[tip:x86/apic] x86, irq: Introduce helper to check whether an IOAPIC has been registered

tip-bot for Jiang Liu
2014-11-03T11:02:23Z

Commit-ID: cf45268eceac09ff4af677f6e876b4d0397e1d3f
Gitweb: http://git.kernel.org/tip/cf45268eceac09ff4af677f6e876b4d0397e1d3f
Author: Jiang Liu <jiang.liu@linux.intel.com>
AuthorDate: Mon, 27 Oct 2014 13:21:47 +0800
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Mon, 3 Nov 2014 11:56:08 +0100

x86, irq: Introduce helper to check whether an IOAPIC has been registered

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>
Acked-by: Pavel Machek <pavel@ucw.cz>
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: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Len Brown <len.brown@intel.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1414387308-27148-18-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/include/asm/io_apic.h | 1 +
arch/x86/kernel/acpi/boot.c | 22 ++++++++++++++++++++++
arch/x86/kernel/apic/io_apic.c | 11 +++++++++++
include/linux/acpi.h | 1 +
4 files changed, 35 insertions(+)

diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index 7c04b8e..ca742d5 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 77107a9..1ae52e0 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -824,6 +824,28 @@ int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base)
}
EXPORT_SYMBOL(acpi_unregister_ioapic);

+/**
+ * acpi_ioapic_registered - Check whether IOAPIC assoicatied with @gsi_base
+ * has been registered
+ * @handle: ACPI handle of the IOAPIC deivce
+ * @gsi_base: GSI base associated with the IOAPIC
+ *
+ * Assume caller holds some type of lock to serialize acpi_ioapic_registered()
+ * with acpi_register_ioapic()/acpi_unregister_ioapic().
+ */
+int acpi_ioapic_registered(acpi_handle handle, u32 gsi_base)
+{
+ int ret = 0;
+
+#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
+ mutex_lock(&acpi_ioapic_lock);
+ ret = mp_ioapic_registered(gsi_base);
+ mutex_unlock(&acpi_ioapic_lock);
+#endif
+
+ 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 011ebca..ff2709e 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -4026,6 +4026,17 @@ 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 77cecd0..be6be0f 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -152,6 +152,7 @@ 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;