[PATCH v5 1/4] PCI: Introduce pcim_alloc_irq_vectors()

[Dejin Zheng <zhengdejin5@gmail.com>]

Introduce pcim_alloc_irq_vectors(), a device-managed version of
pci_alloc_irq_vectors(). Introducing this function can simplify
the error handling path in many drivers.

And use pci_free_irq_vectors() to replace some code in pcim_release(),
they are equivalent, and no functional change. It is more explicit
that pcim_alloc_irq_vectors() is a device-managed function.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
---
v4 -> v5:
	- Remove the check of enable device in pcim_alloc_irq_vectors()
	  and make it as a static line function.
v3 -> v4:
	- No change
v2 -> v3:
	- Add some commit comments for replace some codes in
	  pcim_release() by pci_free_irq_vectors().
v1 -> v2:
	- Use pci_free_irq_vectors() to replace some code in
	  pcim_release().
	- Modify some commit messages.

 drivers/pci/pci.c   |  5 +----
 include/linux/pci.h | 24 ++++++++++++++++++++++++
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 16a17215f633..fecfdc0add2f 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1969,10 +1969,7 @@ static void pcim_release(struct device *gendev, void *res)
 	struct pci_devres *this = res;
 	int i;
 
-	if (dev->msi_enabled)
-		pci_disable_msi(dev);
-	if (dev->msix_enabled)
-		pci_disable_msix(dev);
+	pci_free_irq_vectors(dev);
 
 	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
 		if (this->region_mask & (1 << i))
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 86c799c97b77..5cafd7d65fd7 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1818,6 +1818,30 @@ pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
 					      NULL);
 }
 
+/**
+ * pcim_alloc_irq_vectors - a device-managed pci_alloc_irq_vectors()
+ * @dev:		PCI device to operate on
+ * @min_vecs:		minimum number of vectors required (must be >= 1)
+ * @max_vecs:		maximum (desired) number of vectors
+ * @flags:		flags or quirks for the allocation
+ *
+ * Return the number of vectors allocated, (which might be smaller than
+ * @max_vecs) if successful, or a negative error code on error. If less
+ * than @min_vecs interrupt vectors are available for @dev the function
+ * will fail with -ENOSPC.
+ *
+ * It depends on calling pcim_enable_device() to make IRQ resources
+ * manageable.
+ */
+static inline int
+pcim_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
+			unsigned int max_vecs, unsigned int flags)
+{
+	if (!pci_is_managed(dev))
+		return -EINVAL;
+	return pci_alloc_irq_vectors(dev, min_vecs, max_vecs, flags);
+}
+
 /* Include architecture-dependent settings and functions */
 
 #include <asm/pci.h>
-- 
2.25.0