edac_core: Allow the creation of sysfs groups

Currently, all sysfs nodes are stored at /sys/.*/mc. (regex)
However, sometimes it is needed to create attribute groups.

This patch extends edac_core to allow groups creation.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

2 files changed, 67 insertions, 28 deletions

diff --git a/drivers/edac/edac_core.h b/drivers/edac/edac_core.h
index 001b2e797fb3..97071ff1d22d 100644
--- a/drivers/edac/edac_core.h
+++ b/drivers/edac/edac_core.h
@@ -341,12 +341,22 @@ struct csrow_info {
         struct channel_info *channels;
 };
 
+struct mcidev_sysfs_group {
+        const char *name;
+        struct mcidev_sysfs_attribute *mcidev_attr;
+        struct kobject kobj;
+};
+
+
 /* mcidev_sysfs_attribute structure
  *      used for driver sysfs attributes and in mem_ctl_info
  *      sysfs top level entries
  */
 struct mcidev_sysfs_attribute {
-        struct attribute attr;
+        struct attribute attr;
+
+        struct mcidev_sysfs_group *grp;
+
         ssize_t (*show)(struct mem_ctl_info *,char *);
         ssize_t (*store)(struct mem_ctl_info *, const char *,size_t);
 };
diff --git a/drivers/edac/edac_mc_sysfs.c b/drivers/edac/edac_mc_sysfs.c
index 418b65f1a1da..655aa1a1f4f9 100644
--- a/drivers/edac/edac_mc_sysfs.c
+++ b/drivers/edac/edac_mc_sysfs.c
@@ -728,26 +728,43 @@ void edac_mc_unregister_sysfs_main_kobj(struct mem_ctl_info *mci)
 
 /*
  * edac_create_mci_instance_attributes
- *      create MC driver specific attributes at the topmost level
- *      directory of this mci instance.
+ *      create MC driver specific attributes bellow an specified kobj
+ * This routine calls itself recursively, in order to create an entire
+ * object tree.
  */
-static int edac_create_mci_instance_attributes(struct mem_ctl_info *mci)
+static int edac_create_mci_instance_attributes(
+                                struct mcidev_sysfs_attribute *sysfs_attrib,
+                                struct kobject *kobj)
 {
         int err;
-        struct mcidev_sysfs_attribute *sysfs_attrib;
 
-        /* point to the start of the array and iterate over it
-         * adding each attribute listed to this mci instance's kobject
-         */
-        sysfs_attrib = mci->mc_driver_sysfs_attributes;
+        while (sysfs_attrib) {
+                if (sysfs_attrib->grp) {
+                        struct kobject *newkobj = &sysfs_attrib->grp->kobj;
+                        debugf0("%s() grp %s\n", __func__,
+                                sysfs_attrib->grp->name);
+
+                        err = kobject_init_and_add(newkobj, NULL,
+                                                kobj,
+                                                sysfs_attrib->grp->name);
+                        if (err)
+                                return err;
+
+                        err = edac_create_mci_instance_attributes(
+                                        sysfs_attrib->grp->mcidev_attr, newkobj);
+                        if (err)
+                                return err;
+                } else if (sysfs_attrib->attr.name) {
+                        debugf0("%s() file %s\n", __func__,
+                                sysfs_attrib->attr.name);
+
+                        err = sysfs_create_file(kobj, &sysfs_attrib->attr);
+                } else
+                        break;
 
-        while (sysfs_attrib && sysfs_attrib->attr.name) {
-                err = sysfs_create_file(&mci->edac_mci_kobj,
-                                        (struct attribute*) sysfs_attrib);
                 if (err) {
                         return err;
                 }
-
                 sysfs_attrib++;
         }
 
@@ -759,19 +776,28 @@ static int edac_create_mci_instance_attributes(struct mem_ctl_info *mci)
  *      remove MC driver specific attributes at the topmost level
  *      directory of this mci instance.
  */
-static void edac_remove_mci_instance_attributes(struct mem_ctl_info *mci)
+static void edac_remove_mci_instance_attributes(
+                                struct mcidev_sysfs_attribute *sysfs_attrib,
+                                struct kobject *kobj)
 {
-        struct mcidev_sysfs_attribute *sysfs_attrib;
-
-        /* point to the start of the array and iterate over it
-         * adding each attribute listed to this mci instance's kobject
-         */
-        sysfs_attrib = mci->mc_driver_sysfs_attributes;
-
         /* loop if there are attributes and until we hit a NULL entry */
-        while (sysfs_attrib && sysfs_attrib->attr.name) {
-                sysfs_remove_file(&mci->edac_mci_kobj,
-                                        (struct attribute *) sysfs_attrib);
+        while (sysfs_attrib) {
+                if (sysfs_attrib->grp) {
+                        struct kobject *newkobj = &sysfs_attrib->grp->kobj;
+
+                        debugf0("%s() grp %s\n", __func__,
+                                sysfs_attrib->grp->name);
+
+                        edac_remove_mci_instance_attributes(
+                                sysfs_attrib->grp->mcidev_attr, newkobj);
+
+                        kobject_put(newkobj);
+                } else  if (sysfs_attrib->attr.name) {
+                        debugf0("%s() file %s\n", __func__,
+                                sysfs_attrib->attr.name);
+                        sysfs_remove_file(kobj, &sysfs_attrib->attr);
+                } else
+                        break;
                 sysfs_attrib++;
         }
 }
@@ -806,7 +832,9 @@ int edac_create_sysfs_mci_device(struct mem_ctl_info *mci)
          * then create them now for the driver.
          */
         if (mci->mc_driver_sysfs_attributes) {
-                err = edac_create_mci_instance_attributes(mci);
+                err = edac_create_mci_instance_attributes(
+                                        mci->mc_driver_sysfs_attributes,
+                                        &mci->edac_mci_kobj);
                 if (err) {
                         debugf1("%s() failure to create mci attributes\n",
                                 __func__);
@@ -841,7 +869,8 @@ fail1:
         }
 
         /* remove the mci instance's attributes, if any */
-        edac_remove_mci_instance_attributes(mci);
+        edac_remove_mci_instance_attributes(
+                mci->mc_driver_sysfs_attributes, &mci->edac_mci_kobj);
 
         /* remove the symlink */
         sysfs_remove_link(kobj_mci, EDAC_DEVICE_SYMLINK);
@@ -875,8 +904,8 @@ void edac_remove_sysfs_mci_device(struct mem_ctl_info *mci)
         debugf0("%s()  remove_mci_instance\n", __func__);
 
         /* remove this mci instance's attribtes */
-        edac_remove_mci_instance_attributes(mci);
-
+        edac_remove_mci_instance_attributes(mci->mc_driver_sysfs_attributes,
+                                            &mci->edac_mci_kobj);
         debugf0("%s()  unregister this mci kobj\n", __func__);
 
         /* unregister this instance's kobject */