powerpc/32: Reduce code duplication of system call entry

booke and non booke do pretty similar things in SYSCALL_ENTRY macro
just before calling jumping to transfer_to_syscall().

Do them in transfer_to_syscall() instead.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/552e27fa09394a6bc70585fcdfa237f99a5d1267.1622818435.git.christophe.leroy@csgroup.eu

arch/powerpc/kernel/entry_32.S

@@ -32,6 +32,7 @@
 #include <asm/barrier.h>
 #include <asm/kup.h>
 #include <asm/bug.h>
+#include <asm/interrupt.h>
 
 #include "head_32.h"
 
@@ -74,6 +75,24 @@ _ASM_NOKPROBE_SYMBOL(prepare_transfer_to_handler)
 
 	.globl	transfer_to_syscall
 transfer_to_syscall:
+	stw	r11, GPR1(r1)
+	stw	r11, 0(r1)
+	mflr	r12
+	stw	r12, _LINK(r1)
+#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?) */
+#endif
+	lis	r12,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
+	SAVE_GPR(2, r1)
+	addi	r12,r12,STACK_FRAME_REGS_MARKER@l
+	stw	r9,_MSR(r1)
+	li	r2, INTERRUPT_SYSCALL
+	stw	r12,8(r1)
+	stw	r2,_TRAP(r1)
+	SAVE_GPR(0, r1)
+	SAVE_4GPRS(3, r1)
+	SAVE_2GPRS(7, r1)
+	addi	r2,r10,-THREAD
 	SAVE_NVGPRS(r1)
 
 	/* Calling convention has r9 = orig r0, r10 = regs */

arch/powerpc/kernel/head_32.h

@@ -155,29 +155,10 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt)
 	addi	r1, r1, THREAD_SIZE - INT_FRAME_SIZE
 	rfi
 1:
-	stw	r11,GPR1(r1)
-	stw	r11,0(r1)
-	mr	r11, r1
 	stw	r12,_NIP(r1)
-	mflr	r12
-	stw	r12, _LINK(r11)
 	mfcr	r12
 	rlwinm	r12,r12,0,4,2	/* Clear SO bit in CR */
 	stw	r12,_CCR(r1)
-#ifdef CONFIG_40x
-	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?) */
-#endif
-	lis	r12,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
-	stw	r2,GPR2(r11)
-	addi	r12,r12,STACK_FRAME_REGS_MARKER@l
-	stw	r9,_MSR(r11)
-	li	r2, \trapno
-	stw	r12,8(r11)
-	stw	r2,_TRAP(r11)
-	SAVE_GPR(0, r11)
-	SAVE_4GPRS(3, r11)
-	SAVE_2GPRS(7, r11)
-	addi	r2,r10,-THREAD
 	b	transfer_to_syscall		/* jump to handler */
 .endm
 

arch/powerpc/kernel/head_booke.h

@@ -140,26 +140,8 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
 	rlwinm	r12,r12,0,4,2	/* Clear SO bit in CR */
 	ALLOC_STACK_FRAME(r1, THREAD_SIZE - INT_FRAME_SIZE)
 	stw	r12, _CCR(r1)
-	mflr	r12
-	stw	r12,_LINK(r1)
 	mfspr	r12,SPRN_SRR0
-	stw	r11, GPR1(r1)
-	stw	r11, 0(r1)
-	mr	r11, r1
 	stw	r12,_NIP(r1)
-	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?)	   */
-	lis	r12, STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
-	stw	r2,GPR2(r11)
-	addi	r12, r12, STACK_FRAME_REGS_MARKER@l
-	stw	r9,_MSR(r11)
-	li	r2, \trapno
-	stw	r12, 8(r11)
-	stw	r2,_TRAP(r11)
-	SAVE_GPR(0, r11)
-	SAVE_4GPRS(3, r11)
-	SAVE_2GPRS(7, r11)
-
-	addi	r2,r10,-THREAD
 	b	transfer_to_syscall	/* jump to handler */
 .endm