diff mbox series

[v2,1/5] irqchip/irq-bcm7038-l1: Add PM support

Message ID 20190913191542.9908-2-f.fainelli@gmail.com (mailing list archive)
State Not Applicable
Headers show
Series irqchip/irq-bcm7038-l1 updates | expand

Commit Message

Florian Fainelli Sept. 13, 2019, 7:15 p.m. UTC
From: Justin Chen <justinpopo6@gmail.com>

The current l1 controller does not mask any interrupts when dropping
into suspend. This mean we can receive unexpected wake up sources.
Modified MIPS l1 controller to mask the all non-wake interrupts before
dropping into suspend.

Signed-off-by: Justin Chen <justinpopo6@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/irqchip/irq-bcm7038-l1.c | 98 ++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)

Comments

Marc Zyngier Sept. 22, 2019, 12:31 p.m. UTC | #1
On Fri, 13 Sep 2019 12:15:38 -0700
Florian Fainelli <f.fainelli@gmail.com> wrote:

> From: Justin Chen <justinpopo6@gmail.com>
> 
> The current l1 controller does not mask any interrupts when dropping
> into suspend. This mean we can receive unexpected wake up sources.
> Modified MIPS l1 controller to mask the all non-wake interrupts before
> dropping into suspend.
> 
> Signed-off-by: Justin Chen <justinpopo6@gmail.com>
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> ---
>  drivers/irqchip/irq-bcm7038-l1.c | 98 ++++++++++++++++++++++++++++++++
>  1 file changed, 98 insertions(+)
> 
> diff --git a/drivers/irqchip/irq-bcm7038-l1.c b/drivers/irqchip/irq-bcm7038-l1.c
> index fc75c61233aa..f5e4ff5251ab 100644
> --- a/drivers/irqchip/irq-bcm7038-l1.c
> +++ b/drivers/irqchip/irq-bcm7038-l1.c
> @@ -27,6 +27,7 @@
>  #include <linux/types.h>
>  #include <linux/irqchip.h>
>  #include <linux/irqchip/chained_irq.h>
> +#include <linux/syscore_ops.h>
>  
>  #define IRQS_PER_WORD		32
>  #define REG_BYTES_PER_IRQ_WORD	(sizeof(u32) * 4)
> @@ -39,6 +40,10 @@ struct bcm7038_l1_chip {
>  	unsigned int		n_words;
>  	struct irq_domain	*domain;
>  	struct bcm7038_l1_cpu	*cpus[NR_CPUS];
> +#ifdef CONFIG_PM_SLEEP
> +	struct list_head	list;
> +	u32			wake_mask[MAX_WORDS];
> +#endif
>  	u8			affinity[MAX_WORDS * IRQS_PER_WORD];
>  };
>  
> @@ -47,6 +52,17 @@ struct bcm7038_l1_cpu {
>  	u32			mask_cache[0];
>  };
>  
> +/*
> + * We keep a list of bcm7038_l1_chip used for suspend/resume. This hack is
> + * used because the struct chip_type suspend/resume hooks are not called
> + * unless chip_type is hooked onto a generic_chip. Since this driver does
> + * not use generic_chip, we need to manually hook our resume/suspend to
> + * syscore_ops.
> + */
> +#ifdef CONFIG_PM_SLEEP
> +static LIST_HEAD(bcm7038_l1_intcs_list);
> +#endif

nit: this could be moved down to be close to the rest of the PM_SLEEP
ifdefery.

> +
>  /*
>   * STATUS/MASK_STATUS/MASK_SET/MASK_CLEAR are packed one right after another:
>   *
> @@ -287,6 +303,77 @@ static int __init bcm7038_l1_init_one(struct device_node *dn,
>  	return 0;
>  }
>  
> +#ifdef CONFIG_PM_SLEEP
> +static int bcm7038_l1_suspend(void)
> +{
> +	struct bcm7038_l1_chip *intc;
> +	unsigned long flags;
> +	int boot_cpu, word;
> +
> +	/* Wakeup interrupt should only come from the boot cpu */
> +	boot_cpu = cpu_logical_map(smp_processor_id());

What guarantees that you're actually running on the boot CPU at this
point? If that's actually the case, why isn't cpu_logical_map(0) enough?

