Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

14 files changed, 2558 insertions, 0 deletions

diff --git a/arch/mips/sgi-ip22/Makefile b/arch/mips/sgi-ip22/Makefile
new file mode 100644
index 0000000000..45f42fa08f
--- /dev/null
+++ b/arch/mips/sgi-ip22/Makefile
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the SGI specific kernel interface routines
+# under Linux.
+#
+
+obj-y	+= ip22-mc.o ip22-hpc.o ip22-int.o ip22-time.o ip22-nvram.o \
+	   ip22-platform.o ip22-reset.o ip22-setup.o ip22-gio.o
+
+obj-$(CONFIG_SGI_IP22) += ip22-berr.o
+obj-$(CONFIG_SGI_IP28) += ip28-berr.o
+obj-$(CONFIG_EISA)	+= ip22-eisa.o
diff --git a/arch/mips/sgi-ip22/Platform b/arch/mips/sgi-ip22/Platform
new file mode 100644
index 0000000000..a4c46e3356
--- /dev/null
+++ b/arch/mips/sgi-ip22/Platform
@@ -0,0 +1,27 @@
+#
+# SGI IP22 (Indy/Indigo2)
+#
+# Set the load address to >= 0xffffffff88069000 if you want to leave space for
+# symmon, 0xffffffff80002000 for production kernels.  Note that the value must
+# be aligned to a multiple of the kernel stack size or the handling of the
+# current variable will break so for 64-bit kernels we have to raise the start
+# address by 8kb.
+#
+cflags-$(CONFIG_SGI_IP22)	+= -I$(srctree)/arch/mips/include/asm/mach-ip22
+ifdef CONFIG_32BIT
+load-$(CONFIG_SGI_IP22)		+= 0xffffffff88002000
+endif
+ifdef CONFIG_64BIT
+load-$(CONFIG_SGI_IP22)		+= 0xffffffff88004000
+endif
+
+#
+# SGI IP28 (Indigo2 R10k)
+#
+# Set the load address to >= 0xa800000020080000 if you want to leave space for
+# symmon, 0xa800000020004000 for production kernels ?  Note that the value must
+# be 16kb aligned or the handling of the current variable will break.
+# Simplified: what IP22 does at 128MB+ in ksegN, IP28 does at 512MB+ in xkphys
+#
+cflags-$(CONFIG_SGI_IP28)	+= -mr10k-cache-barrier=store -I$(srctree)/arch/mips/include/asm/mach-ip28
+load-$(CONFIG_SGI_IP28)		+= 0xa800000020004000
diff --git a/arch/mips/sgi-ip22/ip22-berr.c b/arch/mips/sgi-ip22/ip22-berr.c
new file mode 100644
index 0000000000..afe8a61078
--- /dev/null
+++ b/arch/mips/sgi-ip22/ip22-berr.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ip22-berr.c: Bus error handling.
+ *
+ * Copyright (C) 2002, 2003 Ladislav Michl (ladis@linux-mips.org)
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched/signal.h>
+
+#include <asm/addrspace.h>
+#include <asm/traps.h>
+#include <asm/branch.h>
+#include <asm/irq_regs.h>
+#include <asm/sgi/mc.h>
+#include <asm/sgi/hpc3.h>
+#include <asm/sgi/ioc.h>
+#include <asm/sgi/ip22.h>
+
+
+static unsigned int cpu_err_stat;	/* Status reg for CPU */
+static unsigned int gio_err_stat;	/* Status reg for GIO */
+static unsigned int cpu_err_addr;	/* Error address reg for CPU */
+static unsigned int gio_err_addr;	/* Error address reg for GIO */
+static unsigned int extio_stat;
+static unsigned int hpc3_berr_stat;	/* Bus error interrupt status */
+
+static void save_and_clear_buserr(void)
+{
+	/* save status registers */
+	cpu_err_addr = sgimc->cerr;
+	cpu_err_stat = sgimc->cstat;
+	gio_err_addr = sgimc->gerr;
+	gio_err_stat = sgimc->gstat;
+	extio_stat = ip22_is_fullhouse() ? sgioc->extio : (sgint->errstat << 4);
+	hpc3_berr_stat = hpc3c0->bestat;
+
+	sgimc->cstat = sgimc->gstat = 0;
+}
+
+#define GIO_ERRMASK	0xff00
+#define CPU_ERRMASK	0x3f00
+
+static void print_buserr(void)
+{
+	if (extio_stat & EXTIO_MC_BUSERR)
+		printk(KERN_ERR "MC Bus Error\n");
+	if (extio_stat & EXTIO_HPC3_BUSERR)
+		printk(KERN_ERR "HPC3 Bus Error 0x%x:<id=0x%x,%s,lane=0x%x>\n",
+			hpc3_berr_stat,
+			(hpc3_berr_stat & HPC3_BESTAT_PIDMASK) >>
+					  HPC3_BESTAT_PIDSHIFT,
+			(hpc3_berr_stat & HPC3_BESTAT_CTYPE) ? "PIO" : "DMA",
+			hpc3_berr_stat & HPC3_BESTAT_BLMASK);
+	if (extio_stat & EXTIO_EISA_BUSERR)
+		printk(KERN_ERR "EISA Bus Error\n");
+	if (cpu_err_stat & CPU_ERRMASK)
+		printk(KERN_ERR "CPU error 0x%x<%s%s%s%s%s%s> @ 0x%08x\n",
+			cpu_err_stat,
+			cpu_err_stat & SGIMC_CSTAT_RD ? "RD " : "",
+			cpu_err_stat & SGIMC_CSTAT_PAR ? "PAR " : "",
+			cpu_err_stat & SGIMC_CSTAT_ADDR ? "ADDR " : "",
+			cpu_err_stat & SGIMC_CSTAT_SYSAD_PAR ? "SYSAD " : "",
+			cpu_err_stat & SGIMC_CSTAT_SYSCMD_PAR ? "SYSCMD " : "",
+			cpu_err_stat & SGIMC_CSTAT_BAD_DATA ? "BAD_DATA " : "",
+			cpu_err_addr);
+	if (gio_err_stat & GIO_ERRMASK)
+		printk(KERN_ERR "GIO error 0x%x:<%s%s%s%s%s%s%s%s> @ 0x%08x\n",
+			gio_err_stat,
+			gio_err_stat & SGIMC_GSTAT_RD ? "RD " : "",
+			gio_err_stat & SGIMC_GSTAT_WR ? "WR " : "",
+			gio_err_stat & SGIMC_GSTAT_TIME ? "TIME " : "",
+			gio_err_stat & SGIMC_GSTAT_PROM ? "PROM " : "",
+			gio_err_stat & SGIMC_GSTAT_ADDR ? "ADDR " : "",
+			gio_err_stat & SGIMC_GSTAT_BC ? "BC " : "",
+			gio_err_stat & SGIMC_GSTAT_PIO_RD ? "PIO_RD " : "",
+			gio_err_stat & SGIMC_GSTAT_PIO_WR ? "PIO_WR " : "",
+			gio_err_addr);
+}
+
+/*
+ * 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 ip22_be_interrupt(int irq)
+{
+	const int field = 2 * sizeof(unsigned long);
+	struct pt_regs *regs = get_irq_regs();
+
+	save_and_clear_buserr();
+	print_buserr();
+	printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
+	       (regs->cp0_cause & 4) ? "Data" : "Instruction",
+	       field, regs->cp0_epc, field, regs->regs[31]);
+	/* Assume it would be too dangerous to continue ... */
+	die_if_kernel("Oops", regs);
+	force_sig(SIGBUS);
+}
+
+static int ip22_be_handler(struct pt_regs *regs, int is_fixup)
+{
+	save_and_clear_buserr();
+	if (is_fixup)
+		return MIPS_BE_FIXUP;
+	print_buserr();
+	return MIPS_BE_FATAL;
+}
+
+void __init ip22_be_init(void)
+{
+	mips_set_be_handler(ip22_be_handler);
+}
diff --git a/arch/mips/sgi-ip22/ip22-eisa.c b/arch/mips/sgi-ip22/ip22-eisa.c
new file mode 100644
index 0000000000..f3b0e90e01
--- /dev/null
+++ b/arch/mips/sgi-ip22/ip22-eisa.c
@@ -0,0 +1,139 @@
+/*
+ * Basic EISA bus support for the SGI Indigo-2.
