[PATCH V3 15/17] irqchip/gic: Split GIC init in preparation for platform driver

Jon Hunter
2016-05-04T16:26:52Z

To re-use the code that initialises the GIC (found in
__gic_init_bases()), from within a platform driver, it is necessary to
move the code from the __init section so that it is always present and
not removed. Unfortunately, it is not possible to simply drop the __init
from the function declaration for __gic_init_bases() because it contains
calls to set_smp_cross_call() and set_handle_irq() which are both
located in the __init section. Fortunately, these calls are only
required for the root controller and because the initial platform driver
will only support non-root controllers that can be initialised later in
the boot process, we can move these calls to another function.

Move the bulk of the code from __gic_init_bases() to a new function
called gic_init_bases() which is not located in the __init section and
can be used by the platform driver. Update __gic_init_bases() to call
gic_init_bases() and if necessary, set_smp_cross_call() and
set_handle_irq().

To allow the platform driver to dynamically allocate the GIC chip data
structure, rather than passing an index to reference the GIC to
gic_init_bases() pass a pointer to the chip data instead. This means
that the name must be passed to gic_init_bases() as well, because the
name will not be passed upon an index for a platform device.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
---
drivers/irqchip/irq-gic.c | 71 +++++++++++++++++++++++++++++++----------------
1 file changed, 47 insertions(+), 24 deletions(-)

diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 2fc5018d6eb9..15e8a12813cc 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -1002,32 +1002,29 @@ static const struct irq_domain_ops gic_irq_domain_ops = {
.unmap = gic_irq_domain_unmap,
};

-static int __init __gic_init_bases(unsigned int gic_nr, int irq_start,
- void __iomem *dist_base, void __iomem *cpu_base,
- u32 percpu_offset, struct fwnode_handle *handle)
+static int gic_init_bases(struct gic_chip_data *gic, int irq_start,
+ void __iomem *dist_base, void __iomem *cpu_base,
+ u32 percpu_offset, struct fwnode_handle *handle,
+ const char *name)
{
irq_hw_number_t hwirq_base;
- struct gic_chip_data *gic;
- int gic_irqs, irq_base, i, ret;
-
- BUG_ON(gic_nr >= CONFIG_ARM_GIC_MAX_NR);
+ int gic_irqs, irq_base, ret;

- gic = &gic_data[gic_nr];
+ if (WARN_ON(!gic || gic->domain))
+ return -EINVAL;

/* Initialize irq_chip */
gic->chip = gic_chip;
+ gic->chip.name = name;

- if (static_key_true(&supports_deactivate) && gic_nr == 0) {
+ if (static_key_true(&supports_deactivate) && gic == &gic_data[0]) {
gic->chip.irq_mask = gic_eoimode1_mask_irq;
gic->chip.irq_eoi = gic_eoimode1_eoi_irq;
gic->chip.irq_set_vcpu_affinity = gic_irq_set_vcpu_affinity;
- gic->chip.name = kasprintf(GFP_KERNEL, "GICv2");
- } else {
- gic->chip.name = kasprintf(GFP_KERNEL, "GIC-%d", gic_nr);
}

#ifdef CONFIG_SMP
- if (gic_nr == 0)
+ if (gic == &gic_data[0])
gic->chip.irq_set_affinity = gic_set_affinity;
#endif

@@ -1081,7 +1078,7 @@ static int __init __gic_init_bases(unsigned int gic_nr, int irq_start,
* For primary GICs, skip over SGIs.
* For secondary GICs, skip over PPIs, too.
*/
- if (gic_nr == 0 && (irq_start & 31) > 0) {
+ if (gic == &gic_data[0] && (irq_start & 31) > 0) {
hwirq_base = 16;
if (irq_start != -1)
irq_start = (irq_start & ~31) + 16;
@@ -1108,6 +1105,42 @@ static int __init __gic_init_bases(unsigned int gic_nr, int irq_start,
goto error;
}

+ return 0;
+
+error:
+ if (IS_ENABLED(CONFIG_GIC_NON_BANKED) && percpu_offset) {
+ free_percpu(gic->dist_base.percpu_base);
+ free_percpu(gic->cpu_base.percpu_base);
+ }
+
+ return ret;
+}
+
+static int __init __gic_init_bases(unsigned int gic_nr, int irq_start,
+ void __iomem *dist_base, void __iomem *cpu_base,
+ u32 percpu_offset, struct fwnode_handle *handle)
+{
+ struct gic_chip_data *gic;
+ char *name;
+ int i, ret;
+
+ if (WARN_ON(gic_nr >= CONFIG_ARM_GIC_MAX_NR))
+ return -EINVAL;
+
+ gic = &gic_data[gic_nr];
+
+ if (static_key_true(&supports_deactivate) && gic_nr == 0)
+ name = kasprintf(GFP_KERNEL, "GICv2");
+ else
+ name = kasprintf(GFP_KERNEL, "GIC-%d", gic_nr);
+
+ ret = gic_init_bases(gic, irq_start, dist_base, cpu_base, percpu_offset,
+ handle, name);
+ if (ret) {
+ kfree(name);
+ return ret;
+ }
+
if (gic_nr == 0) {
/*
* Initialize the CPU interface map to all CPUs.
@@ -1130,16 +1163,6 @@ static int __init __gic_init_bases(unsigned int gic_nr, int irq_start,
gic_pm_init(gic);

return 0;
-
-error:
- if (IS_ENABLED(CONFIG_GIC_NON_BANKED) && percpu_offset) {
- free_percpu(gic->dist_base.percpu_base);
- free_percpu(gic->cpu_base.percpu_base);
- }
-
- kfree(gic->chip.name);
-
- return ret;
}

void __init gic_init(unsigned int gic_nr, int irq_start,
--
2.1.4