22 files changed, 2831 insertions, 0 deletions
diff --git a/arch/mips/dec/Makefile b/arch/mips/dec/Makefile
new file mode 100644
index 00000000000..688757a97cb
--- /dev/null
+++ b/arch/mips/dec/Makefile
@@ -0,0 +1,11 @@
+#
+# Makefile for the DECstation family specific parts of the kernel
+#
+
+obj-y		:= ecc-berr.o int-handler.o ioasic-irq.o kn02-irq.o reset.o \
+		   setup.o time.o
+
+obj-$(CONFIG_PROM_CONSOLE)	+= promcon.o
+obj-$(CONFIG_CPU_HAS_WB)	+= wbflush.o
+
+EXTRA_AFLAGS := $(CFLAGS)
diff --git a/arch/mips/dec/boot/Makefile b/arch/mips/dec/boot/Makefile
new file mode 100644
index 00000000000..bcea41698ef
--- /dev/null
+++ b/arch/mips/dec/boot/Makefile
@@ -0,0 +1,12 @@
+#
+# Makefile for the DECstation family specific parts of the kernel
+#
+
+netboot: all
+	$(LD) -N -G 0 -T ld.ecoff ../../boot/zImage \
+		dec_boot.o ramdisk.img -o nbImage
+
+obj-y	 := decstation.o
+
+clean:
+	rm -f nbImage
diff --git a/arch/mips/dec/boot/decstation.c b/arch/mips/dec/boot/decstation.c
new file mode 100644
index 00000000000..56fd4277555
--- /dev/null
+++ b/arch/mips/dec/boot/decstation.c
@@ -0,0 +1,83 @@
+/*
+ * arch/mips/dec/decstation.c
+ */
+
+#define RELOC
+#define INITRD
+#define DEBUG_BOOT
+
+/*
+ * Magic number indicating REX PROM available on DECSTATION.
+ */
+#define	REX_PROM_MAGIC		0x30464354
+
+#define REX_PROM_CLEARCACHE	0x7c/4
+#define REX_PROM_PRINTF		0x30/4
+
+#define VEC_RESET		0xBFC00000		/* Prom base address */
+#define	PMAX_PROM_ENTRY(x)	(VEC_RESET+((x)*8))	/* Prom jump table */
+#define	PMAX_PROM_PRINTF	PMAX_PROM_ENTRY(17)
+
+#define PARAM	(k_start + 0x2000)
+
+#define LOADER_TYPE (*(unsigned char *) (PARAM+0x210))
+#define INITRD_START (*(unsigned long *) (PARAM+0x218))
+#define INITRD_SIZE (*(unsigned long *) (PARAM+0x21c))
+
+extern int _ftext, _end;		/* begin and end of kernel image */
+extern void kernel_entry(int, char **, unsigned long, int *);
+
+void * memcpy(void * dest, const void *src, unsigned int count)
+{
+	unsigned long *tmp = (unsigned long *) dest, *s = (unsigned long *) src;
+
+	count >>= 2;
+	while (count--)
+		*tmp++ = *s++;
+
+	return dest;
+}
+
+void dec_entry(int argc, char **argv,
+	       unsigned long magic, int *prom_vec)
+{
+	void (*rex_clear_cache)(void);
+	int (*prom_printf)(char *, ...);
+	unsigned long k_start, len;
+
+	/*
+	 * The DS5100 leaves cpu with BEV enabled, clear it.
+	 */
+	asm(	"lui\t$8,0x3000\n\t"
+		"mtc0\t$8,$12\n\t"
+		".section\t.sdata\n\t"
+		".section\t.sbss\n\t"
+		".section\t.text"
+		: : : "$8");
+
+#ifdef DEBUG_BOOT
+	if (magic == REX_PROM_MAGIC) {
+	prom_printf = (int (*)(char *, ...)) *(prom_vec + REX_PROM_PRINTF);
+	} else {
+		prom_printf = (int (*)(char *, ...)) PMAX_PROM_PRINTF;
+	}
+	prom_printf("Launching kernel...\n");
+#endif
+
+	k_start = (unsigned long) (&kernel_entry) & 0xffff0000;
+
+#ifdef RELOC
+	/*
+	 * Now copy kernel image to its destination.
