diff mbox series

[2/3] irqchip/mips-gic: Get rid of the reliance on irq_cpu_online()

Message ID 20211021170414.3341522-3-maz@kernel.org (mailing list archive)
State Not Applicable
Headers show
Series genirq: Make irq_cpu_{on,off}line() an Octeon-special | expand

Commit Message

Marc Zyngier Oct. 21, 2021, 5:04 p.m. UTC 
The MIPS GIC driver uses irq_cpu_online() to go and program the
per-CPU interrupts. However, this method iterates over all IRQs
in the system, despite only 3 per-CPU interrupts being of interest.

Let's be terribly bold and do the iteration ourselves. To ensure
mutual exclusion, hold the gic_lock spinlock that is otherwise
taken while dealing with these interrupts.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/irqchip/irq-mips-gic.c | 37 ++++++++++++++++++++++++----------
 1 file changed, 26 insertions(+), 11 deletions(-)

Comments

Serge Semin Oct. 22, 2021, 1:57 p.m. UTC | #1 
On Thu, Oct 21, 2021 at 06:04:13PM +0100, Marc Zyngier wrote:
> The MIPS GIC driver uses irq_cpu_online() to go and program the
> per-CPU interrupts. However, this method iterates over all IRQs
> in the system, despite only 3 per-CPU interrupts being of interest.
> 
> Let's be terribly bold and do the iteration ourselves. To ensure
> mutual exclusion, hold the gic_lock spinlock that is otherwise
> taken while dealing with these interrupts.

Please consider a nitpick below. Other than that looks good:
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>

> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
>  drivers/irqchip/irq-mips-gic.c | 37 ++++++++++++++++++++++++----------
>  1 file changed, 26 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
> index 54c7092cc61d..45c83dd804a0 100644
> --- a/drivers/irqchip/irq-mips-gic.c
> +++ b/drivers/irqchip/irq-mips-gic.c
> @@ -381,24 +381,35 @@ static void gic_unmask_local_irq_all_vpes(struct irq_data *d)
>  	spin_unlock_irqrestore(&gic_lock, flags);
>  }
>  
> -static void gic_all_vpes_irq_cpu_online(struct irq_data *d)
> +static void gic_all_vpes_irq_cpu_online(void)
>  {
> -	struct gic_all_vpes_chip_data *cd;
> -	unsigned int intr;

> +	static unsigned int local_intrs[] = {

What about adding 'const' here?

-Sergey

> +		GIC_LOCAL_INT_TIMER,
> +		GIC_LOCAL_INT_PERFCTR,
> +		GIC_LOCAL_INT_FDC,
> +	};
> +	unsigned long flags;
> +	int i;
>  
> -	intr = GIC_HWIRQ_TO_LOCAL(d->hwirq);
> -	cd = irq_data_get_irq_chip_data(d);
> +	spin_lock_irqsave(&gic_lock, flags);
>  
> -	write_gic_vl_map(mips_gic_vx_map_reg(intr), cd->map);
> -	if (cd->mask)
> -		write_gic_vl_smask(BIT(intr));
> +	for (i = 0; i < ARRAY_SIZE(local_intrs); i++) {
> +		unsigned int intr = local_intrs[i];
> +		struct gic_all_vpes_chip_data *cd;
> +
> +		cd = &gic_all_vpes_chip_data[intr];
> +		write_gic_vl_map(mips_gic_vx_map_reg(intr), cd->map);
> +		if (cd->mask)
> +			write_gic_vl_smask(BIT(intr));
> +	}
> +
> +	spin_unlock_irqrestore(&gic_lock, flags);
>  }
>  
>  static struct irq_chip gic_all_vpes_local_irq_controller = {
>  	.name			= "MIPS GIC Local",
>  	.irq_mask		= gic_mask_local_irq_all_vpes,
>  	.irq_unmask		= gic_unmask_local_irq_all_vpes,
> -	.irq_cpu_online		= gic_all_vpes_irq_cpu_online,
>  };
>  
>  static void __gic_irq_dispatch(void)
> @@ -477,6 +488,10 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int virq,
>  	intr = GIC_HWIRQ_TO_LOCAL(hwirq);
>  	map = GIC_MAP_PIN_MAP_TO_PIN | gic_cpu_pin;
>  
> +	/*
> +	 * If adding support for more per-cpu interrupts, keep the the
> +	 * array in gic_all_vpes_irq_cpu_online() in sync.
> +	 */
>  	switch (intr) {
>  	case GIC_LOCAL_INT_TIMER:
>  		/* CONFIG_MIPS_CMP workaround (see __gic_init) */
> @@ -663,8 +678,8 @@ static int gic_cpu_startup(unsigned int cpu)
>  	/* Clear all local IRQ masks (ie. disable all local interrupts) */
>  	write_gic_vl_rmask(~0);
>  
> -	/* Invoke irq_cpu_online callbacks to enable desired interrupts */
> -	irq_cpu_online();
> +	/* Enable desired interrupts */
> +	gic_all_vpes_irq_cpu_online();
>  
>  	return 0;
>  }
> -- 
> 2.30.2
>
Florian Fainelli Oct. 26, 2021, 2:17 a.m. UTC | #2 
On 10/21/2021 10:04 AM, Marc Zyngier wrote:
> The MIPS GIC driver uses irq_cpu_online() to go and program the
> per-CPU interrupts. However, this method iterates over all IRQs
> in the system, despite only 3 per-CPU interrupts being of interest.
> 
> Let's be terribly bold and do the iteration ourselves. To ensure
> mutual exclusion, hold the gic_lock spinlock that is otherwise
> taken while dealing with these interrupts.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
diff mbox series

