On Thu, Dec 10, 2020 at 08:25:38PM +0100, Thomas Gleixner wrote:
> These checks are used by modules and prevent the removal of the export of
> irq_to_desc(). Move the accessor into the core.
>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Yes, but that means that irq_check_status_bit() may be called from modules,
but it is not exported, resulting in build errors such as the following.
arm64:allmodconfig:
ERROR: modpost: "irq_check_status_bit" [drivers/perf/arm_spe_pmu.ko] undefined!
Guenter
> ---
> include/linux/irqdesc.h | 17 +++++------------
> kernel/irq/manage.c | 17 +++++++++++++++++
> 2 files changed, 22 insertions(+), 12 deletions(-)
>
> --- a/include/linux/irqdesc.h
> +++ b/include/linux/irqdesc.h
> @@ -223,28 +223,21 @@ irq_set_chip_handler_name_locked(struct
> data->chip = chip;
> }
>
> +bool irq_check_status_bit(unsigned int irq, unsigned int bitmask);
> +
> static inline bool irq_balancing_disabled(unsigned int irq)
> {
> - struct irq_desc *desc;
> -
> - desc = irq_to_desc(irq);
> - return desc->status_use_accessors & IRQ_NO_BALANCING_MASK;
> + return irq_check_status_bit(irq, IRQ_NO_BALANCING_MASK);
> }
>
> static inline bool irq_is_percpu(unsigned int irq)
> {
> - struct irq_desc *desc;
> -
> - desc = irq_to_desc(irq);
> - return desc->status_use_accessors & IRQ_PER_CPU;
> + return irq_check_status_bit(irq, IRQ_PER_CPU);
> }
>
> static inline bool irq_is_percpu_devid(unsigned int irq)
> {
> - struct irq_desc *desc;
> -
> - desc = irq_to_desc(irq);
> - return desc->status_use_accessors & IRQ_PER_CPU_DEVID;
> + return irq_check_status_bit(irq, IRQ_PER_CPU_DEVID);
> }
>
> static inline void
> --- a/kernel/irq/manage.c
> +++ b/kernel/irq/manage.c
> @@ -2769,3 +2769,23 @@ bool irq_has_action(unsigned int irq)
> return res;
> }
> EXPORT_SYMBOL_GPL(irq_has_action);
> +
> +/**
> + * irq_check_status_bit - Check whether bits in the irq descriptor status are set
> + * @irq: The linux irq number
> + * @bitmask: The bitmask to evaluate
> + *
> + * Returns: True if one of the bits in @bitmask is set
> + */
> +bool irq_check_status_bit(unsigned int irq, unsigned int bitmask)
> +{
> + struct irq_desc *desc;
> + bool res = false;
> +
> + rcu_read_lock();
> + desc = irq_to_desc(irq);
> + if (desc)
> + res = !!(desc->status_use_accessors & bitmask);
> + rcu_read_unlock();
> + return res;
> +}
