PCI/MSI: Enable multiple MSIs with pci_enable_msi_block_auto()
The new function pci_enable_msi_block_auto() tries to allocate
maximum possible number of MSIs up to the number the device
supports. It generalizes a pattern when pci_enable_msi_block()
is contiguously called until it succeeds or fails.
Opposite to pci_enable_msi_block() which takes the number of
MSIs to allocate as a input parameter,
pci_enable_msi_block_auto() could be used by device drivers to
obtain the number of assigned MSIs and the number of MSIs the
device supports.
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/c3de2419df94a0f95ca1a6f755afc421486455e6.1353324359.git.agordeev@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 15472d6..6fa4dd2 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1101,6 +1101,12 @@
return -1;
}
+static inline int
+pci_enable_msi_block_auto(struct pci_dev *dev, unsigned int *maxvec)
+{
+ return -1;
+}
+
static inline void pci_msi_shutdown(struct pci_dev *dev)
{ }
static inline void pci_disable_msi(struct pci_dev *dev)
@@ -1132,6 +1138,7 @@
}
#else
extern int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec);
+extern int pci_enable_msi_block_auto(struct pci_dev *dev, unsigned int *maxvec);
extern void pci_msi_shutdown(struct pci_dev *dev);
extern void pci_disable_msi(struct pci_dev *dev);
extern int pci_msix_table_size(struct pci_dev *dev);