+ *
+ * (C) 2002 Pascal Dameme <netinet@freesurf.fr>
+ *	and Marc Zyngier <mzyngier@freesurf.fr>
+ *
+ * This code is released under both the GPL version 2 and BSD
+ * licenses.  Either license may be used.
+ *
+ * This code offers a very basic support for this EISA bus present in
+ * the SGI Indigo-2. It currently only supports PIO (forget about DMA
+ * for the time being). This is enough for a low-end ethernet card,
+ * but forget about your favorite SCSI card...
+ *
+ * TODO :
+ * - Fix bugs...
+ * - Add ISA support
+ * - Add DMA (yeah, right...).
+ * - Fix more bugs.
+ */
+
+#include <linux/eisa.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/kernel_stat.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/mipsregs.h>
+#include <asm/addrspace.h>
+#include <asm/processor.h>
+#include <asm/sgi/ioc.h>
+#include <asm/sgi/mc.h>
+#include <asm/sgi/ip22.h>
+#include <asm/i8259.h>
+
+/* I2 has four EISA slots. */
+#define IP22_EISA_MAX_SLOTS	  4
+#define EISA_MAX_IRQ		 16
+
+#define EIU_MODE_REG	 0x0001ffc0
+#define EIU_STAT_REG	 0x0001ffc4
+#define EIU_PREMPT_REG	 0x0001ffc8
+#define EIU_QUIET_REG	 0x0001ffcc
+#define EIU_INTRPT_ACK	 0x00010004
+
+static char __init *decode_eisa_sig(unsigned long addr)
+{
+	static char sig_str[EISA_SIG_LEN] __initdata;
+	u8 sig[4];
+	u16 rev;
+	int i;
+
+	for (i = 0; i < 4; i++) {
+		sig[i] = inb(addr + i);
+
+		if (!i && (sig[0] & 0x80))
+			return NULL;
+	}
+
+	sig_str[0] = ((sig[0] >> 2) & 0x1f) + ('A' - 1);
+	sig_str[1] = (((sig[0] & 3) << 3) | (sig[1] >> 5)) + ('A' - 1);
+	sig_str[2] = (sig[1] & 0x1f) + ('A' - 1);
+	rev = (sig[2] << 8) | sig[3];
+	sprintf(sig_str + 3, "%04X", rev);
+
+	return sig_str;
+}
+
+static irqreturn_t ip22_eisa_intr(int irq, void *dev_id)
+{
+	u8 eisa_irq = inb(EIU_INTRPT_ACK);
+
+	inb(EISA_DMA1_STATUS);
+	inb(EISA_DMA2_STATUS);
+
+	if (eisa_irq < EISA_MAX_IRQ) {
+		do_IRQ(eisa_irq);
+		return IRQ_HANDLED;
+	}
+
+	/* Oops, Bad Stuff Happened... */
+	printk(KERN_ERR "eisa_irq %d out of bound\n", eisa_irq);
+
+	outb(0x20, EISA_INT2_CTRL);
+	outb(0x20, EISA_INT1_CTRL);
+
+	return IRQ_NONE;
+}
+
+int __init ip22_eisa_init(void)
+{
+	int i, c;
+	char *str;
+
+	if (!(sgimc->systemid & SGIMC_SYSID_EPRESENT)) {
+		printk(KERN_INFO "EISA: bus not present.\n");
+		return 1;
+	}
+
+	printk(KERN_INFO "EISA: Probing bus...\n");
+	for (c = 0, i = 1; i <= IP22_EISA_MAX_SLOTS; i++) {
+		if ((str = decode_eisa_sig(0x1000 * i + EISA_VENDOR_ID_OFFSET))) {
+			printk(KERN_INFO "EISA: slot %d : %s detected.\n",
+			       i, str);
+			c++;
+		}
+	}
+	printk(KERN_INFO "EISA: Detected %d card%s.\n", c, c < 2 ? "" : "s");
+#ifdef CONFIG_ISA
+	printk(KERN_INFO "ISA support compiled in.\n");
+#endif
+
+	/* Warning : BlackMagicAhead(tm).
+	   Please wave your favorite dead chicken over the busses */
+
+	/* First say hello to the EIU */
+	outl(0x0000FFFF, EIU_PREMPT_REG);
+	outl(1, EIU_QUIET_REG);
+	outl(0x40f3c07F, EIU_MODE_REG);
+
+	/* Now be nice to the EISA chipset */
+	outb(1, EISA_EXT_NMI_RESET_CTRL);
+	udelay(50);	/* Wait long enough for the dust to settle */
+	outb(0, EISA_EXT_NMI_RESET_CTRL);
+	outb(0, EISA_DMA2_WRITE_SINGLE);
+
+	init_i8259_irqs();
+
+	if (request_irq(SGI_EISA_IRQ, ip22_eisa_intr, 0, "EISA", NULL))
+		pr_err("Failed to request irq %d (EISA)\n", SGI_EISA_IRQ);
+
+	EISA_bus = 1;
+	return 0;
+}
diff --git a/arch/mips/sgi-ip22/ip22-gio.c b/arch/mips/sgi-ip22/ip22-gio.c
new file mode 100644
index 0000000000..81c9f0a888
--- /dev/null
+++ b/arch/mips/sgi-ip22/ip22-gio.c
@@ -0,0 +1,432 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+
+#include <asm/addrspace.h>
+#include <asm/paccess.h>
+#include <asm/gio_device.h>
+#include <asm/sgi/gio.h>
+#include <asm/sgi/hpc3.h>
+#include <asm/sgi/mc.h>
+#include <asm/sgi/ip22.h>
+
+static struct bus_type gio_bus_type;
+
+static struct {
+	const char *name;
+	__u8	   id;
+} gio_name_table[] = {
+	{ .name = "SGI Impact", .id = 0x10 },
+	{ .name = "Phobos G160", .id = 0x35 },
+	{ .name = "Phobos G130", .id = 0x36 },
+	{ .name = "Phobos G100", .id = 0x37 },
+	{ .name = "Set Engineering GFE", .id = 0x38 },
+	/* fake IDs */
+	{ .name = "SGI Newport", .id = 0x7e },
+	{ .name = "SGI GR2/GR3", .id = 0x7f },
+};
+
+static void gio_bus_release(struct device *dev)
+{
+	kfree(dev);
+}
+
+static struct device gio_bus = {
+	.init_name = "gio",
+	.release = &gio_bus_release,
+};
+
+/**
+ * gio_match_device - Tell if an of_device structure has a matching
+ * gio_match structure
+ * @ids: array of of device match structures to search in
+ * @dev: the of device structure to match against
+ *
+ * Used by a driver to check whether an of_device present in the
+ * system is in its list of supported devices.
