytes for each of drivers/clk/at91/clk-{generated,peripheral}.o), as __ffs() doesn't need to verify that the value passed is non-zero. --- drivers/clk/at91/clk-peripheral.c | 1 + drivers/clk/at91/pmc.h | 3 --- include/linux/bitfield.h | 30 ++++++++++++++++++++++++++++++ 3 files changed, 31 insertions(+), 3 deletions(-) diff --git a/drivers/clk/at91/clk-peripheral.c b/drivers/clk/at91/clk-peripheral.c index e14fa5ac734cead7..e2f33498139a1b8c 100644 --- a/drivers/clk/at91/clk-peripheral.c +++ b/drivers/clk/at91/clk-peripheral.c @@ -3,6 +3,7 @@ * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com> */ +#include <linux/bitfield.h> #include <linux/bitops.h> #include <linux/clk-provider.h> #include <linux/clkdev.h> diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h index 3a1bf6194c287d09..1256e1ab91526a25 100644 --- a/drivers/clk/at91/pmc.h +++ b/drivers/clk/at91/pmc.h @@ -114,9 +114,6 @@ struct at91_clk_pms { unsigned int parent; }; -#define field_get(_mask, _reg) (((_reg) & (_mask)) >> (ffs(_mask) - 1)) -#define field_prep(_mask, _val) (((_val) << (ffs(_mask) - 1)) & (_mask)) - #define ndck(a, s) (a[s - 1].id + 1) #define nck(a) (a[ARRAY_SIZE(a) - 1].id + 1) struct pmc_data *pmc_data_allocate(unsigned int ncore, unsigned int nsystem, diff --git a/include/linux/bitfield.h b/include/linux/bitfield.h index 4e035aca6f7e6000..f03b0712e4babec1 100644 --- a/include/linux/bitfield.h +++ b/include/linux/bitfield.h @@ -156,4 +156,34 @@ __MAKE_OP(64) #undef __MAKE_OP #undef ____MAKE_OP +/** + * field_prep() - prepare a bitfield element + * @_mask: shifted mask defining the field's length and position + * @_val: value to put in the field + * + * field_prep() masks and shifts up the value. The result should be + * combined with other fields of the bitfield using logical OR. + * Unlike FIELD_PREP(), @_mask is not limited to a compile-time constant. + */ +#define field_prep(_mask, _val) \ + ({ \ + typeof(_mask) ___mask = (_mask); \ + (((_val) << __ffs(___mask)) & (___mask)); \ + }) + +/** + * field_get() - extract a bitfield element + * @_mask: shifted mask defining the field's length and position + * @_reg: value of entire bitfield + * + * field_get() extracts the field specified by @_mask from the + * bitfield passed in as @_reg by masking and shifting it down. + * Unlike FIELD_GET(), @_mask is not limited to a compile-time constant. + */ +#define field_get(_mask, _reg) \ + ({ \ + typeof(_mask) ___mask = _mask; \ + (((_reg) & (___mask)) >> __ffs(___mask)); \ + }) + #endif -- 2.25.1
WARNING: multiple messages have this Message-ID (diff)
