From c8befdc411e5fd1bf95a13e8744c8ca79b412bee Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Fri, 13 Oct 2023 16:57:05 +0200 Subject: pinctrl: qcom: lpass-lpi: fix concurrent register updates The Qualcomm LPASS LPI pin controller driver uses one lock for guarding Read-Modify-Write code for slew rate registers. However the pin configuration and muxing registers have exactly the same RMW code but are not protected. Pin controller framework does not provide locking here, thus it is possible to trigger simultaneous change of pin configuration registers resulting in non-atomic changes. Protect from concurrent access by re-using the same lock used to cover the slew rate register. Using the same lock instead of adding second one will make more sense, once we add support for newer Qualcomm SoC, where slew rate is configured in the same register as pin configuration/muxing. Fixes: 6e261d1090d6 ("pinctrl: qcom: Add sm8250 lpass lpi pinctrl driver") Cc: stable@vger.kernel.org Reviewed-by: Linus Walleij Signed-off-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20231013145705.219954-1-krzysztof.kozlowski@linaro.org Signed-off-by: Linus Walleij --- drivers/pinctrl/qcom/pinctrl-lpass-lpi.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) (limited to 'drivers') diff --git a/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c b/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c index e5a418026ba3..0b2839d27fd6 100644 --- a/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c +++ b/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c @@ -32,7 +32,8 @@ struct lpi_pinctrl { char __iomem *tlmm_base; char __iomem *slew_base; struct clk_bulk_data clks[MAX_LPI_NUM_CLKS]; - struct mutex slew_access_lock; + /* Protects from concurrent register updates */ + struct mutex lock; DECLARE_BITMAP(ever_gpio, MAX_NR_GPIO); const struct lpi_pinctrl_variant_data *data; }; @@ -103,6 +104,7 @@ static int lpi_gpio_set_mux(struct pinctrl_dev *pctldev, unsigned int function, if (WARN_ON(i == g->nfuncs)) return -EINVAL; + mutex_lock(&pctrl->lock); val = lpi_gpio_read(pctrl, pin, LPI_GPIO_CFG_REG); /* @@ -128,6 +130,7 @@ static int lpi_gpio_set_mux(struct pinctrl_dev *pctldev, unsigned int function, u32p_replace_bits(&val, i, LPI_GPIO_FUNCTION_MASK); lpi_gpio_write(pctrl, pin, LPI_GPIO_CFG_REG, val); + mutex_unlock(&pctrl->lock); return 0; } @@ -233,14 +236,14 @@ static int lpi_config_set(struct pinctrl_dev *pctldev, unsigned int group, if (slew_offset == LPI_NO_SLEW) break; - mutex_lock(&pctrl->slew_access_lock); + mutex_lock(&pctrl->lock); sval = ioread32(pctrl->slew_base + LPI_SLEW_RATE_CTL_REG); sval &= ~(LPI_SLEW_RATE_MASK << slew_offset); sval |= arg << slew_offset; iowrite32(sval, pctrl->slew_base + LPI_SLEW_RATE_CTL_REG); - mutex_unlock(&pctrl->slew_access_lock); + mutex_unlock(&pctrl->lock); break; default: return -EINVAL; @@ -256,6 +259,7 @@ static int lpi_config_set(struct pinctrl_dev *pctldev, unsigned int group, lpi_gpio_write(pctrl, group, LPI_GPIO_VALUE_REG, val); } + mutex_lock(&pctrl->lock); val = lpi_gpio_read(pctrl, group, LPI_GPIO_CFG_REG); u32p_replace_bits(&val, pullup, LPI_GPIO_PULL_MASK); @@ -264,6 +268,7 @@ static int lpi_config_set(struct pinctrl_dev *pctldev, unsigned int group, u32p_replace_bits(&val, output_enabled, LPI_GPIO_OE_MASK); lpi_gpio_write(pctrl, group, LPI_GPIO_CFG_REG, val); + mutex_unlock(&pctrl->lock); return 