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

Michal Simek
2020-03-30T08:33:12Z

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@xilinx.com>
> AuthorDate: Tue, 17 Mar 2020 18:25:59 +05:30
> Committer: Marc Zyngier <maz@kernel.org>
> 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@xilinx.com>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> Reviewed-by: Stefan Asserhall <stefan.asserhall@xilinx.com>
> Link: https://lore.kernel.org/r/20200317125600.15913-4-mubin.usman.sayyed@xilinx.com
> ---
> 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@xilinx.com/

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

Thanks,
Michal