> +
> +	list_for_each_entry(intc, &bcm7038_l1_intcs_list, list) {
> +		raw_spin_lock_irqsave(&intc->lock, flags);

And if this can only run on a single CPU, what's the purpose of this
lock?

> +		for (word = 0; word < intc->n_words; word++) {
> +			l1_writel(~intc->wake_mask[word],
> +				intc->cpus[boot_cpu]->map_base +
> +				reg_mask_set(intc, word));
> +			l1_writel(intc->wake_mask[word],
> +				intc->cpus[boot_cpu]->map_base +
> +				reg_mask_clr(intc, word));

nit: Please don't split the write address across two lines, it makes it
harder to read.

> +		}
> +		raw_spin_unlock_irqrestore(&intc->lock, flags);
> +	}
> +
> +	return 0;
> +}
> +
> +static void bcm7038_l1_resume(void)
> +{
> +	struct bcm7038_l1_chip *intc;
> +	unsigned long flags;
> +	int boot_cpu, word;
> +
> +	boot_cpu = cpu_logical_map(smp_processor_id());
> +
> +	list_for_each_entry(intc, &bcm7038_l1_intcs_list, list) {
> +		raw_spin_lock_irqsave(&intc->lock, flags);
> +		for (word = 0; word < intc->n_words; word++) {
> +			l1_writel(intc->cpus[boot_cpu]->mask_cache[word],
> +				intc->cpus[boot_cpu]->map_base +
> +				reg_mask_set(intc, word));
> +			l1_writel(~intc->cpus[boot_cpu]->mask_cache[word],
> +				intc->cpus[boot_cpu]->map_base +
> +				reg_mask_clr(intc, word));
> +		}
> +		raw_spin_unlock_irqrestore(&intc->lock, flags);
> +	}
> +}
> +
> +static struct syscore_ops bcm7038_l1_syscore_ops = {
> +	.suspend	= bcm7038_l1_suspend,
> +	.resume		= bcm7038_l1_resume,
> +};
> +
> +static int bcm7038_l1_set_wake(struct irq_data *d, unsigned int on)
> +{
> +	struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
> +	unsigned long flags;
> +	u32 word = d->hwirq / IRQS_PER_WORD;
> +	u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
> +
> +	raw_spin_lock_irqsave(&intc->lock, flags);
> +	if (on)
> +		intc->wake_mask[word] |= mask;
> +	else
> +		intc->wake_mask[word] &= ~mask;
> +	raw_spin_unlock_irqrestore(&intc->lock, flags);
> +
> +	return 0;
> +}
> +#endif
> +
>  static struct irq_chip bcm7038_l1_irq_chip = {
>  	.name			= "bcm7038-l1",
>  	.irq_mask		= bcm7038_l1_mask,
> @@ -295,6 +382,9 @@ static struct irq_chip bcm7038_l1_irq_chip = {
>  #ifdef CONFIG_SMP
>  	.irq_cpu_offline	= bcm7038_l1_cpu_offline,
>  #endif
> +#ifdef CONFIG_PM_SLEEP
> +	.irq_set_wake		= bcm7038_l1_set_wake,
> +#endif
>  };
>  
>  static int bcm7038_l1_map(struct irq_domain *d, unsigned int virq,
> @@ -340,6 +430,14 @@ int __init bcm7038_l1_of_init(struct device_node *dn,
>  		goto out_unmap;
>  	}
>  
> +#ifdef CONFIG_PM_SLEEP
> +	/* Add bcm7038_l1_chip into a list */
> +	INIT_LIST_HEAD(&intc->list);
> +	list_add_tail(&intc->list, &bcm7038_l1_intcs_list);

No locking to manipulate this list? Is that safe?

