traps.c

linux-2.6.15.6

/*
 *  linux/arch/m68k/kernel/traps.c
 *
 *  Copyright (C) 1993, 1994 by Hamish Macdonald
 *
 *  68040 fixes by Michael Rausch
 *  68040 fixes by Martin Apel
 *  68040 fixes and writeback by Richard Zidlicky
 *  68060 fixes by Roman Hodek
 *  68060 fixes by Jesper Skov
 *
 * 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.
 */

/*
 * Sets up all exception vectors
 */

#include <linux/config.h>
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/a.out.h>
#include <linux/user.h>
#include <linux/string.h>
#include <linux/linkage.h>
#include <linux/init.h>
#include <linux/ptrace.h>
#include <linux/kallsyms.h>

#include <asm/setup.h>
#include <asm/fpu.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/traps.h>
#include <asm/pgalloc.h>
#include <asm/machdep.h>
#include <asm/siginfo.h>

/* assembler routines */
asmlinkage void system_call(void);
asmlinkage void buserr(void);
asmlinkage void trap(void);
asmlinkage void inthandler(void);
asmlinkage void nmihandler(void);
#ifdef CONFIG_M68KFPU_EMU
asmlinkage void fpu_emu(void);
#endif

e_vector vectors[256] = {
	[VEC_BUSERR]	= buserr,
	[VEC_ADDRERR]	= trap,
	[VEC_ILLEGAL]	= trap,
	[VEC_ZERODIV]	= trap,
	[VEC_CHK]	= trap,
	[VEC_TRAP]	= trap,
	[VEC_PRIV]	= trap,
	[VEC_TRACE]	= trap,
	[VEC_LINE10]	= trap,
	[VEC_LINE11]	= trap,
	[VEC_RESV12]	= trap,
	[VEC_COPROC]	= trap,
	[VEC_FORMAT]	= trap,
	[VEC_UNINT]	= trap,
	[VEC_RESV16]	= trap,
	[VEC_RESV17]	= trap,
	[VEC_RESV18]	= trap,
	[VEC_RESV19]	= trap,
	[VEC_RESV20]	= trap,
	[VEC_RESV21]	= trap,
	[VEC_RESV22]	= trap,
	[VEC_RESV23]	= trap,
	[VEC_SPUR]	= inthandler,
	[VEC_INT1]	= inthandler,
	[VEC_INT2]	= inthandler,
	[VEC_INT3]	= inthandler,
	[VEC_INT4]	= inthandler,
	[VEC_INT5]	= inthandler,
	[VEC_INT6]	= inthandler,
	[VEC_INT7]	= inthandler,
	[VEC_SYS]	= system_call,
	[VEC_TRAP1]	= trap,
	[VEC_TRAP2]	= trap,
	[VEC_TRAP3]	= trap,
	[VEC_TRAP4]	= trap,
	[VEC_TRAP5]	= trap,
	[VEC_TRAP6]	= trap,
	[VEC_TRAP7]	= trap,
	[VEC_TRAP8]	= trap,
	[VEC_TRAP9]	= trap,
	[VEC_TRAP10]	= trap,
	[VEC_TRAP11]	= trap,
	[VEC_TRAP12]	= trap,
	[VEC_TRAP13]	= trap,
	[VEC_TRAP14]	= trap,
	[VEC_TRAP15]	= trap,
};

/* nmi handler for the Amiga */
asm(".text\n"
    __ALIGN_STR "\n"
    "nmihandler: rte");

/*
 * this must be called very early as the kernel might
 * use some instruction that are emulated on the 060
 */
void __init base_trap_init(void)
{
	if(MACH_IS_SUN3X) {
		extern e_vector *sun3x_prom_vbr;

		__asm__ volatile ("movec %%vbr, %0" : "=r" ((void*)sun3x_prom_vbr));
	}

	/* setup the exception vector table */
	__asm__ volatile ("movec %0,%%vbr" : : "r" ((void*)vectors));

	if (CPU_IS_060) {
		/* set up ISP entry points */
		asmlinkage void unimp_vec(void) asm ("_060_isp_unimp");

		vectors[VEC_UNIMPII] = unimp_vec;
	}
}

void __init trap_init (void)
{
	int i;

	for (i = 48; i < 64; i++)
		if (!vectors[i])
			vectors[i] = trap;

	for (i = 64; i < 256; i++)
		vectors[i] = inthandler;

