[PATCH 3/5] ARC: MCIP: Use hwirq instead of virq for resolution of IDU IRQ handlers

From: Yuriy Kolerov
Date: Fri Oct 21 2016 - 18:17:54 EST


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.

Signed-off-by: Yuriy Kolerov <yuriy.kolerov@xxxxxxxxxxxx>
---
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 28ff766..51a218c 100644
--- a/arch/arc/kernel/mcip.c
+++ b/arch/arc/kernel/mcip.c
@@ -220,16 +220,14 @@ 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)
@@ -295,7 +293,7 @@ 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");
@@ -313,11 +311,11 @@ 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);
--
2.7.4