MSI: Give archs the option to free all MSI/Xs at once.

This patch introduces an optional function, arch_teardown_msi_irqs(),
which gives an arch the opportunity to do per-device teardown for
MSI/X. If that's not required, the default version simply calls
arch_teardown_msi_irq() for each msi irq required.

arch_teardown_msi_irqs() is simply passed a pdev, attached to the pdev
is a list of msi_descs, it is up to the arch to free the irq associated
with each of these as appropriate.

For archs that _don't_ implement arch_teardown_msi_irqs(), all msi_descs
with irq == 0 are considered unallocated, and the arch teardown routine
is not called on them.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index c71e8e4c716895c659eb424bcd3c0fb25117bea0..9e1321d0d5e683d281c9e10fc42c826c38e8f4cf 100644 (file)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -207,7 +207,7 @@ void unmask_msi_irq(unsigned int irq)
        msix_flush_writes(irq);
 }
 
-static int msi_free_irq(struct pci_dev* dev, int irq);
+static int msi_free_irqs(struct pci_dev* dev);
 
 
 static struct msi_desc* alloc_msi_entry(void)
@@ -339,8 +339,7 @@ static int msi_capability_init(struct pci_dev *dev)
        /* Configure MSI capability structure */
        ret = arch_setup_msi_irqs(dev, 1, PCI_CAP_ID_MSI);
        if (ret) {
-               list_del(&entry->list);
-               kfree(entry);
+               msi_free_irqs(dev);
                return ret;
        }
 
@@ -415,10 +414,11 @@ static int msix_capability_init(struct pci_dev *dev,
                list_for_each_entry(entry, &dev->msi_list, list) {
                        if (entry->irq != 0) {
                                avail++;
-                               msi_free_irq(dev, entry->irq);
                        }
                }
 
+               msi_free_irqs(dev);
+
                /* If we had some success report the number of irqs
                 * we succeeded in setting up.
                 */
@@ -539,39 +539,33 @@ void pci_disable_msi(struct pci_dev* dev)
        }
 
        default_irq = entry->msi_attrib.default_irq;
-       msi_free_irq(dev, entry->irq);
+       msi_free_irqs(dev);
 
        /* Restore dev->irq to its default pin-assertion irq */
        dev->irq = default_irq;
 }
 EXPORT_SYMBOL(pci_disable_msi);
 
-static int msi_free_irq(struct pci_dev* dev, int irq)
+static int msi_free_irqs(struct pci_dev* dev)
 {
-       struct msi_desc *entry;
-       int entry_nr, type;
-       void __iomem *base;
-
-       BUG_ON(irq_has_action(irq));
+       struct msi_desc *entry, *tmp;
 
-       entry = get_irq_msi(irq);
-       if (!entry || entry->dev != dev) {
-               return -EINVAL;
-       }
-       type = entry->msi_attrib.type;
-       entry_nr = entry->msi_attrib.entry_nr;
-       base = entry->mask_base;
-       list_del(&entry->list);
+       list_for_each_entry(entry, &dev->msi_list, list)
+               BUG_ON(irq_has_action(entry->irq));
 
-       arch_teardown_msi_irq(irq);
-       kfree(entry);
+       arch_teardown_msi_irqs(dev);
 
-       if (type == PCI_CAP_ID_MSIX) {
-               writel(1, base + entry_nr * PCI_MSIX_ENTRY_SIZE +
-                       PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET);
+       list_for_each_entry_safe(entry, tmp, &dev->msi_list, list) {
+               if (entry->msi_attrib.type == PCI_CAP_ID_MSIX) {
+                       if (list_is_last(&entry->list, &dev->msi_list))
+                               iounmap(entry->mask_base);
 
-               if (list_empty(&dev->msi_list))
-                       iounmap(base);
+                       writel(1, entry->mask_base + entry->msi_attrib.entry_nr
+                                 * PCI_MSIX_ENTRY_SIZE
+                                 + PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET);
+               }
+               list_del(&entry->list);
+               kfree(entry);
        }
 
        return 0;
@@ -636,10 +630,7 @@ EXPORT_SYMBOL(pci_enable_msix);
 
 static void msix_free_all_irqs(struct pci_dev *dev)
 {
-       struct msi_desc *entry;
-
-       list_for_each_entry(entry, &dev->msi_list, list)
-               msi_free_irq(dev, entry->irq);
+       msi_free_irqs(dev);
 }
 
 void pci_disable_msix(struct pci_dev* dev)
@@ -669,12 +660,8 @@ void msi_remove_pci_irq_vectors(struct pci_dev* dev)
        if (!pci_msi_enable || !dev)
                return;
 
-       if (dev->msi_enabled) {
-               struct msi_desc *entry;
-               BUG_ON(list_empty(&dev->msi_list));
-               entry = list_entry(dev->msi_list.next, struct msi_desc, list);
-               msi_free_irq(dev, entry->irq);
-       }
+       if (dev->msi_enabled)
+               msi_free_irqs(dev);
 
        if (dev->msix_enabled)
                msix_free_all_irqs(dev);
@@ -719,3 +706,19 @@ arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 
        return 0;
 }
+
+void __attribute__ ((weak)) arch_teardown_msi_irq(unsigned int irq)
+{
+       return;
+}
+
+void __attribute__ ((weak))
+arch_teardown_msi_irqs(struct pci_dev *dev)
+{
+       struct msi_desc *entry;
+
+       list_for_each_entry(entry, &dev->msi_list, list) {
+               if (entry->irq != 0)
+                       arch_teardown_msi_irq(entry->irq);
+       }
+}

diff --git a/include/linux/msi.h b/include/linux/msi.h
index 494627ae021fc3342390b5113714ed12d5d63991..94bb46d82efd74fedc12df205e43cc2f9fc8f167 100644 (file)
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -42,6 +42,7 @@ struct msi_desc {
 int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc);
 void arch_teardown_msi_irq(unsigned int irq);
 extern int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type);
+extern void arch_teardown_msi_irqs(struct pci_dev *dev);
 extern int arch_msi_check_device(struct pci_dev* dev, int nvec, int type);