[PATCH] genirq: msi: simplify the msi irq limit policy

[linux-2.6] / drivers / pci / msi.c

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 6d9de026e14128b0439483950a49a0c016220190..a32e75a4417e8c4a3be948dea95d40e3a7d1eab8 100644 (file)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -29,8 +29,6 @@ static kmem_cache_t* msi_cachep;
 static int pci_msi_enable = 1;
 static int last_alloc_vector;
 static int nr_released_vectors;
-static int nr_reserved_vectors = NR_HP_RESERVED_VECTORS;
-static int nr_msix_devices;
 
 #ifndef CONFIG_X86_IO_APIC
 int vector_irq[NR_VECTORS] = { [0 ... NR_VECTORS - 1] = -1};
@@ -534,11 +532,6 @@ void pci_scan_msi_device(struct pci_dev *dev)
 {
        if (!dev)
                return;
-
-       if (pci_find_capability(dev, PCI_CAP_ID_MSIX) > 0)
-               nr_msix_devices++;
-       else if (pci_find_capability(dev, PCI_CAP_ID_MSI) > 0)
-               nr_reserved_vectors++;
 }
 
 #ifdef CONFIG_PM
@@ -869,13 +862,19 @@ static int msix_capability_init(struct pci_dev *dev,
                attach_msi_entry(entry, vector);
        }
        if (i != nvec) {
+               int avail = i - 1;
                i--;
                for (; i >= 0; i--) {
                        vector = (entries + i)->vector;
                        msi_free_vector(dev, vector, 0);
                        (entries + i)->vector = 0;
                }
-               return -EBUSY;
+               /* If we had some success report the number of irqs
+                * we succeeded in setting up.
+                */
+               if (avail <= 0)
+                       avail = -EBUSY;
+               return avail;
        }
        /* Set MSI-X enabled bits */
        enable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);
@@ -954,14 +953,6 @@ int pci_enable_msi(struct pci_dev* dev)
                        return -EINVAL;
        }
        status = msi_capability_init(dev);
-       if (!status) {
-               if (!pos)
-                       nr_reserved_vectors--;  /* Only MSI capable */
-               else if (nr_msix_devices > 0)
-                       nr_msix_devices--;      /* Both MSI and MSI-X capable,
-                                                  but choose enabling MSI */
-       }
-
        return status;
 }
 
@@ -1070,10 +1061,9 @@ static int msi_free_vector(struct pci_dev* dev, int vector, int reassign)
  **/
 int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec)
 {
-       int status, pos, nr_entries, free_vectors;
+       int status, pos, nr_entries;
        int i, j, temp;
        u16 control;
-       unsigned long flags;
 
        if (!entries || pci_msi_supported(dev) < 0)
                return -EINVAL;
@@ -1112,34 +1102,7 @@ int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec)
                dev->irq = temp;
                return -EINVAL;
        }
-
-       spin_lock_irqsave(&msi_lock, flags);
-       /*
-        * msi_lock is provided to ensure that enough vectors resources are
-        * available before granting.
-        */
-       free_vectors = pci_vector_resources(last_alloc_vector,
-                               nr_released_vectors);
-       /* Ensure that each MSI/MSI-X device has one vector reserved by
-          default to avoid any MSI-X driver to take all available
-          resources */
-       free_vectors -= nr_reserved_vectors;
-       /* Find the average of free vectors among MSI-X devices */
-       if (nr_msix_devices > 0)
-               free_vectors /= nr_msix_devices;
-       spin_unlock_irqrestore(&msi_lock, flags);
-
-       if (nvec > free_vectors) {
-               if (free_vectors > 0)
-                       return free_vectors;
-               else
-                       return -EBUSY;
-       }
-
        status = msix_capability_init(dev, entries, nvec);
-       if (!status && nr_msix_devices > 0)
-               nr_msix_devices--;
-
        return status;
 }