path: root/arch/powerpc/kernel/entry_64.S

/*
 *  PowerPC version 
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *  Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
 *    Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
 *  Adapted for Power Macintosh by Paul Mackerras.
 *  Low-level exception handlers and MMU support
 *  rewritten by Paul Mackerras.
 *    Copyright (C) 1996 Paul Mackerras.
 *  MPC8xx modifications Copyright (C) 1997 Dan Malek (dmalek@jlc.net).
 *
 *  This file contains the system call entry code, context switch
 *  code, and exception/interrupt return code for PowerPC.
 *
 *  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/errno.h>
#include <asm/unistd.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/thread_info.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/cputable.h>
#include <asm/firmware.h>
#include <asm/bug.h>
#include <asm/ptrace.h>
#include <asm/irqflags.h>
#include <asm/ftrace.h>
#include <asm/hw_irq.h>

/*
 * System calls.
 */
	.section	".toc","aw"
.SYS_CALL_TABLE:
	.tc .sys_call_table[TC],.sys_call_table

/* This value is used to mark exception frames on the stack. */
exception_marker:
	.tc	ID_EXC_MARKER[TC],STACK_FRAME_REGS_MARKER

	.section	".text"
	.align 7

#undef SHOW_SYSCALLS

	.globl system_call_common
system_call_common:
	andi.	r10,r12,MSR_PR
	mr	r10,r1
	addi	r1,r1,-INT_FRAME_SIZE
	beq-	1f
	ld	r1,PACAKSAVE(r13)
1:	std	r10,0(r1)
	std	r11,_NIP(r1)
	std	r12,_MSR(r1)
	std	r0,GPR0(r1)
	std	r10,GPR1(r1)
	ACCOUNT_CPU_USER_ENTRY(r10, r11)
	std	r2,GPR2(r1)
	std	r3,GPR3(r1)
	mfcr	r2
	std	r4,GPR4(r1)
	std	r5,GPR5(r1)
	std	r6,GPR6(r1)
	std	r7,GPR7(r1)
	std	r8,GPR8(r1)
	li	r11,0
	std	r11,GPR9(r1)
	std	r11,GPR10(r1)
	std	r11,GPR11(r1)
	std	r11,GPR12(r1)
	std	r11,_XER(r1)
	std	r11,_CTR(r1)
	std	r9,GPR13(r1)
	mflr	r10
	/*
	 * This clears CR0.SO (bit 28), which is the error indication on
	 * return from this system call.
	 */
	rldimi	r2,r11,28,(63-28)
	li	r11,0xc01
	std	r10,_LINK(r1)
	std	r11,_TRAP(r1)
	std	r3,ORIG_GPR3(r1)
	std	r2,_CCR(r1)
	ld	r2,PACATOC(r13)
	addi	r9,r1,STACK_FRAME_OVERHEAD
	ld	r11,exception_marker@toc(r2)
	std	r11,-16(r9)		/* "regshere" marker */
#if defined(CONFIG_VIRT_CPU_ACCOUNTING) && defined(CONFIG_PPC_SPLPAR)
BEGIN_FW_FTR_SECTION
	beq	33f
	/* if from user, see if there are any DTL entries to process */
	ld	r10,PACALPPACAPTR(r13)	/* get ptr to VPA */
	ld	r11,PACA_DTL_RIDX(r13)	/* get log read index */
	ld	r10,LPPACA_DTLIDX(r10)	/* get log write index */
	cmpd	cr1,r11,r10
	beq+	cr1,33f
	bl	.accumulate_stolen_time
	REST_GPR(0,r1)
	REST_4GPRS(3,r1)
	REST_2GPRS(7,r1)
	addi	r9,r1,STACK_FRAME_OVERHEAD
33:
END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR)
#endif /* CONFIG_VIRT_CPU_ACCOUNTING && CONFIG_PPC_SPLPAR */

	/*
	 * A syscall should always be called with interrupts enabled
	 * so we just unconditionally hard-enable here. When some kind
	 * of irq tracing is used, we additionally check that condition
	 * is correct
	 */
#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_BUG)
	lbz	r10,PACASOFTIRQEN(r13)
	xori	r10,r10,1
1:	tdnei	r10,0
	EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING
#endif

#ifdef CONFIG_PPC_BOOK3E
	wrteei	1
#else
	ld	r11,PACAKMSR(r13)
	ori	r11,r11,MSR_EE
	mtmsrd	r11,1
#endif /* CONFIG_PPC_BOOK3E */

	/* We do need to set SOFTE in the stack frame or the return
	 * from interrupt will be painful
	 */
	li	r10,1
	std