+	 */
+	len = ((unsigned long) (&_end) - k_start);
+	memcpy((void *)k_start, &_ftext, len);
+#endif
+
+	if (magic == REX_PROM_MAGIC) {
+		rex_clear_cache = (void (*)(void)) * (prom_vec + REX_PROM_CLEARCACHE);
+		rex_clear_cache();
+	}
+
+	kernel_entry(argc, argv, magic, prom_vec);
+}
diff --git a/arch/mips/dec/boot/ld.ecoff b/arch/mips/dec/boot/ld.ecoff
new file mode 100644
index 00000000000..aaa633dfb5f
--- /dev/null
+++ b/arch/mips/dec/boot/ld.ecoff
@@ -0,0 +1,43 @@
+OUTPUT_FORMAT("ecoff-littlemips")
+OUTPUT_ARCH(mips)
+ENTRY(dec_entry)
+SECTIONS
+{
+  . = 0x80200000;
+
+  .text :
+  {
+    _ftext = .;
+    *(.text)
+    *(.fixup)
+  }
+  .rdata :
+  {
+    *(.rodata .rodata.* .rdata)
+  }
+  .data :
+  {
+    . = ALIGN(0x1000);
+    ramdisk.img (.data)
+    *(.data)
+  }
+  .sdata :
+  {
+    *(.sdata)
+  }
+  _gp = .;
+  .sbss :
+  {
+    *(.sbss)
+    *(.scommon)
+  }
+  .bss :
+  {
+   *(.dynbss)
+   *(.bss)
+   *(COMMON)
+  }
+  /DISCARD/ : {
+    *(.reginfo .mdebug .note)
+  }
+}
diff --git a/arch/mips/dec/ecc-berr.c b/arch/mips/dec/ecc-berr.c
new file mode 100644
index 00000000000..133fb7c48e6
--- /dev/null
+++ b/arch/mips/dec/ecc-berr.c
@@ -0,0 +1,280 @@
+/*
+ *	linux/arch/mips/dec/ecc-berr.c
+ *
+ *	Bus error event handling code for systems equipped with ECC
+ *	handling logic, i.e. DECstation/DECsystem 5000/200 (KN02),
+ *	5000/240 (KN03), 5000/260 (KN05) and DECsystem 5900 (KN03),
+ *	5900/260 (KN05) systems.
+ *
+ *	Copyright (c) 2003  Maciej W. Rozycki
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include <asm/addrspace.h>
+#include <asm/bootinfo.h>
+#include <asm/cpu.h>
+#include <asm/processor.h>
+#include <asm/system.h>
+#include <asm/traps.h>
+
+#include <asm/dec/ecc.h>
+#include <asm/dec/kn02.h>
+#include <asm/dec/kn03.h>
+#include <asm/dec/kn05.h>
+
+static volatile u32 *kn0x_erraddr;
+static volatile u32 *kn0x_chksyn;
+
+static inline void dec_ecc_be_ack(void)
+{
+	*kn0x_erraddr = 0;			/* any write clears the IRQ */
+	iob();
+}
+
+static int dec_ecc_be_backend(struct pt_regs *regs, int is_fixup, int invoker)
+{
+	static const char excstr[] = "exception";
+	static const char intstr[] = "interrupt";
+	static const char cpustr[] = "CPU";
+	static const char dmastr[] = "DMA";
+	static const char readstr[] = "read";
+	static const char mreadstr[] = "memory read";
+	static const char writestr[] = "write";
+	static const char mwritstr[] = "partial memory write";
+	static const char timestr[] = "timeout";
+	static const char overstr[] = "overrun";
+	static const char eccstr[] = "ECC error";
+
+	const char *kind, *agent, *cycle, *event;
+	const char *status = "", *xbit = "", *fmt = "";
+	dma_addr_t address;
+	u16 syn = 0, sngl;
+
+	int i = 0;
+
+	u32 erraddr = *kn0x_erraddr;
+	u32 chksyn = *kn0x_chksyn;
+	int action = MIPS_BE_FATAL;
+
+	/* For non-ECC ack ASAP, so any subsequent errors get caught. */
+	if ((erraddr & (KN0X_EAR_VALID | KN0X_EAR_ECCERR)) == KN0X_EAR_VALID)
+		dec_ecc_be_ack();
+
+	kind = invoker ? intstr : excstr;
+
+	if (!(erraddr & KN0X_EAR_VALID)) {
+		/* No idea what happened. */
+		printk(KERN_ALERT "Unidentified bus error %s.\n", kind);
+		return action;
+	}
+
+	agent = (erraddr & KN0X_EAR_CPU) ? cpustr : dmastr;
+
+	if (erraddr & KN0X_EAR_ECCERR) {
+		/* An ECC error on a CPU or DMA transaction. */
+		cycle = (erraddr & KN0X_EAR_WRITE) ? mwritstr : mreadstr;
+		event = eccstr;
