ARM: 9480/1: entry: expand comment in __switch_tografted

As per discussion between the developers in the mail thread
linked, expand the comment in __switch_to so that readers
of the code understand what is going on.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

1 files changed, 35 insertions, 0 deletions

diff --git a/include/asm-generic/vdso/vsyscall.h b/include/asm-generic/vdso/vsyscall.h
new file mode 100644
index 000000000..5c6d9799f
--- /dev/null
+++ b/include/asm-generic/vdso/vsyscall.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_GENERIC_VSYSCALL_H
+#define __ASM_GENERIC_VSYSCALL_H
+
+#ifndef __ASSEMBLY__
+
+#ifndef __arch_get_vdso_u_time_data
+static __always_inline const struct vdso_time_data *__arch_get_vdso_u_time_data(void)
+{
+	return &vdso_u_time_data;
+}
+#endif
+
+#ifndef __arch_get_vdso_u_rng_data
+static __always_inline const struct vdso_rng_data *__arch_get_vdso_u_rng_data(void)
+{
+	return &vdso_u_rng_data;
+}
+#endif
+
+#ifndef __arch_update_vdso_clock
+static __always_inline void __arch_update_vdso_clock(struct vdso_clock *vc)
+{
+}
+#endif /* __arch_update_vdso_clock */
+
+#ifndef __arch_sync_vdso_time_data
+static __always_inline void __arch_sync_vdso_time_data(struct vdso_time_data *vdata)
+{
+}
+#endif /* __arch_sync_vdso_time_data */
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* __ASM_GENERIC_VSYSCALL_H */