0; } @@ -461,7 +466,7 @@ int lpi_pinctrl_probe(struct platform_device *pdev) pctrl->chip.label = dev_name(dev); pctrl->chip.can_sleep = false; - mutex_init(&pctrl->slew_access_lock); + mutex_init(&pctrl->lock); pctrl->ctrl = devm_pinctrl_register(dev, &pctrl->desc, pctrl); if (IS_ERR(pctrl->ctrl)) { @@ -483,7 +488,7 @@ int lpi_pinctrl_probe(struct platform_device *pdev) return 0; err_pinctrl: - mutex_destroy(&pctrl->slew_access_lock); + mutex_destroy(&pctrl->lock); clk_bulk_disable_unprepare(MAX_LPI_NUM_CLKS, pctrl->clks); return ret; @@ -495,7 +500,7 @@ int lpi_pinctrl_remove(struct platform_device *pdev) struct lpi_pinctrl *pctrl = platform_get_drvdata(pdev); int i; - mutex_destroy(&pctrl->slew_access_lock); + mutex_destroy(&pctrl->lock); clk_bulk_disable_unprepare(MAX_LPI_NUM_CLKS, pctrl->clks); for (i = 0; i < pctrl->data->npins; i++) -- cgit v1.2.3-70-g09d2 From 62140a1e4dec4594d5d1e1d353747bf2ef434e8b Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Tue, 17 Oct 2023 17:18:06 +0300 Subject: Revert "pinctrl: avoid unsafe code pattern in find_pinctrl()" The commit breaks MMC enumeration on the Intel Merrifield plaform. Before: [ 36.439057] mmc0: SDHCI controller on PCI [0000:00:01.0] using ADMA [ 36.450924] mmc2: SDHCI controller on PCI [0000:00:01.3] using ADMA [ 36.459355] mmc1: SDHCI controller on PCI [0000:00:01.2] using ADMA [ 36.706399] mmc0: new DDR MMC card at address 0001 [ 37.058972] mmc2: new ultra high speed DDR50 SDIO card at address 0001 [ 37.278977] mmcblk0: mmc0:0001 H4G1d 3.64 GiB [ 37.297300] mmcblk0: p1 p2 p3 p4 p5 p6 p7 p8 p9 p10 After: [ 36.436704] mmc2: SDHCI controller on PCI [0000:00:01.3] using ADMA [ 36.436720] mmc1: SDHCI controller on PCI [0000:00:01.0] using ADMA [ 36.463685] mmc0: SDHCI controller on PCI [0000:00:01.2] using ADMA [ 36.720627] mmc1: new DDR MMC card at address 0001 [ 37.068181] mmc2: new ultra high speed DDR50 SDIO card at address 0001 [ 37.279998] mmcblk1: mmc1:0001 H4G1d 3.64 GiB [ 37.302670] mmcblk1: p1 p2 p3 p4 p5 p6 p7 p8 p9 p10 This reverts commit c153a4edff6ab01370fcac8e46f9c89cca1060c2. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20231017141806.535191-1-andriy.shevchenko@linux.intel.com Signed-off-by: Linus Walleij --- drivers/pinctrl/core.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) (limited to 'drivers') diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c index e2f7519bef04..e9dc9638120a 100644 --- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -1022,20 +1022,17 @@ static int add_setting(struct pinctrl *p, struct pinctrl_dev *pctldev, static struct pinctrl *find_pinctrl(struct device *dev) { - struct pinctrl *entry, *p = NULL; + struct pinctrl *p; mutex_lock(&pinctrl_list_mutex); - - list_for_each_entry(entry, &pinctrl_list, node) { - if (entry->dev == dev) { - p = entry; - kref_get(&p->users); - break; + list_for_each_entry(p, &pinctrl_list, node) + if (p->dev == dev) { + mutex_unlock(&pinctrl_list_mutex); + return p; } - } mutex_unlock(&pinctrl_list_mutex); - return p; + return NULL; } static void pinctrl_free(struct pinctrl *p, bool inlist); @@ -1143,6 +1140,7 @@ struct pinctrl *pinctrl_get(struct device *dev) p = find_pinctrl(dev); if (p) { dev_dbg(dev, "obtain a copy of previously claimed pinctrl\n"); + kref_get(&p->users); return p; } -- cgit v1.2.3-70-g09d2