+	} else {
+		/* A CPU timeout or a DMA overrun. */
+		cycle = (erraddr & KN0X_EAR_WRITE) ? writestr : readstr;
+		event = (erraddr & KN0X_EAR_CPU) ? timestr : overstr;
+	}
+
+	address = erraddr & KN0X_EAR_ADDRESS;
+	/* For ECC errors on reads adjust for MT pipelining. */
+	if ((erraddr & (KN0X_EAR_WRITE | KN0X_EAR_ECCERR)) == KN0X_EAR_ECCERR)
+		address = (address & ~0xfffLL) | ((address - 5) & 0xfffLL);
+	address <<= 2;
+
+	/* Only CPU errors are fixable. */
+	if (erraddr & KN0X_EAR_CPU && is_fixup)
+		action = MIPS_BE_FIXUP;
+
+	if (erraddr & KN0X_EAR_ECCERR) {
+		static const u8 data_sbit[32] = {
+			0x4f, 0x4a, 0x52, 0x54, 0x57, 0x58, 0x5b, 0x5d,
+			0x23, 0x25, 0x26, 0x29, 0x2a, 0x2c, 0x31, 0x34,
+			0x0e, 0x0b, 0x13, 0x15, 0x16, 0x19, 0x1a, 0x1c,
+			0x62, 0x64, 0x67, 0x68, 0x6b, 0x6d, 0x70, 0x75,
+		};
+		static const u8 data_mbit[25] = {
+			0x07, 0x0d, 0x1f,
+			0x2f, 0x32, 0x37, 0x38, 0x3b, 0x3d, 0x3e,
+			0x43, 0x45, 0x46, 0x49, 0x4c, 0x51, 0x5e,
+			0x61, 0x6e, 0x73, 0x76, 0x79, 0x7a, 0x7c, 0x7f,
+		};
+		static const char sbestr[] = "corrected single";
+		static const char dbestr[] = "uncorrectable double";
+		static const char mbestr[] = "uncorrectable multiple";
+
+		if (!(address & 0x4))
+			syn = chksyn;			/* Low bank. */
+		else
+			syn = chksyn >> 16;		/* High bank. */
+
+		if (!(syn & KN0X_ESR_VLDLO)) {
+			/* Ack now, no rewrite will happen. */
+			dec_ecc_be_ack();
+
+			fmt = KERN_ALERT "%s" "invalid.\n";
+		} else {
+			sngl = syn & KN0X_ESR_SNGLO;
+			syn &= KN0X_ESR_SYNLO;
+
+			/*
+			 * Multibit errors may be tagged incorrectly;
+			 * check the syndrome explicitly.
+			 */
+			for (i = 0; i < 25; i++)
+				if (syn == data_mbit[i])
+					break;
+
+			if (i < 25) {
+				status = mbestr;
+			} else if (!sngl) {
+				status = dbestr;
+			} else {
+				volatile u32 *ptr = (void *)KSEG1ADDR(address);
+
+				*ptr = *ptr;		/* Rewrite. */
+				iob();
+
+				status = sbestr;
+				action = MIPS_BE_DISCARD;
+			}
+
+			/* Ack now, now we've rewritten (or not). */
+			dec_ecc_be_ack();
+
+			if (syn && syn == (syn & -syn)) {
+				if (syn == 0x01) {
+					fmt = KERN_ALERT "%s"
+					      "%#04x -- %s bit error "
+					      "at check bit C%s.\n";
+					xbit = "X";
+				} else {
+					fmt = KERN_ALERT "%s"
+					      "%#04x -- %s bit error "
+					      "at check bit C%s%u.\n";
+				}
+				i = syn >> 2;
+			} else {
+				for (i = 0; i < 32; i++)
+					if (syn == data_sbit[i])
+						break;
+				if (i < 32)
+					fmt = KERN_ALERT "%s"
+					      "%#04x -- %s bit error "
+					      "at data bit D%s%u.\n";
+				else
+					fmt = KERN_ALERT "%s"
+					      "%#04x -- %s bit error.\n";
+			}
+		}
+	}
+
+	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 && erraddr & KN0X_EAR_ECCERR)
+		printk(fmt, "  ECC syndrome ", syn, status, xbit, i);
+
+	return action;
+}
+
+int dec_ecc_be_handler(struct pt_regs *regs, int is_fixup)
+{
+	return dec_ecc_be_backend(regs, is_fixup, 0);
+}
+
+irqreturn_t dec_ecc_be_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	int action = dec_ecc_be_backend(regs, 0, 1);
+
+	if (action == MIPS_BE_DISCARD)
+		return IRQ_NONE;
+
+	/*
+	 * FIXME: Find 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);
+}
+
+
+/*
+ * Initialization differs a bit between KN02 and KN03/KN05, so we
+ * need two variants.  Once set up, all systems can be handled the
+ * same way.
