[PATCH v1 1/4] PCI: Introduce pcim_alloc_irq_vectors()

[Dejin Zheng]

Introduce pcim_alloc_irq_vectors(), a explicit device-managed version of
pci_alloc_irq_vectors().

Suggested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Signed-off-by: Dejin Zheng <zhengdejin5@xxxxxxxxx>
---
 drivers/pci/pci.c   | 19 +++++++++++++++++++
 include/linux/pci.h |  3 +++
 2 files changed, 22 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index b67c4327d307..33244b512057 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2054,6 +2054,25 @@ void pcim_pin_device(struct pci_dev *pdev)
 }
 EXPORT_SYMBOL(pcim_pin_device);
 
+/**
+ * pcim_alloc_irq_vectors - a device-managed pci_alloc_irq_vectors()
+ *
+ * It depends on calling pcim_enable_device() to make irq resources manageable.
+ */
+int pcim_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
+				unsigned int max_vecs, unsigned int flags)
+{
+	struct pci_devres *dr;
+
+       /*Ensure that the pcim_enable_device() function has been called*/
+	dr = find_pci_dr(dev);
+	if (!dr || !dr->enabled)
+		return -EINVAL;
+
+	return pci_alloc_irq_vectors(dev, min_vecs, max_vecs, flags);
+}
+EXPORT_SYMBOL(pcim_alloc_irq_vectors);
+
 /*
  * pcibios_add_device - provide arch specific hooks when adding device dev
  * @dev: the PCI device being added
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 86c799c97b77..d75ba85ddfc5 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1818,6 +1818,9 @@ pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
 					      NULL);
 }
 
+int pcim_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
+				unsigned int max_vecs, unsigned int flags);
+
 /* Include architecture-dependent settings and functions */
 
 #include <asm/pci.h>
-- 
2.25.0