Hi Joe,
On 13/08/14 03:11, Joe.C wrote:
> From: "Joe.C" <yingjoe.chen@xxxxxxxxxxxx>
>
> GIC supports the combination with external extensions. But this
> is not reflected in the checks of the interrupt type flag.
> This patch allows interrupt types other than the one supported by GIC,
> if an architecture extension is present and supports them.
>
> Signed-off-by: Joe.C <yingjoe.chen@xxxxxxxxxxxx>
> ---
> drivers/irqchip/irq-gic.c | 27 ++++++++++++++++++---------
> 1 file changed, 18 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
> index 57d165e..66485ab 100644
> --- a/drivers/irqchip/irq-gic.c
> +++ b/drivers/irqchip/irq-gic.c
> @@ -194,23 +194,32 @@ static int gic_set_type(struct irq_data *d, unsigned int type)
> u32 confoff = (gicirq / 16) * 4;
> bool enabled = false;
> u32 val;
> + int ret = 0;
>
> /* Interrupt configuration for SGIs can't be changed */
> if (gicirq < 16)
> return -EINVAL;
>
> - if (type != IRQ_TYPE_LEVEL_HIGH && type != IRQ_TYPE_EDGE_RISING)
> - return -EINVAL;
> -
> raw_spin_lock(&irq_controller_lock);
>
> - if (gic_arch_extn.irq_set_type)
> - gic_arch_extn.irq_set_type(d, type);
> + if (gic_arch_extn.irq_set_type) {
> + ret = gic_arch_extn.irq_set_type(d, type);
> + if (ret)
> + goto out;
> + } else if (type != IRQ_TYPE_LEVEL_HIGH &&
> + type != IRQ_TYPE_EDGE_RISING) {
> + ret = -EINVAL;
> + goto out;
> + }
>
> val = readl_relaxed(base + GIC_DIST_CONFIG + confoff);
> - if (type == IRQ_TYPE_LEVEL_HIGH)
> + /* Check for both edge and level here, so we can support GIC irq
> + polarity extension in gic_arch_extn.irq_set_type. If arch
> + doesn't support polarity extension, the check above will reject
> + improper type. */
> + if (type & IRQ_TYPE_LEVEL_MASK)
> val &= ~confmask;
> - else if (type == IRQ_TYPE_EDGE_RISING)
> + else if (type & IRQ_TYPE_EDGE_BOTH)
> val |= confmask;
>
> /*
> @@ -226,10 +235,10 @@ static int gic_set_type(struct irq_data *d, unsigned int type)
>
> if (enabled)
> writel_relaxed(enablemask, base + GIC_DIST_ENABLE_SET + enableoff);
> -
> +out:
> raw_spin_unlock(&irq_controller_lock);
>
> - return 0;
> + return ret;
> }
>
> static int gic_retrigger(struct irq_data *d)
>
You're really abusing the gic_arch_extn feature. I know this is
tempting, but this is pushing it a bit too far.
This feature exist for one particular reason: if your GIC is in the same
power-domain as the CPUs, it will go down as well when you suspend the
system, hence being enable to wake the CPU up. You then need a shadow
interrupt controller to take over. This is exactly why we call the hook
on every GIC-related operation.
Here, you're using it to program something that sits between the device
and the GIC. This is a separate block, with its own hardware
configuration, that modifies the interrupt signal. This should be
reflected in the device-tree and the code paths.
You can probably model this as a separate irqchip for the few interrupts
that require this, or have it configured at boot time (assuming the
configuration never changes).
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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