140 lines
3.9 KiB
C
140 lines
3.9 KiB
C
/*
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* Bus error event handling code for 5000-series systems equipped
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* with parity error detection logic, i.e. DECstation/DECsystem
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* 5000/120, /125, /133 (KN02-BA), 5000/150 (KN04-BA) and Personal
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* DECstation/DECsystem 5000/20, /25, /33 (KN02-CA), 5000/50
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* (KN04-CA) systems.
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*
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* Copyright (c) 2005 Maciej W. Rozycki
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <asm/addrspace.h>
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#include <asm/irq_regs.h>
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#include <asm/ptrace.h>
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#include <asm/system.h>
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#include <asm/traps.h>
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#include <asm/dec/kn02ca.h>
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#include <asm/dec/kn02xa.h>
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#include <asm/dec/kn05.h>
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static inline void dec_kn02xa_be_ack(void)
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{
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volatile u32 *mer = (void *)CKSEG1ADDR(KN02XA_MER);
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volatile u32 *mem_intr = (void *)CKSEG1ADDR(KN02XA_MEM_INTR);
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*mer = KN02CA_MER_INTR; /* Clear errors; keep the ARC IRQ. */
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*mem_intr = 0; /* Any write clears the bus IRQ. */
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iob();
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}
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static int dec_kn02xa_be_backend(struct pt_regs *regs, int is_fixup,
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int invoker)
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{
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volatile u32 *kn02xa_mer = (void *)CKSEG1ADDR(KN02XA_MER);
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volatile u32 *kn02xa_ear = (void *)CKSEG1ADDR(KN02XA_EAR);
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static const char excstr[] = "exception";
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static const char intstr[] = "interrupt";
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static const char cpustr[] = "CPU";
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static const char mreadstr[] = "memory read";
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static const char readstr[] = "read";
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static const char writestr[] = "write";
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static const char timestr[] = "timeout";
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static const char paritystr[] = "parity error";
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static const char lanestat[][4] = { " OK", "BAD" };
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const char *kind, *agent, *cycle, *event;
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unsigned long address;
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u32 mer = *kn02xa_mer;
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u32 ear = *kn02xa_ear;
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int action = MIPS_BE_FATAL;
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/* Ack ASAP, so that any subsequent errors get caught. */
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dec_kn02xa_be_ack();
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kind = invoker ? intstr : excstr;
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/* No DMA errors? */
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agent = cpustr;
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address = ear & KN02XA_EAR_ADDRESS;
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/* Low 256MB is decoded as memory, high -- as TC. */
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if (address < 0x10000000) {
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cycle = mreadstr;
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event = paritystr;
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} else {
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cycle = invoker ? writestr : readstr;
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event = timestr;
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}
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if (is_fixup)
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action = MIPS_BE_FIXUP;
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if (action != MIPS_BE_FIXUP)
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printk(KERN_ALERT "Bus error %s: %s %s %s at %#010lx\n",
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kind, agent, cycle, event, address);
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if (action != MIPS_BE_FIXUP && address < 0x10000000)
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printk(KERN_ALERT " Byte lane status %#3x -- "
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"#3: %s, #2: %s, #1: %s, #0: %s\n",
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(mer & KN02XA_MER_BYTERR) >> 8,
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lanestat[(mer & KN02XA_MER_BYTERR_3) != 0],
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lanestat[(mer & KN02XA_MER_BYTERR_2) != 0],
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lanestat[(mer & KN02XA_MER_BYTERR_1) != 0],
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lanestat[(mer & KN02XA_MER_BYTERR_0) != 0]);
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return action;
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}
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int dec_kn02xa_be_handler(struct pt_regs *regs, int is_fixup)
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{
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return dec_kn02xa_be_backend(regs, is_fixup, 0);
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}
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irqreturn_t dec_kn02xa_be_interrupt(int irq, void *dev_id)
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{
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struct pt_regs *regs = get_irq_regs();
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int action = dec_kn02xa_be_backend(regs, 0, 1);
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if (action == MIPS_BE_DISCARD)
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return IRQ_HANDLED;
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/*
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* FIXME: Find the affected processes and kill them, otherwise
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* we must die.
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*
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* The interrupt is asynchronously delivered thus EPC and RA
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* may be irrelevant, but are printed for a reference.
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*/
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printk(KERN_ALERT "Fatal bus interrupt, epc == %08lx, ra == %08lx\n",
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regs->cp0_epc, regs->regs[31]);
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die("Unrecoverable bus error", regs);
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}
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void __init dec_kn02xa_be_init(void)
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{
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volatile u32 *mbcs = (void *)CKSEG1ADDR(KN4K_SLOT_BASE + KN4K_MB_CSR);
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/* For KN04 we need to make sure EE (?) is enabled in the MB. */
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if (current_cpu_type() == CPU_R4000SC)
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*mbcs |= KN4K_MB_CSR_EE;
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fast_iob();
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/* Clear any leftover errors from the firmware. */
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dec_kn02xa_be_ack();
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}
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