From: Kent Gibson <warthog618@gmail.com>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Linus Walleij <linus.walleij@linaro.org>,
Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH v9 11/20] gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL
Date: Thu, 24 Sep 2020 15:32:48 +0800 [thread overview]
Message-ID: <20200924073248.GA17562@sol> (raw)
In-Reply-To: <CAHp75Vd6tb09n+okJmoPse992DeoPkJQHReNBo20FQNz1V2c5w@mail.gmail.com>
On Wed, Sep 23, 2020 at 07:18:08PM +0300, Andy Shevchenko wrote:
> On Tue, Sep 22, 2020 at 5:36 AM Kent Gibson <warthog618@gmail.com> wrote:
> >
> > Add support for the GPIO_V2_LINE_SET_VALUES_IOCTL.
>
> > +static long linereq_set_values_unlocked(struct linereq *lr,
> > + struct gpio_v2_line_values *lv)
> > +{
> > + DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX);
> > + struct gpio_desc **descs;
> > + unsigned int i, didx, num_set;
> > + int ret;
> > +
> > + bitmap_zero(vals, GPIO_V2_LINES_MAX);
> > + for (num_set = 0, i = 0; i < lr->num_lines; i++) {
> > + if (lv->mask & BIT_ULL(i)) {
>
> Similar idea
>
> DECLARE_BITMAP(mask, 64) = BITMAP_FROM_U64(lv->mask);
>
> num_set = bitmap_weight();
>
I had played with this option, but bitmap_weight() counts all
the bits set in the mask - which considers bits >= lr->num_lines.
So you would need to mask lv->mask before converting it to a bitmap.
(I'm ok with ignoring those bits in case userspace wants to be lazy and
use an all 1s mask.)
But since we're looping over the bitmap anyway we may as well just
count as we go.
> for_each_set_bit(i, mask, lr->num_lines)
>
Yeah, that should work. I vaguely recall trying this and finding it
generated larger object code, but I'll give it another try and if it
works out then include it in v10.
Cheers,
Kent.
next prev parent reply other threads:[~2020-09-24 7:32 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-22 2:31 [PATCH v9 00/20] gpio: cdev: add uAPI v2 Kent Gibson
2020-09-22 2:31 ` [PATCH v9 01/20] gpiolib: cdev: gpio_desc_to_lineinfo() should set info offset Kent Gibson
2020-09-22 2:31 ` [PATCH v9 02/20] gpiolib: cdev: replace strncpy() with strscpy() Kent Gibson
2020-09-22 2:31 ` [PATCH v9 03/20] gpio: uapi: define GPIO_MAX_NAME_SIZE for array sizes Kent Gibson
2020-09-22 2:31 ` [PATCH v9 04/20] gpio: uapi: define uAPI v2 Kent Gibson
2020-09-22 7:41 ` Arnd Bergmann
2020-09-22 9:50 ` Bartosz Golaszewski
2020-09-22 10:07 ` Kent Gibson
2020-09-28 13:42 ` strace decoding for GPIO uAPI Kent Gibson
2020-09-29 13:20 ` Bartosz Golaszewski
2020-09-29 15:04 ` Kent Gibson
2020-09-29 16:19 ` Andy Shevchenko
2020-09-23 10:04 ` [PATCH v9 04/20] gpio: uapi: define uAPI v2 Andy Shevchenko
2020-09-23 10:30 ` Kent Gibson
2020-09-23 11:16 ` Andy Shevchenko
2020-09-23 12:18 ` Arnd Bergmann
2020-09-23 15:15 ` Andy Shevchenko
2020-09-22 2:31 ` [PATCH v9 05/20] gpiolib: make cdev a build option Kent Gibson
