[v3,1/2] genirq/msi: add wrapper msi allocation API and export msi functions

Commit Message

Nipun Gupta Feb. 26, 2024, 8:48 a.m. UTC

MSI functions can be for allocation and free can be directly
used by the device drivers without any wrapper provided by
bus drivers. So export these MSI functions.

Also, add a wrapper API to allocate MSIs providing only the
number of IRQ's rather than range for simpler driver usage.

Signed-off-by: Nipun Gupta <[e-mail]>
---

Changes in v3:
- New in this patch series. VFIO-CDX uses the new wrapper API
  msi_domain_alloc_irqs and exported APIs. (This patch is moved
  from CDX interrupt support to vfio-cdx patch, where these APIs
  are used).

 include/linux/msi.h | 6 ++++++
 kernel/irq/msi.c    | 2 ++
 2 files changed, 8 insertions(+)

Patch

diff --git a/include/linux/msi.h b/include/linux/msi.h
index ddace8c34dcf..a9f77cbc8847 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -658,6 +658,12 @@  void platform_msi_device_domain_free(struct irq_domain *domain, unsigned int vir
 void *platform_msi_get_host_data(struct irq_domain *domain);
 
 bool msi_device_has_isolated_msi(struct device *dev);
+
+static inline int msi_domain_alloc_irqs(struct device *dev, unsigned int domid, int nirqs)
+{
+	return msi_domain_alloc_irqs_range(dev, domid, 0, nirqs - 1);
+}
+
 #else /* CONFIG_GENERIC_MSI_IRQ */
 static inline bool msi_device_has_isolated_msi(struct device *dev)
 {
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 79b4a58ba9c3..4a324f683858 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -1404,6 +1404,7 @@  int msi_domain_alloc_irqs_range(struct device *dev, unsigned int domid,
 	msi_unlock_descs(dev);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(msi_domain_alloc_irqs_range);
 
 /**
  * msi_domain_alloc_irqs_all_locked - Allocate all interrupts from a MSI interrupt domain
@@ -1596,6 +1597,7 @@  void msi_domain_free_irqs_range(struct device *dev, unsigned int domid,
 	msi_domain_free_irqs_range_locked(dev, domid, first, last);
 	msi_unlock_descs(dev);
 }
+EXPORT_SYMBOL_GPL(msi_domain_free_irqs_all);
 
 /**
  * msi_domain_free_irqs_all_locked - Free all interrupts from a MSI interrupt domain