linux-kernel - RE: [PATCH v3 1/2] Support NVIDIA BlueField-3 GPIO controller

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 13 Feb 2023 23:14:06 +0000
From:   Asmaa Mnebhi <asmaa@...dia.com>
To:     Andy Shevchenko <andriy.shevchenko@...el.com>,
        "linus.walleij@...aro.org" <linus.walleij@...aro.org>
CC:     "linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-acpi@...r.kernel.org" <linux-acpi@...r.kernel.org>
Subject: RE: [PATCH v3 1/2] Support NVIDIA BlueField-3 GPIO controller

Thanks Andy for the feedback! Will address your comment in v4.

> +		generic_handle_irq(irq_find_mapping(gc->irq.domain, level));

There is a helper that unites these two calls together.

I didn't find any helper in v6.2. Could you please point me to it?

> +static int mlxbf3_gpio_init_valid_mask(struct gpio_chip *gc,
> +				       unsigned long *valid_mask,
> +				       unsigned int ngpios)
> +{
> +	struct mlxbf3_gpio_context *gs = gpiochip_get_data(gc);
> +
> +	*valid_mask = gs->valid_mask;
> +
> +	return 0;
> +}

Why do you need this?

Since we only use ACPI tables and we want user space (libgpiod tool) or possibly (in the future)
other kernel drivers to have access to certain GPIO pins, we use this valid_mask to do so.
Linus previously explained that if we ask for a GPIO then it will be muxed in using .gpio_request_enable().
And so we would use .valid_mask to restrict the use of certain gpios.