[PATCH v2 3/4] ARCv2: IRQ: Use build registers for getting numbers of interrupts
Vineet Gupta
Vineet.Gupta1 at synopsys.com
Tue Jan 31 09:46:04 PST 2017
On 01/31/2017 03:45 AM, Yuriy Kolerov wrote:
> This enhancement allows to mask all available common interrupts
> in IDU interrupt controller in boot time since the kernel can
> discover a number of them from the build register. Also now there
> is no need to specify in device tree a list of used core interrupts
> by IDU. E.g. before:
>
> idu_intc: idu-interrupt-controller {
> compatible = "snps,archs-idu-intc";
> interrupt-controller;
> interrupt-parent = <&core_intc>;
> #interrupt-cells = <2>;
> interrupts = <24 25 26 27 28 29 30 31>;
> };
>
> and after:
>
> idu_intc: idu-interrupt-controller {
> compatible = "snps,archs-idu-intc";
> interrupt-controller;
> interrupt-parent = <&core_intc>;
> #interrupt-cells = <2>;
> };
>
> Signed-off-by: Yuriy Kolerov <yuriy.kolerov at synopsys.com>
> ---
> arch/arc/include/asm/irq.h | 4 ++++
> arch/arc/kernel/intc-arcv2.c | 9 +++++++--
> arch/arc/kernel/mcip.c | 31 +++++++++++++++++++------------
> include/soc/arc/mcip.h | 17 +++++++++++++++++
> 4 files changed, 47 insertions(+), 14 deletions(-)
We need to update existing DTs and
Documentation/devicetree/bindings/arc/archs-idu-intc.txt too - addon patch is fine !
>
> diff --git a/arch/arc/include/asm/irq.h b/arch/arc/include/asm/irq.h
> index d28499a..1970d78c 100644
> --- a/arch/arc/include/asm/irq.h
> +++ b/arch/arc/include/asm/irq.h
> @@ -18,6 +18,9 @@
> */
> #define NR_CPU_IRQS 240
>
> +/* A fixed number of exceptions which occupy first interrupt lines */
> +#define NR_EXCEPTIONS 16
> +
> /*
> * ARCv2 can support 240 interrupts in the core interrupts controllers and
> * 128 interrupts in IDU. Thus 512 virtual IRQs must be enough for most
> @@ -28,6 +31,7 @@
> /* Platform Independent IRQs */
> #define IPI_IRQ 19
> #define SOFTIRQ_IRQ 21
> +#define FIRST_EXT_IRQ 24
>
> #else
>
> diff --git a/arch/arc/kernel/intc-arcv2.c b/arch/arc/kernel/intc-arcv2.c
> index 9de0665..31246cc 100644
> --- a/arch/arc/kernel/intc-arcv2.c
> +++ b/arch/arc/kernel/intc-arcv2.c
> @@ -109,7 +109,7 @@ static int arcv2_irq_map(struct irq_domain *d, unsigned int irq,
> * core intc IRQs [16, 23]:
> * Statically assigned always private-per-core (Timers, WDT, IPI, PCT)
> */
> - if (hw < 24) {
> + if (hw < FIRST_EXT_IRQ) {
> /*
> * A subsequent request_percpu_irq() fails if percpu_devid is
> * not set. That in turns sets NOAUTOEN, meaning each core needs
> @@ -134,11 +134,16 @@ static int __init
> init_onchip_IRQ(struct device_node *intc, struct device_node *parent)
> {
> struct irq_domain *root_domain;
> + struct bcr_irq_arcv2 irq_bcr;
> + unsigned int nr_cpu_irqs;
> +
> + READ_BCR(ARC_REG_IRQ_BCR, irq_bcr);
> + nr_cpu_irqs = irq_bcr.irqs + NR_EXCEPTIONS;
>
> if (parent)
> panic("DeviceTree incore intc not a root irq controller\n");
>
> - root_domain = irq_domain_add_linear(intc, NR_CPU_IRQS, &arcv2_irq_ops, NULL);
> + root_domain = irq_domain_add_linear(intc, nr_cpu_irqs, &arcv2_irq_ops, NULL);
> if (!root_domain)
> panic("root irq domain not avail\n");
>
> diff --git a/arch/arc/kernel/mcip.c b/arch/arc/kernel/mcip.c
> index 9988b42..45d45fc 100644
> --- a/arch/arc/kernel/mcip.c
> +++ b/arch/arc/kernel/mcip.c
> @@ -157,15 +157,20 @@ static void idu_set_mode(unsigned int cmn_irq, unsigned int lvl,
> __mcip_cmd_data(CMD_IDU_SET_MODE, cmn_irq, data.word);
> }
>
> -static void idu_irq_mask(struct irq_data *data)
> +static void idu_irq_mask_raw(irq_hw_number_t hwirq)
> {
> unsigned long flags;
>
> raw_spin_lock_irqsave(&mcip_lock, flags);
> - __mcip_cmd_data(CMD_IDU_SET_MASK, data->hwirq, 1);
> + __mcip_cmd_data(CMD_IDU_SET_MASK, hwirq, 1);
> raw_spin_unlock_irqrestore(&mcip_lock, flags);
> }
>
> +static void idu_irq_mask(struct irq_data *data)
> +{
> + idu_irq_mask_raw(data->hwirq);
> +}
> +
> static void idu_irq_unmask(struct irq_data *data)
> {
> unsigned long flags;
> @@ -231,14 +236,12 @@ static struct irq_chip idu_irq_chip = {
>
> };
>
> -static irq_hw_number_t idu_first_hwirq;
> -
> static void idu_cascade_isr(struct irq_desc *desc)
> {
> struct irq_domain *idu_domain = irq_desc_get_handler_data(desc);
> struct irq_chip *core_chip = irq_desc_get_chip(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;
> + irq_hw_number_t idu_hwirq = core_hwirq - FIRST_EXT_IRQ;
>
> chained_irq_enter(core_chip, desc);
> generic_handle_irq(irq_find_mapping(idu_domain, idu_hwirq));
> @@ -284,33 +287,37 @@ static int __init
> 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 nr_irqs;
> int i, virq;
> struct mcip_bcr mp;
> + struct mcip_idu_bcr idu_bcr;
>
> READ_BCR(ARC_REG_MCIP_BCR, mp);
>
> if (!mp.idu)
> panic("IDU not detected, but DeviceTree using it");
>
> - pr_info("MCIP: IDU referenced from Devicetree %d irqs\n", nr_irqs);
> + READ_BCR(ARC_REG_MCIP_IDU_BCR, idu_bcr);
> + nr_irqs = mcip_idu_bcr_to_nr_irqs(idu_bcr);
> +
> + pr_info("MCIP: IDU supports %u common irqs\n", nr_irqs);
>
> domain = irq_domain_add_linear(intc, nr_irqs, &idu_irq_ops, NULL);
>
> /* Parent interrupts (core-intc) are already mapped */
>
> for (i = 0; i < nr_irqs; i++) {
> + /* Mask all common interrupts by default */
> + idu_irq_mask_raw(i);
> +
This deserves to be seperate patch - this is a semantical change and needs to
called out seperately - in case it we want to quickly revert it etc.
> /*
> * Return parent uplink IRQs (towards core intc) 24,25,.....
> * this step has been done before already
> * however we need it to get the parent virq and set IDU handler
> * as first level isr
> */
> - virq = irq_of_parse_and_map(intc, i);
> - if (!i)
> - idu_first_hwirq = irqd_to_hwirq(irq_get_irq_data(virq));
> -
> + virq = irq_create_mapping(NULL, i + FIRST_EXT_IRQ);
> + BUG_ON(!virq);
> irq_set_chained_handler_and_data(virq, idu_cascade_isr, domain);
> }
>
> diff --git a/include/soc/arc/mcip.h b/include/soc/arc/mcip.h
> index 6902c2a..798c01b 100644
> --- a/include/soc/arc/mcip.h
> +++ b/include/soc/arc/mcip.h
> @@ -14,6 +14,7 @@
> #include <soc/arc/aux.h>
>
> #define ARC_REG_MCIP_BCR 0x0d0
> +#define ARC_REG_MCIP_IDU_BCR 0x0D5
> #define ARC_REG_MCIP_CMD 0x600
> #define ARC_REG_MCIP_WDATA 0x601
> #define ARC_REG_MCIP_READBACK 0x602
> @@ -69,6 +70,22 @@ struct mcip_bcr {
> #endif
> };
>
> +struct mcip_idu_bcr {
> +#ifdef CONFIG_CPU_BIG_ENDIAN
> + unsigned int pad:21, cirqnum:3, ver:8;
> +#else
> + unsigned int ver:8, cirqnum:3, pad:21;
> +#endif
> +};
> +
> +
> +/*
> + * Build register for IDU contains not an actual number of supported common
> + * interrupts but an exponent of 2 which must be multiplied by 4 to
> + * get a number of supported common interrupts.
> + */
> +#define mcip_idu_bcr_to_nr_irqs(bcr) (4 * (1 << (bcr).cirqnum))
> +
> /*
> * MCIP programming model
> *
>
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