> +
> +	register_syscore_ops(&bcm7038_l1_syscore_ops);

Do you really register the syscore_ops for each and every L1 irqchip?

> +#endif
> +
>  	pr_info("registered BCM7038 L1 intc (%pOF, IRQs: %d)\n",
>  		dn, IRQS_PER_WORD * intc->n_words);
>  

Thanks,

	M.
Florian Fainelli Sept. 22, 2019, 6:50 p.m. UTC | #2
On 9/22/2019 5:31 AM, Marc Zyngier wrote:
>> +#ifdef CONFIG_PM_SLEEP
>> +static int bcm7038_l1_suspend(void)
>> +{
>> +	struct bcm7038_l1_chip *intc;
>> +	unsigned long flags;
>> +	int boot_cpu, word;
>> +
>> +	/* Wakeup interrupt should only come from the boot cpu */
>> +	boot_cpu = cpu_logical_map(smp_processor_id());
> 
> What guarantees that you're actually running on the boot CPU at this
> point? If that's actually the case, why isn't cpu_logical_map(0) enough?

This is executed from syscore_suspend() which is executed after
suspend_disable_secondary_cpus(), so we are guaranteed to be
uni-processor at that point. Good point about using 0 for addressing the
boot CPU.

> 
>> +
>> +	list_for_each_entry(intc, &bcm7038_l1_intcs_list, list) {
>> +		raw_spin_lock_irqsave(&intc->lock, flags);
> 
> And if this can only run on a single CPU, what's the purpose of this
> lock?

Humm, yes, we probably do not need that lock, syscore_suspend() is after
arch_suspend_disable_irqs().

> 
>> +		for (word = 0; word < intc->n_words; word++) {
>> +			l1_writel(~intc->wake_mask[word],
>> +				intc->cpus[boot_cpu]->map_base +
>> +				reg_mask_set(intc, word));
>> +			l1_writel(intc->wake_mask[word],
>> +				intc->cpus[boot_cpu]->map_base +
>> +				reg_mask_clr(intc, word));
> 
> nit: Please don't split the write address across two lines, it makes it
> harder to read.
> 
>> +		}
>> +		raw_spin_unlock_irqrestore(&intc->lock, flags);
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static void bcm7038_l1_resume(void)
>> +{
>> +	struct bcm7038_l1_chip *intc;
>> +	unsigned long flags;
>> +	int boot_cpu, word;
>> +
>> +	boot_cpu = cpu_logical_map(smp_processor_id());
>> +
>> +	list_for_each_entry(intc, &bcm7038_l1_intcs_list, list) {
>> +		raw_spin_lock_irqsave(&intc->lock, flags);
>> +		for (word = 0; word < intc->n_words; word++) {
>> +			l1_writel(intc->cpus[boot_cpu]->mask_cache[word],
>> +				intc->cpus[boot_cpu]->map_base +
>> +				reg_mask_set(intc, word));
>> +			l1_writel(~intc->cpus[boot_cpu]->mask_cache[word],
>> +				intc->cpus[boot_cpu]->map_base +
>> +				reg_mask_clr(intc, word));
>> +		}
>> +		raw_spin_unlock_irqrestore(&intc->lock, flags);
>> +	}
>> +}
>> +
>> +static struct syscore_ops bcm7038_l1_syscore_ops = {
>> +	.suspend	= bcm7038_l1_suspend,
>> +	.resume		= bcm7038_l1_resume,
>> +};
>> +
>> +static int bcm7038_l1_set_wake(struct irq_data *d, unsigned int on)
>> +{
>> +	struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
>> +	unsigned long flags;
>> +	u32 word = d->hwirq / IRQS_PER_WORD;
>> +	u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
>> +
>> +	raw_spin_lock_irqsave(&intc->lock, flags);
>> +	if (on)
>> +		intc->wake_mask[word] |= mask;
>> +	else
>> +		intc->wake_mask[word] &= ~mask;
>> +	raw_spin_unlock_irqrestore(&intc->lock, flags);
>> +
>> +	return 0;
>> +}
>> +#endif
>> +
>>  static struct irq_chip bcm7038_l1_irq_chip = {
>>  	.name			= "bcm7038-l1",
>>  	.irq_mask		= bcm7038_l1_mask,
>> @@ -295,6 +382,9 @@ static struct irq_chip bcm7038_l1_irq_chip = {
>>  #ifdef CONFIG_SMP
>>  	.irq_cpu_offline	= bcm7038_l1_cpu_offline,
>>  #endif
>> +#ifdef CONFIG_PM_SLEEP
>> +	.irq_set_wake		= bcm7038_l1_set_wake,
>> +#endif
>>  };
>>  
>>  static int bcm7038_l1_map(struct irq_domain *d, unsigned int virq,
>> @@ -340,6 +430,14 @@ int __init bcm7038_l1_of_init(struct device_node *dn,
>>  		goto out_unmap;
>>  	}
>>  
>> +#ifdef CONFIG_PM_SLEEP
>> +	/* Add bcm7038_l1_chip into a list */
>> +	INIT_LIST_HEAD(&intc->list);
>> +	list_add_tail(&intc->list, &bcm7038_l1_intcs_list);
> 
> No locking to manipulate this list? Is that safe?

It is safe, by virtue of of_irq_init() having being called at init_IRQ()
and that interrupt controller being initialized early on boot, but it
does not feel safe to assume that, I will add relevant protection to the
list.

> 
>> +
>> +	register_syscore_ops(&bcm7038_l1_syscore_ops);
> 
> Do you really register the syscore_ops for each and every L1 irqchip?

We do not need, indeed thanks, I will fix those things in v3.
diff mbox series

Patch

diff --git a/drivers/irqchip/irq-bcm7038-l1.c b/drivers/irqchip/irq-bcm7038-l1.c
index fc75c61233aa..f5e4ff5251ab 100644
--- a/drivers/irqchip/irq-bcm7038-l1.c
+++ b/drivers/irqchip/irq-bcm7038-l1.c
@@ -27,6 +27,7 @@ 
 #include <linux/types.h>
 #include <linux/irqchip.h>
 #include <linux/irqchip/chained_irq.h>
+#include <linux/syscore_ops.h>
 
 #define IRQS_PER_WORD		32
 #define REG_BYTES_PER_IRQ_WORD	(sizeof(u32) * 4)
@@ -39,6 +40,10 @@  struct bcm7038_l1_chip {
 	unsigned int		n_words;
 	struct irq_domain	*domain;
 	struct bcm7038_l1_cpu	*cpus[NR_CPUS];
+#ifdef CONFIG_PM_SLEEP
+	struct list_head	list;
+	u32			wake_mask[MAX_WORDS];
+#endif
 	u8			affinity[MAX_WORDS * IRQS_PER_WORD];
 };
 
@@ -47,6 +52,17 @@  struct bcm7038_l1_cpu {
 	u32			mask_cache[0];
 };
 
