v4.19.13 snapshot.
diff --git a/drivers/edac/debugfs.c b/drivers/edac/debugfs.c
new file mode 100644
index 0000000..92dbb7e
--- /dev/null
+++ b/drivers/edac/debugfs.c
@@ -0,0 +1,163 @@
+#include "edac_module.h"
+
+static struct dentry *edac_debugfs;
+
+static ssize_t edac_fake_inject_write(struct file *file,
+ const char __user *data,
+ size_t count, loff_t *ppos)
+{
+ struct device *dev = file->private_data;
+ struct mem_ctl_info *mci = to_mci(dev);
+ static enum hw_event_mc_err_type type;
+ u16 errcount = mci->fake_inject_count;
+
+ if (!errcount)
+ errcount = 1;
+
+ type = mci->fake_inject_ue ? HW_EVENT_ERR_UNCORRECTED
+ : HW_EVENT_ERR_CORRECTED;
+
+ printk(KERN_DEBUG
+ "Generating %d %s fake error%s to %d.%d.%d to test core handling. NOTE: this won't test the driver-specific decoding logic.\n",
+ errcount,
+ (type == HW_EVENT_ERR_UNCORRECTED) ? "UE" : "CE",
+ errcount > 1 ? "s" : "",
+ mci->fake_inject_layer[0],
+ mci->fake_inject_layer[1],
+ mci->fake_inject_layer[2]
+ );
+ edac_mc_handle_error(type, mci, errcount, 0, 0, 0,
+ mci->fake_inject_layer[0],
+ mci->fake_inject_layer[1],
+ mci->fake_inject_layer[2],
+ "FAKE ERROR", "for EDAC testing only");
+
+ return count;
+}
+
+static const struct file_operations debug_fake_inject_fops = {
+ .open = simple_open,
+ .write = edac_fake_inject_write,
+ .llseek = generic_file_llseek,
+};
+
+int __init edac_debugfs_init(void)
+{
+ edac_debugfs = debugfs_create_dir("edac", NULL);
+ if (IS_ERR(edac_debugfs)) {
+ edac_debugfs = NULL;
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+void edac_debugfs_exit(void)
+{
+ debugfs_remove_recursive(edac_debugfs);
+}
+
+int edac_create_debugfs_nodes(struct mem_ctl_info *mci)
+{
+ struct dentry *d, *parent;
+ char name[80];
+ int i;
+
+ if (!edac_debugfs)
+ return -ENODEV;
+
+ d = debugfs_create_dir(mci->dev.kobj.name, edac_debugfs);
+ if (!d)
+ return -ENOMEM;
+ parent = d;
+
+ for (i = 0; i < mci->n_layers; i++) {
+ sprintf(name, "fake_inject_%s",
+ edac_layer_name[mci->layers[i].type]);
+ d = debugfs_create_u8(name, S_IRUGO | S_IWUSR, parent,
+ &mci->fake_inject_layer[i]);
+ if (!d)
+ goto nomem;
+ }
+
+ d = debugfs_create_bool("fake_inject_ue", S_IRUGO | S_IWUSR, parent,
+ &mci->fake_inject_ue);
+ if (!d)
+ goto nomem;
+
+ d = debugfs_create_u16("fake_inject_count", S_IRUGO | S_IWUSR, parent,
+ &mci->fake_inject_count);
+ if (!d)
+ goto nomem;
+
+ d = debugfs_create_file("fake_inject", S_IWUSR, parent,
+ &mci->dev,
+ &debug_fake_inject_fops);
+ if (!d)
+ goto nomem;
+
+ mci->debugfs = parent;
+ return 0;
+nomem:
+ edac_debugfs_remove_recursive(mci->debugfs);
+ return -ENOMEM;
+}
+
+/* Create a toplevel dir under EDAC's debugfs hierarchy */
+struct dentry *edac_debugfs_create_dir(const char *dirname)
+{
+ if (!edac_debugfs)
+ return NULL;
+
+ return debugfs_create_dir(dirname, edac_debugfs);
+}
+EXPORT_SYMBOL_GPL(edac_debugfs_create_dir);
+
+/* Create a toplevel dir under EDAC's debugfs hierarchy with parent @parent */
+struct dentry *
+edac_debugfs_create_dir_at(const char *dirname, struct dentry *parent)
+{
+ return debugfs_create_dir(dirname, parent);
+}
+EXPORT_SYMBOL_GPL(edac_debugfs_create_dir_at);
+
+/*
+ * Create a file under EDAC's hierarchy or a sub-hierarchy:
+ *
+ * @name: file name
+ * @mode: file permissions
+ * @parent: parent dentry. If NULL, it becomes the toplevel EDAC dir
+ * @data: private data of caller
+ * @fops: file operations of this file
+ */
+struct dentry *
+edac_debugfs_create_file(const char *name, umode_t mode, struct dentry *parent,
+ void *data, const struct file_operations *fops)
+{
+ if (!parent)
+ parent = edac_debugfs;
+
+ return debugfs_create_file(name, mode, parent, data, fops);
+}
+EXPORT_SYMBOL_GPL(edac_debugfs_create_file);
+
+/* Wrapper for debugfs_create_x8() */
+struct dentry *edac_debugfs_create_x8(const char *name, umode_t mode,
+ struct dentry *parent, u8 *value)
+{
+ if (!parent)
+ parent = edac_debugfs;
+
+ return debugfs_create_x8(name, mode, parent, value);
+}
+EXPORT_SYMBOL_GPL(edac_debugfs_create_x8);
+
+/* Wrapper for debugfs_create_x16() */
+struct dentry *edac_debugfs_create_x16(const char *name, umode_t mode,
+ struct dentry *parent, u16 *value)
+{
+ if (!parent)
+ parent = edac_debugfs;
+
+ return debugfs_create_x16(name, mode, parent, value);
+}
+EXPORT_SYMBOL_GPL(edac_debugfs_create_x16);