+ */
+static const struct gio_device_id *
+gio_match_device(const struct gio_device_id *match,
+		 const struct gio_device *dev)
+{
+	const struct gio_device_id *ids;
+
+	for (ids = match; ids->id != 0xff; ids++)
+		if (ids->id == dev->id.id)
+			return ids;
+
+	return NULL;
+}
+
+struct gio_device *gio_dev_get(struct gio_device *dev)
+{
+	struct device *tmp;
+
+	if (!dev)
+		return NULL;
+	tmp = get_device(&dev->dev);
+	if (tmp)
+		return to_gio_device(tmp);
+	else
+		return NULL;
+}
+EXPORT_SYMBOL_GPL(gio_dev_get);
+
+void gio_dev_put(struct gio_device *dev)
+{
+	if (dev)
+		put_device(&dev->dev);
+}
+EXPORT_SYMBOL_GPL(gio_dev_put);
+
+/**
+ * gio_release_dev - free an gio device structure when all users of it are finished.
+ * @dev: device that's been disconnected
+ *
+ * Will be called only by the device core when all users of this gio device are
+ * done.
+ */
+void gio_release_dev(struct device *dev)
+{
+	struct gio_device *giodev;
+
+	giodev = to_gio_device(dev);
+	kfree(giodev);
+}
+EXPORT_SYMBOL_GPL(gio_release_dev);
+
+int gio_device_register(struct gio_device *giodev)
+{
+	giodev->dev.bus = &gio_bus_type;
+	giodev->dev.parent = &gio_bus;
+	return device_register(&giodev->dev);
+}
+EXPORT_SYMBOL_GPL(gio_device_register);
+
+void gio_device_unregister(struct gio_device *giodev)
+{
+	device_unregister(&giodev->dev);
+}
+EXPORT_SYMBOL_GPL(gio_device_unregister);
+
+static int gio_bus_match(struct device *dev, struct device_driver *drv)
+{
+	struct gio_device *gio_dev = to_gio_device(dev);
+	struct gio_driver *gio_drv = to_gio_driver(drv);
+
+	return gio_match_device(gio_drv->id_table, gio_dev) != NULL;
+}
+
+static int gio_device_probe(struct device *dev)
+{
+	int error = -ENODEV;
+	struct gio_driver *drv;
+	struct gio_device *gio_dev;
+	const struct gio_device_id *match;
+
+	drv = to_gio_driver(dev->driver);
+	gio_dev = to_gio_device(dev);
+
+	if (!drv->probe)
+		return error;
+
+	gio_dev_get(gio_dev);
+
+	match = gio_match_device(drv->id_table, gio_dev);
+	if (match)
+		error = drv->probe(gio_dev, match);
+	if (error)
+		gio_dev_put(gio_dev);
+
+	return error;
+}
+
+static void gio_device_remove(struct device *dev)
+{
+	struct gio_device *gio_dev = to_gio_device(dev);
+	struct gio_driver *drv = to_gio_driver(dev->driver);
+
+	if (drv->remove)
+		drv->remove(gio_dev);
+}
+
+static void gio_device_shutdown(struct device *dev)
+{
+	struct gio_device *gio_dev = to_gio_device(dev);
+	struct gio_driver *drv = to_gio_driver(dev->driver);
+
+	if (dev->driver && drv->shutdown)
+		drv->shutdown(gio_dev);
+}
+
+static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
+			     char *buf)
+{
+	struct gio_device *gio_dev = to_gio_device(dev);
+	int len = snprintf(buf, PAGE_SIZE, "gio:%x\n", gio_dev->id.id);
+
+	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
+}
+static DEVICE_ATTR_RO(modalias);
+
+static ssize_t name_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct gio_device *giodev;
+
+	giodev = to_gio_device(dev);
+	return sprintf(buf, "%s", giodev->name);
+}
+static DEVICE_ATTR_RO(name);
+
+static ssize_t id_show(struct device *dev,
+		       struct device_attribute *attr, char *buf)
+{
+	struct gio_device *giodev;
+
+	giodev = to_gio_device(dev);
+	return sprintf(buf, "%x", giodev->id.id);
+}
+static DEVICE_ATTR_RO(id);
+
+static struct attribute *gio_dev_attrs[] = {
+	&dev_attr_modalias.attr,
+	&dev_attr_name.attr,
+	&dev_attr_id.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(gio_dev);
+
+static int gio_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
+{
+	const struct gio_device *gio_dev = to_gio_device(dev);
+
+	add_uevent_var(env, "MODALIAS=gio:%x", gio_dev->id.id);
+	return 0;
+}
+
+int gio_register_driver(struct gio_driver *drv)
+{
+	/* initialize common driver fields */
+	if (!drv->driver.name)
+		drv->driver.name = drv->name;
+	if (!drv->driver.owner)
+		drv->driver.owner = drv->owner;
+	drv->driver.bus = &gio_bus_type;
+
+	/* register with core */
+	return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(gio_register_driver);
+
+void gio_unregister_driver(struct gio_driver *drv)
+{
+	driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(gio_unregister_driver);
+
+void gio_set_master(struct gio_device *dev)
+{
+	u32 tmp = sgimc->giopar;
+
+	switch (dev->slotno) {
+	case 0:
+		tmp |= SGIMC_GIOPAR_MASTERGFX;
+		break;
+	case 1:
+		tmp |= SGIMC_GIOPAR_MASTEREXP0;
+		break;
+	case 2:
+		tmp |= SGIMC_GIOPAR_MASTEREXP1;
+		break;
+	}
+	sgimc->giopar = tmp;
+}
+EXPORT_SYMBOL_GPL(gio_set_master);
+
+void ip22_gio_set_64bit(int slotno)
+{
+	u32 tmp = sgimc->giopar;
+
+	switch (slotno) {
+	case 0:
+		tmp |= SGIMC_GIOPAR_GFX64;
+		break;
+	case 1:
+		tmp |= SGIMC_GIOPAR_EXP064;
+		break;
+	case 2:
+		tmp |= SGIMC_GIOPAR_EXP164;
+		break;
+	}
+	sgimc->giopar = tmp;
+}
+
+static int ip22_gio_id(unsigned long addr, u32 *res)
+{
+	u8 tmp8;
+	u8 tmp16;
+	u32 tmp32;
+	u8 *ptr8;
+	u16 *ptr16;
+	u32 *ptr32;
+
+	ptr32 = (void *)CKSEG1ADDR(addr);
+	if (!get_dbe(tmp32, ptr32)) {
+		/*
+		 * We got no DBE, but this doesn't mean anything.
