LoongArch: Add VDSO and VSYSCALL support

Add VDSO and VSYSCALL support (sigreturn, gettimeofday and its friends)
for LoongArch.

Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

1 files changed, 25 insertions, 0 deletions

diff --git a/arch/loongarch/vdso/vgettimeofday.c b/arch/loongarch/vdso/vgettimeofday.c
new file mode 100644
index 000000000000..b1f4548dae92
--- /dev/null
+++ b/arch/loongarch/vdso/vgettimeofday.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * LoongArch userspace implementations of gettimeofday() and similar.
+ *
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#include <linux/types.h>
+
+int __vdso_clock_gettime(clockid_t clock,
+			 struct __kernel_timespec *ts)
+{
+	return __cvdso_clock_gettime(clock, ts);
+}
+
+int __vdso_gettimeofday(struct __kernel_old_timeval *tv,
+			struct timezone *tz)
+{
+	return __cvdso_gettimeofday(tv, tz);
+}
+
+int __vdso_clock_getres(clockid_t clock_id,
+			struct __kernel_timespec *res)
+{
+	return __cvdso_clock_getres(clock_id, res);
+}