path: root/arch/powerpc/kernel/exceptions-64e.S

/*
 *  Boot code and exception vectors for Book3E processors
 *
 *  Copyright (C) 2007 Ben. Herrenschmidt (benh@kernel.crashing.org), IBM Corp.
 *
 *  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/threads.h>
#include <asm/reg.h>
#include <asm/page.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/cputable.h>
#include <asm/setup.h>
#include <asm/thread_info.h>
#include <asm/reg_a2.h>
#include <asm/exception-64e.h>
#include <asm/bug.h>
#include <asm/irqflags.h>
#include <asm/ptrace.h>
#include <asm/ppc-opcode.h>
#include <asm/mmu.h>
#include <asm/hw_irq.h>

/* XXX This will ultimately add space for a special exception save
 *     structure used to save things like SRR0/SRR1, SPRGs, MAS, etc...
 *     when taking special interrupts. For now we don't support that,
 *     special interrupts from within a non-standard level will probably
 *     blow you up
 */
#define	SPECIAL_EXC_FRAME_SIZE	INT_FRAME_SIZE

/* Exception prolog code for all exceptions */
#define EXCEPTION_PROLOG(n, type, addition)				    \
	mtspr	SPRN_SPRG_##type##_SCRATCH,r13;	/* get spare registers */   \
	mfspr	r13,SPRN_SPRG_PACA;	/* get PACA */			    \
	std	r10,PACA_EX##type+EX_R10(r13);				    \
	std	r11,PACA_EX##type+EX_R11(r13);				    \
	mfcr	r10;			/* save CR */			    \
	addition;			/* additional code for that exc. */ \
	std	r1,PACA_EX##type+EX_R1(r13); /* save old r1 in the PACA */  \
	stw	r10,PACA_EX##type+EX_CR(r13); /* save old CR in the PACA */ \
	mfspr	r11,SPRN_##type##_SRR1;/* what are we coming from */	    \
	type##_SET_KSTACK;		/* get special stack if necessary */\
	andi.	r10,r11,MSR_PR;		/* save stack pointer */	    \
	beq	1f;			/* branch around if supervisor */   \
	ld	r1,PACAKSAVE(r13);	/* get kernel stack coming from usr */\
1:	cmpdi	cr1,r1,0;		/* check if SP makes sense */	    \
	bge-	cr1,exc_##n##_bad_stack;/* bad stack (TODO: out of line) */ \
	mfspr	r10,SPRN_##type##_SRR0;	/* read SRR0 before touching stack */

/* Exception type-specific macros */
#define	GEN_SET_KSTACK							    \
	subi	r1,r1,INT_FRAME_SIZE;	/* alloc frame on kernel stack */
#define SPRN_GEN_SRR0	SPRN_SRR0
#define SPRN_GEN_SRR1	SPRN_SRR1

#define CRIT_SET_KSTACK						            \
	ld	r1,PACA_CRIT_STACK(r13);				    \
	subi	r1,r1,SPECIAL_EXC_FRAME_SIZE;
#define SPRN_CRIT_SRR0	SPRN_CSRR0
#define SPRN_CRIT_SRR1	SPRN_CSRR1

#define DBG_SET_KSTACK						            \
	ld	r1,PACA_DBG_STACK(r13);					    \
	subi	r1,r1,SPECIAL_EXC_FRAME_SIZE;
#define SPRN_DBG_SRR0	SPRN_DSRR0
#define SPRN_DBG_SRR1	SPRN_DSRR1

#define MC_SET_KSTACK						            \
	ld	r1,PACA_MC_STACK(r13);					    \
	subi	r1,r1,SPECIAL_EXC_FRAME_SIZE;
#define SPRN_MC_SRR0	SPRN_MCSRR0
#define SPRN_MC_SRR1	SPRN_MCSRR1

#define NORMAL_EXCEPTION_PROLOG(n, addition)				    \
	EXCEPTION_PROLOG(n, GEN, addition##_GEN(n))

#define CRIT_EXCEPTION_PROLOG(n, addition)				    \
	EXCEPTION_PROLOG(n, CRIT, addition##_CRIT(n))

#define DBG_EXCEPTION_PROLOG(n, addition)				    \
	EXCEPTION_PROLOG(n, DBG, addition##_DBG(n))

#define MC_EXCEPTION_PROLOG(n, addition)				    \
	EXCEPTION_PROLOG(n, MC, addition##_MC(n))


/* Variants of the "addition" argument for the prolog
 */
#define PROLOG_ADDITION_NONE_GEN(n)
#define PROLOG_ADDITION_NONE_CRIT(n)
#define PROLOG_ADDITION_NONE_DBG(n)
#define PROLOG_ADDITION_NONE_MC(n)

#define PROLOG_ADDITION_MASKABLE_GEN(n)					    \
	lbz	r11,PACASOFTIRQEN(r13); /* are irqs soft-disabled ? */	    \
	cmpwi	cr0,r11,0;		/* yes -> go out of line */	    \
	beq	masked_interrupt_book3e_##n

#define PROLOG_ADDITION_2REGS_GEN(n)					    \
	std	r14,PACA_EXGEN+EX_R14(r13);				    \
	std	r15,PACA_EXGEN+EX_R15(r13)

#define PROLOG_ADDITION_1REG_GEN(n)					    \
	std	r14,PACA_EXGEN+EX_R14(r13);

#define PROLOG_ADDITION_2REGS_CRIT(n)					    \
	std	r14,PACA_EXCRIT+EX_R14(r13);				    \
	std	r15,PACA_EXCRIT+EX_R15(r13)

#define PROLOG_ADDITION_2REGS_DBG(n)					    \
	std	r14,PACA_EXDBG+EX_R14(r13);				    \
	std	r15,PACA_EXDBG+EX_R15(r13)

#define PROLOG_ADDITION_2REGS_MC(n)					    \
	std	r14,PACA_EXMC+EX_R14(r13);				    \
	std	r15,PACA_EXMC+EX_R15(r13)


/* Core exception code for all exceptions except TLB misses.
 * XXX: Needs to make SPRN_SPRG_GEN depend on exception type
 */
#define EXCEPTION_COMMON(n, excf, ints)					    \
exc_##n##_common:							    \
	std	r0,GPR0(r1);		/* save r0 in stackframe */	    \
	std	r2,GPR2(r1);		/* save r2 in stackframe */	    \
	SAVE_4GPRS(3, r1);		/* save r3 - r6 in stackframe */    \
	SAVE_2GPRS(7, r1);		/* save r7, r8 in stackframe */	    \
	std	r9,GPR9(r1);		/* save r9 in stackframe */	    \
	std	r10,_NIP(r1);		/* save SRR0 to stackframe */	    \
	std	r11,_MSR(r1);		/* save SRR1 to stackframe */	    \
	ACCOUNT_CPU_USER_ENTRY(r10,r11);/* accounting (uses cr0+eq) */	    \
	ld	r3,excf+EX_R10(r13);	/* get back r10 */		    \
	ld	r4,excf+EX_R11(r13);	/* get back r11 */		    \
	mfspr	r5,SPRN_SPRG_GEN_SCRATCH;/* get back r13 */		    \
	std	r12,GPR12(r1);		/* save r12 in stackframe */	    \
	ld	r2,PACATOC(r13);	/* get kernel TOC into r2 */	    \
	mflr	r6;