+		 * If GIO is pipelined (which can't be disabled
+		 * for GFX slot) we don't get a DBE, but we see
+		 * the transfer size as data. So we do an 8bit
+		 * and a 16bit access and check whether the common
+		 * data matches
+		 */
+		ptr8 = (void *)CKSEG1ADDR(addr + 3);
+		if (get_dbe(tmp8, ptr8)) {
+			/*
+			 * 32bit access worked, but 8bit doesn't
+			 * so we don't see phantom reads on
+			 * a pipelined bus, but a real card which
+			 * doesn't support 8 bit reads
+			 */
+			*res = tmp32;
+			return 1;
+		}
+		ptr16 = (void *)CKSEG1ADDR(addr + 2);
+		get_dbe(tmp16, ptr16);
+		if (tmp8 == (tmp16 & 0xff) &&
+		    tmp8 == (tmp32 & 0xff) &&
+		    tmp16 == (tmp32 & 0xffff)) {
+			*res = tmp32;
+			return 1;
+		}
+	}
+	return 0; /* nothing here */
+}
+
+#define HQ2_MYSTERY_OFFS       0x6A07C
+#define NEWPORT_USTATUS_OFFS   0xF133C
+
+static int ip22_is_gr2(unsigned long addr)
+{
+	u32 tmp;
+	u32 *ptr;
+
+	/* HQ2 only allows 32bit accesses */
+	ptr = (void *)CKSEG1ADDR(addr + HQ2_MYSTERY_OFFS);
+	if (!get_dbe(tmp, ptr)) {
+		if (tmp == 0xdeadbeef)
+			return 1;
+	}
+	return 0;
+}
+
+
+static void ip22_check_gio(int slotno, unsigned long addr, int irq)
+{
+	const char *name = "Unknown";
+	struct gio_device *gio_dev;
+	u32 tmp;
+	__u8 id;
+	int i;
+
+	/* first look for GR2/GR3 by checking mystery register */
+	if (ip22_is_gr2(addr))
+		tmp = 0x7f;
+	else {
+		if (!ip22_gio_id(addr, &tmp)) {
+			/*
+			 * no GIO signature at start address of slot
+			 * since Newport doesn't have one, we check if
+			 * user status register is readable
+			 */
+			if (ip22_gio_id(addr + NEWPORT_USTATUS_OFFS, &tmp))
+				tmp = 0x7e;
+			else
+				tmp = 0;
+		}
+	}
+	if (tmp) {
+		id = GIO_ID(tmp);
+		if (tmp & GIO_32BIT_ID) {
+			if (tmp & GIO_64BIT_IFACE)
+				ip22_gio_set_64bit(slotno);
+		}
+		for (i = 0; i < ARRAY_SIZE(gio_name_table); i++) {
+			if (id == gio_name_table[i].id) {
+				name = gio_name_table[i].name;
+				break;
+			}
+		}
+		printk(KERN_INFO "GIO: slot %d : %s (id %x)\n",
+		       slotno, name, id);
+		gio_dev = kzalloc(sizeof *gio_dev, GFP_KERNEL);
+		if (!gio_dev)
+			return;
+		gio_dev->name = name;
+		gio_dev->slotno = slotno;
+		gio_dev->id.id = id;
+		gio_dev->resource.start = addr;
+		gio_dev->resource.end = addr + 0x3fffff;
+		gio_dev->resource.flags = IORESOURCE_MEM;
+		gio_dev->irq = irq;
+		dev_set_name(&gio_dev->dev, "%d", slotno);
+		gio_device_register(gio_dev);
+	} else
+		printk(KERN_INFO "GIO: slot %d : Empty\n", slotno);
+}
+
+static struct bus_type gio_bus_type = {
+	.name	   = "gio",
+	.dev_groups = gio_dev_groups,
+	.match	   = gio_bus_match,
+	.probe	   = gio_device_probe,
+	.remove	   = gio_device_remove,
+	.shutdown  = gio_device_shutdown,
+	.uevent	   = gio_device_uevent,
+};
+
+static struct resource gio_bus_resource = {
+	.start = GIO_SLOT_GFX_BASE,
+	.end   = GIO_SLOT_GFX_BASE + 0x9fffff,
+	.name  = "GIO Bus",
+	.flags = IORESOURCE_MEM,
+};
+
+int __init ip22_gio_init(void)
+{
+	unsigned int pbdma __maybe_unused;
+	int ret;
+
+	ret = device_register(&gio_bus);
+	if (ret) {
+		put_device(&gio_bus);
+		return ret;
+	}
+
+	ret = bus_register(&gio_bus_type);
+	if (!ret) {
+		request_resource(&iomem_resource, &gio_bus_resource);
+		printk(KERN_INFO "GIO: Probing bus...\n");
+
+		if (ip22_is_fullhouse()) {
+			/* Indigo2 */
+			ip22_check_gio(0, GIO_SLOT_GFX_BASE, SGI_GIO_1_IRQ);
+			ip22_check_gio(1, GIO_SLOT_EXP0_BASE, SGI_GIO_1_IRQ);
+		} else {
+			/* Indy/Challenge S */
+			if (get_dbe(pbdma, (unsigned int *)&hpc3c1->pbdma[1]))
+				ip22_check_gio(0, GIO_SLOT_GFX_BASE,
+					       SGI_GIO_0_IRQ);
+			ip22_check_gio(1, GIO_SLOT_EXP0_BASE, SGI_GIOEXP0_IRQ);
+			ip22_check_gio(2, GIO_SLOT_EXP1_BASE, SGI_GIOEXP1_IRQ);
+		}
+	} else
+		device_unregister(&gio_bus);
+
+	return ret;
+}
+
+subsys_initcall(ip22_gio_init);
diff --git a/arch/mips/sgi-ip22/ip22-hpc.c b/arch/mips/sgi-ip22/ip22-hpc.c
new file mode 100644
index 0000000000..49922e86cf
--- /dev/null
+++ b/arch/mips/sgi-ip22/ip22-hpc.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ip22-hpc.c: Routines for generic manipulation of the HPC controllers.
