ixgbevf: fix possible use of uninitialized variable

[~andy/linux] / drivers / pci / msi.c

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 0e6d04d7ba4f7c0a2f8494f3e99aceaed1eecacb..a825d78fd0aa7e50bfb50520d6af16604436890e 100644 (file)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -86,6 +86,31 @@ void default_teardown_msi_irqs(struct pci_dev *dev)
 }
 #endif
 
+#ifndef arch_restore_msi_irqs
+# define arch_restore_msi_irqs default_restore_msi_irqs
+# define HAVE_DEFAULT_MSI_RESTORE_IRQS
+#endif
+
+#ifdef HAVE_DEFAULT_MSI_RESTORE_IRQS
+void default_restore_msi_irqs(struct pci_dev *dev, int irq)
+{
+       struct msi_desc *entry;
+
+       entry = NULL;
+       if (dev->msix_enabled) {
+               list_for_each_entry(entry, &dev->msi_list, list) {
+                       if (irq == entry->irq)
+                               break;
+               }
+       } else if (dev->msi_enabled)  {
+               entry = irq_get_msi_desc(irq);
+       }
+
+       if (entry)
+               write_msi_msg(irq, &entry->msg);
+}
+#endif
+
 static void msi_set_enable(struct pci_dev *dev, int pos, int enable)
 {
        u16 control;
@@ -323,6 +348,18 @@ static void free_msi_irqs(struct pci_dev *dev)
                        if (list_is_last(&entry->list, &dev->msi_list))
                                iounmap(entry->mask_base);
                }
+
+               /*
+                * Its possible that we get into this path
+                * When populate_msi_sysfs fails, which means the entries
+                * were not registered with sysfs.  In that case don't
+                * unregister them.
+                */
+               if (entry->kobj.parent) {
+                       kobject_del(&entry->kobj);
+                       kobject_put(&entry->kobj);
+               }
+
                list_del(&entry->list);
                kfree(entry);
        }
@@ -360,7 +397,7 @@ static void __pci_restore_msi_state(struct pci_dev *dev)
 
        pci_intx_for_msi(dev, 0);
        msi_set_enable(dev, pos, 0);
-       write_msi_msg(dev->irq, &entry->msg);
+       arch_restore_msi_irqs(dev, dev->irq);
 
        pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);
        msi_mask_irq(entry, msi_capable_mask(control), entry->masked);
@@ -388,7 +425,7 @@ static void __pci_restore_msix_state(struct pci_dev *dev)
        pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
 
        list_for_each_entry(entry, &dev->msi_list, list) {
-               write_msi_msg(entry->irq, &entry->msg);
+               arch_restore_msi_irqs(dev, entry->irq);
                msix_mask_irq(entry, entry->masked);
        }
 
@@ -403,6 +440,98 @@ void pci_restore_msi_state(struct pci_dev *dev)
 }
 EXPORT_SYMBOL_GPL(pci_restore_msi_state);
 