+ */
+static inline void dec_kn02_be_init(void)
+{
+	volatile u32 *csr = (void *)KN02_CSR_BASE;
+	unsigned long flags;
+
+	kn0x_erraddr = (void *)(KN02_SLOT_BASE + KN02_ERRADDR);
+	kn0x_chksyn = (void *)(KN02_SLOT_BASE + KN02_CHKSYN);
+
+	spin_lock_irqsave(&kn02_lock, flags);
+
+	/* Preset write-only bits of the Control Register cache. */
+	cached_kn02_csr = *csr | KN03_CSR_LEDS;
+
+	/* Set normal ECC detection and generation. */
+	cached_kn02_csr &= ~(KN02_CSR_DIAGCHK | KN02_CSR_DIAGGEN);
+	/* Enable ECC correction. */
+	cached_kn02_csr |= KN02_CSR_CORRECT;
+	*csr = cached_kn02_csr;
+	iob();
+
+	spin_unlock_irqrestore(&kn02_lock, flags);
+}
+
+static inline void dec_kn03_be_init(void)
+{
+	volatile u32 *mcr = (void *)(KN03_SLOT_BASE + IOASIC_MCR);
+	volatile u32 *mbcs = (void *)(KN03_SLOT_BASE + KN05_MB_CSR);
+
+	kn0x_erraddr = (void *)(KN03_SLOT_BASE + IOASIC_ERRADDR);
+	kn0x_chksyn = (void *)(KN03_SLOT_BASE + IOASIC_CHKSYN);
+			
+	/*
+	 * Set normal ECC detection and generation, enable ECC correction.
+	 * For KN05 we also need to make sure EE (?) is enabled in the MB.
+	 * Otherwise DBE/IBE exceptions would be masked but bus error
+	 * interrupts would still arrive, resulting in an inevitable crash
+	 * if get_dbe() triggers one.
+	 */
+	*mcr = (*mcr & ~(KN03_MCR_DIAGCHK | KN03_MCR_DIAGGEN)) |
+	       KN03_MCR_CORRECT;
+	if (current_cpu_data.cputype == CPU_R4400SC)
+		*mbcs |= KN05_MB_CSR_EE;
+	fast_iob();
+}
+
+void __init dec_ecc_be_init(void)
+{
+	if (mips_machtype == MACH_DS5000_200)
+		dec_kn02_be_init();
+	else
+		dec_kn03_be_init();
+
+	/* Clear any leftover errors from the firmware. */
+	dec_ecc_be_ack();
+}
diff --git a/arch/mips/dec/int-handler.S b/arch/mips/dec/int-handler.S
new file mode 100644
index 00000000000..3b379099321
--- /dev/null
+++ b/arch/mips/dec/int-handler.S
@@ -0,0 +1,297 @@
+/*
+ * arch/mips/dec/int-handler.S
+ *
+ * Copyright (C) 1995, 1996, 1997 Paul M. Antoine and Harald Koerfgen
+ * Copyright (C) 2000, 2001, 2002, 2003  Maciej W. Rozycki
+ *
+ * Written by Ralf Baechle and Andreas Busse, modified for DECStation
+ * support by Paul Antoine and Harald Koerfgen.
+ *
+ * completly rewritten:
+ * Copyright (C) 1998 Harald Koerfgen
+ *
+ * Rewritten extensively for controller-driven IRQ support
+ * by Maciej W. Rozycki.
+ */
+#include <linux/config.h>
+#include <asm/asm.h>
+#include <asm/regdef.h>
+#include <asm/mipsregs.h>
+#include <asm/stackframe.h>
+#include <asm/addrspace.h>
+
+#include <asm/dec/interrupts.h>
+#include <asm/dec/ioasic_addrs.h>
+#include <asm/dec/ioasic_ints.h>
+#include <asm/dec/kn01.h>
+#include <asm/dec/kn02.h>
+#include <asm/dec/kn02xa.h>
+#include <asm/dec/kn03.h>
+
+
+		.text
+		.set	noreorder
+/*
+ * decstation_handle_int: Interrupt handler for DECStations
+ *
+ * We follow the model in the Indy interrupt code by David Miller, where he
+ * says: a lot of complication here is taken away because:
+ *
+ * 1) We handle one interrupt and return, sitting in a loop
+ *    and moving across all the pending IRQ bits in the cause
+ *    register is _NOT_ the answer, the common case is one
+ *    pending IRQ so optimize in that direction.