Patch

diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index 54c7092cc61d..45c83dd804a0 100644
--- a/drivers/irqchip/irq-mips-gic.c
+++ b/drivers/irqchip/irq-mips-gic.c
@@ -381,24 +381,35 @@  static void gic_unmask_local_irq_all_vpes(struct irq_data *d)
 	spin_unlock_irqrestore(&gic_lock, flags);
 }
 
-static void gic_all_vpes_irq_cpu_online(struct irq_data *d)
+static void gic_all_vpes_irq_cpu_online(void)
 {
-	struct gic_all_vpes_chip_data *cd;
-	unsigned int intr;
+	static unsigned int local_intrs[] = {
+		GIC_LOCAL_INT_TIMER,
+		GIC_LOCAL_INT_PERFCTR,
+		GIC_LOCAL_INT_FDC,
+	};
+	unsigned long flags;
+	int i;
 
-	intr = GIC_HWIRQ_TO_LOCAL(d->hwirq);
-	cd = irq_data_get_irq_chip_data(d);
+	spin_lock_irqsave(&gic_lock, flags);
 
-	write_gic_vl_map(mips_gic_vx_map_reg(intr), cd->map);
-	if (cd->mask)
-		write_gic_vl_smask(BIT(intr));
+	for (i = 0; i < ARRAY_SIZE(local_intrs); i++) {
+		unsigned int intr = local_intrs[i];
+		struct gic_all_vpes_chip_data *cd;
+
+		cd = &gic_all_vpes_chip_data[intr];
+		write_gic_vl_map(mips_gic_vx_map_reg(intr), cd->map);
+		if (cd->mask)
+			write_gic_vl_smask(BIT(intr));
+	}
+
+	spin_unlock_irqrestore(&gic_lock, flags);
 }
 
 static struct irq_chip gic_all_vpes_local_irq_controller = {
 	.name			= "MIPS GIC Local",
 	.irq_mask		= gic_mask_local_irq_all_vpes,
 	.irq_unmask		= gic_unmask_local_irq_all_vpes,
-	.irq_cpu_online		= gic_all_vpes_irq_cpu_online,
 };
 
 static void __gic_irq_dispatch(void)
@@ -477,6 +488,10 @@  static int gic_irq_domain_map(struct irq_domain *d, unsigned int virq,
 	intr = GIC_HWIRQ_TO_LOCAL(hwirq);
 	map = GIC_MAP_PIN_MAP_TO_PIN | gic_cpu_pin;
 
+	/*
+	 * If adding support for more per-cpu interrupts, keep the the
+	 * array in gic_all_vpes_irq_cpu_online() in sync.
+	 */
 	switch (intr) {
 	case GIC_LOCAL_INT_TIMER:
 		/* CONFIG_MIPS_CMP workaround (see __gic_init) */
@@ -663,8 +678,8 @@  static int gic_cpu_startup(unsigned int cpu)
 	/* Clear all local IRQ masks (ie. disable all local interrupts) */
 	write_gic_vl_rmask(~0);
 
-	/* Invoke irq_cpu_online callbacks to enable desired interrupts */
-	irq_cpu_online();
+	/* Enable desired interrupts */
+	gic_all_vpes_irq_cpu_online();
 
 	return 0;
 }