#ifdef CONFIG_M68KFPU_EMU
	if (FPU_IS_EMU)
		vectors[VEC_LINE11] = fpu_emu;
#endif

	if (CPU_IS_040 && !FPU_IS_EMU) {
		/* set up FPSP entry points */
		asmlinkage void dz_vec(void) asm ("dz");
		asmlinkage void inex_vec(void) asm ("inex");
		asmlinkage void ovfl_vec(void) asm ("ovfl");
		asmlinkage void unfl_vec(void) asm ("unfl");
		asmlinkage void snan_vec(void) asm ("snan");
		asmlinkage void operr_vec(void) asm ("operr");
		asmlinkage void bsun_vec(void) asm ("bsun");
		asmlinkage void fline_vec(void) asm ("fline");
		asmlinkage void unsupp_vec(void) asm ("unsupp");

		vectors[VEC_FPDIVZ] = dz_vec;
		vectors[VEC_FPIR] = inex_vec;
		vectors[VEC_FPOVER] = ovfl_vec;
		vectors[VEC_FPUNDER] = unfl_vec;
		vectors[VEC_FPNAN] = snan_vec;
		vectors[VEC_FPOE] = operr_vec;
		vectors[VEC_FPBRUC] = bsun_vec;
		vectors[VEC_LINE11] = fline_vec;
		vectors[VEC_FPUNSUP] = unsupp_vec;
	}

	if (CPU_IS_060 && !FPU_IS_EMU) {
		/* set up IFPSP entry points */
		asmlinkage void snan_vec(void) asm ("_060_fpsp_snan");
		asmlinkage void operr_vec(void) asm ("_060_fpsp_operr");
		asmlinkage void ovfl_vec(void) asm ("_060_fpsp_ovfl");
		asmlinkage void unfl_vec(void) asm ("_060_fpsp_unfl");
		asmlinkage void dz_vec(void) asm ("_060_fpsp_dz");
		asmlinkage void inex_vec(void) asm ("_060_fpsp_inex");
		asmlinkage void fline_vec(void) asm ("_060_fpsp_fline");
		asmlinkage void unsupp_vec(void) asm ("_060_fpsp_unsupp");
		asmlinkage void effadd_vec(void) asm ("_060_fpsp_effadd");

		vectors[VEC_FPNAN] = snan_vec;
		vectors[VEC_FPOE] = operr_vec;
		vectors[VEC_FPOVER] = ovfl_vec;
		vectors[VEC_FPUNDER] = unfl_vec;
		vectors[VEC_FPDIVZ] = dz_vec;
		vectors[VEC_FPIR] = inex_vec;
		vectors[VEC_LINE11] = fline_vec;
		vectors[VEC_FPUNSUP] = unsupp_vec;
		vectors[VEC_UNIMPEA] = effadd_vec;
	}

        /* if running on an amiga, make the NMI interrupt do nothing */
	if (MACH_IS_AMIGA) {
		vectors[VEC_INT7] = nmihandler;
	}
}


