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

Marc Zyngier
2020-03-30T08:45:15Z

On 2020-03-30 09:32, Michal Simek wrote:
> 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.

Did you? I can't possibly find these emails.

> 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/

You want to remove exising platforms two days before the start of the
merge window?
I don't think this is acceptable with such short notice.

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

I think the only option is to revert (at least partially) the Xilinx
series.

M.
--
Jazz is not dead. It just smells funny...