ppc64: use sstep.c from powerpc/lib

since it is identical to sstep.c from ppc64/lib.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

arch/powerpc/lib/Makefile

@@ -5,7 +5,7 @@
 ifeq ($(CONFIG_PPC_MERGE),y)
 obj-y			:= strcase.o string.o
 obj-$(CONFIG_PPC32)	+= div64.o copy_32.o checksum_32.o
-obj-$(CONFIG_PPC64)	+= usercopy_64.o sstep.o mem_64.o
+obj-$(CONFIG_PPC64)	+= usercopy_64.o mem_64.o
 endif
 
 obj-$(CONFIG_PPC64)	+= checksum_64.o copypage_64.o copyuser_64.o \
@@ -13,4 +13,5 @@ obj-$(CONFIG_PPC64)	+= checksum_64.o copypage_64.o copyuser_64.o \
 obj-$(CONFIG_PPC_ISERIES) += e2a.o
 ifeq ($(CONFIG_PPC64),y)
 obj-$(CONFIG_SMP)	+= locks.o
+obj-$(CONFIG_DEBUG_KERNEL) += sstep.o
 endif

arch/ppc64/lib/Makefile

@@ -4,5 +4,3 @@
 
 lib-y := string.o strcase.o
 lib-y += usercopy.o
-
-lib-$(CONFIG_DEBUG_KERNEL) += sstep.o

arch/ppc64/lib/sstep.c

-/*
- * Single-step support.
- *
- * Copyright (C) 2004 Paul Mackerras <paulus@au.ibm.com>, IBM
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-#include <linux/kernel.h>
-#include <linux/ptrace.h>
-#include <asm/sstep.h>
-#include <asm/processor.h>
-
-extern char system_call_common[];
-
-/* Bits in SRR1 that are copied from MSR */
-#define MSR_MASK	0xffffffff87c0ffff
-
-/*
- * Determine whether a conditional branch instruction would branch.
- */
-static int branch_taken(unsigned int instr, struct pt_regs *regs)
-{
-	unsigned int bo = (instr >> 21) & 0x1f;
-	unsigned int bi;
-
-	if ((bo & 4) == 0) {
-		/* decrement counter */
-		--regs->ctr;
-		if (((bo >> 1) & 1) ^ (regs->ctr == 0))
-			return 0;
-	}
-	if ((bo & 0x10) == 0) {
-		/* check bit from CR */
-		bi = (instr >> 16) & 0x1f;
-		if (((regs->ccr >> (31 - bi)) & 1) != ((bo >> 3) & 1))
-			return 0;
-	}
-	return 1;
-}
-
-/*
- * Emulate instructions that cause a transfer of control.
- * Returns 1 if the step was emulated, 0 if not,
- * or -1 if the instruction is one that should not be stepped,
- * such as an rfid, or a mtmsrd that would clear MSR_RI.
- */
-int emulate_step(struct pt_regs *regs, unsigned int instr)
-{
-	unsigned int opcode, rd;
-	unsigned long int imm;
-
-	opcode = instr >> 26;
-	switch (opcode) {
-	case 16:	/* bc */
-		imm = (signed short)(instr & 0xfffc);
-		if ((instr & 2) == 0)
-			imm += regs->nip;
-		regs->nip += 4;
-		if ((regs->msr & MSR_SF) == 0)
-			regs->nip &= 0xffffffffUL;
-		if (instr & 1)
-			regs->link = regs->nip;
-		if (branch_taken(instr, regs))
-			regs->nip = imm;
-		return 1;
-	case 17:	/* sc */
-		/*
-		 * N.B. this uses knowledge about how the syscall
-		 * entry code works.  If that is changed, this will
-		 * need to be changed also.
-		 */
-		regs->gpr[9] = regs->gpr[13];
-		regs->gpr[11] = regs->nip + 4;
-		regs->gpr[12] = regs->msr & MSR_MASK;
-		regs->gpr[13] = (unsigned long) get_paca();
-		regs->nip = (unsigned long) &system_call_common;
-		regs->msr = MSR_KERNEL;
-		return 1;
-	case 18:	/* b */
-		imm = instr & 0x03fffffc;
-		if (imm & 0x02000000)
-			imm -= 0x04000000;
-		if ((instr & 2) == 0)
-			imm += regs->nip;
-		if (instr & 1) {
-			regs->link = regs->nip + 4;
-			if ((regs->msr & MSR_SF) == 0)
-				regs->link &= 0xffffffffUL;
-		}
-		if ((regs->msr & MSR_SF) == 0)
-			imm &= 0xffffffffUL;
-		regs->nip = imm;
-		return 1;
-	case 19:
-		switch (instr & 0x7fe) {
-		case 0x20:	/* bclr */
-		case 0x420:	/* bcctr */
-			imm = (instr & 0x400)? regs->ctr: regs->link;
-			regs->nip += 4;
-			if ((regs->msr & MSR_SF) == 0) {
-				regs->nip &= 0xffffffffUL;
-				imm &= 0xffffffffUL;
-			}
-			if (instr & 1)
-				regs->link = regs->nip;
-			if (branch_taken(instr, regs))
-				regs->nip = imm;
-			return 1;
-		case 0x24:	/* rfid, scary */
-			return -1;
-		}
-	case 31:
-		rd = (instr >> 21) & 0x1f;
-		switch (instr & 0x7fe) {
-		case 0xa6:	/* mfmsr */
-			regs->gpr[rd] = regs->msr & MSR_MASK;
-			regs->nip += 4;
-			if ((regs->msr & MSR_SF) == 0)
-				regs->nip &= 0xffffffffUL;
-			return 1;
-		case 0x164:	/* mtmsrd */
-			/* only MSR_EE and MSR_RI get changed if bit 15 set */
-			/* mtmsrd doesn't change MSR_HV and MSR_ME */
-			imm = (instr & 0x10000)? 0x8002: 0xefffffffffffefffUL;
-			imm = (regs->msr & MSR_MASK & ~imm)
-				| (regs->gpr[rd] & imm);
-			if ((imm & MSR_RI) == 0)
-				/* can't step mtmsrd that would clear MSR_RI */
-				return -1;
-			regs->msr = imm;
-			regs->nip += 4;
-			if ((imm & MSR_SF) == 0)
-				regs->nip &= 0xffffffffUL;
-			return 1;
-		}
-	}
-	return 0;
-}