[U-Boot] [PATCH 2/2] powerpc/mpc85xx: Remove some dead code

[Scott Wood]

U-Boot does not have system calls (the services it exposes to
standalone commands use a different mechanism), so the syscall handler
is dead code.  It's also broken code, as it assumes it is located at
0xc00 -- while even before the patch to stop relocating exception
vectors to 0, U-Boot had the syscall at 0x900.

The critical and machine check return paths are never called -- the
regular exception return path is used instead, which works because
xSRR0/1 have already been saved and can be restored via the regular
SRR0/1 (we don't care too much in U-Boot about taking a critical/mcheck
inside another exception prolog/epilog).

Also remove a few other small unused functions.

Signed-off-by: Scott Wood <scottwood at freescale.com>
---
 arch/powerpc/cpu/mpc85xx/start.S | 138 +--------------------------------------
 include/common.h                 |   1 -
 2 files changed, 1 insertion(+), 138 deletions(-)

diff --git a/arch/powerpc/cpu/mpc85xx/start.S b/arch/powerpc/cpu/mpc85xx/start.S
index 61883cb..28f04ee 100644
--- a/arch/powerpc/cpu/mpc85xx/start.S
+++ b/arch/powerpc/cpu/mpc85xx/start.S
@@ -1201,73 +1201,7 @@ ProgramCheck:
 	/* No FPU on MPC85xx.  This exception is not supposed to happen.
 	*/
 	STD_EXCEPTION(0x0800, FPUnavailable, UnknownException)
-
-/*
- * r0 - SYSCALL number
- * r3-... arguments
- */
-SystemCall:
-	addis	r11,r0,0	/* get functions table addr */
-	ori	r11,r11,0	/* Note: this code is patched in trap_init */
-	addis	r12,r0,0	/* get number of functions */
-	ori	r12,r12,0
-
-	cmplw	0,r0,r12
-	bge	1f
-
-	rlwinm	r0,r0,2,0,31	/* fn_addr = fn_tbl[r0] */
-	add	r11,r11,r0
-	lwz	r11,0(r11)
-
-	li	r20,0xd00-4	/* Get stack pointer */
-	lwz	r12,0(r20)
-	subi	r12,r12,12	/* Adjust stack pointer */
-	li	r0,0xc00+_end_back-SystemCall
-	cmplw	0,r0,r12	/* Check stack overflow */
-	bgt	1f
-	stw	r12,0(r20)
-
-	mflr	r0
-	stw	r0,0(r12)
-	mfspr	r0,SRR0
-	stw	r0,4(r12)
-	mfspr	r0,SRR1
-	stw	r0,8(r12)
-
-	li	r12,0xc00+_back-SystemCall
-	mtlr	r12
-	mtspr	SRR0,r11
-
-1:	SYNC
-	rfi
-_back:
-
-	mfmsr	r11			/* Disable interrupts */
-	li	r12,0
-	ori	r12,r12,MSR_EE
-	andc	r11,r11,r12
-	SYNC				/* Some chip revs need this... */
-	mtmsr	r11
-	SYNC
-
-	li	r12,0xd00-4		/* restore regs */
-	lwz	r12,0(r12)
-
-	lwz	r11,0(r12)
-	mtlr	r11
-	lwz	r11,4(r12)
-	mtspr	SRR0,r11
-	lwz	r11,8(r12)
-	mtspr	SRR1,r11
-
-	addi	r12,r12,12		/* Adjust stack pointer */
-	li	r20,0xd00-4
-	stw	r12,0(r20)
-
-	SYNC
-	rfi
-_end_back:
-
+	STD_EXCEPTION(0x0900, SystemCall, UnknownException)
 	STD_EXCEPTION(0x0a00, Decrementer, timer_interrupt)
 	STD_EXCEPTION(0x0b00, IntervalTimer, UnknownException)
 	STD_EXCEPTION(0x0c00, WatchdogTimer, UnknownException)
@@ -1334,66 +1268,6 @@ int_return:
 	SYNC
 	rfi
 
-crit_return:
-	mfmsr	r28		/* Disable interrupts */
-	li	r4,0
-	ori	r4,r4,MSR_EE
-	andc	r28,r28,r4
-	SYNC			/* Some chip revs need this... */
-	mtmsr	r28
-	SYNC
-	lwz	r2,_CTR(r1)
-	lwz	r0,_LINK(r1)
-	mtctr	r2
-	mtlr	r0
-	lwz	r2,_XER(r1)
-	lwz	r0,_CCR(r1)
-	mtspr	XER,r2
-	mtcrf	0xFF,r0
-	REST_10GPRS(3, r1)
-	REST_10GPRS(13, r1)
-	REST_8GPRS(23, r1)
-	REST_GPR(31, r1)
-	lwz	r2,_NIP(r1)	/* Restore environment */
-	lwz	r0,_MSR(r1)
-	mtspr	SPRN_CSRR0,r2
-	mtspr	SPRN_CSRR1,r0
-	lwz	r0,GPR0(r1)
-	lwz	r2,GPR2(r1)
-	lwz	r1,GPR1(r1)
-	SYNC
-	rfci
-
-mck_return:
-	mfmsr	r28		/* Disable interrupts */
-	li	r4,0
-	ori	r4,r4,MSR_EE
-	andc	r28,r28,r4
-	SYNC			/* Some chip revs need this... */
-	mtmsr	r28
-	SYNC
-	lwz	r2,_CTR(r1)
-	lwz	r0,_LINK(r1)
-	mtctr	r2
-	mtlr	r0
-	lwz	r2,_XER(r1)
-	lwz	r0,_CCR(r1)
-	mtspr	XER,r2
-	mtcrf	0xFF,r0
-	REST_10GPRS(3, r1)
-	REST_10GPRS(13, r1)
-	REST_8GPRS(23, r1)
-	REST_GPR(31, r1)
-	lwz	r2,_NIP(r1)	/* Restore environment */
-	lwz	r0,_MSR(r1)
-	mtspr	SPRN_MCSRR0,r2
-	mtspr	SPRN_MCSRR1,r0
-	lwz	r0,GPR0(r1)
-	lwz	r2,GPR2(r1)
-	lwz	r1,GPR1(r1)
-	SYNC
-	rfmci
-
 /* Cache functions.
 */
 .globl flush_icache
@@ -1478,11 +1352,6 @@ dcache_status:
 	andi.	r3,r3,L1CSR0_DCE
 	blr
 
-	.globl get_pir
-get_pir:
-	mfspr	r3,PIR
-	blr
-
 	.globl get_pvr
 get_pvr:
 	mfspr	r3,PVR
@@ -1493,11 +1362,6 @@ get_svr:
 	mfspr	r3,SVR
 	blr
 
-	.globl wr_tcr
-wr_tcr:
-	mtspr	TCR,r3
-	blr
-
 /*------------------------------------------------------------------------------- */
 /* Function:	 in8 */
 /* Description:	 Input 8 bits */
diff --git a/include/common.h b/include/common.h
index 6df05b8..f2d0f64 100644
--- a/include/common.h
+++ b/include/common.h
@@ -471,7 +471,6 @@ int testdram(void);
     defined(CONFIG_8xx)
 uint	get_immr      (uint);
 #endif
-uint	get_pir	      (void);
 #if defined(CONFIG_MPC5xxx)
 uint	get_svr       (void);
 #endif
-- 
2.1.0