Virtualization - Feb 2023 - [PATCH v4 1/6] drivers/clocksource/hyper-v: non ACPI support in hyperv clock

From: Saurabh Sengar <ssengar at linux.microsoft.com> Sent: Monday,
February 6, 2023 11:50 PM
> 
> Add a placeholder function for the hv_setup_stimer0_irq API to accommodate
> systems without ACPI support. Since this function is not utilized on
> x86/x64 systems and non-ACPI support is only intended for x86/x64 systems,
> a placeholder function is sufficient for now and can be improved upon if
> necessary in the future.
> 
> This change will make it easier to add device tree support for VMBus in
> subsequent commits.
> 
> Signed-off-by: Saurabh Sengar <ssengar at linux.microsoft.com>
> ---
>  drivers/clocksource/hyperv_timer.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/clocksource/hyperv_timer.c
b/drivers/clocksource/hyperv_timer.c
> index c0cef92..f32948c 100644
> --- a/drivers/clocksource/hyperv_timer.c
> +++ b/drivers/clocksource/hyperv_timer.c
> @@ -49,7 +49,7 @@
> 
>  static int stimer0_irq = -1;
>  static int stimer0_message_sint;
> -static DEFINE_PER_CPU(long, stimer0_evt);
> +static __maybe_unused DEFINE_PER_CPU(long, stimer0_evt);
> 
>  /*
>   * Common code for stimer0 interrupts coming via Direct Mode or
> @@ -68,7 +68,7 @@ void hv_stimer0_isr(void)
>   * stimer0 interrupt handler for architectures that support
>   * per-cpu interrupts, which also implies Direct Mode.
>   */
> -static irqreturn_t hv_stimer0_percpu_isr(int irq, void *dev_id)
> +static irqreturn_t __maybe_unused hv_stimer0_percpu_isr(int irq, void
*dev_id)
>  {
>  	hv_stimer0_isr();
>  	return IRQ_HANDLED;
> @@ -196,6 +196,7 @@ void __weak hv_remove_stimer0_handler(void)
>  {
>  };
> 
> +#ifdef CONFIG_ACPI
>  /* Called only on architectures with per-cpu IRQs (i.e., not x86/x64) */
>  static int hv_setup_stimer0_irq(void)
>  {
> @@ -230,6 +231,16 @@ static void hv_remove_stimer0_irq(void)
>  		stimer0_irq = -1;
>  	}
>  }
> +#else
> +static int hv_setup_stimer0_irq(void)
> +{
> +	return 0;
> +}
> +
> +static void hv_remove_stimer0_irq(void)
> +{
> +}
> +#endif
> 
>  /* hv_stimer_alloc - Global initialization of the clockevent and stimer0
*/
>  int hv_stimer_alloc(bool have_percpu_irqs)
> --
> 1.8.3.1
Reviewed-by: Michael Kelley <mikelley at microsoft.com>