Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/csky/kernel/syscall.c b/arch/csky/kernel/syscall.c
new file mode 100644
index 0000000..3d30e58
--- /dev/null
+++ b/arch/csky/kernel/syscall.c
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/syscalls.h>
+
+SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
+{
+ struct thread_info *ti = task_thread_info(current);
+ struct pt_regs *reg = current_pt_regs();
+
+ reg->tls = addr;
+ ti->tp_value = addr;
+
+ return 0;
+}
+
+SYSCALL_DEFINE6(mmap2,
+ unsigned long, addr,
+ unsigned long, len,
+ unsigned long, prot,
+ unsigned long, flags,
+ unsigned long, fd,
+ off_t, offset)
+{
+ if (unlikely(offset & (~PAGE_MASK >> 12)))
+ return -EINVAL;
+
+ return ksys_mmap_pgoff(addr, len, prot, flags, fd,
+ offset >> (PAGE_SHIFT - 12));
+}
+
+/*
+ * for abiv1 the 64bits args should be even th, So we need mov the advice
+ * forward.
+ */
+SYSCALL_DEFINE4(csky_fadvise64_64,
+ int, fd,
+ int, advice,
+ loff_t, offset,
+ loff_t, len)
+{
+ return ksys_fadvise64_64(fd, offset, len, advice);
+}