From: Geert Uytterhoeven <geert+renesas@glider.be> To: Tony Lindgren <tony@atomide.com>, Russell King <linux@armlinux.org.uk>, Rajendra Nayak <rnayak@codeaurora.org>, Paul Walmsley <paul@pwsan.com>, Michael Turquette <mturquette@baylibre.com>, Stephen Boyd <sboyd@kernel.org>, Nicolas Ferre <nicolas.ferre@microchip.com>, Alexandre Belloni <alexandre.belloni@bootlin.com>, Ludovic Desroches <ludovic.desroches@microchip.com>, Tero Kristo <kristo@kernel.org>, Jonathan Cameron <jic23@kernel.org>, Lars-Peter Clausen <lars@metafoo.de>, Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>, Benoit Parrot <bparrot@ti.com>, Mauro Carvalho Chehab <mchehab@kernel.org>, Adrian Hunter <adrian.hunter@intel.com>, Andrew Jeffery <andrew@aj.id.au>, Ulf Hansson <ulf.hansson@linaro.org>, Joel Stanley <joel@jms.id.au>, Ping-Ke Shih <pkshih@realtek.com>, Kalle Valo <kvalo@codeaurora.org>, "David S . Miller" <davem@davemloft.net>, Jakub Kicinski <kuba@kernel.org>, Linus Walleij <linus.walleij@linaro.org>, Liam Girdwood <lgirdwood@gmail.com>, Mark Brown <broonie@kernel.org>, Magnus Damm <magnus.damm@gmail.com>, Eduardo Valentin <edubezval@gmail.com>, Keerthy <j-keerthy@ti.com>, "Rafael J . Wysocki" <rafael@kernel.org>, Daniel Lezcano <daniel.lezcano@linaro.org>, Amit Kucheria <amitk@kernel.org>, Zhang Rui <rui.zhang@intel.com>, Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com> Cc: alsa-devel@alsa-project.org, Geert Uytterhoeven <geert+renesas@glider.be>, linux-aspeed@lists.ozlabs.org, linux-pm@vger.kernel.org, linux-iio@vger.kernel.org, linux-wireless@vger.kernel.org, openbmc@lists.ozlabs.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-gpio@vger.kernel.org, netdev@vger.kernel.org, linux-omap@vger.kernel.org, linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org Subject: [PATCH 01/17] bitfield: Add non-constant field_{prep,get}() helpers Date: Mon, 22 Nov 2021 16:53:54 +0100 [thread overview] Message-ID: <3a54a6703879d10f08cf0275a2a69297ebd2b1d4.1637592133.git.geert+renesas@glider.be> (raw) In-Reply-To: <cover.1637592133.git.geert+renesas@glider.be> The existing FIELD_{GET,PREP}() macros are limited to compile-time constants. However, it is very common to prepare or extract bitfield elements where the bitfield mask is not a compile-time constant. To avoid this limitation, the AT91 clock driver already has its own field_{prep,get}() macros. Make them available for general use by moving them to <linux/bitfield.h>, and improve them slightly: 1. Avoid evaluating macro parameters more than once, 2. Replace "ffs() - 1" by "__ffs()", as the latter operates on "unsigned long", just like BIT() and GENMASK(). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> --- Using __ffs() actually reduces code size (16 bytes for each of drivers/clk/at91/clk-{generated,peripheral}.o), as __ffs() doesn't need to verify that the value passed is non-zero. --- drivers/clk/at91/clk-peripheral.c | 1 + drivers/clk/at91/pmc.h | 3 --- include/linux/bitfield.h | 30 ++++++++++++++++++++++++++++++ 3 files changed, 31 insertions(+), 3 deletions(-) diff --git a/drivers/clk/at91/clk-peripheral.c b/drivers/clk/at91/clk-peripheral.c index e14fa5ac734cead7..e2f33498139a1b8c 100644 --- a/drivers/clk/at91/clk-peripheral.c +++ b/drivers/clk/at91/clk-peripheral.c @@ -3,6 +3,7 @@ * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com> */ +#include <linux/bitfield.h> #include <linux/bitops.h> #include <linux/clk-provider.h> #include <linux/clkdev.h> diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h index 3a1bf6194c287d09..1256e1ab91526a25 100644 --- a/drivers/clk/at91/pmc.h +++ b/drivers/clk/at91/pmc.h @@ -114,9 +114,6 @@ struct at91_clk_pms { unsigned int parent; }; -#define field_get(_mask, _reg) (((_reg) & (_mask)) >> (ffs(_mask) - 1)) -#define field_prep(_mask, _val) (((_val) << (ffs(_mask) - 1)) & (_mask)) - #define ndck(a, s) (a[s - 1].id + 1) #define nck(a) (a[ARRAY_SIZE(a) - 1].id + 1) struct pmc_data *pmc_data_allocate(unsigned int ncore, unsigned int nsystem, diff --git a/include/linux/bitfield.h b/include/linux/bitfield.h index 4e035aca6f7e6000..f03b0712e4babec1 100644 --- a/include/linux/bitfield.h +++ b/include/linux/bitfield.h @@ -156,4 +156,34 @@ __MAKE_OP(64) #undef __MAKE_OP #undef ____MAKE_OP +/** + * field_prep() - prepare a bitfield element + * @_mask: shifted mask defining the field's length and position + * @_val: value to put in the field + * + * field_prep() masks and shifts up the value. The result should be + * combined with other fields of the bitfield using logical OR. + * Unlike FIELD_PREP(), @_mask is not limited to a compile-time constant. + */ +#define field_prep(_mask, _val) \ + ({ \ + typeof(_mask) ___mask = (_mask); \ + (((_val) << __ffs(___mask)) & (___mask)); \ + }) + +/** + * field_get() - extract a bitfield element + * @_mask: shifted mask defining the field's length and position + * @_reg: value of entire bitfield + * + * field_get() extracts the field specified by @_mask from the + * bitfield passed in as @_reg by masking and shifting it down. + * Unlike FIELD_GET(), @_mask is not limited to a compile-time constant. + */ +#define field_get(_mask, _reg) \ + ({ \ + typeof(_mask) ___mask = _mask; \ + (((_reg) & (___mask)) >> __ffs(___mask)); \ + }) + #endif -- 2.25.1
next prev parent reply other threads:[~2021-11-22 15:56 UTC|newest] Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-11-22 15:53 [PATCH 00/17] Non-const bitfield helper conversions Geert Uytterhoeven 2021-11-22 15:53 ` Geert Uytterhoeven 2021-11-22 15:53 ` Geert Uytterhoeven [this message] 2021-11-22 15:53 ` [PATCH 01/17] bitfield: Add non-constant field_{prep,get}() helpers Geert Uytterhoeven 2021-11-22 16:32 ` Johannes Berg 2021-11-22 16:32 ` Johannes Berg 2021-11-23 1:17 ` Jakub Kicinski 2021-11-23 1:17 ` Jakub Kicinski 2021-11-23 8:36 ` Geert Uytterhoeven 2021-11-23 8:36 ` [PATCH 01/17] bitfield: Add non-constant field_{prep, get}() helpers Geert Uytterhoeven 2021-11-23 16:24 ` [PATCH 01/17] bitfield: Add non-constant field_{prep,get}() helpers Johannes Berg 2021-11-23 16:24 ` Johannes Berg 2021-11-23 23:49 ` Jakub Kicinski 2021-11-23 23:49 ` Jakub Kicinski 2021-11-24 8:03 ` Johannes Berg 2021-11-24 13:59 ` Jakub Kicinski 2021-11-24 14:07 ` Johannes Berg 2021-11-23 23:39 ` Jakub Kicinski 2021-11-23 23:39 ` Jakub Kicinski 2021-11-23 1:52 ` Alex Elder 2021-11-23 1:52 ` Alex Elder 2021-11-23 8:38 ` Geert Uytterhoeven 2021-11-23 8:38 ` [PATCH 01/17] bitfield: Add non-constant field_{prep, get}() helpers Geert Uytterhoeven 