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[209.132.180.67]) by mx.google.com with ESMTP id h6-v6si4168275pll.328.2018.03.21.10.01.36; Wed, 21 Mar 2018 10:02:05 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@chromium.org header.s=google header.b=CPB8xJ4B; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752297AbeCUQ7q (ORCPT + 99 others); Wed, 21 Mar 2018 12:59:46 -0400 Received: from mail-pg0-f67.google.com ([74.125.83.67]:37910 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752002AbeCUQ6x (ORCPT ); Wed, 21 Mar 2018 12:58:53 -0400 Received: by mail-pg0-f67.google.com with SMTP id a15so2163877pgn.5 for ; Wed, 21 Mar 2018 09:58:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=I5kzN9Lak1dkyQmXG7fgEFlSGMI1oR7RK56a3QuzoXg=; b=CPB8xJ4Bw9fSX1PjGORwJ+bNaT864WFDMK5+g7n885O5Rwsh/3ACNObG36ay9P61ox l39H70q2MwxtRPA1NO3KbzQlQ0bUWWCIX/i/uCdZOmSttZ69QgPgsQj6AGQ40cyPDXyc nwhSMCuwdXErZCAZNnvcozWKPJcEPFxTXE5EQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=I5kzN9Lak1dkyQmXG7fgEFlSGMI1oR7RK56a3QuzoXg=; b=HNNfNRemkx4R1+ukHJBLNf8yS/gB5g291Y8pbn9FBjk4mfRVnY9i6EjKlNsxaggtwE EtZkSnQZov1uCGfxu0bjRJ5gtiuzqU7x3VrAn3053UFyUUDIWenbZGFl3UsybmP2MVYE S1MWP2eLu8VVfXYgmCAXwi++bN23genSNS4y+eLSAQWX7FHn5DSBvUkqAizsQX3WxPyt Sljd5tH+RuzQK+mUq8+8GYb5YIsFzl8WNaYQA6ncZ2tVX/pwzJfOsWeoZVyO9UhitfyU 1jYFUpyvOBh4a6JGPTRcmvChVLhIPLlGmnwR8sbu1x1qvj7iRs6dcQ5eWKb/KBWINUM1 BW9A== X-Gm-Message-State: AElRT7FBHaR0s3UCOX/UjCh3mHqwPri6YDixRZa2tQme3n1LUguyCxie +xp0J9W9GxozJ9d5i20J2fP3Ww== X-Received: by 10.98.32.134 with SMTP id m6mr17647270pfj.27.1521651533088; Wed, 21 Mar 2018 09:58:53 -0700 (PDT) Received: from swboyd.mtv.corp.google.com ([2620:0:1000:1511:d30e:62c6:f82c:ff40]) by smtp.gmail.com with ESMTPSA id u28sm10121806pfl.19.2018.03.21.09.58.52 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 21 Mar 2018 09:58:52 -0700 (PDT) From: Stephen Boyd To: Linus Walleij Cc: Stephen Boyd , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-arm-msm@vger.kernel.org, Timur Tabi , Bjorn Andersson , Grant Likely , linux-gpio@vger.kernel.org, Andy Shevchenko Subject: [PATCH v3 2/3] gpiolib: Support 'gpio-reserved-ranges' property Date: Wed, 21 Mar 2018 09:58:47 -0700 Message-Id: <20180321165848.89751-3-swboyd@chromium.org> X-Mailer: git-send-email 2.16.2.804.g6dcf76e118-goog In-Reply-To: <20180321165848.89751-1-swboyd@chromium.org> References: <20180321165848.89751-1-swboyd@chromium.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stephen Boyd Some qcom platforms make some GPIOs or pins unavailable for use by non-secure operating systems, and thus reading or writing the registers for those pins will cause access control issues. Add support for a DT property to describe the set of GPIOs that are available for use so that higher level OSes are able to know what pins to avoid reading/writing. Non-DT platforms can add support by directly updating the chip->valid_mask. Signed-off-by: Stephen Boyd Signed-off-by: Stephen Boyd --- drivers/gpio/gpiolib-of.c | 24 ++++++++++++++++++ drivers/gpio/gpiolib.c | 50 +++++++++++++++++++++++++++++++++++++ include/linux/gpio/driver.h | 16 ++++++++++++ 3 files changed, 90 insertions(+) diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index 84e5a9df2344..ed81d9a6316f 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -511,6 +511,28 @@ void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc) } EXPORT_SYMBOL(of_mm_gpiochip_remove); +static void of_gpiochip_init_valid_mask(struct gpio_chip *chip) +{ + int len, i; + u32 start, count; + struct device_node *np = chip->of_node; + + len = of_property_count_u32_elems(np, "gpio-reserved-ranges"); + if (len < 0 || len % 2 != 0) + return; + + for (i = 0; i < len; i += 2) { + of_property_read_u32_index(np, "gpio-reserved-ranges", + i, &start); + of_property_read_u32_index(np, "gpio-reserved-ranges", + i + 1, &count); + if (start >= chip->ngpio || start + count >= chip->ngpio) + continue; + + bitmap_clear(chip->valid_mask, start, count); + } +}; + #ifdef CONFIG_PINCTRL static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { @@ -615,6 +637,8 @@ int of_gpiochip_add(struct gpio_chip *chip) if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS) return -EINVAL; + of_gpiochip_init_valid_mask(chip); + status = of_gpiochip_add_pin_range(chip); if (status) return status; diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index d66de67ef307..5861984774ac 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -337,6 +337,47 @@ static int gpiochip_set_desc_names(struct gpio_chip *gc) return 0; } +static int gpiochip_init_valid_mask(struct gpio_chip *gpiochip) +{ +#ifdef CONFIG_OF_GPIO + int size; + struct device_node *np = gpiochip->of_node; + + size = of_property_count_u32_elems(np, "gpio-reserved-ranges"); + if (size > 0 && size % 2 == 0) + gpiochip->need_valid_mask = true; +#endif + + if (!gpiochip->need_valid_mask) + return 0; + + gpiochip->valid_mask = kcalloc(BITS_TO_LONGS(gpiochip->ngpio), + sizeof(long), GFP_KERNEL); + if (!gpiochip->valid_mask) + return -ENOMEM; + + /* Assume by default all GPIOs are valid */ + bitmap_fill(gpiochip->valid_mask, gpiochip->ngpio); + + return 0; +} + +static void gpiochip_free_valid_mask(struct gpio_chip *gpiochip) +{ + kfree(gpiochip->valid_mask); + gpiochip->valid_mask = NULL; +} + +bool gpiochip_line_is_valid(const struct gpio_chip *gpiochip, + unsigned int offset) +{ + /* No mask means all valid */ + if (likely(!gpiochip->valid_mask)) + return true; + return test_bit(offset, gpiochip->valid_mask); +} +EXPORT_SYMBOL_GPL(gpiochip_line_is_valid); + /* * GPIO line handle management */ @@ -1261,6 +1302,10 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data, if (status) goto err_remove_from_list; + status = gpiochip_init_valid_mask(chip); + if (status) + goto err_remove_irqchip_mask; + status = gpiochip_add_irqchip(chip, lock_key, request_key); if (status) goto err_remove_chip; @@ -1290,6 +1335,8 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data, acpi_gpiochip_remove(chip); gpiochip_free_hogs(chip); of_gpiochip_remove(chip); + gpiochip_free_valid_mask(chip); +err_remove_irqchip_mask: gpiochip_irqchip_free_valid_mask(chip); err_remove_from_list: spin_lock_irqsave(&gpio_lock, flags); @@ -1346,6 +1393,7 @@ void gpiochip_remove(struct gpio_chip *chip) acpi_gpiochip_remove(chip); gpiochip_remove_pin_ranges(chip); of_gpiochip_remove(chip); + gpiochip_free_valid_mask(chip); /* * We accept no more calls into the driver from this point, so * NULL the driver data pointer @@ -1526,6 +1574,8 @@ static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip) bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip, unsigned int offset) { + if (!gpiochip_line_is_valid(gpiochip, offset)) + return false; /* No mask means all valid */ if (likely(!gpiochip->irq.valid_mask)) return true; diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 1ba9a331ec51..5382b5183b7e 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -288,6 +288,21 @@ struct gpio_chip { struct gpio_irq_chip irq; #endif + /** + * @need_valid_mask: + * + * If set core allocates @valid_mask with all bits set to one. + */ + bool need_valid_mask; + + /** + * @valid_mask: + * + * If not %NULL holds bitmask of GPIOs which are valid to be used + * from the chip. + */ + unsigned long *valid_mask; + #if defined(CONFIG_OF_GPIO) /* * If CONFIG_OF is enabled, then all GPIO controllers described in the @@ -384,6 +399,7 @@ bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset); /* Sleep persistence inquiry for drivers */ bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset); +bool gpiochip_line_is_valid(const struct gpio_chip *chip, unsigned int offset); /* get driver data */ void *gpiochip_get_data(struct gpio_chip *chip); -- Sent by a computer through tubes