static const char *vec_names[] = {
	[VEC_RESETSP]	= "RESET SP",
	[VEC_RESETPC]	= "RESET PC",
	[VEC_BUSERR]	= "BUS ERROR",
	[VEC_ADDRERR]	= "ADDRESS ERROR",
	[VEC_ILLEGAL]	= "ILLEGAL INSTRUCTION",
	[VEC_ZERODIV]	= "ZERO DIVIDE",
	[VEC_CHK]	= "CHK",
	[VEC_TRAP]	= "TRAPcc",
	[VEC_PRIV]	= "PRIVILEGE VIOLATION",
	[VEC_TRACE]	= "TRACE",
	[VEC_LINE10]	= "LINE 1010",
	[VEC_LINE11]	= "LINE 1111",
	[VEC_RESV12]	= "UNASSIGNED RESERVED 12",
	[VEC_COPROC]	= "COPROCESSOR PROTOCOL VIOLATION",
	[VEC_FORMAT]	= "FORMAT ERROR",
	[VEC_UNINT]	= "UNINITIALIZED INTERRUPT",
	[VEC_RESV16]	= "UNASSIGNED RESERVED 16",
	[VEC_RESV17]	= "UNASSIGNED RESERVED 17",
	[VEC_RESV18]	= "UNASSIGNED RESERVED 18",
	[VEC_RESV19]	= "UNASSIGNED RESERVED 19",
	[VEC_RESV20]	= "UNASSIGNED RESERVED 20",
	[VEC_RESV21]	= "UNASSIGNED RESERVED 21",
	[VEC_RESV22]	= "UNASSIGNED RESERVED 22",
	[VEC_RESV23]	= "UNASSIGNED RESERVED 23",
	[VEC_SPUR]	= "SPURIOUS INTERRUPT",
	[VEC_INT1]	= "LEVEL 1 INT",
	[VEC_INT2]	= "LEVEL 2 INT",
	[VEC_INT3]	= "LEVEL 3 INT",
	[VEC_INT4]	= "LEVEL 4 INT",
	[VEC_INT5]	= "LEVEL 5 INT",
	[VEC_INT6]	= "LEVEL 6 INT",
	[VEC_INT7]	= "LEVEL 7 INT",
	[VEC_SYS]	= "SYSCALL",
	[VEC_TRAP1]	= "TRAP #1",
	[VEC_TRAP2]	= "TRAP #2",
	[VEC_TRAP3]	= "TRAP #3",
	[VEC_TRAP4]	= "TRAP #4",
	[VEC_TRAP5]	= "TRAP #5",
	[VEC_TRAP6]	= "TRAP #6",
	[VEC_TRAP7]	= "TRAP #7",
	[VEC_TRAP8]	= "TRAP #8",
	[VEC_TRAP9]	= "TRAP #9",
	[VEC_TRAP10]	= "TRAP #10",
	[VEC_TRAP11]	= "TRAP #11",
	[VEC_TRAP12]	= "TRAP #12",
	[VEC_TRAP13]	= "TRAP #13",
	[VEC_TRAP14]	= "TRAP #14",
	[VEC_TRAP15]	= "TRAP #15",
	[VEC_FPBRUC]	= "FPCP BSUN",
	[VEC_FPIR]	= "FPCP INEXACT",
	[VEC_FPDIVZ]	= "FPCP DIV BY 0",
	[VEC_FPUNDER]	= "FPCP UNDERFLOW",
	[VEC_FPOE]	= "FPCP OPERAND ERROR",
	[VEC_FPOVER]	= "FPCP OVERFLOW",
	[VEC_FPNAN]	= "FPCP SNAN",
	[VEC_FPUNSUP]	= "FPCP UNSUPPORTED OPERATION",
	[VEC_MMUCFG]	= "MMU CONFIGURATION ERROR",
	[VEC_MMUILL]	= "MMU ILLEGAL OPERATION ERROR",
	[VEC_MMUACC]	= "MMU ACCESS LEVEL VIOLATION ERROR",
	[VEC_RESV59]	= "UNASSIGNED RESERVED 59",
	[VEC_UNIMPEA]	= "UNASSIGNED RESERVED 60",
	[VEC_UNIMPII]	= "UNASSIGNED RESERVED 61",
	[VEC_RESV62]	= "UNASSIGNED RESERVED 62",
	[VEC_RESV63]	= "UNASSIGNED RESERVED 63",
};

static const char *space_names[] = {
	[0]		= "Space 0",
	[USER_DATA]	= "User Data",
	[USER_PROGRAM]	= "User Program",
#ifndef CONFIG_SUN3
	[3]		= "Space 3",
#else
	[FC_CONTROL]	= "Control",
#endif
	[4]		= "Space 4",
	[SUPER_DATA]	= "Super Data",
	[SUPER_PROGRAM]	= "Super Program",
	[CPU_SPACE]	= "CPU"
};

void die_if_kernel(char *,struct pt_regs *,int);
asmlinkage int do_page_fault(struct pt_regs *regs, unsigned long address,
                             unsigned long error_code);
int send_fault_sig(struct pt_regs *regs);

asmlinkage void trap_c(struct frame *fp);

#if defined (CONFIG_M68060)
static inline void access_error060 (struct frame *fp)
{
	unsigned long fslw = fp->un.fmt4.pc; /* is really FSLW for access error */