+/*
+ * We keep a list of bcm7038_l1_chip used for suspend/resume. This hack is
+ * used because the struct chip_type suspend/resume hooks are not called
+ * unless chip_type is hooked onto a generic_chip. Since this driver does
+ * not use generic_chip, we need to manually hook our resume/suspend to
+ * syscore_ops.
+ */
+#ifdef CONFIG_PM_SLEEP
+static LIST_HEAD(bcm7038_l1_intcs_list);
+#endif
+
 /*
  * STATUS/MASK_STATUS/MASK_SET/MASK_CLEAR are packed one right after another:
  *
@@ -287,6 +303,77 @@  static int __init bcm7038_l1_init_one(struct device_node *dn,
 	return 0;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int bcm7038_l1_suspend(void)
+{
+	struct bcm7038_l1_chip *intc;
+	unsigned long flags;
+	int boot_cpu, word;
+
+	/* Wakeup interrupt should only come from the boot cpu */
+	boot_cpu = cpu_logical_map(smp_processor_id());
+
+	list_for_each_entry(intc, &bcm7038_l1_intcs_list, list) {
+		raw_spin_lock_irqsave(&intc->lock, flags);
+		for (word = 0; word < intc->n_words; word++) {
+			l1_writel(~intc->wake_mask[word],
+				intc->cpus[boot_cpu]->map_base +
+				reg_mask_set(intc, word));
+			l1_writel(intc->wake_mask[word],
+				intc->cpus[boot_cpu]->map_base +
+				reg_mask_clr(intc, word));
+		}
+		raw_spin_unlock_irqrestore(&intc->lock, flags);
+	}
+
+	return 0;
+}
+
+static void bcm7038_l1_resume(void)
+{
+	struct bcm7038_l1_chip *intc;
+	unsigned long flags;
+	int boot_cpu, word;
+
+	boot_cpu = cpu_logical_map(smp_processor_id());
+
+	list_for_each_entry(intc, &bcm7038_l1_intcs_list, list) {
+		raw_spin_lock_irqsave(&intc->lock, flags);
+		for (word = 0; word < intc->n_words; word++) {
+			l1_writel(intc->cpus[boot_cpu]->mask_cache[word],
+				intc->cpus[boot_cpu]->map_base +
+				reg_mask_set(intc, word));
+			l1_writel(~intc->cpus[boot_cpu]->mask_cache[word],
+				intc->cpus[boot_cpu]->map_base +
+				reg_mask_clr(intc, word));
+		}
+		raw_spin_unlock_irqrestore(&intc->lock, flags);
+	}
+}
+
+static struct syscore_ops bcm7038_l1_syscore_ops = {
+	.suspend	= bcm7038_l1_suspend,
+	.resume		= bcm7038_l1_resume,
+};
+
+static int bcm7038_l1_set_wake(struct irq_data *d, unsigned int on)
+{
+	struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
+	unsigned long flags;
+	u32 word = d->hwirq / IRQS_PER_WORD;
+	u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
+
+	raw_spin_lock_irqsave(&intc->lock, flags);
+	if (on)
+		intc->wake_mask[word] |= mask;
+	else
+		intc->wake_mask[word] &= ~mask;
+	raw_spin_unlock_irqrestore(&intc->lock, flags);
+
+	return 0;
+}
+#endif
+
 static struct irq_chip bcm7038_l1_irq_chip = {
 	.name			= "bcm7038-l1",
 	.irq_mask		= bcm7038_l1_mask,
@@ -295,6 +382,9 @@  static struct irq_chip bcm7038_l1_irq_chip = {
 #ifdef CONFIG_SMP
 	.irq_cpu_offline	= bcm7038_l1_cpu_offline,
 #endif
+#ifdef CONFIG_PM_SLEEP
+	.irq_set_wake		= bcm7038_l1_set_wake,
+#endif
 };
 
 static int bcm7038_l1_map(struct irq_domain *d, unsigned int virq,
@@ -340,6 +430,14 @@  int __init bcm7038_l1_of_init(struct device_node *dn,
 		goto out_unmap;
 	}
 
+#ifdef CONFIG_PM_SLEEP
+	/* Add bcm7038_l1_chip into a list */
+	INIT_LIST_HEAD(&intc->list);
+	list_add_tail(&intc->list, &bcm7038_l1_intcs_list);
+
+	register_syscore_ops(&bcm7038_l1_syscore_ops);
+#endif
+
 	pr_info("registered BCM7038 L1 intc (%pOF, IRQs: %d)\n",
 		dn, IRQS_PER_WORD * intc->n_words);