+ *
+ * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
+ * Copyright (C) 1998 Ralf Baechle
+ */
+
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/types.h>
+
+#include <asm/io.h>
+#include <asm/sgi/hpc3.h>
+#include <asm/sgi/ioc.h>
+#include <asm/sgi/ip22.h>
+
+struct hpc3_regs *hpc3c0, *hpc3c1;
+
+EXPORT_SYMBOL(hpc3c0);
+EXPORT_SYMBOL(hpc3c1);
+
+struct sgioc_regs *sgioc;
+
+EXPORT_SYMBOL(sgioc);
+
+/* We need software copies of these because they are write only. */
+u8 sgi_ioc_reset, sgi_ioc_write;
+
+extern char *system_type;
+
+void __init sgihpc_init(void)
+{
+	/* ioremap can't fail */
+	hpc3c0 = (struct hpc3_regs *)
+		 ioremap(HPC3_CHIP0_BASE, sizeof(struct hpc3_regs));
+	hpc3c1 = (struct hpc3_regs *)
+		 ioremap(HPC3_CHIP1_BASE, sizeof(struct hpc3_regs));
+	/* IOC lives in PBUS PIO channel 6 */
+	sgioc = (struct sgioc_regs *)hpc3c0->pbus_extregs[6];
+
+	hpc3c0->pbus_piocfg[6][0] |= HPC3_PIOCFG_DS16;
+	if (ip22_is_fullhouse()) {
+		/* Full House comes with INT2 which lives in PBUS PIO
+		 * channel 4 */
+		sgint = (struct sgint_regs *)hpc3c0->pbus_extregs[4];
+		system_type = "SGI Indigo2";
+	} else {
+		/* Guiness comes with INT3 which is part of IOC */
+		sgint = &sgioc->int3;
+		system_type = "SGI Indy";
+	}
+
+	sgi_ioc_reset = (SGIOC_RESET_PPORT | SGIOC_RESET_KBDMOUSE |
+			 SGIOC_RESET_EISA | SGIOC_RESET_ISDN |
+			 SGIOC_RESET_LC0OFF);
+
+	sgi_ioc_write = (SGIOC_WRITE_EASEL | SGIOC_WRITE_NTHRESH |
+			 SGIOC_WRITE_TPSPEED | SGIOC_WRITE_EPSEL |
+			 SGIOC_WRITE_U0AMODE | SGIOC_WRITE_U1AMODE);
+
+	sgioc->reset = sgi_ioc_reset;
+	sgioc->write = sgi_ioc_write;
+}
diff --git a/arch/mips/sgi-ip22/ip22-int.c b/arch/mips/sgi-ip22/ip22-int.c
new file mode 100644
index 0000000000..96798a4ab2
--- /dev/null
+++ b/arch/mips/sgi-ip22/ip22-int.c
@@ -0,0 +1,320 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ip22-int.c: Routines for generic manipulation of the INT[23] ASIC
+ *	       found on INDY and Indigo2 workstations.
+ *
+ * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
+ * Copyright (C) 1997, 1998 Ralf Baechle (ralf@gnu.org)
+ * Copyright (C) 1999 Andrew R. Baker (andrewb@uab.edu)
+ *		      - Indigo2 changes
+ *		      - Interrupt handling fixes
+ * Copyright (C) 2001, 2003 Ladislav Michl (ladis@linux-mips.org)
+ */
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/kernel_stat.h>
+#include <linux/interrupt.h>
+#include <linux/ftrace.h>
+
+#include <asm/irq_cpu.h>
+#include <asm/sgi/hpc3.h>
+#include <asm/sgi/ip22.h>
+
+/* So far nothing hangs here */
+#undef USE_LIO3_IRQ
+
+struct sgint_regs *sgint;
+
+static char lc0msk_to_irqnr[256];
+static char lc1msk_to_irqnr[256];
+static char lc2msk_to_irqnr[256];
+static char lc3msk_to_irqnr[256];
+
+extern int ip22_eisa_init(void);
+
+static void enable_local0_irq(struct irq_data *d)
+{
+	/* don't allow mappable interrupt to be enabled from setup_irq,
+	 * we have our own way to do so */
+	if (d->irq != SGI_MAP_0_IRQ)
+		sgint->imask0 |= (1 << (d->irq - SGINT_LOCAL0));
+}
+
+static void disable_local0_irq(struct irq_data *d)
+{
+	sgint->imask0 &= ~(1 << (d->irq - SGINT_LOCAL0));
+}
+
+static struct irq_chip ip22_local0_irq_type = {
+	.name		= "IP22 local 0",
+	.irq_mask	= disable_local0_irq,
+	.irq_unmask	= enable_local0_irq,
+};
+
+static void enable_local1_irq(struct irq_data *d)
+{
+	/* don't allow mappable interrupt to be enabled from setup_irq,
+	 * we have our own way to do so */
+	if (d->irq != SGI_MAP_1_IRQ)
+		sgint->imask1 |= (1 << (d->irq - SGINT_LOCAL1));
+}
+
+static void disable_local1_irq(struct irq_data *d)
+{
+	sgint->imask1 &= ~(1 << (d->irq - SGINT_LOCAL1));
+}
+
+static struct irq_chip ip22_local1_irq_type = {
+	.name		= "IP22 local 1",
+	.irq_mask	= disable_local1_irq,
+	.irq_unmask	= enable_local1_irq,
+};
+
+static void enable_local2_irq(struct irq_data *d)
+{
+	sgint->imask0 |= (1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0));
+	sgint->cmeimask0 |= (1 << (d->irq - SGINT_LOCAL2));
+}
+
+static void disable_local2_irq(struct irq_data *d)
+{
+	sgint->cmeimask0 &= ~(1 << (d->irq - SGINT_LOCAL2));
+	if (!sgint->cmeimask0)
+		sgint->imask0 &= ~(1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0));
+}
+
+static struct irq_chip ip22_local2_irq_type = {
+	.name		= "IP22 local 2",
+	.irq_mask	= disable_local2_irq,
+	.irq_unmask	= enable_local2_irq,
+};
+
+static void enable_local3_irq(struct irq_data *d)
+{
+	sgint->imask1 |= (1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1));
+	sgint->cmeimask1 |= (1 << (d->irq - SGINT_LOCAL3));
+}
+
+static void disable_local3_irq(struct irq_data *d)
+{
+	sgint->cmeimask1 &= ~(1 << (d->irq - SGINT_LOCAL3));
+	if (!sgint->cmeimask1)
+		sgint->imask1 &= ~(1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1));
+}
+
+static struct irq_chip ip22_local3_irq_type = {
+	.name		= "IP22 local 3",
+	.irq_mask	= disable_local3_irq,
+	.irq_unmask	= enable_local3_irq,
+};
+
+static void indy_local0_irqdispatch(void)
+{
+	u8 mask = sgint->istat0 & sgint->imask0;
+	u8 mask2;
+	int irq;
+
+	if (mask & SGINT_ISTAT0_LIO2) {
+		mask2 = sgint->vmeistat & sgint->cmeimask0;
+		irq = lc2msk_to_irqnr[mask2];
+	} else
+		irq = lc0msk_to_irqnr[mask];
+
+	/*
+	 * workaround for INT2 bug; if irq == 0, INT2 has seen a fifo full
+	 * irq, but failed to latch it into status register
+	 */
+	if (irq)
+		do_IRQ(irq);
+	else
+		do_IRQ(SGINT_LOCAL0 + 0);
+}
+
+static void indy_local1_irqdispatch(void)
+{
+	u8 mask = sgint->istat1 & sgint->imask1;
+	u8 mask2;
+	int irq;
+
+	if (mask & SGINT_ISTAT1_LIO3) {
+		mask2 = sgint->vmeistat & sgint->cmeimask1;
+		irq = lc3msk_to_irqnr[mask2];
+	} else
+		irq = lc1msk_to_irqnr[mask];
+
+	/* if irq == 0, then the interrupt has already been cleared */
+	if (irq)
+		do_IRQ(irq);
+}
+
+extern void ip22_be_interrupt(int irq);
+
