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irqchip/irq-brcmstb-l2: Avoid saving mask on shutdown

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The interrupt controller shutdown path does not need to save the mask of
enabled interrupts because the next state the system is going to be in is
akin to a cold boot, or a kexec'd kernel. Saving the mask only makes sense
if the software state needs to preserve the hardware state across a system
suspend/resume cycle.

As an optimization, and given that there are systems with dozens of such
interrupt controller, save a "slow" memory mapped I/O read in the shutdown
path where no saving/restoring is required.

Reported-by: Tim Ross <tim.ross@broadcom.com>
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240424175732.1526531-1-florian.fainelli@broadcom.com
This commit is contained in:
Florian Fainelli 2024-04-24 10:57:32 -07:00 committed by Thomas Gleixner
parent 6678ae1918
commit c7cad38d37
1 changed files with 14 additions and 3 deletions
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17
drivers/irqchip/irq-brcmstb-l2.c
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@ -118,7 +118,7 @@ static void brcmstb_l2_intc_irq_handle(struct irq_desc *desc)
chained_irq_exit(chip, desc);
}
static void brcmstb_l2_intc_suspend(struct irq_data *d)
static void __brcmstb_l2_intc_suspend(struct irq_data *d, bool save)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
struct irq_chip_type *ct = irq_data_get_chip_type(d);
@ -127,7 +127,8 @@ static void brcmstb_l2_intc_suspend(struct irq_data *d)
irq_gc_lock_irqsave(gc, flags);
/* Save the current mask */
b->saved_mask = irq_reg_readl(gc, ct->regs.mask);
if (save)
b->saved_mask = irq_reg_readl(gc, ct->regs.mask);
if (b->can_wake) {
/* Program the wakeup mask */
@ -137,6 +138,16 @@ static void brcmstb_l2_intc_suspend(struct irq_data *d)
irq_gc_unlock_irqrestore(gc, flags);
}
static void brcmstb_l2_intc_shutdown(struct irq_data *d)
{
__brcmstb_l2_intc_suspend(d, false);
}
static void brcmstb_l2_intc_suspend(struct irq_data *d)
{
__brcmstb_l2_intc_suspend(d, true);
}
static void brcmstb_l2_intc_resume(struct irq_data *d)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
@ -252,7 +263,7 @@ static int __init brcmstb_l2_intc_of_init(struct device_node *np,
ct->chip.irq_suspend = brcmstb_l2_intc_suspend;
ct->chip.irq_resume = brcmstb_l2_intc_resume;
ct->chip.irq_pm_shutdown = brcmstb_l2_intc_suspend;
ct->chip.irq_pm_shutdown = brcmstb_l2_intc_shutdown;
if (data->can_wake) {
/* This IRQ chip can wake the system, set all child interrupts