PCI/MSI: Add pci_enable_msi_exact() and pci_enable_msix_exact()
The new functions are special cases for pci_enable_msi_range() and
pci_enable_msix_range() when a particular number of MSI or MSI-X
is needed.
By contrast with pci_enable_msi_range() and pci_enable_msix_range()
functions, pci_enable_msi_exact() and pci_enable_msix_exact()
return zero in case of success, which indicates MSI or MSI-X
interrupts have been successfully allocated.
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/include/linux/pci.h b/include/linux/pci.h
index fb57c89..33aa2ca 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1169,8 +1169,23 @@
void pci_restore_msi_state(struct pci_dev *dev);
int pci_msi_enabled(void);
int pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec);
+static inline int pci_enable_msi_exact(struct pci_dev *dev, int nvec)
+{
+ int rc = pci_enable_msi_range(dev, nvec, nvec);
+ if (rc < 0)
+ return rc;
+ return 0;
+}
int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
int minvec, int maxvec);
+static inline int pci_enable_msix_exact(struct pci_dev *dev,
+ struct msix_entry *entries, int nvec)
+{
+ int rc = pci_enable_msix_range(dev, entries, nvec, nvec);
+ if (rc < 0)
+ return rc;
+ return 0;
+}
#else
static inline int pci_msi_vec_count(struct pci_dev *dev) { return -ENOSYS; }
static inline int pci_enable_msi_block(struct pci_dev *dev, int nvec)
@@ -1189,9 +1204,14 @@
static inline int pci_enable_msi_range(struct pci_dev *dev, int minvec,
int maxvec)
{ return -ENOSYS; }
+static inline int pci_enable_msi_exact(struct pci_dev *dev, int nvec)
+{ return -ENOSYS; }
static inline int pci_enable_msix_range(struct pci_dev *dev,
struct msix_entry *entries, int minvec, int maxvec)
{ return -ENOSYS; }
+static inline int pci_enable_msix_exact(struct pci_dev *dev,
+ struct msix_entry *entries, int nvec)
+{ return -ENOSYS; }
#endif
#ifdef CONFIG_PCIEPORTBUS