Re: [tip: irq/core] irqchip/xilinx: Enable generic irq multi handler

[Michal Simek]

Hi Thomas and Marc,

On 29. 03. 20 22:26, tip-bot2 for Michal Simek wrote:
> The following commit has been merged into the irq/core branch of tip:
> 
> Commit-ID:     a0789993bf8266e62fea6b4613945ba081c71e7d
> Gitweb:        https://git.kernel.org/tip/a0789993bf8266e62fea6b4613945ba081c71e7d
> Author:        Michal Simek <michal.simek@xxxxxxxxxx>
> AuthorDate:    Tue, 17 Mar 2020 18:25:59 +05:30
> Committer:     Marc Zyngier <maz@xxxxxxxxxx>
> CommitterDate: Sun, 22 Mar 2020 11:52:53 
> 
> irqchip/xilinx: Enable generic irq multi handler
> 
> Register default arch handler via driver instead of directly pointing to
> xilinx intc controller. This patch makes architecture code more generic.
> 
> Driver calls generic domain specific irq handler which does the most of
> things self. Also get rid of concurrent_irq counting which hasn't been
> exported anywhere.
> Based on this loop was also optimized by using do/while loop instead of
> goto loop.
> 
> Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
> Reviewed-by: Stefan Asserhall <stefan.asserhall@xxxxxxxxxx>
> Link: https://lore.kernel.org/r/20200317125600.15913-4-mubin.usman.sayyed@xxxxxxxxxx
> ---
>  arch/microblaze/Kconfig           |  2 ++-
>  arch/microblaze/include/asm/irq.h |  3 +---
>  arch/microblaze/kernel/irq.c      | 21 +-------------------
>  drivers/irqchip/irq-xilinx-intc.c | 34 +++++++++++++++++-------------
>  4 files changed, 23 insertions(+), 37 deletions(-)
> 
> diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
> index 6a331bd..242f58e 100644
> --- a/arch/microblaze/Kconfig
> +++ b/arch/microblaze/Kconfig
> @@ -47,6 +47,8 @@ config MICROBLAZE
>  	select CPU_NO_EFFICIENT_FFS
>  	select MMU_GATHER_NO_RANGE if MMU
>  	select SPARSE_IRQ
> +	select GENERIC_IRQ_MULTI_HANDLER
> +	select HANDLE_DOMAIN_IRQ
>  
>  # Endianness selection
>  choice
> diff --git a/arch/microblaze/include/asm/irq.h b/arch/microblaze/include/asm/irq.h
> index eac2fb4..5166f08 100644
> --- a/arch/microblaze/include/asm/irq.h
> +++ b/arch/microblaze/include/asm/irq.h
> @@ -14,7 +14,4 @@
>  struct pt_regs;
>  extern void do_IRQ(struct pt_regs *regs);
>  
> -/* should be defined in each interrupt controller driver */
> -extern unsigned int xintc_get_irq(void);
> -
>  #endif /* _ASM_MICROBLAZE_IRQ_H */
> diff --git a/arch/microblaze/kernel/irq.c b/arch/microblaze/kernel/irq.c
> index 903dad8..0b37dde 100644
> --- a/arch/microblaze/kernel/irq.c
> +++ b/arch/microblaze/kernel/irq.c
> @@ -20,29 +20,10 @@
>  #include <linux/irqchip.h>
>  #include <linux/of_irq.h>
>  
> -static u32 concurrent_irq;
> -
>  void __irq_entry do_IRQ(struct pt_regs *regs)
>  {
> -	unsigned int irq;
> -	struct pt_regs *old_regs = set_irq_regs(regs);
>  	trace_hardirqs_off();
> -
> -	irq_enter();
> -	irq = xintc_get_irq();
> -next_irq:
> -	BUG_ON(!irq);
> -	generic_handle_irq(irq);
> -
> -	irq = xintc_get_irq();
> -	if (irq != -1U) {
> -		pr_debug("next irq: %d\n", irq);
> -		++concurrent_irq;
> -		goto next_irq;
> -	}
> -
> -	irq_exit();
> -	set_irq_regs(old_regs);
> +	handle_arch_irq(regs);
>  	trace_hardirqs_on();
>  }
>  
> diff --git a/drivers/irqchip/irq-xilinx-intc.c b/drivers/irqchip/irq-xilinx-intc.c
> index 1d3d273..ea74181 100644
> --- a/drivers/irqchip/irq-xilinx-intc.c
> +++ b/drivers/irqchip/irq-xilinx-intc.c
> @@ -124,20 +124,6 @@ static unsigned int xintc_get_irq_local(struct xintc_irq_chip *irqc)
>  	return irq;
>  }
>  
> -unsigned int xintc_get_irq(void)
> -{
> -	unsigned int irq = -1;
> -	u32 hwirq;
> -
> -	hwirq = xintc_read(primary_intc, IVR);
> -	if (hwirq != -1U)
> -		irq = irq_find_mapping(primary_intc->root_domain, hwirq);
> -
> -	pr_debug("irq-xilinx: hwirq=%d, irq=%d\n", hwirq, irq);
> -
> -	return irq;
> -}
> -
>  static int xintc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
>  {
>  	struct xintc_irq_chip *irqc = d->host_data;
> @@ -177,6 +163,25 @@ static void xil_intc_irq_handler(struct irq_desc *desc)
>  	chained_irq_exit(chip, desc);
>  }
>  
> +static void xil_intc_handle_irq(struct pt_regs *regs)
> +{
> +	u32 hwirq;
> +	struct xintc_irq_chip *irqc = primary_intc;
> +
> +	do {
> +		hwirq = xintc_read(irqc, IVR);
> +		if (likely(hwirq != -1U)) {
> +			int ret;
> +
> +			ret = handle_domain_irq(irqc->root_domain, hwirq, regs);
> +			WARN_ONCE(ret, "Unhandled HWIRQ %d\n", hwirq);
> +			continue;
> +		}
> +
> +		break;
> +	} while (1);
> +}
> +
>  static int __init xilinx_intc_of_init(struct device_node *intc,
>  					     struct device_node *parent)
>  {
> @@ -246,6 +251,7 @@ static int __init xilinx_intc_of_init(struct device_node *intc,
>  	} else {
>  		primary_intc = irqc;
>  		irq_set_default_host(primary_intc->root_domain);
> +		set_handle_irq(xil_intc_handle_irq);
>  	}
>  
>  	return 0;
> 

Stephen reported compilation issue when this patch is applied because of
removal of xintc_get_irq() which is also used by ancient ppc405/ppc440
xilinx platforms. I have reported this twice to Marc already last week.

On Friday I have also send v1 of removal of that platforms (need to send v2)
https://lore.kernel.org/alsa-devel/cover.1585311091.git.michal.simek@xxxxxxxxxx/

That's why please really consider next steps and let us know.

Thanks,
Michal