From 109fdf1572be86aaf681e69b30dc5ada90ce6f35 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Mon, 17 Aug 2015 16:13:30 +0300 Subject: [PATCH] pinctrl: cherryview: Use raw_spinlock for locking When running -rt kernel and an interrupt happens on a GPIO line controlled by Intel Cherryview/Braswell pinctrl driver we get: BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:917 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/0 Preemption disabled at:[] cpu_startup_entry+0x17f/0x480 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.1.5-rt5 #16 ... Call Trace: [] dump_stack+0x4a/0x61 [] ___might_sleep+0xe7/0x170 [] rt_spin_lock+0x1f/0x50 [] chv_gpio_irq_ack+0x3d/0xa0 [] handle_edge_irq+0x75/0x180 [] generic_handle_irq+0x27/0x40 [] chv_gpio_irq_handler+0x7e/0x110 [] handle_irq+0xaa/0x190 ... This is because desc->lock is raw_spinlock and is held when chv_gpio_irq_ack() is called by the genirq core. chv_gpio_irq_ack() in turn takes pctrl->lock which in -rt is an rt-mutex causing might_sleep() rightfully to complain about sleeping function called from invalid context. In order to keep -rt happy but at the same time make sure that register accesses get serialized, convert the driver to use raw_spinlock instead. Suggested-by: Linus Walleij Signed-off-by: Mika Westerberg Signed-off-by: Linus Walleij --- drivers/pinctrl/intel/pinctrl-cherryview.c | 70 +++++++++++----------- 1 file changed, 35 insertions(+), 35 deletions(-) diff --git a/drivers/pinctrl/intel/pinctrl-cherryview.c b/drivers/pinctrl/intel/pinctrl-cherryview.c index 2984b460bbc5..2d5d3ddc36e5 100644 --- a/drivers/pinctrl/intel/pinctrl-cherryview.c +++ b/drivers/pinctrl/intel/pinctrl-cherryview.c @@ -174,7 +174,7 @@ struct chv_pinctrl { struct pinctrl_dev *pctldev; struct gpio_chip chip; void __iomem *regs; - spinlock_t lock; + raw_spinlock_t lock; unsigned intr_lines[16]; const struct chv_community *community; u32 saved_intmask; @@ -720,13 +720,13 @@ static void chv_pin_dbg_show(struct pinctrl_dev *pctldev, struct seq_file *s, u32 ctrl0, ctrl1; bool locked; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); ctrl0 = readl(chv_padreg(pctrl, offset, CHV_PADCTRL0)); ctrl1 = readl(chv_padreg(pctrl, offset, CHV_PADCTRL1)); locked = chv_pad_locked(pctrl, offset); - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); if (ctrl0 & CHV_PADCTRL0_GPIOEN) { seq_puts(s, "GPIO "); @@ -789,14 +789,14 @@ static int chv_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned function, grp = &pctrl->community->groups[group]; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); /* Check first that the pad is not locked */ for (i = 0; i < grp->npins; i++) { if (chv_pad_locked(pctrl, grp->pins[i])) { dev_warn(pctrl->dev, "unable to set mode for locked pin %u\n", grp->pins[i]); - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); return -EBUSY; } } @@ -839,7 +839,7 @@ static int chv_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned function, pin, altfunc->mode, altfunc->invert_oe ? "" : "not "); } - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); return 0; } @@ -853,13 +853,13 @@ static int chv_gpio_request_enable(struct pinctrl_dev *pctldev, void __iomem *reg; u32 value; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); if (chv_pad_locked(pctrl, offset)) { value = readl(chv_padreg(pctrl, offset, CHV_PADCTRL0)); if (!(value & CHV_PADCTRL0_GPIOEN)) { /* Locked so cannot enable */ - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); return -EBUSY; } } else { @@ -899,7 +899,7 @@ static int chv_gpio_request_enable(struct pinctrl_dev *pctldev, chv_writel(value, reg); } - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); return 0; } @@ -913,13 +913,13 @@ static void chv_gpio_disable_free(struct pinctrl_dev *pctldev, void __iomem *reg; u32 value; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); reg = chv_padreg(pctrl, offset, CHV_PADCTRL0); value = readl(reg) & ~CHV_PADCTRL0_GPIOEN; chv_writel(value, reg); - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); } static int chv_gpio_set_direction(struct pinctrl_dev *pctldev, @@ -931,7 +931,7 @@ static int chv_gpio_set_direction(struct pinctrl_dev *pctldev, unsigned long flags; u32 ctrl0; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); ctrl0 = readl(reg) & ~CHV_PADCTRL0_GPIOCFG_MASK; if (input) @@ -940,7 +940,7 @@ static int chv_gpio_set_direction(struct pinctrl_dev *pctldev, ctrl0 |= CHV_PADCTRL0_GPIOCFG_GPO << CHV_PADCTRL0_GPIOCFG_SHIFT; chv_writel(ctrl0, reg); - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); return 0; } @@ -965,10 +965,10 @@ static int chv_config_get(struct pinctrl_dev *pctldev, unsigned pin, u16 arg = 0; u32 term; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); ctrl0 = readl(chv_padreg(pctrl, pin, CHV_PADCTRL0)); ctrl1 = readl(chv_padreg(pctrl, pin, CHV_PADCTRL1)); - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); term = (ctrl0 & CHV_PADCTRL0_TERM_MASK) >> CHV_PADCTRL0_TERM_SHIFT; @@ -1042,7 +1042,7 @@ static int chv_config_set_pull(struct chv_pinctrl *pctrl, unsigned pin, unsigned long flags; u32 ctrl0, pull; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); ctrl0 = readl(reg); switch (param) { @@ -1065,7 +1065,7 @@ static int chv_config_set_pull(struct chv_pinctrl *pctrl, unsigned pin, pull = CHV_PADCTRL0_TERM_20K << CHV_PADCTRL0_TERM_SHIFT; break; default: - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); return -EINVAL; } @@ -1083,7 +1083,7 @@ static int chv_config_set_pull(struct chv_pinctrl *pctrl, unsigned pin, pull = CHV_PADCTRL0_TERM_20K << CHV_PADCTRL0_TERM_SHIFT; break; default: - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); return -EINVAL; } @@ -1091,12 +1091,12 @@ static int chv_config_set_pull(struct chv_pinctrl *pctrl, unsigned pin, break; default: - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); return -EINVAL; } chv_writel(ctrl0, reg); - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); return 0; } @@ -1172,9 +1172,9 @@ static int chv_gpio_get(struct gpio_chip *chip, unsigned offset) unsigned long flags; u32 ctrl0, cfg; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); ctrl0 = readl(chv_padreg(pctrl, pin, CHV_PADCTRL0)); - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); cfg = ctrl0 & CHV_PADCTRL0_GPIOCFG_MASK; cfg >>= CHV_PADCTRL0_GPIOCFG_SHIFT; @@ -1192,7 +1192,7 @@ static void chv_gpio_set(struct gpio_chip *chip, unsigned offset, int value) void __iomem *reg; u32 ctrl0; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); reg = chv_padreg(pctrl, pin, CHV_PADCTRL0); ctrl0 = readl(reg); @@ -1204,7 +1204,7 @@ static void chv_gpio_set(struct gpio_chip *chip, unsigned offset, int value) chv_writel(ctrl0, reg); - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); } static int chv_gpio_get_direction(struct gpio_chip *chip, unsigned offset) @@ -1214,9 +1214,9 @@ static int chv_gpio_get_direction(struct gpio_chip *chip, unsigned offset) u32 ctrl0, direction; unsigned long flags; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); ctrl0 = readl(chv_padreg(pctrl, pin, CHV_PADCTRL0)); - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); direction = ctrl0 & CHV_PADCTRL0_GPIOCFG_MASK; direction >>= CHV_PADCTRL0_GPIOCFG_SHIFT; @@ -1254,14 +1254,14 @@ static void chv_gpio_irq_ack(struct irq_data *d) int pin = chv_gpio_offset_to_pin(pctrl, irqd_to_hwirq(d)); u32 intr_line; - spin_lock(&pctrl->lock); + raw_spin_lock(&pctrl->lock); intr_line = readl(chv_padreg(pctrl, pin, CHV_PADCTRL0)); intr_line &= CHV_PADCTRL0_INTSEL_MASK; intr_line >>= CHV_PADCTRL0_INTSEL_SHIFT; chv_writel(BIT(intr_line), pctrl->regs + CHV_INTSTAT); - spin_unlock(&pctrl->lock); + raw_spin_unlock(&pctrl->lock); } static void chv_gpio_irq_mask_unmask(struct irq_data *d, bool mask) @@ -1272,7 +1272,7 @@ static void chv_gpio_irq_mask_unmask(struct irq_data *d, bool mask) u32 value, intr_line; unsigned long flags; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); intr_line = readl(chv_padreg(pctrl, pin, CHV_PADCTRL0)); intr_line &= CHV_PADCTRL0_INTSEL_MASK; @@ -1285,7 +1285,7 @@ static void chv_gpio_irq_mask_unmask(struct irq_data *d, bool mask) value |= BIT(intr_line); chv_writel(value, pctrl->regs + CHV_INTMASK); - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); } static void chv_gpio_irq_mask(struct irq_data *d) @@ -1319,7 +1319,7 @@ static unsigned chv_gpio_irq_startup(struct irq_data *d) unsigned long flags; u32 intsel, value; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); intsel = readl(chv_padreg(pctrl, pin, CHV_PADCTRL0)); intsel &= CHV_PADCTRL0_INTSEL_MASK; intsel >>= CHV_PADCTRL0_INTSEL_SHIFT; @@ -1334,7 +1334,7 @@ static unsigned chv_gpio_irq_startup(struct irq_data *d) irq_set_handler_locked(d, handler); pctrl->intr_lines[intsel] = offset; } - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); } chv_gpio_irq_unmask(d); @@ -1350,7 +1350,7 @@ static int chv_gpio_irq_type(struct irq_data *d, unsigned type) unsigned long flags; u32 value; - spin_lock_irqsave(&pctrl->lock, flags); + raw_spin_lock_irqsave(&pctrl->lock, flags); /* * Pins which can be used as shared interrupt are configured in @@ -1399,7 +1399,7 @@ static int chv_gpio_irq_type(struct irq_data *d, unsigned type) else if (type & IRQ_TYPE_LEVEL_MASK) irq_set_handler_locked(d, handle_level_irq); - spin_unlock_irqrestore(&pctrl->lock, flags); + raw_spin_unlock_irqrestore(&pctrl->lock, flags); return 0; } @@ -1511,7 +1511,7 @@ static int chv_pinctrl_probe(struct platform_device *pdev) if (i == ARRAY_SIZE(chv_communities)) return -ENODEV; - spin_lock_init(&pctrl->lock); + raw_spin_lock_init(&pctrl->lock); pctrl->dev = &pdev->dev; #ifdef CONFIG_PM_SLEEP