+static void __irq_entry indy_buserror_irq(void)
+{
+	int irq = SGI_BUSERR_IRQ;
+
+	irq_enter();
+	kstat_incr_irq_this_cpu(irq);
+	ip22_be_interrupt(irq);
+	irq_exit();
+}
+
+#ifdef USE_LIO3_IRQ
+#define SGI_INTERRUPTS	SGINT_END
+#else
+#define SGI_INTERRUPTS	SGINT_LOCAL3
+#endif
+
+extern void indy_8254timer_irq(void);
+
+/*
+ * IRQs on the INDY look basically (barring software IRQs which we don't use
+ * at all) like:
+ *
+ *	MIPS IRQ	Source
+ *	--------	------
+ *	       0	Software (ignored)
+ *	       1	Software (ignored)
+ *	       2	Local IRQ level zero
+ *	       3	Local IRQ level one
+ *	       4	8254 Timer zero
+ *	       5	8254 Timer one
+ *	       6	Bus Error
+ *	       7	R4k timer (what we use)
+ *
+ * We handle the IRQ according to _our_ priority which is:
+ *
+ * Highest ----	    R4k Timer
+ *		    Local IRQ zero
+ *		    Local IRQ one
+ *		    Bus Error
+ *		    8254 Timer zero
+ * Lowest  ----	    8254 Timer one
+ *
+ * then we just return, if multiple IRQs are pending then we will just take
+ * another exception, big deal.
+ */
+
+asmlinkage void plat_irq_dispatch(void)
+{
+	unsigned int pending = read_c0_status() & read_c0_cause();
+
+	/*
+	 * First we check for r4k counter/timer IRQ.
+	 */
+	if (pending & CAUSEF_IP7)
+		do_IRQ(SGI_TIMER_IRQ);
+	else if (pending & CAUSEF_IP2)
+		indy_local0_irqdispatch();
+	else if (pending & CAUSEF_IP3)
+		indy_local1_irqdispatch();
+	else if (pending & CAUSEF_IP6)
+		indy_buserror_irq();
+	else if (pending & (CAUSEF_IP4 | CAUSEF_IP5))
+		indy_8254timer_irq();
+}
+
+void __init arch_init_irq(void)
+{
+	int i;
+
+	/* Init local mask --> irq tables. */
+	for (i = 0; i < 256; i++) {
+		if (i & 0x80) {
+			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 7;
+			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 7;
+			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 7;
+			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 7;
+		} else if (i & 0x40) {
+			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 6;
+			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 6;
+			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 6;
+			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 6;
+		} else if (i & 0x20) {
+			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 5;
+			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 5;
+			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 5;
+			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 5;
+		} else if (i & 0x10) {
+			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 4;
+			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 4;
+			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 4;
+			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 4;
+		} else if (i & 0x08) {
+			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 3;
+			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 3;
+			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 3;
+			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 3;
+		} else if (i & 0x04) {
+			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 2;
+			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 2;
+			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 2;
+			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 2;
+		} else if (i & 0x02) {
+			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 1;
+			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 1;
+			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 1;
+			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 1;
+		} else if (i & 0x01) {
+			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 0;
+			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 0;
+			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 0;
+			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 0;
+		} else {
+			lc0msk_to_irqnr[i] = 0;
+			lc1msk_to_irqnr[i] = 0;
+			lc2msk_to_irqnr[i] = 0;
+			lc3msk_to_irqnr[i] = 0;
+		}
+	}
+
+	/* Mask out all interrupts. */
+	sgint->imask0 = 0;
+	sgint->imask1 = 0;
+	sgint->cmeimask0 = 0;
+	sgint->cmeimask1 = 0;
+
+	/* init CPU irqs */
+	mips_cpu_irq_init();
+
+	for (i = SGINT_LOCAL0; i < SGI_INTERRUPTS; i++) {
+		struct irq_chip *handler;
+
+		if (i < SGINT_LOCAL1)
+			handler		= &ip22_local0_irq_type;
+		else if (i < SGINT_LOCAL2)
+			handler		= &ip22_local1_irq_type;
+		else if (i < SGINT_LOCAL3)
+			handler		= &ip22_local2_irq_type;
+		else
+			handler		= &ip22_local3_irq_type;
+
+		irq_set_chip_and_handler(i, handler, handle_level_irq);
+	}
+
+	/* vector handler. this register the IRQ as non-sharable */
+	if (request_irq(SGI_LOCAL_0_IRQ, no_action, IRQF_NO_THREAD,
+			"local0 cascade", NULL))
+		pr_err("Failed to register local0 cascade interrupt\n");
+	if (request_irq(SGI_LOCAL_1_IRQ, no_action, IRQF_NO_THREAD,
+			"local1 cascade", NULL))
+		pr_err("Failed to register local1 cascade interrupt\n");
+	if (request_irq(SGI_BUSERR_IRQ, no_action, IRQF_NO_THREAD,
+			"Bus Error", NULL))
+		pr_err("Failed to register Bus Error interrupt\n");
+
+	/* cascade in cascade. i love Indy ;-) */
+	if (request_irq(SGI_MAP_0_IRQ, no_action, IRQF_NO_THREAD,
+			"mapable0 cascade", NULL))
+		pr_err("Failed to register mapable0 cascade interrupt\n");
+#ifdef USE_LIO3_IRQ
+	if (request_irq(SGI_MAP_1_IRQ, no_action, IRQF_NO_THREAD,
+			"mapable1 cascade", NULL))
+		pr_err("Failed to register mapable1 cascade interrupt\n");
+#endif
+
+#ifdef CONFIG_EISA
+	if (ip22_is_fullhouse())	/* Only Indigo-2 has EISA stuff */
+		ip22_eisa_init();
+#endif
+}
diff --git a/arch/mips/sgi-ip22/ip22-mc.c b/arch/mips/sgi-ip22/ip22-mc.c
new file mode 100644
index 0000000000..74e5b9e27d
--- /dev/null
+++ b/arch/mips/sgi-ip22/ip22-mc.c
@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ip22-mc.c: Routines for manipulating SGI Memory Controller.