2020-09-22 2:31 ` [PATCH v9 06/20] gpiolib: add build option for CDEV v1 ABI Kent Gibson
2020-09-22 2:31 ` [PATCH v9 07/20] gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL Kent Gibson
2020-09-23 11:11 ` Andy Shevchenko
2020-09-24 8:09 ` Kent Gibson
2020-09-25 10:06 ` Andy Shevchenko
2020-09-26 9:16 ` Kent Gibson
2020-09-27 9:00 ` Andy Shevchenko
2020-09-27 12:39 ` Kent Gibson
2020-09-24 14:29 ` Bartosz Golaszewski
2020-09-22 2:31 ` [PATCH v9 08/20] gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL Kent Gibson
2020-09-23 15:41 ` Andy Shevchenko
2020-09-24 2:39 ` Kent Gibson
2020-09-24 8:39 ` Andy Shevchenko
2020-09-24 9:48 ` Kent Gibson
2020-09-25 10:12 ` Andy Shevchenko
2020-09-25 11:56 ` Kent Gibson
2020-09-25 14:43 ` Andy Shevchenko
2020-09-25 5:32 ` Kent Gibson
2020-09-22 2:31 ` [PATCH v9 09/20] gpiolib: cdev: support edge detection for uAPI v2 Kent Gibson
2020-09-23 15:47 ` Andy Shevchenko
2020-09-24 3:07 ` Kent Gibson
2020-09-25 9:35 ` Andy Shevchenko
2020-09-25 12:26 ` Kent Gibson
2020-09-25 14:48 ` Andy Shevchenko
2020-09-22 2:31 ` [PATCH v9 10/20] gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL Kent Gibson
2020-09-23 16:14 ` Andy Shevchenko
2020-09-23 16:15 ` Andy Shevchenko
2020-09-24 3:24 ` Kent Gibson
2020-09-24 8:26 ` Andy Shevchenko
2020-09-24 9:26 ` Kent Gibson
2020-09-25 9:49 ` Andy Shevchenko
2020-09-22 2:31 ` [PATCH v9 11/20] gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL Kent Gibson
2020-09-23 16:18 ` Andy Shevchenko
2020-09-24 7:32 ` Kent Gibson [this message]
2020-09-24 8:21 ` Andy Shevchenko
2020-09-24 9:08 ` Kent Gibson
2020-09-24 12:46 ` Kent Gibson
2020-09-25 9:57 ` Andy Shevchenko
2020-09-25 12:16 ` Kent Gibson
2020-09-22 2:31 ` [PATCH v9 12/20] gpiolib: cdev: support setting debounce Kent Gibson
2020-09-23 16:27 ` Andy Shevchenko
2020-09-24 7:48 ` Kent Gibson
2020-09-25 9:43 ` Andy Shevchenko
2020-09-22 2:31 ` [PATCH v9 13/20] gpio: uapi: document uAPI v1 as deprecated Kent Gibson
2020-09-22 7:49 ` Arnd Bergmann
2020-09-22 8:11 ` Andy Shevchenko
2020-09-22 9:05 ` Kent Gibson
2020-09-22 2:31 ` [PATCH v9 14/20] tools: gpio: port lsgpio to v2 uAPI Kent Gibson
2020-09-22 2:31 ` [PATCH v9 15/20] tools: gpio: port gpio-watch " Kent Gibson
2020-09-22 2:31 ` [PATCH v9 16/20] tools: gpio: rename nlines to num_lines Kent Gibson
2020-09-22 2:31 ` [PATCH v9 17/20] tools: gpio: port gpio-hammer to v2 uAPI Kent Gibson
2020-09-23 16:30 ` Andy Shevchenko
2020-09-24 7:50 ` Kent Gibson
2020-09-22 2:31 ` [PATCH v9 18/20] tools: gpio: port gpio-event-mon " Kent Gibson
2020-09-22 2:31 ` [PATCH v9 19/20] tools: gpio: add multi-line monitoring to gpio-event-mon Kent Gibson
2020-09-22 2:31 ` [PATCH v9 20/20] tools: gpio: add debounce support " Kent Gibson
2020-09-23 16:35 ` [PATCH v9 00/20] gpio: cdev: add uAPI v2 Andy Shevchenko
2020-09-24 8:00 ` Kent Gibson
2020-09-25 9:44 ` Andy Shevchenko
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