[Patch Part1 v8 34/37] x86/irq: Refine the way to allocate irq_cfg for legacy IRQs

Jiang Liu
2015-04-13T06:16:57Z

To support legacy ISA IRQs, we need to preallocate irq_cfg structures
for legacy ISA IRQs. Refine the way to allocate irq_cfg for legacy ISA
IRQs, so it's more friend to hierarchy irqdomain implementation.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Grant Likely <grant.likely@linaro.org>
Link: http://lkml.kernel.org/r/1416901802-24211-7-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Joerg Roedel <jroedel@suse.de>
---
arch/x86/kernel/apic/io_apic.c | 13 +------------
arch/x86/kernel/apic/vector.c | 42 +++++++++++++++++++++++++++++++++++++++-
2 files changed, 42 insertions(+), 13 deletions(-)

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 3406dbec1570..16d4ba3ac844 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -254,8 +254,7 @@ static void free_ioapic_saved_registers(int idx)

int __init arch_early_ioapic_init(void)
{
- struct irq_cfg *cfg;
- int i, node = cpu_to_node(0);
+ int i;

if (!nr_legacy_irqs())
io_apic_irqs = ~0UL;
@@ -263,16 +262,6 @@ int __init arch_early_ioapic_init(void)
for_each_ioapic(i)
alloc_ioapic_saved_registers(i);

- /*
- * For legacy IRQ's, start with assigning irq0 to irq15 to
- * IRQ0_VECTOR to IRQ15_VECTOR for all cpu's.
- */
- for (i = 0; i < nr_legacy_irqs(); i++) {
- cfg = alloc_irq_and_cfg_at(i, node);
- cfg->vector = IRQ0_VECTOR + i;
- cpumask_setall(cfg->domain);
- }
-
return 0;
}

diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index 609db1910fd3..4b8fad9aa685 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -24,6 +24,9 @@
struct irq_domain *x86_vector_domain;
static DEFINE_RAW_SPINLOCK(vector_lock);
static struct irq_chip lapic_controller;
+#ifdef CONFIG_X86_IO_APIC
+static struct irq_cfg *legacy_irq_cfgs[NR_IRQS_LEGACY];
+#endif

void lock_vector_lock(void)
{
@@ -283,6 +286,10 @@ static void x86_vector_free_irqs(struct irq_domain *domain,
free_remapped_irq(virq);
clear_irq_vector(virq + i, irq_data->chip_data);
free_irq_cfg(irq_data->chip_data);
+#ifdef CONFIG_X86_IO_APIC
+ if (virq + i < nr_legacy_irqs())
+ legacy_irq_cfgs[virq + i] = NULL;
+#endif
irq_domain_reset_irq_data(irq_data);
}
}
@@ -308,7 +315,12 @@ static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq,
for (i = 0; i < nr_irqs; i++) {
irq_data = irq_domain_get_irq_data(domain, virq + i);
BUG_ON(!irq_data);
- cfg = alloc_irq_cfg(irq_data->node);
+#ifdef CONFIG_X86_IO_APIC
+ if (virq + i < nr_legacy_irqs() && legacy_irq_cfgs[virq + i])
+ cfg = legacy_irq_cfgs[virq + i];
+ else
+#endif
+ cfg = alloc_irq_cfg(irq_data->node);
if (!cfg) {
err = -ENOMEM;
goto error;
@@ -357,8 +369,36 @@ int __init arch_probe_nr_irqs(void)
return nr_legacy_irqs();
}

+#ifdef CONFIG_X86_IO_APIC
+static void init_legacy_irqs(void)
+{
+ int i, node = cpu_to_node(0);
+ struct irq_cfg *cfg;
+
+ /*
+ * For legacy IRQ's, start with assigning irq0 to irq15 to
+ * IRQ0_VECTOR to IRQ15_VECTOR for all cpu's.
+ */
+ for (i = 0; i < nr_legacy_irqs(); i++) {
+ cfg = legacy_irq_cfgs[i] = alloc_irq_cfg(node);
+ BUG_ON(!cfg);
+ /*
+ * For legacy IRQ's, start with assigning irq0 to irq15 to
+ * IRQ0_VECTOR to IRQ15_VECTOR for all cpu's.
+ */
+ cfg->vector = IRQ0_VECTOR + i;
+ cpumask_setall(cfg->domain);
+ irq_set_chip_data(i, cfg);
+ }
+}
+#else
+static void init_legacy_irqs(void) { }
+#endif
+
int __init arch_early_irq_init(void)
{
+ init_legacy_irqs();
+
x86_vector_domain = irq_domain_add_tree(NULL, &x86_vector_domain_ops,
NULL);
BUG_ON(x86_vector_domain == NULL);
--
1.7.10.4