1 files changed, 112 insertions, 0 deletions
diff --git a/mm/cma_sysfs.c b/mm/cma_sysfs.c
new file mode 100644
index 000000000000..56347d15b7e8
--- /dev/null
+++ b/mm/cma_sysfs.c
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CMA SysFS Interface
+ *
+ * Copyright (c) 2021 Minchan Kim <minchan@kernel.org>
+ */
+
+#include <linux/cma.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+#include "cma.h"
+
+#define CMA_ATTR_RO(_name) \
+	static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
+
+void cma_sysfs_account_success_pages(struct cma *cma, unsigned long nr_pages)
+{
+	atomic64_add(nr_pages, &cma->nr_pages_succeeded);
+}
+
+void cma_sysfs_account_fail_pages(struct cma *cma, unsigned long nr_pages)
+{
+	atomic64_add(nr_pages, &cma->nr_pages_failed);
+}
+
+static inline struct cma *cma_from_kobj(struct kobject *kobj)
+{
+	return container_of(kobj, struct cma_kobject, kobj)->cma;
+}
+
+static ssize_t alloc_pages_success_show(struct kobject *kobj,
+					struct kobj_attribute *attr, char *buf)
+{
+	struct cma *cma = cma_from_kobj(kobj);
+
+	return sysfs_emit(buf, "%llu\n",
+			  atomic64_read(&cma->nr_pages_succeeded));
+}
+CMA_ATTR_RO(alloc_pages_success);
+
+static ssize_t alloc_pages_fail_show(struct kobject *kobj,
+				     struct kobj_attribute *attr, char *buf)
+{
+	struct cma *cma = cma_from_kobj(kobj);
+
+	return sysfs_emit(buf, "%llu\n", atomic64_read(&cma->nr_pages_failed));
+}
+CMA_ATTR_RO(alloc_pages_fail);
+
+static void cma_kobj_release(struct kobject *kobj)
+{
+	struct cma *cma = cma_from_kobj(kobj);
+	struct cma_kobject *cma_kobj = cma->cma_kobj;
+
+	kfree(cma_kobj);
+	cma->cma_kobj = NULL;
+}
+
+static struct attribute *cma_attrs[] = {
+	&alloc_pages_success_attr.attr,
+	&alloc_pages_fail_attr.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(cma);
+
+static const struct kobj_type cma_ktype = {
+	.release = cma_kobj_release,
+	.sysfs_ops = &kobj_sysfs_ops,
+	.default_groups = cma_groups,
+};
+
+static int __init cma_sysfs_init(void)
+{
+	struct kobject *cma_kobj_root;
+	struct cma_kobject *cma_kobj;
+	struct cma *cma;
+	int i, err;
+
+	cma_kobj_root = kobject_create_and_add("cma", mm_kobj);
+	if (!cma_kobj_root)
+		return -ENOMEM;
+
+	for (i = 0; i < cma_area_count; i++) {
+		cma_kobj = kzalloc(sizeof(*cma_kobj), GFP_KERNEL);
+		if (!cma_kobj) {
+			err = -ENOMEM;
+			goto out;
+		}
+
+		cma = &cma_areas[i];
+		cma->cma_kobj = cma_kobj;
+		cma_kobj->cma = cma;
+		err = kobject_init_and_add(&cma_kobj->kobj, &cma_ktype,
+					   cma_kobj_root, "%s", cma->name);
+		if (err) {
+			kobject_put(&cma_kobj->kobj);
+			goto out;
+		}
+	}
+
+	return 0;
+out:
+	while (--i >= 0) {
+		cma = &cma_areas[i];
+		kobject_put(&cma->cma_kobj->kobj);
+	}
+	kobject_put(cma_kobj_root);
+
+	return err;
+}
+subsys_initcall(cma_sysfs_init);