diff mbox series

[v4,1/2] gpio: mxc: Protect GPIO irqchip RMW with bgpio spinlock

Message ID 20220724224943.294057-1-marex@denx.de
State Superseded
Headers show
Series [v4,1/2] gpio: mxc: Protect GPIO irqchip RMW with bgpio spinlock | expand

Commit Message

Marek Vasut July 24, 2022, 10:49 p.m. UTC 
The driver currently performs register read-modify-write without locking
in its irqchip part, this could lead to a race condition when configuring
interrupt mode setting. Add the missing bgpio spinlock lock/unlock around
the register read-modify-write.

Fixes: 07bd1a6cc7cbb ("MXC arch: Add gpio support for the whole platform")
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Loic Poulain <loic.poulain@linaro.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Shawn Guo <shawnguo@kernel.org>
---
V3: New patch
V4: Include linux/spinlock.h
---
 drivers/gpio/gpio-mxc.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

Comments

kernel test robot July 28, 2022, 10:21 p.m. UTC | #1 
Hi Marek,

I love your patch! Yet something to improve:

[auto build test ERROR on brgl/gpio/for-next]
[also build test ERROR on linus/master v5.19-rc8 next-20220728]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Marek-Vasut/gpio-mxc-Protect-GPIO-irqchip-RMW-with-bgpio-spinlock/20220725-065121
base:   https://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux.git gpio/for-next
config: mips-randconfig-r006-20220728 (https://download.01.org/0day-ci/archive/20220729/202207290626.5eWctWgO-lkp@intel.com/config)
compiler: mipsel-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/670bfed8938f593e99c7784ff2efe48bc5b9e21d
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Marek-Vasut/gpio-mxc-Protect-GPIO-irqchip-RMW-with-bgpio-spinlock/20220725-065121
        git checkout 670bfed8938f593e99c7784ff2efe48bc5b9e21d
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=mips SHELL=/bin/bash drivers/gpio/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from include/linux/rwsem.h:15,
                    from include/linux/notifier.h:15,
                    from include/linux/clk.h:14,
                    from drivers/gpio/gpio-mxc.c:10:
   drivers/gpio/gpio-mxc.c: In function 'gpio_set_irq_type':
>> drivers/gpio/gpio-mxc.c:190:27: error: passing argument 1 of 'spinlock_check' from incompatible pointer type [-Werror=incompatible-pointer-types]
     190 |         spin_lock_irqsave(&port->gc.bgpio_lock, flags);
         |                           ^~~~~~~~~~~~~~~~~~~~
         |                           |
         |                           raw_spinlock_t * {aka struct raw_spinlock *}
   include/linux/spinlock.h:242:48: note: in definition of macro 'raw_spin_lock_irqsave'
     242 |                 flags = _raw_spin_lock_irqsave(lock);   \
         |                                                ^~~~
   drivers/gpio/gpio-mxc.c:190:9: note: in expansion of macro 'spin_lock_irqsave'
     190 |         spin_lock_irqsave(&port->gc.bgpio_lock, flags);
         |         ^~~~~~~~~~~~~~~~~
   include/linux/spinlock.h:322:67: note: expected 'spinlock_t *' {aka 'struct spinlock *'} but argument is of type 'raw_spinlock_t *' {aka 'struct raw_spinlock *'}
     322 | static __always_inline raw_spinlock_t *spinlock_check(spinlock_t *lock)
         |                                                       ~~~~~~~~~~~~^~~~
>> drivers/gpio/gpio-mxc.c:211:32: error: passing argument 1 of 'spin_unlock_irqrestore' from incompatible pointer type [-Werror=incompatible-pointer-types]
     211 |         spin_unlock_irqrestore(&port->gc.bgpio_lock, flags);
         |                                ^~~~~~~~~~~~~~~~~~~~
         |                                |
         |                                raw_spinlock_t * {aka struct raw_spinlock *}
   include/linux/spinlock.h:402:64: note: expected 'spinlock_t *' {aka 'struct spinlock *'} but argument is of type 'raw_spinlock_t *' {aka 'struct raw_spinlock *'}
     402 | static __always_inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
         |                                                    ~~~~~~~~~~~~^~~~
   drivers/gpio/gpio-mxc.c: In function 'mxc_flip_edge':
   drivers/gpio/gpio-mxc.c:223:27: error: passing argument 1 of 'spinlock_check' from incompatible pointer type [-Werror=incompatible-pointer-types]
     223 |         spin_lock_irqsave(&port->gc.bgpio_lock, flags);
         |                           ^~~~~~~~~~~~~~~~~~~~
         |                           |
         |                           raw_spinlock_t * {aka struct raw_spinlock *}
   include/linux/spinlock.h:242:48: note: in definition of macro 'raw_spin_lock_irqsave'
     242 |                 flags = _raw_spin_lock_irqsave(lock);   \
         |                                                ^~~~
   drivers/gpio/gpio-mxc.c:223:9: note: in expansion of macro 'spin_lock_irqsave'
     223 |         spin_lock_irqsave(&port->gc.bgpio_lock, flags);
         |         ^~~~~~~~~~~~~~~~~
   include/linux/spinlock.h:322:67: note: expected 'spinlock_t *' {aka 'struct spinlock *'} but argument is of type 'raw_spinlock_t *' {aka 'struct raw_spinlock *'}
     322 | static __always_inline raw_spinlock_t *spinlock_check(spinlock_t *lock)
         |                                                       ~~~~~~~~~~~~^~~~
   drivers/gpio/gpio-mxc.c:243:32: error: passing argument 1 of 'spin_unlock_irqrestore' from incompatible pointer type [-Werror=incompatible-pointer-types]
     243 |         spin_unlock_irqrestore(&port->gc.bgpio_lock, flags);
         |                                ^~~~~~~~~~~~~~~~~~~~
         |                                |
         |                                raw_spinlock_t * {aka struct raw_spinlock *}
   include/linux/spinlock.h:402:64: note: expected 'spinlock_t *' {aka 'struct spinlock *'} but argument is of type 'raw_spinlock_t *' {aka 'struct raw_spinlock *'}
     402 | static __always_inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
         |                                                    ~~~~~~~~~~~~^~~~
   cc1: some warnings being treated as errors


