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-rw-r--r--arch/mips/dec/kn02xa-berr.c135
1 files changed, 135 insertions, 0 deletions
diff --git a/arch/mips/dec/kn02xa-berr.c b/arch/mips/dec/kn02xa-berr.c
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index 000000000..9699fc4e6
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+++ b/arch/mips/dec/kn02xa-berr.c
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+// 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();
+}