diff options
Diffstat (limited to 'arch/mips/dec/kn02xa-berr.c')
| -rw-r--r-- | arch/mips/dec/kn02xa-berr.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/arch/mips/dec/kn02xa-berr.c b/arch/mips/dec/kn02xa-berr.c new file mode 100644 index 000000000..9699fc4e6 --- /dev/null +++ b/arch/mips/dec/kn02xa-berr.c @@ -0,0 +1,135 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Bus error event handling code for 5000-series systems equipped + * with parity error detection logic, i.e. DECstation/DECsystem + * 5000/120, /125, /133 (KN02-BA), 5000/150 (KN04-BA) and Personal + * DECstation/DECsystem 5000/20, /25, /33 (KN02-CA), 5000/50 + * (KN04-CA) systems. + * + * Copyright (c) 2005 Maciej W. Rozycki + */ + +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/types.h> + +#include <asm/addrspace.h> +#include <asm/cpu-type.h> +#include <asm/irq_regs.h> +#include <asm/ptrace.h> +#include <asm/traps.h> + +#include <asm/dec/kn02ca.h> +#include <asm/dec/kn02xa.h> +#include <asm/dec/kn05.h> + +static inline void dec_kn02xa_be_ack(void) +{ + volatile u32 *mer = (void *)CKSEG1ADDR(KN02XA_MER); + volatile u32 *mem_intr = (void *)CKSEG1ADDR(KN02XA_MEM_INTR); + + *mer = KN02CA_MER_INTR; /* Clear errors; keep the ARC IRQ. */ + *mem_intr = 0; /* Any write clears the bus IRQ. */ + iob(); +} + +static int dec_kn02xa_be_backend(struct pt_regs *regs, int is_fixup, + int invoker) +{ + volatile u32 *kn02xa_mer = (void *)CKSEG1ADDR(KN02XA_MER); + volatile u32 *kn02xa_ear = (void *)CKSEG1ADDR(KN02XA_EAR); + + static const char excstr[] = "exception"; + static const char intstr[] = "interrupt"; + static const char cpustr[] = "CPU"; + static const char mreadstr[] = "memory read"; + static const char readstr[] = "read"; + static const char writestr[] = "write"; + static const char timestr[] = "timeout"; + static const char paritystr[] = "parity error"; + static const char lanestat[][4] = { " OK", "BAD" }; + + const char *kind, *agent, *cycle, *event; + unsigned long address; + + u32 mer = *kn02xa_mer; + u32 ear = *kn02xa_ear; + int action = MIPS_BE_FATAL; + + /* Ack ASAP, so that any subsequent errors get caught. */ + dec_kn02xa_be_ack(); + + kind = invoker ? intstr : excstr; + + /* No DMA errors? */ + agent = cpustr; + + address = ear & KN02XA_EAR_ADDRESS; + + /* Low 256MB is decoded as memory, high -- as TC. */ + if (address < 0x10000000) { + cycle = mreadstr; + event = paritystr; + } else { + cycle = invoker ? writestr : readstr; + event = timestr; + } + + if (is_fixup) + action = MIPS_BE_FIXUP; + + if (action != MIPS_BE_FIXUP) + printk(KERN_ALERT "Bus error %s: %s %s %s at %#010lx\n", + kind, agent, cycle, event, address); + + if (action != MIPS_BE_FIXUP && address < 0x10000000) + printk(KERN_ALERT " Byte lane status %#3x -- " + "#3: %s, #2: %s, #1: %s, #0: %s\n", + (mer & KN02XA_MER_BYTERR) >> 8, + lanestat[(mer & KN02XA_MER_BYTERR_3) != 0], + lanestat[(mer & KN02XA_MER_BYTERR_2) != 0], + lanestat[(mer & KN02XA_MER_BYTERR_1) != 0], + lanestat[(mer & KN02XA_MER_BYTERR_0) != 0]); + + return action; +} + +int dec_kn02xa_be_handler(struct pt_regs *regs, int is_fixup) +{ + return dec_kn02xa_be_backend(regs, is_fixup, 0); +} + +irqreturn_t dec_kn02xa_be_interrupt(int irq, void *dev_id) +{ + struct pt_regs *regs = get_irq_regs(); + int action = dec_kn02xa_be_backend(regs, 0, 1); + + if (action == MIPS_BE_DISCARD) + return IRQ_HANDLED; + + /* + * FIXME: Find the affected processes and kill them, otherwise + * we must die. + * + * The interrupt is asynchronously delivered thus EPC and RA + * may be irrelevant, but are printed for a reference. + */ + printk(KERN_ALERT "Fatal bus interrupt, epc == %08lx, ra == %08lx\n", + regs->cp0_epc, regs->regs[31]); + die("Unrecoverable bus error", regs); +} + + +void __init dec_kn02xa_be_init(void) +{ + volatile u32 *mbcs = (void *)CKSEG1ADDR(KN4K_SLOT_BASE + KN4K_MB_CSR); + + /* For KN04 we need to make sure EE (?) is enabled in the MB. */ + if (current_cpu_type() == CPU_R4000SC) + *mbcs |= KN4K_MB_CSR_EE; + fast_iob(); + + /* Clear any leftover errors from the firmware. */ + dec_kn02xa_be_ack(); +} |