These changes are the raw update to linux-4.4.6-rt14. Kernel sources
[kvmfornfv.git] / kernel / lib / test_static_keys.c
diff --git a/kernel/lib/test_static_keys.c b/kernel/lib/test_static_keys.c
new file mode 100644 (file)
index 0000000..c61b299
--- /dev/null
@@ -0,0 +1,225 @@
+/*
+ * Kernel module for testing static keys.
+ *
+ * Copyright 2015 Akamai Technologies Inc. All Rights Reserved
+ *
+ * Authors:
+ *      Jason Baron       <jbaron@akamai.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/jump_label.h>
+
+/* old keys */
+struct static_key old_true_key = STATIC_KEY_INIT_TRUE;
+struct static_key old_false_key        = STATIC_KEY_INIT_FALSE;
+
+/* new api */
+DEFINE_STATIC_KEY_TRUE(true_key);
+DEFINE_STATIC_KEY_FALSE(false_key);
+
+/* external */
+extern struct static_key base_old_true_key;
+extern struct static_key base_inv_old_true_key;
+extern struct static_key base_old_false_key;
+extern struct static_key base_inv_old_false_key;
+
+/* new api */
+extern struct static_key_true base_true_key;
+extern struct static_key_true base_inv_true_key;
+extern struct static_key_false base_false_key;
+extern struct static_key_false base_inv_false_key;
+
+
+struct test_key {
+       bool                    init_state;
+       struct static_key       *key;
+       bool                    (*test_key)(void);
+};
+
+#define test_key_func(key, branch) \
+       ({bool func(void) { return branch(key); } func; })
+
+static void invert_key(struct static_key *key)
+{
+       if (static_key_enabled(key))
+               static_key_disable(key);
+       else
+               static_key_enable(key);
+}
+
+static void invert_keys(struct test_key *keys, int size)
+{
+       struct static_key *previous = NULL;
+       int i;
+
+       for (i = 0; i < size; i++) {
+               if (previous != keys[i].key) {
+                       invert_key(keys[i].key);
+                       previous = keys[i].key;
+               }
+       }
+}
+
+static int verify_keys(struct test_key *keys, int size, bool invert)
+{
+       int i;
+       bool ret, init;
+
+       for (i = 0; i < size; i++) {
+               ret = static_key_enabled(keys[i].key);
+               init = keys[i].init_state;
+               if (ret != (invert ? !init : init))
+                       return -EINVAL;
+               ret = keys[i].test_key();
+               if (static_key_enabled(keys[i].key)) {
+                       if (!ret)
+                               return -EINVAL;
+               } else {
+                       if (ret)
+                               return -EINVAL;
+               }
+       }
+       return 0;
+}
+
+static int __init test_static_key_init(void)
+{
+       int ret;
+       int size;
+
+       struct test_key static_key_tests[] = {
+               /* internal keys - old keys */
+               {
+                       .init_state     = true,
+                       .key            = &old_true_key,
+                       .test_key       = test_key_func(&old_true_key, static_key_true),
+               },
+               {
+                       .init_state     = false,
+                       .key            = &old_false_key,
+                       .test_key       = test_key_func(&old_false_key, static_key_false),
+               },
+               /* internal keys - new keys */
+               {
+                       .init_state     = true,
+                       .key            = &true_key.key,
+                       .test_key       = test_key_func(&true_key, static_branch_likely),
+               },
+               {
+                       .init_state     = true,
+                       .key            = &true_key.key,
+                       .test_key       = test_key_func(&true_key, static_branch_unlikely),
+               },
+               {
+                       .init_state     = false,
+                       .key            = &false_key.key,
+                       .test_key       = test_key_func(&false_key, static_branch_likely),
+               },
+               {
+                       .init_state     = false,
+                       .key            = &false_key.key,
+                       .test_key       = test_key_func(&false_key, static_branch_unlikely),
+               },
+               /* external keys - old keys */
+               {
+                       .init_state     = true,
+                       .key            = &base_old_true_key,
+                       .test_key       = test_key_func(&base_old_true_key, static_key_true),
+               },
+               {
+                       .init_state     = false,
+                       .key            = &base_inv_old_true_key,
+                       .test_key       = test_key_func(&base_inv_old_true_key, static_key_true),
+               },
+               {
+                       .init_state     = false,
+                       .key            = &base_old_false_key,
+                       .test_key       = test_key_func(&base_old_false_key, static_key_false),
+               },
+               {
+                       .init_state     = true,
+                       .key            = &base_inv_old_false_key,
+                       .test_key       = test_key_func(&base_inv_old_false_key, static_key_false),
+               },
+               /* external keys - new keys */
+               {
+                       .init_state     = true,
+                       .key            = &base_true_key.key,
+                       .test_key       = test_key_func(&base_true_key, static_branch_likely),
+               },
+               {
+                       .init_state     = true,
+                       .key            = &base_true_key.key,
+                       .test_key       = test_key_func(&base_true_key, static_branch_unlikely),
+               },
+               {
+                       .init_state     = false,
+                       .key            = &base_inv_true_key.key,
+                       .test_key       = test_key_func(&base_inv_true_key, static_branch_likely),
+               },
+               {
+                       .init_state     = false,
+                       .key            = &base_inv_true_key.key,
+                       .test_key       = test_key_func(&base_inv_true_key, static_branch_unlikely),
+               },
+               {
+                       .init_state     = false,
+                       .key            = &base_false_key.key,
+                       .test_key       = test_key_func(&base_false_key, static_branch_likely),
+               },
+               {
+                       .init_state     = false,
+                       .key            = &base_false_key.key,
+                       .test_key       = test_key_func(&base_false_key, static_branch_unlikely),
+               },
+               {
+                       .init_state     = true,
+                       .key            = &base_inv_false_key.key,
+                       .test_key       = test_key_func(&base_inv_false_key, static_branch_likely),
+               },
+               {
+                       .init_state     = true,
+                       .key            = &base_inv_false_key.key,
+                       .test_key       = test_key_func(&base_inv_false_key, static_branch_unlikely),
+               },
+       };
+
+       size = ARRAY_SIZE(static_key_tests);
+
+       ret = verify_keys(static_key_tests, size, false);
+       if (ret)
+               goto out;
+
+       invert_keys(static_key_tests, size);
+       ret = verify_keys(static_key_tests, size, true);
+       if (ret)
+               goto out;
+
+       invert_keys(static_key_tests, size);
+       ret = verify_keys(static_key_tests, size, false);
+       if (ret)
+               goto out;
+       return 0;
+out:
+       return ret;
+}
+
+static void __exit test_static_key_exit(void)
+{
+}
+
+module_init(test_static_key_init);
+module_exit(test_static_key_exit);
+
+MODULE_AUTHOR("Jason Baron <jbaron@akamai.com>");
+MODULE_LICENSE("GPL");