/* * ip22-berr.c: Bus error handling. * * Copyright (C) 2002 Ladislav Michl */#include <linux/init.h>#include <linux/kernel.h>#include <linux/sched.h>#include <asm/addrspace.h>#include <asm/system.h>#include <asm/traps.h>#include <asm/branch.h>#include <asm/sgi/sgimc.h>#include <asm/sgi/sgihpc.h>unsigned int cpu_err_stat;	/* Status reg for CPU */unsigned int gio_err_stat;	/* Status reg for GIO */unsigned int cpu_err_addr;	/* Error address reg for CPU */unsigned int gio_err_addr;	/* Error address reg for GIO */volatile int nofault;static void save_and_clear_buserr(void){	/* save memory controler's error status registers */	cpu_err_addr = mcmisc_regs->cerr;	cpu_err_stat = mcmisc_regs->cstat;	gio_err_addr = mcmisc_regs->gerr;	gio_err_stat = mcmisc_regs->gstat;	mcmisc_regs->cstat = mcmisc_regs->gstat = 0;}/* * MC sends an interrupt whenever bus or parity errors occur. In addition, * if the error happened during a CPU read, it also asserts the bus error * pin on the R4K. Code in bus error handler save the MC bus error registers * and then clear the interrupt when this happens. */void be_ip22_interrupt(int irq, struct pt_regs *regs){	save_and_clear_buserr();	printk(KERN_ALERT "Bus error, epc == %08lx, ra == %08lx\n",	       regs->cp0_epc, regs->regs[31]);	die_if_kernel("Oops", regs);	force_sig(SIGBUS, current);}int be_ip22_handler(struct pt_regs *regs, int is_fixup){	save_and_clear_buserr();	if (nofault) {		nofault = 0;		compute_return_epc(regs);		return MIPS_BE_DISCARD;	}	return MIPS_BE_FIXUP;}int ip22_baddr(unsigned int *val, unsigned long addr){	nofault = 1;	*val = *(volatile unsigned int *) addr;	__asm__ __volatile__("nop;nop;nop;nop");	if (nofault) {		nofault = 0;		return 0;	}	return -EFAULT;}void __init bus_error_init(void){	be_board_handler = be_ip22_handler;}