x86/irq: Export functions to allow MSI domains in modules

The Linux kernel already has the concept of IRQ domain, wherein a
component can expose a set of IRQs which are managed by a particular
interrupt controller chip or other subsystem. The PCI driver exposes
the notion of an IRQ domain for Message-Signaled Interrupts (MSI) from
PCI Express devices. This patch exposes the functions which are
necessary for creating a MSI IRQ domain within a module.

[ tglx: Split it into x86 and core irq parts ]

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Cc: gregkh@linuxfoundation.org
Cc: kys@microsoft.com
Cc: devel@linuxdriverproject.org
Cc: olaf@aepfle.de
Cc: apw@canonical.com
Cc: vkuznets@redhat.com
Cc: haiyangz@microsoft.com
Cc: marc.zyngier@arm.com
Cc: bhelgaas@google.com
Link: http://lkml.kernel.org/r/1449769983-12948-4-git-send-email-jakeo@microsoft.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

3 files changed, 13 insertions, 3 deletions

diff --git a/arch/x86/include/asm/msi.h b/arch/x86/include/asm/msi.h
index 93724cc62177..eb4b09b41df5 100644
--- a/arch/x86/include/asm/msi.h
+++ b/arch/x86/include/asm/msi.h
@@ -1,7 +1,13 @@
 #ifndef _ASM_X86_MSI_H
 #define _ASM_X86_MSI_H
 #include <asm/hw_irq.h>
+#include <asm/irqdomain.h>
 
 typedef struct irq_alloc_info msi_alloc_info_t;
 
+int pci_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec,
+                    msi_alloc_info_t *arg);
+
+void pci_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc);
+
 #endif /* _ASM_X86_MSI_H */
diff --git a/arch/x86/kernel/apic/msi.c b/arch/x86/kernel/apic/msi.c
index 5f1feb6854af..ade25320df96 100644
--- a/arch/x86/kernel/apic/msi.c
+++ b/arch/x86/kernel/apic/msi.c
@@ -96,8 +96,8 @@ static irq_hw_number_t pci_msi_get_hwirq(struct msi_domain_info *info,
         return arg->msi_hwirq;
 }
 
-static int pci_msi_prepare(struct irq_domain *domain, struct device *dev,
-                           int nvec, msi_alloc_info_t *arg)
+int pci_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec,
+                    msi_alloc_info_t *arg)
 {
         struct pci_dev *pdev = to_pci_dev(dev);
         struct msi_desc *desc = first_pci_msi_entry(pdev);
@@ -113,11 +113,13 @@ static int pci_msi_prepare(struct irq_domain *domain, struct device *dev,
 
         return 0;
 }
+EXPORT_SYMBOL_GPL(pci_msi_prepare);
 
-static void pci_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
+void pci_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
 {
         arg->msi_hwirq = pci_msi_domain_calc_hwirq(arg->msi_dev, desc);
 }
+EXPORT_SYMBOL_GPL(pci_msi_set_desc);
 
 static struct msi_domain_ops pci_msi_domain_ops = {
         .get_hwirq      = pci_msi_get_hwirq,
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index 861bc59c8f25..908cb37da171 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -29,6 +29,7 @@ struct apic_chip_data {
 };
 
 struct irq_domain *x86_vector_domain;
+EXPORT_SYMBOL_GPL(x86_vector_domain);
 static DEFINE_RAW_SPINLOCK(vector_lock);
 static cpumask_var_t vector_cpumask;
 static struct irq_chip lapic_controller;
@@ -66,6 +67,7 @@ struct irq_cfg *irqd_cfg(struct irq_data *irq_data)
 
         return data ? &data->cfg : NULL;
 }
+EXPORT_SYMBOL_GPL(irqd_cfg);
 
 struct irq_cfg *irq_cfg(unsigned int irq)
 {