1 files changed, 114 insertions, 39 deletions

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index fdefa7dcd156..a1d2e979b17f 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -117,6 +117,7 @@ is_enabled_store(struct device *dev, struct device_attribute *attr,
                 const char *buf, size_t count)
 {
         struct pci_dev *pdev = to_pci_dev(dev);
+        int retval = 0;
 
         /* this can crash the machine when done on the "wrong" device */
         if (!capable(CAP_SYS_ADMIN))
@@ -126,11 +127,53 @@ is_enabled_store(struct device *dev, struct device_attribute *attr,
                 pci_disable_device(pdev);
 
         if (*buf == '1')
-                pci_enable_device(pdev);
+                retval = pci_enable_device(pdev);
 
+        if (retval)
+                return retval;
         return count;
 }
 
+static ssize_t
+msi_bus_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+        struct pci_dev *pdev = to_pci_dev(dev);
+
+        if (!pdev->subordinate)
+                return 0;
+
+        return sprintf (buf, "%u\n",
+                        !(pdev->subordinate->bus_flags & PCI_BUS_FLAGS_NO_MSI));
+}
+
+static ssize_t
+msi_bus_store(struct device *dev, struct device_attribute *attr,
+              const char *buf, size_t count)
+{
+        struct pci_dev *pdev = to_pci_dev(dev);
+
+        /* bad things may happen if the no_msi flag is changed
+         * while some drivers are loaded */
+        if (!capable(CAP_SYS_ADMIN))
+                return count;
+
+        if (!pdev->subordinate)
+                return count;
+
+        if (*buf == '0') {
+                pdev->subordinate->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
+                dev_warn(&pdev->dev, "forced subordinate bus to not support MSI,"
+                         " bad things could happen.\n");
+        }
+
+        if (*buf == '1') {
+                pdev->subordinate->bus_flags &= ~PCI_BUS_FLAGS_NO_MSI;
+                dev_warn(&pdev->dev, "forced subordinate bus to support MSI,"
+                         " bad things could happen.\n");
+        }
+
+        return count;
+}
 
 struct device_attribute pci_dev_attrs[] = {
         __ATTR_RO(resource),
@@ -145,6 +188,7 @@ struct device_attribute pci_dev_attrs[] = {
         __ATTR(enable, 0600, is_enabled_show, is_enabled_store),
         __ATTR(broken_parity_status,(S_IRUGO|S_IWUSR),
                 broken_parity_status_show,broken_parity_status_store),
+        __ATTR(msi_bus, 0644, msi_bus_show, msi_bus_store),
         __ATTR_NULL,
 };
 
@@ -385,15 +429,38 @@ pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
 }
 
 /**
+ * pci_remove_resource_files - cleanup resource files
+ * @dev: dev to cleanup
+ *
+ * If we created resource files for @dev, remove them from sysfs and
+ * free their resources.
+ */
+static void
+pci_remove_resource_files(struct pci_dev *pdev)
+{
+        int i;
+
+        for (i = 0; i < PCI_ROM_RESOURCE; i++) {
+                struct bin_attribute *res_attr;
+
+                res_attr = pdev->res_attr[i];
+                if (res_attr) {
+                        sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
+                        kfree(res_attr);
+                }
+        }
+}
+
+/**
  * pci_create_resource_files - create resource files in sysfs for @dev
  * @dev: dev in question
  *
  * Walk the resources in @dev creating files for each resource available.
  */
-static void
-pci_create_resource_files(struct pci_dev *pdev)
+static int pci_create_resource_files(struct pci_dev *pdev)
 {
         int i;
+        int retval;
 
