[PATCH v2 4/4] arm64: apply __ro_after_init to some objects

These objects are set during initialization, thereafter are read only.

Previously I only want to mark vdso_pages, vdso_spec, vectors_page and
cpu_ops as __read_mostly from performance point of view. Then inspired
by Kees's patch[1] to apply more __ro_after_init for arm, I think it's
better to mark them as __ro_after_init. What's more, I find some more
objects are also read only after init. So apply __ro_after_init to all
of them.

This patch also removes global vdso_pagelist and tries to clean up
vdso_spec[] assignment code.

[1] http://www.spinics.net/lists/arm-kernel/msg523188.html

Signed-off-by: Jisheng Zhang <redacted>
---
 arch/arm64/kernel/cpu_ops.c |  2 +-
 arch/arm64/kernel/kaslr.c   |  2 +-
 arch/arm64/kernel/vdso.c    | 27 +++++++++++++--------------
 arch/arm64/mm/dma-mapping.c |  2 +-
 arch/arm64/mm/init.c        |  4 ++--
 arch/arm64/mm/mmu.c         |  2 +-
 6 files changed, 19 insertions(+), 20 deletions(-)

diff --git a/arch/arm64/kernel/cpu_ops.c b/arch/arm64/kernel/cpu_ops.c
index c7cfb8f..6d32d1a 100644
--- a/arch/arm64/kernel/cpu_ops.c
+++ b/arch/arm64/kernel/cpu_ops.c

@@ -28,7 +28,7 @@ extern const struct cpu_operations smp_spin_table_ops;
 extern const struct cpu_operations acpi_parking_protocol_ops;
 extern const struct cpu_operations cpu_psci_ops;
 
-const struct cpu_operations *cpu_ops[NR_CPUS];
+const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init;