vim +/spinlock_check +190 drivers/gpio/gpio-mxc.c

   146	
   147	static int gpio_set_irq_type(struct irq_data *d, u32 type)
   148	{
   149		struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
   150		struct mxc_gpio_port *port = gc->private;
   151		unsigned long flags;
   152		u32 bit, val;
   153		u32 gpio_idx = d->hwirq;
   154		int edge;
   155		void __iomem *reg = port->base;
   156	
   157		port->both_edges &= ~(1 << gpio_idx);
   158		switch (type) {
   159		case IRQ_TYPE_EDGE_RISING:
   160			edge = GPIO_INT_RISE_EDGE;
   161			break;
   162		case IRQ_TYPE_EDGE_FALLING:
   163			edge = GPIO_INT_FALL_EDGE;
   164			break;
   165		case IRQ_TYPE_EDGE_BOTH:
   166			if (GPIO_EDGE_SEL >= 0) {
   167				edge = GPIO_INT_BOTH_EDGES;
   168			} else {
   169				val = port->gc.get(&port->gc, gpio_idx);
   170				if (val) {
   171					edge = GPIO_INT_LOW_LEV;
   172					pr_debug("mxc: set GPIO %d to low trigger\n", gpio_idx);
   173				} else {
   174					edge = GPIO_INT_HIGH_LEV;
   175					pr_debug("mxc: set GPIO %d to high trigger\n", gpio_idx);
   176				}
   177				port->both_edges |= 1 << gpio_idx;
   178			}
   179			break;
   180		case IRQ_TYPE_LEVEL_LOW:
   181			edge = GPIO_INT_LOW_LEV;
   182			break;
   183		case IRQ_TYPE_LEVEL_HIGH:
   184			edge = GPIO_INT_HIGH_LEV;
   185			break;
   186		default:
   187			return -EINVAL;
   188		}
   189	
 > 190		spin_lock_irqsave(&port->gc.bgpio_lock, flags);
   191	
   192		if (GPIO_EDGE_SEL >= 0) {
   193			val = readl(port->base + GPIO_EDGE_SEL);
   194			if (edge == GPIO_INT_BOTH_EDGES)
   195				writel(val | (1 << gpio_idx),
   196					port->base + GPIO_EDGE_SEL);
   197			else
   198				writel(val & ~(1 << gpio_idx),
   199					port->base + GPIO_EDGE_SEL);
   200		}
   201	
   202		if (edge != GPIO_INT_BOTH_EDGES) {
   203			reg += GPIO_ICR1 + ((gpio_idx & 0x10) >> 2); /* lower or upper register */
   204			bit = gpio_idx & 0xf;
   205			val = readl(reg) & ~(0x3 << (bit << 1));
   206			writel(val | (edge << (bit << 1)), reg);
   207		}
   208	
   209		writel(1 << gpio_idx, port->base + GPIO_ISR);
   210	
 > 211		spin_unlock_irqrestore(&port->gc.bgpio_lock, flags);
   212	
   213		return 0;
   214	}
   215
diff mbox series

Patch

diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c
index c871602fc5ba9..75e7aceecac0a 100644
--- a/drivers/gpio/gpio-mxc.c
+++ b/drivers/gpio/gpio-mxc.c
@@ -18,6 +18,7 @@ 
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
+#include <linux/spinlock.h>
 #include <linux/syscore_ops.h>
 #include <linux/gpio/driver.h>
 #include <linux/of.h>
@@ -147,6 +148,7 @@  static int gpio_set_irq_type(struct irq_data *d, u32 type)
 {
 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
 	struct mxc_gpio_port *port = gc->private;
+	unsigned long flags;
 	u32 bit, val;
 	u32 gpio_idx = d->hwirq;
 	int edge;
@@ -185,6 +187,8 @@  static int gpio_set_irq_type(struct irq_data *d, u32 type)
 		return -EINVAL;
 	}
 
+	spin_lock_irqsave(&port->gc.bgpio_lock, flags);
+
 	if (GPIO_EDGE_SEL >= 0) {
 		val = readl(port->base + GPIO_EDGE_SEL);
 		if (edge == GPIO_INT_BOTH_EDGES)
@@ -204,15 +208,20 @@  static int gpio_set_irq_type(struct irq_data *d, u32 type)
 
 	writel(1 << gpio_idx, port->base + GPIO_ISR);
 
+	spin_unlock_irqrestore(&port->gc.bgpio_lock, flags);
+
 	return 0;
 }
 
 static void mxc_flip_edge(struct mxc_gpio_port *port, u32 gpio)
 {
 	void __iomem *reg = port->base;
+	unsigned long flags;
 	u32 bit, val;
 	int edge;
 
+	spin_lock_irqsave(&port->gc.bgpio_lock, flags);
+
 	reg += GPIO_ICR1 + ((gpio & 0x10) >> 2); /* lower or upper register */
 	bit = gpio & 0xf;
 	val = readl(reg);
@@ -230,6 +239,8 @@  static void mxc_flip_edge(struct mxc_gpio_port *port, u32 gpio)
 		return;
 	}
 	writel(val | (edge << (bit << 1)), reg);
+
+	spin_unlock_irqrestore(&port->gc.bgpio_lock, flags);
 }
 
 /* handle 32 interrupts in one status register */