From c075f8efc5513551233dabce366eed01e32b62a4 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 1 Jun 2017 13:12:18 +0800 Subject: [PATCH] pinctrl/amd: Use regular interrupt instead of chained MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit BugLink: https://bugs.launchpad.net/bugs/1671360 The AMD pinctrl driver uses a chained interrupt to demultiplex the GPIO interrupts. Kevin Vandeventer reported, that his new AMD Ryzen locks up hard on boot when the AMD pinctrl driver is initialized. The reason is an interrupt storm. It's not clear whether that's caused by hardware or firmware or both. Using chained interrupts on X86 is a dangerous endavour. If a system is misconfigured or the hardware buggy there is no safety net to catch an interrupt storm. Convert the driver to use a regular interrupt for the demultiplex handler. This allows the interrupt storm detector to catch the malfunction and lets the system boot up. This should be backported to stable because it's likely that more users run into this problem as the AMD Ryzen machines are spreading. Reported-by: Kevin Vandeventer Link: https://bugzilla.suse.com/show_bug.cgi?id=1034261 Signed-off-by: Thomas Gleixner Signed-off-by: Linus Walleij (backported from commit babdc22b0ccf4ef5a3075ce6e4afc26b7a279faf linux-next) Signed-off-by: Kai-Heng Feng Acked-by: Stefan Bader Acked-by: Seth Forshee Signed-off-by: Kleber Sacilotto de Souza Signed-off-by: Fabian Grünbichler --- drivers/pinctrl/pinctrl-amd.c | 90 +++++++++++++++++++------------------------ 1 file changed, 40 insertions(+), 50 deletions(-) diff --git a/drivers/pinctrl/pinctrl-amd.c b/drivers/pinctrl/pinctrl-amd.c index cfcf9db02c7d..07a88b83e02b 100644 --- a/drivers/pinctrl/pinctrl-amd.c +++ b/drivers/pinctrl/pinctrl-amd.c @@ -478,64 +478,54 @@ static struct irq_chip amd_gpio_irqchip = { .irq_set_type = amd_gpio_irq_set_type, }; -static void amd_gpio_irq_handler(struct irq_desc *desc) +#define PIN_IRQ_PENDING (BIT(INTERRUPT_STS_OFF) | BIT(WAKE_STS_OFF)) + +static irqreturn_t amd_gpio_irq_handler(int irq, void *dev_id) { - u32 i; - u32 off; - u32 reg; - u32 pin_reg; - u64 reg64; - int handled = 0; - unsigned int irq; + struct amd_gpio *gpio_dev = dev_id; + struct gpio_chip *gc = &gpio_dev->gc; + irqreturn_t ret = IRQ_NONE; + unsigned int i, irqnr; unsigned long flags; - struct irq_chip *chip = irq_desc_get_chip(desc); - struct gpio_chip *gc = irq_desc_get_handler_data(desc); - struct amd_gpio *gpio_dev = gpiochip_get_data(gc); + u32 *regs, regval; + u64 status, mask; - chained_irq_enter(chip, desc); - /*enable GPIO interrupt again*/ + /* Read the wake status */ raw_spin_lock_irqsave(&gpio_dev->lock, flags); - reg = readl(gpio_dev->base + WAKE_INT_STATUS_REG1); - reg64 = reg; - reg64 = reg64 << 32; - - reg = readl(gpio_dev->base + WAKE_INT_STATUS_REG0); - reg64 |= reg; + status = readl(gpio_dev->base + WAKE_INT_STATUS_REG1); + status <<= 32; + status |= readl(gpio_dev->base + WAKE_INT_STATUS_REG0); raw_spin_unlock_irqrestore(&gpio_dev->lock, flags); - /* - * first 46 bits indicates interrupt status. - * one bit represents four interrupt sources. - */ - for (off = 0; off < 46 ; off++) { - if (reg64 & BIT(off)) { - for (i = 0; i < 4; i++) { - pin_reg = readl(gpio_dev->base + - (off * 4 + i) * 4); - if ((pin_reg & BIT(INTERRUPT_STS_OFF)) || - (pin_reg & BIT(WAKE_STS_OFF))) { - irq = irq_find_mapping(gc->irqdomain, - off * 4 + i); - generic_handle_irq(irq); - writel(pin_reg, - gpio_dev->base - + (off * 4 + i) * 4); - handled++; - } - } + /* Bit 0-45 contain the relevant status bits */ + status &= (1ULL << 46) - 1; + regs = gpio_dev->base; + for (mask = 1, irqnr = 0; status; mask <<= 1, regs += 4, irqnr += 4) { + if (!(status & mask)) + continue; + status &= ~mask; + + /* Each status bit covers four pins */ + for (i = 0; i < 4; i++) { + regval = readl(regs + i); + if (!(regval & PIN_IRQ_PENDING)) + continue; + irq = irq_find_mapping(gc->irqdomain, irqnr + i); + generic_handle_irq(irq); + /* Clear interrupt */ + writel(regval, regs + i); + ret = IRQ_HANDLED; } } - if (handled == 0) - handle_bad_irq(desc); - + /* Signal EOI to the GPIO unit */ raw_spin_lock_irqsave(&gpio_dev->lock, flags); - reg = readl(gpio_dev->base + WAKE_INT_MASTER_REG); - reg |= EOI_MASK; - writel(reg, gpio_dev->base + WAKE_INT_MASTER_REG); + regval = readl(gpio_dev->base + WAKE_INT_MASTER_REG); + regval |= EOI_MASK; + writel(regval, gpio_dev->base + WAKE_INT_MASTER_REG); raw_spin_unlock_irqrestore(&gpio_dev->lock, flags); - chained_irq_exit(chip, desc); + return ret; } static int amd_get_groups_count(struct pinctrl_dev *pctldev) @@ -803,10 +793,10 @@ static int amd_gpio_probe(struct platform_device *pdev) goto out2; } - gpiochip_set_chained_irqchip(&gpio_dev->gc, - &amd_gpio_irqchip, - irq_base, - amd_gpio_irq_handler); + ret = devm_request_irq(&pdev->dev, irq_base, amd_gpio_irq_handler, 0, + KBUILD_MODNAME, gpio_dev); + if (ret) + goto out2; platform_set_drvdata(pdev, gpio_dev); -- 2.11.0