On 11/03/2016 05:23 AM, Yuriy Kolerov wrote:
> Multicore ARC configurations use IDU (Interrupt Distribution Unit) for
> distributing of common interrupts. In fact IDU is a interrupt controller
> on top of main per core interrupt controller.
>
> All common IRQs are physically and linearly mapped to per core
> interrupts. E.g. <0, 1, 2, 3> common IDU interrupts may be mapped to per
> core <24, 25, 26, 27> interrupts. An initialization code of IDU
> controller (idu_of_init) creates mappings for all parent interrupts
> <24, 25, ...> and sets a chained IDU handler for them. In the same
> time idu_of_init must save the first met parent hwirq (idu_first_irq)
> thus in future it is possible to figure out what common hwirq has come
> by subtracting of idu_first_irq from the current parent hwirq (see
> idu_cascade_isr).
>
> The problem is that idu_of_init and idu_cascade_isr use parent virtual
> IRQs as hardware IRQs and perform all the above-described manipulations
> on virtual IRQs. But it is wrong and hardware IRQs must be used instead.
Is this series bisectable ?
So if one only applies patch 1/3 (and not 2/3) - as might happen in case of a
bisect for some arbit problem, will it still work - to me it seems not.
>
> Signed-off-by: Yuriy Kolerov <yuriy.kole...@synopsys.com>
> ---
> arch/arc/kernel/mcip.c | 20 +++++++++-----------
> 1 file changed, 9 insertions(+), 11 deletions(-)
>
> diff --git a/arch/arc/kernel/mcip.c b/arch/arc/kernel/mcip.c
> index 72f9179..4f4f04b 100644
> --- a/arch/arc/kernel/mcip.c
> +++ b/arch/arc/kernel/mcip.c
> @@ -219,16 +219,14 @@ static struct irq_chip idu_irq_chip = {
>
> };
>
> -static int idu_first_irq;
> +static irq_hw_number_t idu_first_hwirq;
>
> static void idu_cascade_isr(struct irq_desc *desc)
> {
> - struct irq_domain *domain = irq_desc_get_handler_data(desc);
> - unsigned int core_irq = irq_desc_get_irq(desc);
> - unsigned int idu_irq;
> -
> - idu_irq = core_irq - idu_first_irq;
> - generic_handle_irq(irq_find_mapping(domain, idu_irq));
> + struct irq_domain *idu_domain = irq_desc_get_handler_data(desc);
> + irq_hw_number_t core_hwirq = irqd_to_hwirq(irq_desc_get_irq_data(desc));
> + irq_hw_number_t idu_hwirq = core_hwirq - idu_first_hwirq;
> + generic_handle_irq(irq_find_mapping(idu_domain, idu_hwirq));
> }
>
> static int idu_irq_map(struct irq_domain *d, unsigned int virq,
> irq_hw_number_t hwirq)
> @@ -294,7 +292,7 @@ idu_of_init(struct device_node *intc, struct device_node
> *parent)
> struct irq_domain *domain;
> /* Read IDU BCR to confirm nr_irqs */
> int nr_irqs = of_irq_count(intc);
> - int i, irq;
> + int i, virq;
>
> if (!idu_detected)
> panic("IDU not detected, but DeviceTree using it");
> @@ -312,11 +310,11 @@ idu_of_init(struct device_node *intc, struct
> device_node *parent)
> * however we need it to get the parent virq and set IDU handler
> * as first level isr
> */
> - irq = irq_of_parse_and_map(intc, i);
> + virq = irq_of_parse_and_map(intc, i);
> if (!i)
> - idu_first_irq = irq;
> + idu_first_hwirq = irqd_to_hwirq(irq_get_irq_data(virq));
>
> - irq_set_chained_handler_and_data(irq, idu_cascade_isr, domain);
> + irq_set_chained_handler_and_data(virq, idu_cascade_isr, domain);
> }
>
> __mcip_cmd(CMD_IDU_ENABLE, 0);
>
_______________________________________________
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc
