Re: [PATCH 3/3] ARM: gic: add OF based initialization

From: Cousson, Benoit
Date: Wed Sep 21 2011 - 13:16:23 EST


Hi Rob,

I'm testing that series with OMAP4 but have some issues for the moment :-(

[ 0.000000] WARNING: at kernel/irq/irqdomain.c:34 gic_of_init+0x10c/0x180()
[ 0.000000] error: irq_desc already assigned to a domain
[ 0.000000] Modules linked in:
[ 0.000000] [<c001b284>] (unwind_backtrace+0x0/0xf0) from [<c0051c34>] (warn_slowpath_common+0x4c/0x64)
[ 0.000000] [<c0051c34>] (warn_slowpath_common+0x4c/0x64) from [<c0051ce0>] (warn_slowpath_fmt+0x30/0x40)
[ 0.000000] [<c0051ce0>] (warn_slowpath_fmt+0x30/0x40) from [<c05f6874>] (gic_of_init+0x10c/0x180)
[ 0.000000] [<c05f6874>] (gic_of_init+0x10c/0x180) from [<c05fa2e0>] (omap_gic_of_init+0x8/0x28)
[ 0.000000] [<c05fa2e0>] (omap_gic_of_init+0x8/0x28) from [<c0616b44>] (of_irq_init+0x148/0x28c)
[ 0.000000] [<c0616b44>] (of_irq_init+0x148/0x28c) from [<c05f3074>] (init_IRQ+0x14/0x1c)
[ 0.000000] [<c05f3074>] (init_IRQ+0x14/0x1c) from [<c05f0650>] (start_kernel+0x184/0x2fc)
[ 0.000000] [<c05f0650>] (start_kernel+0x184/0x2fc) from [<80008040>] (0x80008040)

I'm not super familiar with all the irq stuff but I'm wondering if there is not something wrong with the test that print that message:

void irq_domain_add(struct irq_domain *domain)
{
struct irq_data *d;
int hwirq;

/*
* This assumes that the irq_domain owner has already allocated
* the irq_descs. This block will be removed when support for dynamic
* allocation of irq_descs is added to irq_domain.
*/
for (hwirq = 0; hwirq < domain->nr_irq; hwirq++) {
d = irq_get_irq_data(irq_domain_to_irq(domain, hwirq));
if (d || d->domain) {
/* things are broken; just report, don't clean up */
WARN(1, "error: irq_desc already assigned to a domain");
return;
}
[...]

Is the (d || d->domain) correct? Shouldn't it be (d && d->domain)?

But since that used to work properly, I have some doubt. Moreover the driver will not even get the proper interrupt later...

Do you have any clue?

Thanks,
Benoit


On 9/20/2011 10:24 PM, Rob Herring wrote:
> From: Rob Herring<rob.herring@xxxxxxxxxxx>
>
> This adds ARM gic interrupt controller initialization using device tree
> data.
>
> The initialization function is intended to be called by of_irq_init
> function like this:
>
> const static struct of_device_id irq_match[] = {
> { .compatible = "arm,cortex-a9-gic", .data = gic_of_init, },
> {}
> };
>
> static void __init init_irqs(void)
> {
> of_irq_init(irq_match);
> }
>
> Signed-off-by: Rob Herring<rob.herring@xxxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/arm/gic.txt | 55 +++++++++++++++
> arch/arm/common/gic.c | 89 +++++++++++++++++++++++-
> arch/arm/include/asm/hardware/gic.h | 12 ++++
> 3 files changed, 152 insertions(+), 4 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/arm/gic.txt
>
> diff --git a/Documentation/devicetree/bindings/arm/gic.txt b/Documentation/devicetree/bindings/arm/gic.txt
> new file mode 100644
> index 0000000..52916b4
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/gic.txt
> @@ -0,0 +1,55 @@
> +* ARM Generic Interrupt Controller
> +
> +ARM SMP cores are often associated with a GIC, providing per processor
> +interrupts (PPI), shared processor interrupts (SPI) and software
> +generated interrupts (SGI).
> +
> +Primary GIC is attached directly to the CPU and typically has PPIs and SGIs.
> +Secondary GICs are cascaded into the upward interrupt controller and do not
> +have PPIs or SGIs.
> +
> +Main node required properties:
> +
> +- compatible : should be one of:
> + "arm,cortex-a9-gic"
> + "arm,arm11mp-gic"
> +- interrupt-controller : Identifies the node as an interrupt controller
> +- #interrupt-cells : Specifies the number of cells needed to encode an
> + interrupt source. The type shall be a<u32> and the value shall be 3.
> +
> + The 1st cell is the interrupt type; 0 for SPI interrupts, 1 for PPI
> + interrupts.
> +
> + The 2nd cell contains the interrupt number for the interrupt type.
> + SPI interrupts are in the range [0-987]. PPI interrupts are in the
> + range [0-15].
> +
> + The 3rd cell is the flags, encoded as follows:
> + bits[3:0] trigger type and level flags.
> + 1 = low-to-high edge triggered
> + 2 = high-to-low edge triggered
> + 4 = active high level-sensitive
> + 8 = active low level-sensitive
> + bits[15:8] PPI interrupt cpu mask. Each bit corresponds to each of
> + the 8 possible cpus attached to the GIC. A bit set to '1' indicated
> + the interrupt is wired to that CPU. Only valid for PPI interrupts.
> +
> +- reg : Specifies base physical address(s) and size of the GIC registers. The
> + first region is the GIC distributor register base and size. The 2nd region is
> + the GIC cpu interface register base and size.
> +
> +Optional
> +- interrupts : Interrupt source of the parent interrupt controller. Only
> + present on secondary GICs.
> +
> +Example:
> +
> + intc: interrupt-controller@fff11000 {
> + compatible = "arm,cortex-a9-gic";
> + #interrupt-cells =<3>;
> + #address-cells =<1>;
> + interrupt-controller;
> + reg =<0xfff11000 0x1000>,
> + <0xfff10100 0x100>;
> + };
> +
> diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
> index 666b278..84e69a4 100644
> --- a/arch/arm/common/gic.c
> +++ b/arch/arm/common/gic.c
> @@ -28,6 +28,10 @@
> #include<linux/smp.h>
> #include<linux/cpumask.h>
> #include<linux/io.h>
> +#include<linux/of.h>
> +#include<linux/of_address.h>
> +#include<linux/of_irq.h>
> +#include<linux/irqdomain.h>
>
> #include<asm/irq.h>
> #include<asm/mach/irq.h>
> @@ -255,6 +259,15 @@ void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)
> irq_set_chained_handler(irq, gic_handle_cascade_irq);
> }
>
> +static int gic_irq_count(void __iomem *dist_base)
> +{
> + int gic_irqs = readl_relaxed(dist_base + GIC_DIST_CTR)& 0x1f;
> + gic_irqs = (gic_irqs + 1) * 32;
> + if (gic_irqs> 1020)
> + gic_irqs = 1020;
> + return gic_irqs;
> +}
> +
> static void __init gic_dist_init(struct gic_chip_data *gic,
> unsigned int irq_start)
> {
> @@ -277,10 +290,7 @@ static void __init gic_dist_init(struct gic_chip_data *gic,
> * Find out how many interrupts are supported.
> * The GIC only supports up to 1020 interrupt sources.
> */
> - gic_irqs = readl_relaxed(base + GIC_DIST_CTR)& 0x1f;
> - gic_irqs = (gic_irqs + 1) * 32;
> - if (gic_irqs> 1020)
> - gic_irqs = 1020;
> + gic_irqs = gic_irq_count(base);
>
> /*
> * Set all global interrupts to be level triggered, active low.
> @@ -405,3 +415,74 @@ void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
> writel_relaxed(map<< 16 | irq, gic_data[0].dist_base + GIC_DIST_SOFTINT);
> }
> #endif
> +
> +#ifdef CONFIG_OF
> +static int gic_cnt __initdata = 0;
> +
> +int gic_irq_domain_dt_translate(struct irq_domain *d,
> + struct device_node *controller,
> + const u32 *intspec, unsigned int intsize,
> + unsigned long *out_hwirq, unsigned int *out_type)
> +{
> + struct gic_chip_data *gic_data = d->priv;
> +
> + if (d->of_node != controller)
> + return -EINVAL;
> + if (intsize< 3)
> + return -EINVAL;
> +
> + *out_hwirq = intspec[1];
> + /*
> + * We've already skipped over SGIs, so PPIs need no translation.
> + * For SPIs, we need to skip over 16 PPIs on primary GICs.
> + */
> + if (!intspec[0]&& !gic_data->irq_offset)
> + *out_hwirq += 16;
> +
> + *out_type = intspec[2]& IRQ_TYPE_SENSE_MASK;
> + return 0;
> +}
> +
> +struct irq_domain_ops gic_irq_domain_ops = {
> + .dt_translate = gic_irq_domain_dt_translate,
> +};
> +
> +int __init gic_of_init(struct device_node *node, struct device_node *parent)
> +{
> + void __iomem *cpu_base;
> + void __iomem *dist_base;
> + int irq;
> + struct irq_domain *domain =&gic_data[gic_cnt].domain;
> +
> + if (WARN_ON(!node))
> + return -ENODEV;
> +
> + dist_base = of_iomap(node, 0);
> + WARN(!dist_base, "unable to map gic dist registers\n");
> +
> + cpu_base = of_iomap(node, 1);
> + WARN(!cpu_base, "unable to map gic cpu registers\n");
> +
> + domain->nr_irq = gic_irq_count(dist_base);
> + /* subtract off SGIs. Also subtract off PPIs for secondary GICs */
> + if (parent)
> + domain->nr_irq -= 32;
> + else
> + domain->nr_irq -= 16;
> +
> + domain->irq_base = irq_alloc_descs(-1, 16, domain->nr_irq, numa_node_id());
> + domain->of_node = of_node_get(node);
> + domain->ops =&gic_irq_domain_ops;
> + domain->priv =&gic_data[gic_cnt];
> + irq_domain_add(domain);
> +
> + gic_init(gic_cnt, domain->irq_base, dist_base, cpu_base);
> +
> + if (parent) {
> + irq = irq_of_parse_and_map(node, 0);
> + gic_cascade_irq(gic_cnt, irq);
> + }
> + gic_cnt++;
> + return 0;
> +}
> +#endif
> diff --git a/arch/arm/include/asm/hardware/gic.h b/arch/arm/include/asm/hardware/gic.h
> index 435d3f8..2862d0e 100644
> --- a/arch/arm/include/asm/hardware/gic.h
> +++ b/arch/arm/include/asm/hardware/gic.h
> @@ -33,10 +33,21 @@
> #define GIC_DIST_SOFTINT 0xf00
>
> #ifndef __ASSEMBLY__
> +#include<linux/irqdomain.h>
> +
> extern void __iomem *gic_cpu_base_addr;
> extern struct irq_chip gic_arch_extn;
>
> void gic_init(unsigned int, unsigned int, void __iomem *, void __iomem *);
> +#ifdef CONFIG_OF
> +int gic_of_init(struct device_node *node, struct device_node *parent);
> +#else
> +static inline void gic_of_init(struct device_node *node,
> + struct device_node *parent)
> +{
> + return -ENODEV;
> +}
> +#endif
> void gic_secondary_init(unsigned int);
> void gic_cascade_irq(unsigned int gic_nr, unsigned int irq);
> void gic_raise_softirq(const struct cpumask *mask, unsigned int irq);
> @@ -46,6 +57,7 @@ struct gic_chip_data {
> unsigned int irq_offset;
> void __iomem *dist_base;
> void __iomem *cpu_base;
> + struct irq_domain domain;
> };
> #endif
>

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