         /* Expose the PCI resources from this device as files */
         for (i = 0; i < PCI_ROM_RESOURCE; i++) {
@@ -416,35 +483,19 @@ pci_create_resource_files(struct pci_dev *pdev)
                         res_attr->size = pci_resource_len(pdev, i);
                         res_attr->mmap = pci_mmap_resource;
                         res_attr->private = &pdev->resource[i];
-                        sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
-                }
-        }
-}
-
-/**
- * pci_remove_resource_files - cleanup resource files
- * @dev: dev to cleanup
- *
- * If we created resource files for @dev, remove them from sysfs and
- * free their resources.
- */
-static void
-pci_remove_resource_files(struct pci_dev *pdev)
-{
-        int i;
-
-        for (i = 0; i < PCI_ROM_RESOURCE; i++) {
-                struct bin_attribute *res_attr;
-
-                res_attr = pdev->res_attr[i];
-                if (res_attr) {
-                        sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
-                        kfree(res_attr);
+                        retval = sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
+                        if (retval) {
+                                pci_remove_resource_files(pdev);
+                                return retval;
+                        }
+                } else {
+                        return -ENOMEM;
                 }
         }
+        return 0;
 }
 #else /* !HAVE_PCI_MMAP */
-static inline void pci_create_resource_files(struct pci_dev *dev) { return; }
+static inline int pci_create_resource_files(struct pci_dev *dev) { return 0; }
 static inline void pci_remove_resource_files(struct pci_dev *dev) { return; }
 #endif /* HAVE_PCI_MMAP */
 
@@ -529,22 +580,27 @@ static struct bin_attribute pcie_config_attr = {
         .write = pci_write_config,
 };
 
-int pci_create_sysfs_dev_files (struct pci_dev *pdev)
+int __must_check pci_create_sysfs_dev_files (struct pci_dev *pdev)
 {
+        struct bin_attribute *rom_attr = NULL;
+        int retval;
+
         if (!sysfs_initialized)
                 return -EACCES;
 
         if (pdev->cfg_size < 4096)
-                sysfs_create_bin_file(&pdev->dev.kobj, &pci_config_attr);
+                retval = sysfs_create_bin_file(&pdev->dev.kobj, &pci_config_attr);
         else
-                sysfs_create_bin_file(&pdev->dev.kobj, &pcie_config_attr);
+                retval = sysfs_create_bin_file(&pdev->dev.kobj, &pcie_config_attr);
+        if (retval)
+                goto err;
 
-        pci_create_resource_files(pdev);
+        retval = pci_create_resource_files(pdev);
+        if (retval)
+                goto err_bin_file;
 
         /* If the device has a ROM, try to expose it in sysfs. */
         if (pci_resource_len(pdev, PCI_ROM_RESOURCE)) {
-                struct bin_attribute *rom_attr;
-                
                 rom_attr = kzalloc(sizeof(*rom_attr), GFP_ATOMIC);
                 if (rom_attr) {
                         pdev->rom_attr = rom_attr;
@@ -554,13 +610,28 @@ int pci_create_sysfs_dev_files (struct pci_dev *pdev)
                         rom_attr->attr.owner = THIS_MODULE;
                         rom_attr->read = pci_read_rom;
                         rom_attr->write = pci_write_rom;
-                        sysfs_create_bin_file(&pdev->dev.kobj, rom_attr);
+                        retval = sysfs_create_bin_file(&pdev->dev.kobj, rom_attr);
+                        if (retval)
+                                goto err_rom;
+                } else {
+                        retval = -ENOMEM;
+                        goto err_bin_file;
                 }
         }
         /* add platform-specific attributes */
         pcibios_add_platform_entries(pdev);
-        
+
         return 0;
+
+err_rom:
+        kfree(rom_attr);
+err_bin_file:
+        if (pdev->cfg_size < 4096)
+                sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
+        else
+                sysfs_remove_bin_file(&pdev->dev.kobj, &pcie_config_attr);
+err:
+        return retval;
 }
 
 /**
@@ -589,10 +660,14 @@ void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
 static int __init pci_sysfs_init(void)
 {
         struct pci_dev *pdev = NULL;
-        
+        int retval;
+
         sysfs_initialized = 1;
-        for_each_pci_dev(pdev)
-                pci_create_sysfs_dev_files(pdev);
+        for_each_pci_dev(pdev) {
+                retval = pci_create_sysfs_dev_files(pdev);
+                if (retval)
+                        return retval;
+        }
 
         return 0;
 }