riscv: Constify sbi_ipi_ops

Constify the sbi_ipi_ops so that it will be placed in the .rodata
section. This will cause attempts to modify it to fail when strict
page permissions are in place.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

arch/riscv/include/asm/smp.h

@@ -46,7 +46,7 @@ int riscv_hartid_to_cpuid(int hartid);
 void riscv_cpuid_to_hartid_mask(const struct cpumask *in, struct cpumask *out);
 
 /* Set custom IPI operations */
-void riscv_set_ipi_ops(struct riscv_ipi_ops *ops);
+void riscv_set_ipi_ops(const struct riscv_ipi_ops *ops);
 
 /* Clear IPI for current CPU */
 void riscv_clear_ipi(void);
@@ -92,7 +92,7 @@ static inline void riscv_cpuid_to_hartid_mask(const struct cpumask *in,
 	cpumask_set_cpu(boot_cpu_hartid, out);
 }
 
-static inline void riscv_set_ipi_ops(struct riscv_ipi_ops *ops)
+static inline void riscv_set_ipi_ops(const struct riscv_ipi_ops *ops)
 {
 }
 

arch/riscv/kernel/sbi.c

@@ -571,7 +571,7 @@ static void sbi_send_cpumask_ipi(const struct cpumask *target)
 	sbi_send_ipi(cpumask_bits(&hartid_mask));
 }
 
-static struct riscv_ipi_ops sbi_ipi_ops = {
+static const struct riscv_ipi_ops sbi_ipi_ops = {
 	.ipi_inject = sbi_send_cpumask_ipi
 };
 

arch/riscv/kernel/smp.c

@@ -87,9 +87,9 @@ static void ipi_stop(void)
 		wait_for_interrupt();
 }
 
-static struct riscv_ipi_ops *ipi_ops __ro_after_init;
+static const struct riscv_ipi_ops *ipi_ops __ro_after_init;
 
-void riscv_set_ipi_ops(struct riscv_ipi_ops *ops)
+void riscv_set_ipi_ops(const struct riscv_ipi_ops *ops)
 {
 	ipi_ops = ops;
 }