PCI MSI: Add support for multiple MSI

Add the new API pci_enable_msi_block() to allow drivers to
request multiple MSI and reimplement pci_enable_msi in terms of
pci_enable_msi_block.  Ensure that the architecture back ends don't
have to know about multiple MSI.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

2 files changed, 5 insertions, 2 deletions

diff --git a/include/linux/msi.h b/include/linux/msi.h
index 37c1bbe546e5..6991ab5b24d1 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -21,6 +21,7 @@ extern void write_msi_msg(unsigned int irq, struct msi_msg *msg);
 struct msi_desc {
         struct {
                 __u8    is_msix : 1;
+                __u8    multiple: 3;    /* log2 number of messages */
                 __u8    maskbit : 1;    /* mask-pending bit supported ?   */
                 __u8    is_64   : 1;    /* Address size: 0=32bit 1=64bit  */
                 __u8    pos;            /* Location of the msi capability */
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 7baf2a5db12a..1f6c5ddaae36 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -789,7 +789,7 @@ struct msix_entry {
 
 
 #ifndef CONFIG_PCI_MSI
-static inline int pci_enable_msi(struct pci_dev *dev)
+static inline int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec)
 {
         return -1;
 }
@@ -824,7 +824,7 @@ static inline int pci_msi_enabled(void)
         return 0;
 }
 #else
-extern int pci_enable_msi(struct pci_dev *dev);
+extern int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec);
 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);
@@ -846,6 +846,8 @@ static inline int pcie_aspm_enabled(void)
 extern int pcie_aspm_enabled(void);
 #endif
 
+#define pci_enable_msi(pdev)    pci_enable_msi_block(pdev, 1)
+
 #ifdef CONFIG_HT_IRQ
 /* The functions a driver should call */
 int  ht_create_irq(struct pci_dev *dev, int idx);