+ *
+ * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
+ * Copyright (C) 1999 Andrew R. Baker (andrewb@uab.edu) - Indigo2 changes
+ * Copyright (C) 2003 Ladislav Michl  (ladis@linux-mips.org)
+ * Copyright (C) 2004 Peter Fuerst    (pf@net.alphadv.de) - IP28
+ */
+
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/memblock.h>
+#include <linux/spinlock.h>
+
+#include <asm/io.h>
+#include <asm/bootinfo.h>
+#include <asm/sgialib.h>
+#include <asm/sgi/mc.h>
+#include <asm/sgi/hpc3.h>
+#include <asm/sgi/ip22.h>
+
+struct sgimc_regs *sgimc;
+
+EXPORT_SYMBOL(sgimc);
+
+static inline unsigned long get_bank_addr(unsigned int memconfig)
+{
+	return (memconfig & SGIMC_MCONFIG_BASEADDR) << ((sgimc->systemid & SGIMC_SYSID_MASKREV) >= 5 ? 24 : 22);
+}
+
+static inline unsigned long get_bank_size(unsigned int memconfig)
+{
+	return ((memconfig & SGIMC_MCONFIG_RMASK) + 0x0100) << ((sgimc->systemid & SGIMC_SYSID_MASKREV) >= 5 ? 16 : 14);
+}
+
+static inline unsigned int get_bank_config(int bank)
+{
+	unsigned int res = bank > 1 ? sgimc->mconfig1 : sgimc->mconfig0;
+	return bank % 2 ? res & 0xffff : res >> 16;
+}
+
+#if defined(CONFIG_SGI_IP28) || defined(CONFIG_32BIT)
+static void __init probe_memory(void)
+{
+	/* prom detects all usable memory */
+}
+#else
+/*
+ * Detect installed memory, which PROM misses
+ */
+static void __init probe_memory(void)
+{
+	unsigned long addr, size;
+	int i;
+
+	printk(KERN_INFO "MC: Probing memory configuration:\n");
+	for (i = 0; i < 4; i++) {
+		unsigned int tmp = get_bank_config(i);
+		if (!(tmp & SGIMC_MCONFIG_BVALID))
+			continue;
+
+		size = get_bank_size(tmp);
+		addr = get_bank_addr(tmp);
+		printk(KERN_INFO " bank%d: %3ldM @ %08lx\n",
+			i, size / 1024 / 1024, addr);
+
+		if (addr >= SGIMC_SEG1_BADDR)
+			memblock_add(addr, size);
+	}
+}
+#endif
+
+void __init sgimc_init(void)
+{
+	u32 tmp;
+
+	/* ioremap can't fail */
+	sgimc = (struct sgimc_regs *)
+		ioremap(SGIMC_BASE, sizeof(struct sgimc_regs));
+
+	printk(KERN_INFO "MC: SGI memory controller Revision %d\n",
+	       (int) sgimc->systemid & SGIMC_SYSID_MASKREV);
+
+	/* Place the MC into a known state.  This must be done before
+	 * interrupts are first enabled etc.
+	 */
+
+	/* Step 0: Make sure we turn off the watchdog in case it's
+	 *	   still running (which might be the case after a
+	 *	   soft reboot).
+	 */
+	tmp = sgimc->cpuctrl0;
+	tmp &= ~SGIMC_CCTRL0_WDOG;
+	sgimc->cpuctrl0 = tmp;
+
+	/* Step 1: The CPU/GIO error status registers will not latch
+	 *	   up a new error status until the register has been
+	 *	   cleared by the cpu.	These status registers are
+	 *	   cleared by writing any value to them.
+	 */
+	sgimc->cstat = sgimc->gstat = 0;
+
+	/* Step 2: Enable all parity checking in cpu control register
+	 *	   zero.
+	 */
+	/* don't touch parity settings for IP28 */
+	tmp = sgimc->cpuctrl0;
+#ifndef CONFIG_SGI_IP28
+	tmp |= SGIMC_CCTRL0_EPERRGIO | SGIMC_CCTRL0_EPERRMEM;
+#endif
+	tmp |= SGIMC_CCTRL0_R4KNOCHKPARR;
+	sgimc->cpuctrl0 = tmp;
+
+	/* Step 3: Setup the MC write buffer depth, this is controlled
+	 *	   in cpu control register 1 in the lower 4 bits.
+	 */
+	tmp = sgimc->cpuctrl1;
+	tmp &= ~0xf;
+	tmp |= 0xd;
+	sgimc->cpuctrl1 = tmp;
+
+	/* Step 4: Initialize the RPSS divider register to run as fast
+	 *	   as it can correctly operate.	 The register is laid
+	 *	   out as follows:
+	 *
+	 *	   ----------------------------------------
+	 *	   |  RESERVED	|   INCREMENT	| DIVIDER |
+	 *	   ----------------------------------------
+	 *	    31	      16 15	       8 7	 0
+	 *
+	 *	   DIVIDER determines how often a 'tick' happens,
+	 *	   INCREMENT determines by how the RPSS increment
+	 *	   registers value increases at each 'tick'. Thus,
+	 *	   for IP22 we get INCREMENT=1, DIVIDER=1 == 0x101
+	 */
+	sgimc->divider = 0x101;
+
+	/* Step 5: Initialize GIO64 arbitrator configuration register.
+	 *
+	 * NOTE: HPC init code in sgihpc_init() must run before us because
+	 *	 we need to know Guiness vs. FullHouse and the board
+	 *	 revision on this machine. You have been warned.
