X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;ds=sidebyside;f=include%2Fwrapper%2Fwriteback.h;fp=include%2Fwrapper%2Fwriteback.h;h=e5f36c258534a211ba76d8b3a316c2dc4bdb3ce1;hb=117ab60f69a98dcbc365de8008ab93e6699d153a;hp=0000000000000000000000000000000000000000;hpb=7c6d929d62a6e24fb1dbeaee5cd2c8afe77720b7;p=lttng-modules.git

diff --git a/include/wrapper/writeback.h b/include/wrapper/writeback.h
new file mode 100644
index 00000000..e5f36c25
--- /dev/null
+++ b/include/wrapper/writeback.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
+ *
+ * wrapper/writeback.h
+ *
+ * wrapper around global_dirty_limit read. Using KALLSYMS with KALLSYMS_ALL
+ * to get its address when available, else we need to have a kernel that
+ * exports this variable to GPL modules.
+ *
+ * Copyright (C) 2013 Mentor Graphics Corp.
+ */
+
+#ifndef _LTTNG_WRAPPER_WRITEBACK_H
+#define _LTTNG_WRAPPER_WRITEBACK_H
+
+#include <lttng/kernel-version.h>
+
+#ifdef CONFIG_KALLSYMS_ALL
+#include <linux/kallsyms.h>
+#include <wrapper/kallsyms.h>
+
+
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,2,0)
+
+static struct wb_domain *global_wb_domain_sym;
+
+static inline
+unsigned long wrapper_global_dirty_limit(void)
+{
+	if (!global_wb_domain_sym)
+		global_wb_domain_sym =
+			(void *) kallsyms_lookup_dataptr("global_wb_domain");
+	if (global_wb_domain_sym) {
+		return global_wb_domain_sym->dirty_limit;
+	} else {
+		printk_once(KERN_WARNING "LTTng: global_wb_domain symbol lookup failed.\n");
+		return 0;
+	}
+}
+#else
+
+static unsigned long *global_dirty_limit_sym;
+
+static inline
+unsigned long wrapper_global_dirty_limit(void)
+{
+	if (!global_dirty_limit_sym)
+		global_dirty_limit_sym =
+			(void *) kallsyms_lookup_dataptr("global_dirty_limit");
+	if (global_dirty_limit_sym) {
+		return *global_dirty_limit_sym;
+	} else {
+		printk_once(KERN_WARNING "LTTng: global_dirty_limit symbol lookup failed.\n");
+		return 0;
+	}
+}
+#endif
+
+#else /* CONFIG_KALLSYMS_ALL */
+
+#include <linux/writeback.h>
+
+static inline
+unsigned long wrapper_global_dirty_limit(void)
+{
+	return global_dirty_limit;
+}
+
+#endif
+
+#endif /* _LTTNG_WRAPPER_WRITEBACK_H */