#ifdef DEBUG
	printk("fslw=%#lx, fa=%#lx\n", fslw, fp->un.fmt4.effaddr);
#endif

	if (fslw & MMU060_BPE) {
		/* branch prediction error -> clear branch cache */
		__asm__ __volatile__ ("movec %/cacr,%/d0\n\t"
				      "orl   #0x00400000,%/d0\n\t"
				      "movec %/d0,%/cacr"
				      : : : "d0" );
		/* return if there's no other error */
		if (!(fslw & MMU060_ERR_BITS) && !(fslw & MMU060_SEE))
			return;
	}

	if (fslw & (MMU060_DESC_ERR | MMU060_WP | MMU060_SP)) {
		unsigned long errorcode;
		unsigned long addr = fp->un.fmt4.effaddr;

		if (fslw & MMU060_MA)
			addr = (addr + PAGE_SIZE - 1) & PAGE_MASK;

		errorcode = 1;
		if (fslw & MMU060_DESC_ERR) {
			__flush_tlb040_one(addr);
			errorcode = 0;
		}
		if (fslw & MMU060_W)
			errorcode |= 2;
#ifdef DEBUG
		printk("errorcode = %d\n", errorcode );
#endif
		do_page_fault(&fp->ptregs, addr, errorcode);
	} else if (fslw & (MMU060_SEE)){
		/* Software Emulation Error.
		 * fault during mem_read/mem_write in ifpsp060/os.S
		 */
		send_fault_sig(&fp->ptregs);
	} else if (!(fslw & (MMU060_RE|MMU060_WE)) ||
		   send_fault_sig(&fp->ptregs) > 0) {
		printk("pc=%#lx, fa=%#lx\n", fp->ptregs.pc, fp->un.fmt4.effaddr);
		printk( "68060 access error, fslw=%lx\n", fslw );
		trap_c( fp );
	}
}
#endif /* CONFIG_M68060 */

#if defined (CONFIG_M68040)
static inline unsigned long probe040(int iswrite, unsigned long addr, int wbs)
{
	unsigned long mmusr;
	mm_segment_t old_fs = get_fs();

	set_fs(MAKE_MM_SEG(wbs));

	if (iswrite)
		asm volatile (".chip 68040; ptestw (%0); .chip 68k" : : "a" (addr));
	else
		asm volatile (".chip 68040; ptestr (%0); .chip 68k" : : "a" (addr));

	asm volatile (".chip 68040; movec %%mmusr,%0; .chip 68k" : "=r" (mmusr));

	set_fs(old_fs);

	return mmusr;
}

static inline int do_040writeback1(unsigned short wbs, unsigned long wba,
				   unsigned long wbd)
{
	int res = 0;
	mm_segment_t old_fs = get_fs();

	/* set_fs can not be moved, otherwise put_user() may oops */
	set_fs(MAKE_MM_SEG(wbs));

	switch (wbs & WBSIZ_040) {
	case BA_SIZE_BYTE:
		res = put_user(wbd & 0xff, (char *)wba);
		break;
	case BA_SIZE_WORD:
		res = put_user(wbd & 0xffff, (short *)wba);
		break;
	case BA_SIZE_LONG:
		res = put_user(wbd, (int *)wba);
		break;
	}

	/* set_fs can not be moved, otherwise put_user() may oops */
	set_fs(old_fs);


#ifdef DEBUG
	printk("do_040writeback1, res=%d\n",res);
#endif

	return res;
}

/* after an exception in a writeback the stack frame corresponding
 * to that exception is discarded, set a few bits in the old frame
 * to simulate what it should look like
 */
static inline void fix_xframe040(struct frame *fp, unsigned long wba, unsigned short wbs)
{
	fp->un.fmt7.faddr = wba;
	fp->un.fmt7.ssw = wbs & 0xff;
	if (wba != current->thread.faddr)
	    fp->un.fmt7.ssw |= MA_040;
}

static inline void do_040writebacks(struct frame *fp)
{
	int res = 0;
#if 0
	if (fp->un.fmt7.wb1s & WBV_040)
		printk("access_error040: cannot handle 1st writeback. oops.\n");