powerpc/irq: Make __do_irq() static

Since commit 48cf12d8 ("powerpc/irq: Inline call_do_irq() and
call_do_softirq()"), __do_irq() is not used outside irq.c

Reorder functions and make __do_irq() static and
drop the declaration in irq.h.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/adbe1c8315ec2d63259f41468e82e51677bb1eda.1654769775.git.christophe.leroy@csgroup.eu

arch/powerpc/include/asm/irq.h

@@ -54,7 +54,6 @@ extern void *softirq_ctx[NR_CPUS];
 
 void __do_IRQ(struct pt_regs *regs);
 extern void __init init_IRQ(void);
-extern void __do_irq(struct pt_regs *regs);
 
 int irq_choose_cpu(const struct cpumask *mask);
 

arch/powerpc/kernel/irq.c

@@ -220,31 +220,9 @@ static __always_inline void call_do_softirq(const void *sp)
 	);
 }
 
-static __always_inline void call_do_irq(struct pt_regs *regs, void *sp)
-{
-	register unsigned long r3 asm("r3") = (unsigned long)regs;
-
-	/* Temporarily switch r1 to sp, call __do_irq() then restore r1. */
-	asm volatile (
-		 PPC_STLU "	%%r1, %[offset](%[sp])	;"
-		"mr		%%r1, %[sp]		;"
-		"bl		%[callee]		;"
-		 PPC_LL "	%%r1, 0(%%r1)		;"
-		 : // Outputs
-		   "+r" (r3)
-		 : // Inputs
-		   [sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_OVERHEAD),
-		   [callee] "i" (__do_irq)
-		 : // Clobbers
-		   "lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6",
-		   "cr7", "r0", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
-		   "r11", "r12"
-	);
-}
-
 DEFINE_STATIC_CALL_RET0(ppc_get_irq, *ppc_md.get_irq);
 
-void __do_irq(struct pt_regs *regs)
+static void __do_irq(struct pt_regs *regs)
 {
 	unsigned int irq;
 
@@ -270,6 +248,28 @@ void __do_irq(struct pt_regs *regs)
 	trace_irq_exit(regs);
 }
 
+static __always_inline void call_do_irq(struct pt_regs *regs, void *sp)
+{
+	register unsigned long r3 asm("r3") = (unsigned long)regs;
+
+	/* Temporarily switch r1 to sp, call __do_irq() then restore r1. */
+	asm volatile (
+		 PPC_STLU "	%%r1, %[offset](%[sp])	;"
+		"mr		%%r1, %[sp]		;"
+		"bl		%[callee]		;"
+		 PPC_LL "	%%r1, 0(%%r1)		;"
+		 : // Outputs
+		   "+r" (r3)
+		 : // Inputs
+		   [sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_OVERHEAD),
+		   [callee] "i" (__do_irq)
+		 : // Clobbers
+		   "lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6",
+		   "cr7", "r0", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
+		   "r11", "r12"
+	);
+}
+
 void __do_IRQ(struct pt_regs *regs)
 {
 	struct pt_regs *old_regs = set_irq_regs(regs);