Merge branch 'pci/alexander-msi' into next

* pci/alexander-msi:
  x86/MSI: Conserve interrupt resources when using multiple-MSIs
  PCI: Allocate only as many MSI vectors as requested by driver

3 files changed, 16 insertions, 7 deletions

diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c
index dcfea4e39be7..39f81aeefcd6 100644
--- a/drivers/iommu/irq_remapping.c
+++ b/drivers/iommu/irq_remapping.c
@@ -51,26 +51,27 @@ static void irq_remapping_disable_io_apic(void)
 
 static int do_setup_msi_irqs(struct pci_dev *dev, int nvec)
 {
-        int node, ret, sub_handle, index = 0;
+        int node, ret, sub_handle, nvec_pow2, index = 0;
         unsigned int irq;
         struct msi_desc *msidesc;
 
-        nvec = __roundup_pow_of_two(nvec);
-
         WARN_ON(!list_is_singular(&dev->msi_list));
         msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
         WARN_ON(msidesc->irq);
         WARN_ON(msidesc->msi_attrib.multiple);
+        WARN_ON(msidesc->nvec_used);
 
         node = dev_to_node(&dev->dev);
         irq = __create_irqs(get_nr_irqs_gsi(), nvec, node);
         if (irq == 0)
                 return -ENOSPC;
 
-        msidesc->msi_attrib.multiple = ilog2(nvec);
+        nvec_pow2 = __roundup_pow_of_two(nvec);
+        msidesc->nvec_used = nvec;
+        msidesc->msi_attrib.multiple = ilog2(nvec_pow2);
         for (sub_handle = 0; sub_handle < nvec; sub_handle++) {
                 if (!sub_handle) {
-                        index = msi_alloc_remapped_irq(dev, irq, nvec);
+                        index = msi_alloc_remapped_irq(dev, irq, nvec_pow2);
                         if (index < 0) {
                                 ret = index;
                                 goto error;
@@ -95,6 +96,7 @@ error:
          * IRQs from tearing down again in default_teardown_msi_irqs()
          */
         msidesc->irq = 0;
+        msidesc->nvec_used = 0;
         msidesc->msi_attrib.multiple = 0;
 
         return ret;
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 2c1075213bec..aca7578b05e5 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -81,7 +81,10 @@ void default_teardown_msi_irqs(struct pci_dev *dev)
                 int i, nvec;
                 if (entry->irq == 0)
                         continue;
-                nvec = 1 << entry->msi_attrib.multiple;
+                if (entry->nvec_used)
+                        nvec = entry->nvec_used;
+                else
+                        nvec = 1 << entry->msi_attrib.multiple;
                 for (i = 0; i < nvec; i++)
                         arch_teardown_msi_irq(entry->irq + i);
         }
@@ -336,7 +339,10 @@ static void free_msi_irqs(struct pci_dev *dev)
                 int i, nvec;
                 if (!entry->irq)
                         continue;
-                nvec = 1 << entry->msi_attrib.multiple;
+                if (entry->nvec_used)
+                        nvec = entry->nvec_used;
+                else
+                        nvec = 1 << entry->msi_attrib.multiple;
 #ifdef CONFIG_GENERIC_HARDIRQS
                 for (i = 0; i < nvec; i++)
                         BUG_ON(irq_has_action(entry->irq + i));
diff --git a/include/linux/msi.h b/include/linux/msi.h
index 20c2d6dd5d25..ee66f3a12fb6 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -35,6 +35,7 @@ struct msi_desc {
 
         u32 masked;                     /* mask bits */
         unsigned int irq;
+        unsigned int nvec_used;         /* number of messages */
         struct list_head list;
 
         union {