+ *
+ * 2) We need not check against bits in the status register
+ *    IRQ mask, that would make this routine slow as hell.
+ *
+ * 3) Linux only thinks in terms of all IRQs on or all IRQs
+ *    off, nothing in between like BSD spl() brain-damage.
+ *
+ * Furthermore, the IRQs on the DECStations look basically (barring
+ * software IRQs which we don't use at all) like...
+ *
+ * DS2100/3100's, aka kn01, aka Pmax:
+ *
+ *	MIPS IRQ	Source
+ *      --------        ------
+ *             0	Software (ignored)
+ *             1        Software (ignored)
+ *             2        SCSI
+ *             3        Lance Ethernet
+ *             4        DZ11 serial
+ *             5        RTC
+ *             6        Memory Controller
+ *             7        FPU
+ *
+ * DS5000/200, aka kn02, aka 3max:
+ *
+ *	MIPS IRQ	Source
+ *      --------        ------
+ *             0	Software (ignored)
+ *             1        Software (ignored)
+ *             2        TurboChannel
+ *             3        RTC
+ *             4        Reserved
+ *             5        Memory Controller
+ *             6        Reserved
+ *             7        FPU
+ *
+ * DS5000/1xx's, aka kn02ba, aka 3min:
+ *
+ *	MIPS IRQ	Source
+ *      --------        ------
+ *             0	Software (ignored)
+ *             1        Software (ignored)
+ *             2        TurboChannel Slot 0
+ *             3        TurboChannel Slot 1
+ *             4        TurboChannel Slot 2
+ *             5        TurboChannel Slot 3 (ASIC)
+ *             6        Halt button
+ *             7        FPU/R4k timer
+ *
+ * DS5000/2x's, aka kn02ca, aka maxine:
+ *
+ *	MIPS IRQ	Source
+ *      --------        ------
+ *             0	Software (ignored)
+ *             1        Software (ignored)
+ *             2        Periodic Interrupt (100usec)
+ *             3        RTC
+ *             4        I/O write timeout
+ *             5        TurboChannel (ASIC)
+ *             6        Halt Keycode from Access.Bus keyboard (CTRL-ALT-ENTER)
+ *             7        FPU/R4k timer
+ *
+ * DS5000/2xx's, aka kn03, aka 3maxplus:
+ *
+ *	MIPS IRQ	Source
+ *      --------        ------
+ *             0	Software (ignored)
+ *             1        Software (ignored)
+ *             2        System Board (ASIC)
+ *             3        RTC
+ *             4        Reserved
+ *             5        Memory
+ *             6        Halt Button
+ *             7        FPU/R4k timer
+ *
+ * We handle the IRQ according to _our_ priority (see setup.c),
+ * then we just return.  If multiple IRQs are pending then we will
+ * just take another exception, big deal.
+ */
+		.align	5
+		NESTED(decstation_handle_int, PT_SIZE, ra)
+		.set	noat
+		SAVE_ALL
+		CLI				# TEST: interrupts should be off
+		.set	at
+		.set	noreorder
+
+		/*
+		 * Get pending Interrupts
+		 */
+		mfc0	t0,CP0_CAUSE		# get pending interrupts
+		mfc0	t1,CP0_STATUS
+#ifdef CONFIG_MIPS32
+		lw	t2,cpu_fpu_mask
+#endif
+		andi	t0,ST0_IM		# CAUSE.CE may be non-zero!
+		and	t0,t1			# isolate allowed ones
+
+		beqz	t0,spurious
+
+#ifdef CONFIG_MIPS32
+		 and	t2,t0
+		bnez	t2,fpu			# handle FPU immediately
+#endif
+
+		/*
+		 * Find irq with highest priority
+		 */
+		 PTR_LA	t1,cpu_mask_nr_tbl
+1:		lw	t2,(t1)
+		nop
+		and	t2,t0
+		beqz	t2,1b
+		 addu	t1,2*PTRSIZE		# delay slot
+
+		/*
+		 * Do the low-level stuff
+		 */
+		lw	a0,(-PTRSIZE)(t1)
+		nop
+		bgez	a0,handle_it		# irq_nr >= 0?
+						# irq_nr < 0: it is an address
+		 nop
+		jr	a0
+						# a trick to save a branch:
+		 lui	t2,(KN03_IOASIC_BASE>>16)&0xffff
+						# upper part of IOASIC Address
+
+/*
+ * Handle "IRQ Controller" Interrupts
+ * Masked Interrupts are still visible and have to be masked "by hand".
