path: root/arch/microblaze/kernel/entry.S

/*
 * Low-level system-call handling, trap handlers and context-switching
 *
 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
 * Copyright (C) 2008-2009 PetaLogix
 * Copyright (C) 2003		John Williams <jwilliams@itee.uq.edu.au>
 * Copyright (C) 2001,2002	NEC Corporation
 * Copyright (C) 2001,2002	Miles Bader <miles@gnu.org>
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License. See the file COPYING in the main directory of this
 * archive for more details.
 *
 * Written by Miles Bader <miles@gnu.org>
 * Heavily modified by John Williams for Microblaze
 */

#include <linux/sys.h>
#include <linux/linkage.h>

#include <asm/entry.h>
#include <asm/current.h>
#include <asm/processor.h>
#include <asm/exceptions.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>

#include <asm/page.h>
#include <asm/unistd.h>

#include <linux/errno.h>
#include <asm/signal.h>

#undef DEBUG

/* The size of a state save frame. */
#define STATE_SAVE_SIZE		(PT_SIZE + STATE_SAVE_ARG_SPACE)

/* The offset of the struct pt_regs in a `state save frame' on the stack. */
#define PTO	STATE_SAVE_ARG_SPACE /* 24 the space for args */

#define C_ENTRY(name)	.globl name; .align 4; name

/*
 * Various ways of setting and clearing BIP in flags reg.
 * This is mucky, but necessary using microblaze version that
 * allows msr ops to write to BIP
 */
#if CONFIG_XILINX_MICROBLAZE0_USE_MSR_INSTR
	.macro	clear_bip
	msrclr	r0, MSR_BIP
	nop
	.endm

	.macro	set_bip
	msrset	r0, MSR_BIP
	nop
	.endm

	.macro	clear_eip
	msrclr	r0, MSR_EIP
	nop
	.endm

	.macro	set_ee
	msrset	r0, MSR_EE
	nop
	.endm

	.macro	disable_irq
	msrclr	r0, MSR_IE
	nop
	.endm

	.macro	enable_irq
	msrset	r0, MSR_IE
	nop
	.endm

	.macro	set_ums
	msrset	r0, MSR_UMS
	nop
	msrclr	r0, MSR_VMS
	nop
	.endm

	.macro	set_vms
	msrclr	r0, MSR_UMS
	nop
	msrset	r0, MSR_VMS
	nop
	.endm

	.macro	clear_ums
	msrclr	r0, MSR_UMS
	nop
	.endm

	.macro	clear_vms_ums
	msrclr	r0, MSR_VMS | MSR_UMS
	nop
	.endm
#else
	.macro	clear_bip
	mfs	r11, rmsr
	nop
	andi	r11, r11, ~MSR_BIP
	mts	rmsr, r11
	nop
	.endm

	.macro	set_bip
	mfs	r11, rmsr
	nop
	ori	r11, r11, MSR_BIP
	mts	rmsr, r11
	nop
	.endm

	.macro	clear_eip
	mfs	r11, rmsr
	nop
	andi	r11, r11, ~MSR_EIP
	mts	rmsr, r11
	nop
	.endm

	.macro	set_ee
	mfs	r11, rmsr
	nop
	ori	r11, r11, MSR_EE
	mts	rmsr, r11
	nop
	.endm

	.macro	disable_irq
	mfs	r11, rmsr
	nop
	andi	r11, r11, ~MSR_IE
	mts	rmsr, r11
	nop
	.endm

	.macro	enable_irq
	mfs	r11, rmsr
	nop
	ori	r11, r11, MSR_IE
	mts	rmsr, r11
	nop
	.endm

	.macro set_ums
	mfs	r11, rmsr
	nop
	ori	r11, r11, MSR_VMS
	andni	r11, r11, MSR_UMS
	mts	rmsr, r11
	nop
	.endm

	.macro	set_vms
	mfs	r11, rmsr
	nop
	ori	r11, r11, MSR_VMS
	andni	r11, r11, MSR_UMS
	mts	rmsr, r11
	nop
	.endm

	.macro	clear_ums
	mfs	r11, rmsr
	nop
	andni	r11, r11, MSR_UMS
	mts	rmsr,r11
	nop
	.endm

	.macro	clear_vms_ums
	mfs	r11, rmsr
	nop
	andni	r11, r11, (MSR_VMS|MSR_UMS)
	mts	rmsr,r11
	nop
	.endm
#endif

/* Define how to call high-level functions. With MMU, virtual mode must be
 * enabled when calling the high-level function. Clobbers R11.
 * VM_ON, VM_OFF, DO_JUMP_BIPCLR, DO_CALL
 */

/* turn on virtual protected mode save */
#define VM_ON		\
	set_ums;	\
	rted	r0, 2f;	\
	nop; \
2:

/* turn off virtual protected mode save and user mode save*/
#define VM_OFF			\
	clear_vms_ums;		\
	rted	r0, TOPHYS(1f);	\
	nop; \
1:

#define SAVE_REGS \
	swi	r2, r1, PTO+PT_R2;	/* Save SDA */			\
	swi	r3, r1, PTO+PT_R3;					\
	swi	r4, r1, PTO+PT_R4;					\
	swi	r5, r1, PTO+PT_R5;					\
	swi	r6, r1, PTO+PT_R6;