[Patch v4 14/16] x86, irq: Introduce helper to check whether an IOAPIC has been registered

Jiang Liu
2014-08-28T02:22:39Z

Introduce acpi_ioapic_registered() to check whether an IOAPIC has already
been registered, it will be used when enabling IOAPIC hotplug.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
arch/x86/include/asm/io_apic.h | 1 +
arch/x86/kernel/acpi/boot.c | 11 +++++++++++
arch/x86/kernel/apic/io_apic.c | 11 +++++++++++
include/linux/acpi.h | 1 +
4 files changed, 24 insertions(+)

diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index ce63cf34c93c..0db2b7037e4b 100644
--- a/arch/x86/include/asm/io_apic.h
+++ b/arch/x86/include/asm/io_apic.h
@@ -191,6 +191,7 @@ extern void mp_unmap_irq(int irq);
extern int mp_register_ioapic(int id, u32 address, u32 gsi_base,
struct ioapic_domain_cfg *cfg);
extern int mp_unregister_ioapic(u32 gsi_base);
+extern int mp_ioapic_registered(u32 gsi_base);
extern int mp_irqdomain_map(struct irq_domain *domain, unsigned int virq,
irq_hw_number_t hwirq);
extern void mp_irqdomain_unmap(struct irq_domain *domain, unsigned int virq);
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 560a6d1cb0f4..6aa796f77b71 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -810,6 +810,17 @@ int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base)
}
EXPORT_SYMBOL(acpi_unregister_ioapic);

+int acpi_ioapic_registered(acpi_handle handle, u32 gsi_base)
+{
+ int ret;
+
+ down_write(&acpi_ioapic_rwsem);
+ ret = mp_ioapic_registered(gsi_base);
+ up_write(&acpi_ioapic_rwsem);
+
+ return ret;
+}
+
static int __init acpi_parse_sbf(struct acpi_table_header *table)
{
struct acpi_table_boot *sb;
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index fc1e1f9567bc..e104993a2394 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -4010,6 +4010,17 @@ int mp_unregister_ioapic(u32 gsi_base)
return 0;
}

+int mp_ioapic_registered(u32 gsi_base)
+{
+ int ioapic;
+
+ for_each_ioapic(ioapic)
+ if (ioapics[ioapic].gsi_config.gsi_base == gsi_base)
+ return 1;
+
+ return 0;
+}
+
int mp_irqdomain_map(struct irq_domain *domain, unsigned int virq,
irq_hw_number_t hwirq)
{
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index b41c5aef5336..754d99d5f258 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -155,6 +155,7 @@ int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr);

int acpi_register_ioapic(acpi_handle handle, u64 phys_addr, u32 gsi_base);
int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base);
+int acpi_ioapic_registered(acpi_handle handle, u32 gsi_base);
void acpi_irq_stats_init(void);
extern u32 acpi_irq_handled;
extern u32 acpi_irq_not_handled;
--
1.7.10.4