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>

1 files changed, 39 insertions, 36 deletions

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index c71e8e4c716..9e1321d0d5e 100644
--- 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);
+        }
+}