+ */
+		FEXPORT(kn02_io_int)		# 3max
+		lui	t0,(KN02_CSR_BASE>>16)&0xffff
+						# get interrupt status and mask
+		lw	t0,(t0)
+		nop
+		andi	t1,t0,KN02_IRQ_ALL
+		b	1f
+		 srl	t0,16			# shift interrupt mask
+
+		FEXPORT(kn02xa_io_int)		# 3min/maxine
+		lui	t2,(KN02XA_IOASIC_BASE>>16)&0xffff
+						# upper part of IOASIC Address
+
+		FEXPORT(kn03_io_int)		# 3max+ (t2 loaded earlier)
+		lw	t0,IO_REG_SIR(t2)	# get status: IOASIC sir
+		lw	t1,IO_REG_SIMR(t2)	# get mask:   IOASIC simr
+		nop
+
+1:		and	t0,t1			# mask out allowed ones
+
+		beqz	t0,spurious
+
+		/*
+		 * Find irq with highest priority
+		 */
+		 PTR_LA	t1,asic_mask_nr_tbl
+2:		lw	t2,(t1)
+		nop
+		and	t2,t0
+		beq	zero,t2,2b
+		 addu	t1,2*PTRSIZE		# delay slot
+
+		/*
+		 * Do the low-level stuff
+		 */
+		lw	a0,%lo(-PTRSIZE)(t1)
+		nop
+		bgez	a0,handle_it		# irq_nr >= 0?
+						# irq_nr < 0: it is an address
+		 nop
+		jr	a0
+		 nop				# delay slot
+
+/*
+ * Dispatch low-priority interrupts.  We reconsider all status
+ * bits again, which looks like a lose, but it makes the code
+ * simple and O(log n), so it gets compensated.
+ */
+		FEXPORT(cpu_all_int)		# HALT, timers, software junk
+		li	a0,DEC_CPU_IRQ_BASE
+		srl	t0,CAUSEB_IP
+		li	t1,CAUSEF_IP>>CAUSEB_IP	# mask
+		b	1f
+		 li	t2,4			# nr of bits / 2
+
+		FEXPORT(kn02_all_int)		# impossible ?
+		li	a0,KN02_IRQ_BASE
+		li	t1,KN02_IRQ_ALL		# mask
+		b	1f
+		 li	t2,4			# nr of bits / 2
+
+		FEXPORT(asic_all_int)		# various I/O ASIC junk
+		li	a0,IO_IRQ_BASE
+		li	t1,IO_IRQ_ALL		# mask
+		b	1f
+		 li	t2,8			# nr of bits / 2
+
+/*
+ * Dispatch DMA interrupts -- O(log n).
+ */
+		FEXPORT(asic_dma_int)		# I/O ASIC DMA events
+		li	a0,IO_IRQ_BASE+IO_INR_DMA
+		srl	t0,IO_INR_DMA
+		li	t1,IO_IRQ_DMA>>IO_INR_DMA # mask
+		li	t2,8			# nr of bits / 2
+
+		/*
+		 * Find irq with highest priority.
+		 * Highest irq number takes precedence.
+		 */
+1:		srlv	t3,t1,t2
+2:		xor	t1,t3
+		and	t3,t0,t1
+		beqz	t3,3f
+		 nop
+		move	t0,t3
+		addu	a0,t2
+3:		srl	t2,1
+		bnez	t2,2b
+		 srlv	t3,t1,t2
+
+handle_it:
+		jal	do_IRQ
+		 move	a1,sp
+
+		j	ret_from_irq
+		 nop
+
+#ifdef CONFIG_MIPS32
+fpu:
+		j	handle_fpe_int
+		 nop
+#endif
+
+spurious:
+		j	spurious_interrupt
+		 nop
+		END(decstation_handle_int)
+
+/*
+ * Generic unimplemented interrupt routines -- cpu_mask_nr_tbl
+ * and asic_mask_nr_tbl are initialized to point all interrupts here.
+ * The tables are then filled in by machine-specific initialisation
+ * in dec_setup().
+ */
+		FEXPORT(dec_intr_unimplemented)
+		move	a1,t0			# cheats way of printing an arg!
+		PANIC("Unimplemented cpu interrupt! CP0_CAUSE: 0x%08x");
+
+		FEXPORT(asic_intr_unimplemented)
+		move	a1,t0			# cheats way of printing an arg!
