MIPS: SMP: Constify smp ops

smp_ops providers do not modify their ops structures, so they should be
made const for robustness. Since currently the MIPS kernel is not mapped
with memory protection, this does not in itself provide any security
benefit, but it still makes sense to make this change.

There are also slight code size efficincies from the structure being
made read-only, saving 128 bytes of kernel text on a
pistachio_defconfig.
Before:
   text	   data	    bss	    dec	    hex	filename
7187239	1772752	 470224	9430215	 8fe4c7	vmlinux
After:
   text	   data	    bss	    dec	    hex	filename
7187111	1772752	 470224	9430087	 8fe447	vmlinux

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Doug Ledford <dledford@redhat.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Joe Perches <joe@perches.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven J. Hill <steven.hill@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16784/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

6 files changed, 9 insertions, 9 deletions

diff --git a/arch/mips/kernel/smp-bmips.c b/arch/mips/kernel/smp-bmips.c
index 1b070a76fcdd..f86d755e3d75 100644
--- a/arch/mips/kernel/smp-bmips.c
+++ b/arch/mips/kernel/smp-bmips.c
@@ -409,7 +409,7 @@ void __ref play_dead(void)
 
 #endif /* CONFIG_HOTPLUG_CPU */
 
-struct plat_smp_ops bmips43xx_smp_ops = {
+const struct plat_smp_ops bmips43xx_smp_ops = {
 	.smp_setup		= bmips_smp_setup,
 	.prepare_cpus		= bmips_prepare_cpus,
 	.boot_secondary		= bmips_boot_secondary,
@@ -423,7 +423,7 @@ struct plat_smp_ops bmips43xx_smp_ops = {
 #endif
 };
 
-struct plat_smp_ops bmips5000_smp_ops = {
+const struct plat_smp_ops bmips5000_smp_ops = {
 	.smp_setup		= bmips_smp_setup,
 	.prepare_cpus		= bmips_prepare_cpus,
 	.boot_secondary		= bmips_boot_secondary,
diff --git a/arch/mips/kernel/smp-cmp.c b/arch/mips/kernel/smp-cmp.c
index 76923349b4fe..1acffdee88f4 100644
--- a/arch/mips/kernel/smp-cmp.c
+++ b/arch/mips/kernel/smp-cmp.c
@@ -148,7 +148,7 @@ void __init cmp_prepare_cpus(unsigned int max_cpus)
 
 }
 
-struct plat_smp_ops cmp_smp_ops = {
+const struct plat_smp_ops cmp_smp_ops = {
 	.send_ipi_single	= mips_smp_send_ipi_single,
 	.send_ipi_mask		= mips_smp_send_ipi_mask,
 	.init_secondary		= cmp_init_secondary,
diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
index f832e99ad4c3..a6b8700563c7 100644
--- a/arch/mips/kernel/smp-cps.c
+++ b/arch/mips/kernel/smp-cps.c
@@ -571,7 +571,7 @@ static void cps_cpu_die(unsigned int cpu)
 
 #endif /* CONFIG_HOTPLUG_CPU */
 
-static struct plat_smp_ops cps_smp_ops = {
+static const struct plat_smp_ops cps_smp_ops = {
 	.smp_setup		= cps_smp_setup,
 	.prepare_cpus		= cps_prepare_cpus,
 	.boot_secondary		= cps_boot_secondary,
@@ -587,7 +587,7 @@ static struct plat_smp_ops cps_smp_ops = {
 
 bool mips_cps_smp_in_use(void)
 {
-	extern struct plat_smp_ops *mp_ops;
+	extern const struct plat_smp_ops *mp_ops;
 	return mp_ops == &cps_smp_ops;
 }
 
diff --git a/arch/mips/kernel/smp-mt.c b/arch/mips/kernel/smp-mt.c
index ed6b4df583ea..004ff5e8a820 100644
--- a/arch/mips/kernel/smp-mt.c
+++ b/arch/mips/kernel/smp-mt.c
@@ -239,7 +239,7 @@ static void __init vsmp_prepare_cpus(unsigned int max_cpus)
 	mips_mt_set_cpuoptions();
 }
 
-struct plat_smp_ops vsmp_smp_ops = {
+const struct plat_smp_ops vsmp_smp_ops = {
 	.send_ipi_single	= mips_smp_send_ipi_single,
 	.send_ipi_mask		= mips_smp_send_ipi_mask,
 	.init_secondary		= vsmp_init_secondary,
diff --git a/arch/mips/kernel/smp-up.c b/arch/mips/kernel/smp-up.c
index 17878d71ef2b..4cf015a624d1 100644
--- a/arch/mips/kernel/smp-up.c
+++ b/arch/mips/kernel/smp-up.c
@@ -63,7 +63,7 @@ static void up_cpu_die(unsigned int cpu)
 }
 #endif
 
-struct plat_smp_ops up_smp_ops = {
+const struct plat_smp_ops up_smp_ops = {
 	.send_ipi_single	= up_send_ipi_single,
 	.send_ipi_mask		= up_send_ipi_mask,
 	.init_secondary		= up_init_secondary,
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index 6bace7695788..20c1f9ac946a 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -146,10 +146,10 @@ void calculate_cpu_foreign_map(void)
 			       &temp_foreign_map, &cpu_sibling_map[i]);
 }
 
-struct plat_smp_ops *mp_ops;
+const struct plat_smp_ops *mp_ops;
 EXPORT_SYMBOL(mp_ops);
 
-void register_smp_ops(struct plat_smp_ops *ops)
+void register_smp_ops(const struct plat_smp_ops *ops)
 {
 	if (mp_ops)
 		printk(KERN_WARNING "Overriding previously set SMP ops\n");