2021-11-23 8:30 ` [PATCH 01/17] bitfield: Add non-constant field_{prep,get}() helpers Geert Uytterhoeven 2021-11-23 8:30 ` [PATCH 01/17] bitfield: Add non-constant field_{prep, get}() helpers Geert Uytterhoeven 2021-11-23 16:21 ` [PATCH 01/17] bitfield: Add non-constant field_{prep,get}() helpers Johannes Berg 2021-11-23 16:21 ` Johannes Berg 2021-11-23 16:31 ` Geert Uytterhoeven 2021-11-23 16:31 ` [PATCH 01/17] bitfield: Add non-constant field_{prep, get}() helpers Geert Uytterhoeven 2021-11-24 8:24 ` [PATCH 01/17] bitfield: Add non-constant field_{prep,get}() helpers Kalle Valo 2021-11-22 15:53 ` [PATCH 02/17] clk: renesas: Use bitfield helpers Geert Uytterhoeven 2021-11-22 15:53 ` Geert Uytterhoeven 2021-11-22 15:53 ` [PATCH/RFC 03/17] soc: " Geert Uytterhoeven 2021-11-22 15:53 ` Geert Uytterhoeven 2021-11-22 15:53 ` [PATCH/RFC 04/17] ARM: OMAP2+: " Geert Uytterhoeven 2021-11-22 15:53 ` Geert Uytterhoeven 2021-11-22 15:53 ` [PATCH/RFC 05/17] bus: omap_l3_noc: " Geert Uytterhoeven 2021-11-22 15:53 ` Geert Uytterhoeven 2021-11-22 15:53 ` [PATCH/RFC 06/17] clk: ti: " Geert Uytterhoeven 2021-11-22 15:53 ` Geert Uytterhoeven 2021-11-22 15:54 ` [PATCH/RFC 07/17] iio: st_sensors: " Geert Uytterhoeven 2021-11-22 15:54 ` Geert Uytterhoeven 2021-11-23 23:35 ` Linus Walleij 2021-11-23 23:35 ` Linus Walleij 2021-11-22 15:54 ` [PATCH/RFC 08/17] iio: humidity: hts221: " Geert Uytterhoeven 2021-11-22 15:54 ` Geert Uytterhoeven 2021-11-24 15:21 ` Jonathan Cameron 2021-11-22 15:54 ` [PATCH/RFC 09/17] iio: imu: st_lsm6dsx: " Geert Uytterhoeven 2021-11-22 15:54 ` Geert Uytterhoeven 2021-11-22 15:54 ` [PATCH/RFC 10/17] media: ti-vpe: cal: " Geert Uytterhoeven 2021-11-22 15:54 ` Geert Uytterhoeven 2021-11-22 15:54 ` [PATCH/RFC 11/17] mmc: sdhci-of-aspeed: " Geert Uytterhoeven 2021-11-22 15:54 ` Geert Uytterhoeven 2021-11-22 15:54 ` [PATCH/RFC 12/17] pinctrl: aspeed: " Geert Uytterhoeven 2021-11-22 15:54 ` Geert Uytterhoeven 2021-11-22 15:54 ` [PATCH/RFC 13/17] pinctl: ti: iodelay: " Geert Uytterhoeven 2021-11-22 15:54 ` Geert Uytterhoeven 2021-11-22 17:52 ` Alexandre Belloni 2021-11-22 17:52 ` Alexandre Belloni 2021-11-22 15:54 ` [PATCH/RFC 14/17] regulator: ti-abb: " Geert Uytterhoeven 2021-11-22 15:54 ` Geert Uytterhoeven 2021-11-22 16:31 ` Mark Brown 2021-11-22 16:31 ` Mark Brown 2021-11-22 15:54 ` [PATCH/RFC 15/17] thermal/ti-soc-thermal: " Geert Uytterhoeven 2021-11-22 15:54 ` Geert Uytterhoeven 2021-11-22 15:54 ` [PATCH/RFC 16/17] ALSA: ice1724: " Geert Uytterhoeven 2021-11-22 15:54 ` Geert Uytterhoeven 2021-11-23 11:24 ` Takashi Iwai 2021-11-23 11:24 ` Takashi Iwai 2021-11-22 15:54 ` [PATCH/RFC 17/17] rtw89: " Geert Uytterhoeven 2021-11-22 15:54 ` Geert Uytterhoeven 2021-11-22 18:38 ` Larry Finger 2021-11-22 18:38 ` Larry Finger 2021-11-22 17:50 ` [PATCH 00/17] Non-const bitfield helper conversions Alexandre Belloni 2021-11-22 17:50 ` Alexandre Belloni 2021-11-23 8:20 ` Geert Uytterhoeven 2021-11-23 8:20 ` Geert Uytterhoeven
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