+		PANIC("Unimplemented asic interrupt! ASIC ISR: 0x%08x");
diff --git a/arch/mips/dec/ioasic-irq.c b/arch/mips/dec/ioasic-irq.c
new file mode 100644
index 00000000000..d5bca5d233b
--- /dev/null
+++ b/arch/mips/dec/ioasic-irq.c
@@ -0,0 +1,157 @@
+/*
+ *	linux/arch/mips/dec/ioasic-irq.c
+ *
+ *	DEC I/O ASIC interrupts.
+ *
+ *	Copyright (c) 2002, 2003  Maciej W. Rozycki
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include <asm/dec/ioasic.h>
+#include <asm/dec/ioasic_addrs.h>
+#include <asm/dec/ioasic_ints.h>
+
+
+static DEFINE_SPINLOCK(ioasic_lock);
+
+static int ioasic_irq_base;
+
+
+static inline void unmask_ioasic_irq(unsigned int irq)
+{
+	u32 simr;
+
+	simr = ioasic_read(IO_REG_SIMR);
+	simr |= (1 << (irq - ioasic_irq_base));
+	ioasic_write(IO_REG_SIMR, simr);
+}
+
+static inline void mask_ioasic_irq(unsigned int irq)
+{
+	u32 simr;
+
+	simr = ioasic_read(IO_REG_SIMR);
+	simr &= ~(1 << (irq - ioasic_irq_base));
+	ioasic_write(IO_REG_SIMR, simr);
+}
+
+static inline void clear_ioasic_irq(unsigned int irq)
+{
+	u32 sir;
+
+	sir = ~(1 << (irq - ioasic_irq_base));
+	ioasic_write(IO_REG_SIR, sir);
+}
+
+static inline void enable_ioasic_irq(unsigned int irq)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ioasic_lock, flags);
+	unmask_ioasic_irq(irq);
+	spin_unlock_irqrestore(&ioasic_lock, flags);
+}
+
+static inline void disable_ioasic_irq(unsigned int irq)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ioasic_lock, flags);
+	mask_ioasic_irq(irq);
+	spin_unlock_irqrestore(&ioasic_lock, flags);
+}
+
+
+static inline unsigned int startup_ioasic_irq(unsigned int irq)
+{
+	enable_ioasic_irq(irq);
+	return 0;
+}
+
+#define shutdown_ioasic_irq disable_ioasic_irq
+
+static inline void ack_ioasic_irq(unsigned int irq)
+{
+	spin_lock(&ioasic_lock);
+	mask_ioasic_irq(irq);
+	spin_unlock(&ioasic_lock);
+	fast_iob();
+}
+
+static inline void end_ioasic_irq(unsigned int irq)
+{
+	if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS)))
+		enable_ioasic_irq(irq);
+}
+
+static struct hw_interrupt_type ioasic_irq_type = {
+	.typename = "IO-ASIC",
+	.startup = startup_ioasic_irq,
+	.shutdown = shutdown_ioasic_irq,
+	.enable = enable_ioasic_irq,
+	.disable = disable_ioasic_irq,
+	.ack = ack_ioasic_irq,
+	.end = end_ioasic_irq,
+};
+
+
+#define startup_ioasic_dma_irq startup_ioasic_irq
+
+#define shutdown_ioasic_dma_irq shutdown_ioasic_irq
+
+#define enable_ioasic_dma_irq enable_ioasic_irq
+
+#define disable_ioasic_dma_irq disable_ioasic_irq
+
+#define ack_ioasic_dma_irq ack_ioasic_irq
+
+static inline void end_ioasic_dma_irq(unsigned int irq)
+{
+	clear_ioasic_irq(irq);
+	fast_iob();
+	end_ioasic_irq(irq);
+}
+
+static struct hw_interrupt_type ioasic_dma_irq_type = {
+	.typename = "IO-ASIC-DMA",
+	.startup = startup_ioasic_dma_irq,
+	.shutdown = shutdown_ioasic_dma_irq,
+	.enable = enable_ioasic_dma_irq,
+	.disable = disable_ioasic_dma_irq,
+	.ack = ack_ioasic_dma_irq,
+	.end = end_ioasic_dma_irq,
+};
+
+
+void __init init_ioasic_irqs(int base)
+{
+	int i;
+
+	/* Mask interrupts. */
+	ioasic_write(IO_REG_SIMR, 0);
+	fast_iob();
+
+	for (i = base; i < base + IO_INR_DMA; i++) {
+		irq_desc[i].status = IRQ_DISABLED;
+		irq_desc[i].action = 0;
+		irq_desc[i].depth = 1;
+		irq_desc[i].handler = &ioasic_irq_type;
+	}
+	for (; i < base + IO_IRQ_LINES; i++) {
+		irq_desc[i].status = IRQ_DISABLED;
+		irq_desc[i].action = 0;
+		irq_desc[i].depth = 1;
+		irq_desc[i].handler = &ioasic_dma_irq_type;
+	}
+
+	ioasic_irq_base = base;
+}
diff --git a/arch/mips/dec/kn02-irq.c b/arch/mips/dec/kn02-irq.c
new file mode 100644
index 00000000000..e0bfcd1521e
--- /dev/null
+++ b/arch/mips/dec/kn02-irq.c
@@ -0,0 +1,127 @@
+/*
+ *	linux/arch/mips/dec/kn02-irq.c
+ *
+ *	DECstation 5000/200 (KN02) Control and Status Register
+ *	interrupts.
