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>

1 files changed, 6 insertions, 6 deletions

diff --git a/arch/mips/include/asm/smp-ops.h b/arch/mips/include/asm/smp-ops.h
index db7c322f057f..38859e7b1f1f 100644
--- a/arch/mips/include/asm/smp-ops.h
+++ b/arch/mips/include/asm/smp-ops.h
@@ -35,11 +35,11 @@ struct plat_smp_ops {
 #endif
 };
 
-extern void register_smp_ops(struct plat_smp_ops *ops);
+extern void register_smp_ops(const struct plat_smp_ops *ops);
 
 static inline void plat_smp_setup(void)
 {
-	extern struct plat_smp_ops *mp_ops;	/* private */
+	extern const struct plat_smp_ops *mp_ops;	/* private */
 
 	mp_ops->smp_setup();
 }
@@ -57,7 +57,7 @@ static inline void plat_smp_setup(void)
 	/* UP, nothing to do ...  */
 }
 
-static inline void register_smp_ops(struct plat_smp_ops *ops)
+static inline void register_smp_ops(const struct plat_smp_ops *ops)
 {
 }
 
@@ -66,7 +66,7 @@ static inline void register_smp_ops(struct plat_smp_ops *ops)
 static inline int register_up_smp_ops(void)
 {
 #ifdef CONFIG_SMP_UP
-	extern struct plat_smp_ops up_smp_ops;
+	extern const struct plat_smp_ops up_smp_ops;
 
 	register_smp_ops(&up_smp_ops);
 
@@ -79,7 +79,7 @@ static inline int register_up_smp_ops(void)
 static inline int register_cmp_smp_ops(void)
 {
 #ifdef CONFIG_MIPS_CMP
-	extern struct plat_smp_ops cmp_smp_ops;
+	extern const struct plat_smp_ops cmp_smp_ops;
 
 	if (!mips_cm_present())
 		return -ENODEV;
@@ -95,7 +95,7 @@ static inline int register_cmp_smp_ops(void)
 static inline int register_vsmp_smp_ops(void)
 {
 #ifdef CONFIG_MIPS_MT_SMP
-	extern struct plat_smp_ops vsmp_smp_ops;
+	extern const struct plat_smp_ops vsmp_smp_ops;
 
 	register_smp_ops(&vsmp_smp_ops);