+
+#define to_msi_attr(obj) container_of(obj, struct msi_attribute, attr)
+#define to_msi_desc(obj) container_of(obj, struct msi_desc, kobj)
+
+struct msi_attribute {
+       struct attribute        attr;
+       ssize_t (*show)(struct msi_desc *entry, struct msi_attribute *attr,
+                       char *buf);
+       ssize_t (*store)(struct msi_desc *entry, struct msi_attribute *attr,
+                        const char *buf, size_t count);
+};
+
+static ssize_t show_msi_mode(struct msi_desc *entry, struct msi_attribute *atr,
+                            char *buf)
+{
+       return sprintf(buf, "%s\n", entry->msi_attrib.is_msix ? "msix" : "msi");
+}
+
+static ssize_t msi_irq_attr_show(struct kobject *kobj,
+                                struct attribute *attr, char *buf)
+{
+       struct msi_attribute *attribute = to_msi_attr(attr);
+       struct msi_desc *entry = to_msi_desc(kobj);
+
+       if (!attribute->show)
+               return -EIO;
+
+       return attribute->show(entry, attribute, buf);
+}
+
+static const struct sysfs_ops msi_irq_sysfs_ops = {
+       .show = msi_irq_attr_show,
+};
+
+static struct msi_attribute mode_attribute =
+       __ATTR(mode, S_IRUGO, show_msi_mode, NULL);
+
+
+struct attribute *msi_irq_default_attrs[] = {
+       &mode_attribute.attr,
+       NULL
+};
+
+void msi_kobj_release(struct kobject *kobj)
+{
+       struct msi_desc *entry = to_msi_desc(kobj);
+
+       pci_dev_put(entry->dev);
+}
+
+static struct kobj_type msi_irq_ktype = {
+       .release = msi_kobj_release,
+       .sysfs_ops = &msi_irq_sysfs_ops,
+       .default_attrs = msi_irq_default_attrs,
+};
+
+static int populate_msi_sysfs(struct pci_dev *pdev)
+{
+       struct msi_desc *entry;
+       struct kobject *kobj;
+       int ret;
+       int count = 0;
+
+       pdev->msi_kset = kset_create_and_add("msi_irqs", NULL, &pdev->dev.kobj);
+       if (!pdev->msi_kset)
+               return -ENOMEM;
+
+       list_for_each_entry(entry, &pdev->msi_list, list) {
+               kobj = &entry->kobj;
+               kobj->kset = pdev->msi_kset;
+               pci_dev_get(pdev);
+               ret = kobject_init_and_add(kobj, &msi_irq_ktype, NULL,
+                                    "%u", entry->irq);
+               if (ret)
+                       goto out_unroll;
+
+               count++;
+       }
+
+       return 0;
+
+out_unroll:
+       list_for_each_entry(entry, &pdev->msi_list, list) {
+               if (!count)
+                       break;
+               kobject_del(&entry->kobj);
+               kobject_put(&entry->kobj);
+               count--;
+       }
+       return ret;
+}
+
 /**
  * msi_capability_init - configure device's MSI capability structure
  * @dev: pointer to the pci_dev data structure of MSI device function
@@ -454,6 +583,13 @@ static int msi_capability_init(struct pci_dev *dev, int nvec)
                return ret;
        }
 
+       ret = populate_msi_sysfs(dev);
+       if (ret) {
+               msi_mask_irq(entry, mask, ~mask);
+               free_msi_irqs(dev);
+               return ret;
+       }
+
        /* Set MSI enabled bits  */
        pci_intx_for_msi(dev, 0);
        msi_set_enable(dev, pos, 1);
@@ -574,6 +710,12 @@ static int msix_capability_init(struct pci_dev *dev,
 
        msix_program_entries(dev, entries);
 
+       ret = populate_msi_sysfs(dev);
+       if (ret) {
+               ret = 0;
+               goto error;
+       }
+
        /* Set MSI-X enabled bits and unmask the function */
        pci_intx_for_msi(dev, 0);
        dev->msix_enabled = 1;
@@ -732,6 +874,8 @@ void pci_disable_msi(struct pci_dev *dev)
 
        pci_msi_shutdown(dev);
        free_msi_irqs(dev);
+       kset_unregister(dev->msi_kset);
+       dev->msi_kset = NULL;
 }
 EXPORT_SYMBOL(pci_disable_msi);
 
@@ -830,6 +974,8 @@ void pci_disable_msix(struct pci_dev *dev)
 
        pci_msix_shutdown(dev);
        free_msi_irqs(dev);
+       kset_unregister(dev->msi_kset);
+       dev->msi_kset = NULL;
 }
 EXPORT_SYMBOL(pci_disable_msix);
 
@@ -870,5 +1016,15 @@ EXPORT_SYMBOL(pci_msi_enabled);
 
 void pci_msi_init_pci_dev(struct pci_dev *dev)
 {
+       int pos;
        INIT_LIST_HEAD(&dev->msi_list);
+
+       /* Disable the msi hardware to avoid screaming interrupts
+        * during boot.  This is the power on reset default so
+        * usually this should be a noop.
+        */
+       pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
+       if (pos)
+               msi_set_enable(dev, pos, 0);
+       msix_set_enable(dev, 0);
 }