+ *
+ *	Copyright (c) 2002, 2003  Maciej W. Rozycki
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include <asm/dec/kn02.h>
+
+
+/*
+ * Bits 7:0 of the Control Register are write-only -- the
+ * corresponding bits of the Status Register have a different
+ * meaning.  Hence we use a cache.  It speeds up things a bit
+ * as well.
+ *
+ * There is no default value -- it has to be initialized.
+ */
+u32 cached_kn02_csr;
+DEFINE_SPINLOCK(kn02_lock);
+
+
+static int kn02_irq_base;
+
+
+static inline void unmask_kn02_irq(unsigned int irq)
+{
+	volatile u32 *csr = (volatile u32 *)KN02_CSR_BASE;
+
+	cached_kn02_csr |= (1 << (irq - kn02_irq_base + 16));
+	*csr = cached_kn02_csr;
+}
+
+static inline void mask_kn02_irq(unsigned int irq)
+{
+	volatile u32 *csr = (volatile u32 *)KN02_CSR_BASE;
+
+	cached_kn02_csr &= ~(1 << (irq - kn02_irq_base + 16));
+	*csr = cached_kn02_csr;
+}
+
+static inline void enable_kn02_irq(unsigned int irq)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&kn02_lock, flags);
+	unmask_kn02_irq(irq);
+	spin_unlock_irqrestore(&kn02_lock, flags);
+}
+
+static inline void disable_kn02_irq(unsigned int irq)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&kn02_lock, flags);
+	mask_kn02_irq(irq);
+	spin_unlock_irqrestore(&kn02_lock, flags);
+}
+
+
+static unsigned int startup_kn02_irq(unsigned int irq)
+{
+	enable_kn02_irq(irq);
+	return 0;
+}
+
+#define shutdown_kn02_irq disable_kn02_irq
+
+static void ack_kn02_irq(unsigned int irq)
+{
+	spin_lock(&kn02_lock);
+	mask_kn02_irq(irq);
+	spin_unlock(&kn02_lock);
+	iob();
+}
+
+static void end_kn02_irq(unsigned int irq)
+{
+	if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS)))
+		enable_kn02_irq(irq);
+}
+
+static struct hw_interrupt_type kn02_irq_type = {
+	.typename = "KN02-CSR",
+	.startup = startup_kn02_irq,
+	.shutdown = shutdown_kn02_irq,
+	.enable = enable_kn02_irq,
+	.disable = disable_kn02_irq,
+	.ack = ack_kn02_irq,
+	.end = end_kn02_irq,
+};
+
+
+void __init init_kn02_irqs(int base)
+{
+	volatile u32 *csr = (volatile u32 *)KN02_CSR_BASE;
+	unsigned long flags;
+	int i;
+
+	/* Mask interrupts. */
+	spin_lock_irqsave(&kn02_lock, flags);
+	cached_kn02_csr &= ~KN03_CSR_IOINTEN;
+	*csr = cached_kn02_csr;
+	iob();
+	spin_unlock_irqrestore(&kn02_lock, flags);
+
+	for (i = base; i < base + KN02_IRQ_LINES; i++) {
+		irq_desc[i].status = IRQ_DISABLED;
+		irq_desc[i].action = 0;
+		irq_desc[i].depth = 1;
+		irq_desc[i].handler = &kn02_irq_type;
+	}
+
+	kn02_irq_base = base;
+}
diff --git a/arch/mips/dec/prom/Makefile b/arch/mips/dec/prom/Makefile
new file mode 100644
index 00000000000..373822ec2d8
--- /dev/null
+++ b/arch/mips/dec/prom/Makefile