PCI/MSI: Add pci_enable_msi_range() and pci_enable_msix_range()
This adds pci_enable_msi_range(), which supersedes the pci_enable_msi()
and pci_enable_msi_block() MSI interfaces.
It also adds pci_enable_msix_range(), which supersedes the
pci_enable_msix() MSI-X interface.
The old interfaces have three categories of return values:
negative: failure; caller should not retry
positive: failure; value indicates number of interrupts that *could*
have been allocated, and caller may retry with a smaller request
zero: success; at least as many interrupts allocated as requested
It is error-prone to handle these three cases correctly in drivers.
The new functions return either a negative error code or a number of
successfully allocated MSI/MSI-X interrupts, which is expected to lead to
clearer device driver code.
pci_enable_msi(), pci_enable_msi_block() and pci_enable_msix() still exist
unchanged, but are deprecated and may be removed after callers are updated.
[bhelgaas: tweak changelog]
Suggested-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Tejun Heo <tj@kernel.org>diff --git a/include/linux/pci.h b/include/linux/pci.h
index cf6125b..6e32a28 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1193,6 +1193,17 @@
{
return 0;
}
+
+static inline int pci_enable_msi_range(struct pci_dev *dev, int minvec,
+ int maxvec)
+{
+ return -ENOSYS;
+}
+static inline int pci_enable_msix_range(struct pci_dev *dev,
+ struct msix_entry *entries, int minvec, int maxvec)
+{
+ return -ENOSYS;
+}
#else
int pci_msi_vec_count(struct pci_dev *dev);
int pci_enable_msi_block(struct pci_dev *dev, int nvec);
@@ -1205,6 +1216,9 @@
void msi_remove_pci_irq_vectors(struct pci_dev *dev);
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);
+int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
+ int minvec, int maxvec);
#endif
#ifdef CONFIG_PCIEPORTBUS