+	 */
+
+	/* First the basic invariants across all GIO64 implementations. */
+	tmp = sgimc->giopar & SGIMC_GIOPAR_GFX64; /* keep gfx 64bit settings */
+	tmp |= SGIMC_GIOPAR_HPC64;	/* All 1st HPC's interface at 64bits */
+	tmp |= SGIMC_GIOPAR_ONEBUS;	/* Only one physical GIO bus exists */
+
+	if (ip22_is_fullhouse()) {
+		/* Fullhouse specific settings. */
+		if (SGIOC_SYSID_BOARDREV(sgioc->sysid) < 2) {
+			tmp |= SGIMC_GIOPAR_HPC264;	/* 2nd HPC at 64bits */
+			tmp |= SGIMC_GIOPAR_PLINEEXP0;	/* exp0 pipelines */
+			tmp |= SGIMC_GIOPAR_MASTEREXP1; /* exp1 masters */
+			tmp |= SGIMC_GIOPAR_RTIMEEXP0;	/* exp0 is realtime */
+		} else {
+			tmp |= SGIMC_GIOPAR_HPC264;	/* 2nd HPC 64bits */
+			tmp |= SGIMC_GIOPAR_PLINEEXP0;	/* exp[01] pipelined */
+			tmp |= SGIMC_GIOPAR_PLINEEXP1;
+			tmp |= SGIMC_GIOPAR_MASTEREISA; /* EISA masters */
+		}
+	} else {
+		/* Guiness specific settings. */
+		tmp |= SGIMC_GIOPAR_EISA64;	/* MC talks to EISA at 64bits */
+		tmp |= SGIMC_GIOPAR_MASTEREISA; /* EISA bus can act as master */
+	}
+	sgimc->giopar = tmp;	/* poof */
+
+	probe_memory();
+}
+
+#ifdef CONFIG_SGI_IP28
+void __init prom_cleanup(void)
+{
+	u32 mconfig1;
+	unsigned long flags;
+	spinlock_t lock;
+
+	/*
+	 * because ARCS accesses memory uncached we wait until ARCS
+	 * isn't needed any longer, before we switch from slow to
+	 * normal mode
+	 */
+	spin_lock_irqsave(&lock, flags);
+	mconfig1 = sgimc->mconfig1;
+	/* map ECC register */
+	sgimc->mconfig1 = (mconfig1 & 0xffff0000) | 0x2060;
+	iob();
+	/* switch to normal mode */
+	*(unsigned long *)PHYS_TO_XKSEG_UNCACHED(0x60000000) = 0;
+	iob();
+	/* reduce WR_COL */
+	sgimc->cmacc = (sgimc->cmacc & ~0xf) | 4;
+	iob();
+	/* restore old config */
+	sgimc->mconfig1 = mconfig1;
+	iob();
+	spin_unlock_irqrestore(&lock, flags);
+}
+#endif
diff --git a/arch/mips/sgi-ip22/ip22-nvram.c b/arch/mips/sgi-ip22/ip22-nvram.c
new file mode 100644
index 0000000000..e727ef519a
--- /dev/null
+++ b/arch/mips/sgi-ip22/ip22-nvram.c
@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ip22-nvram.c: NVRAM and serial EEPROM handling.
+ *
+ * Copyright (C) 2003 Ladislav Michl (ladis@linux-mips.org)
+ */
+#include <linux/export.h>
+
+#include <asm/sgi/hpc3.h>
+#include <asm/sgi/ip22.h>
+
+/* Control opcode for serial eeprom  */
+#define EEPROM_READ	0xc000	/* serial memory read */
+#define EEPROM_WEN	0x9800	/* write enable before prog modes */
+#define EEPROM_WRITE	0xa000	/* serial memory write */
+#define EEPROM_WRALL	0x8800	/* write all registers */
+#define EEPROM_WDS	0x8000	/* disable all programming */
+#define EEPROM_PRREAD	0xc000	/* read protect register */
+#define EEPROM_PREN	0x9800	/* enable protect register mode */
+#define EEPROM_PRCLEAR	0xffff	/* clear protect register */
+#define EEPROM_PRWRITE	0xa000	/* write protect register */
+#define EEPROM_PRDS	0x8000	/* disable protect register, forever */
+
+#define EEPROM_EPROT	0x01	/* Protect register enable */
+#define EEPROM_CSEL	0x02	/* Chip select */
+#define EEPROM_ECLK	0x04	/* EEPROM clock */
+#define EEPROM_DATO	0x08	/* Data out */
+#define EEPROM_DATI	0x10	/* Data in */
+
+/* We need to use these functions early... */
+#define delay() ({						\
+	int x;							\
+	for (x=0; x<100000; x++) __asm__ __volatile__(""); })
+
+#define eeprom_cs_on(ptr) ({	\
+	__raw_writel(__raw_readl(ptr) & ~EEPROM_DATO, ptr);	\
+	__raw_writel(__raw_readl(ptr) & ~EEPROM_ECLK, ptr);	\
+	__raw_writel(__raw_readl(ptr) & ~EEPROM_EPROT, ptr);	\
+	delay();						\
+	__raw_writel(__raw_readl(ptr) | EEPROM_CSEL, ptr);	\
+	__raw_writel(__raw_readl(ptr) | EEPROM_ECLK, ptr); })
+
+
+#define eeprom_cs_off(ptr) ({	\
+	__raw_writel(__raw_readl(ptr) & ~EEPROM_ECLK, ptr);	\
+	__raw_writel(__raw_readl(ptr) & ~EEPROM_CSEL, ptr);	\
+	__raw_writel(__raw_readl(ptr) | EEPROM_EPROT, ptr);	\
+	__raw_writel(__raw_readl(ptr) | EEPROM_ECLK, ptr); })
+
+#define BITS_IN_COMMAND 11
+/*
+ * clock in the nvram command and the register number. For the
+ * national semiconductor nv ram chip the op code is 3 bits and
+ * the address is 6/8 bits.
+ */
+static inline void eeprom_cmd(unsigned int *ctrl, unsigned cmd, unsigned reg)
+{
+	unsigned short ser_cmd;
+	int i;
+
+	ser_cmd = cmd | (reg << (16 - BITS_IN_COMMAND));
+	for (i = 0; i < BITS_IN_COMMAND; i++) {
+		if (ser_cmd & (1<<15))	/* if high order bit set */
+			__raw_writel(__raw_readl(ctrl) | EEPROM_DATO, ctrl);
+		else
+			__raw_writel(__raw_readl(ctrl) & ~EEPROM_DATO, ctrl);
+		__raw_writel(__raw_readl(ctrl) & ~EEPROM_ECLK, ctrl);
+		delay();
+		__raw_writel(__raw_readl(ctrl) | EEPROM_ECLK, ctrl);
+		delay();
+		ser_cmd <<= 1;
+	}
+	/* see data sheet timing diagram */
+	__raw_writel(__raw_readl(ctrl) & ~EEPROM_DATO, ctrl);
+}
+
+unsigned short ip22_eeprom_read(unsigned int *ctrl, int reg)
+{
+	unsigned short res = 0;
+	int i;
+
+	__raw_writel(__raw_readl(ctrl) & ~EEPROM_EPROT, ctrl);
+	eeprom_cs_on(ctrl);
+	eeprom_cmd(ctrl, EEPROM_READ, reg);
+
+	/* clock the data ouf of serial mem */
+	for (i = 0; i < 16; i++) {
+		__raw_writel(__raw_readl(ctrl) & ~EEPROM_ECLK, ctrl);
+		delay();
+		__raw_writel(__raw_readl(ctrl) | EEPROM_ECLK, ctrl);
+		delay();
+		res <<= 1;
+		if (__raw_readl(ctrl) & EEPROM_DATI)
+			res |= 1;
+	}
+
+	eeprom_cs_off(ctrl);
+
+	return res;
+}
+
+EXPORT_SYMBOL(ip22_eeprom_read);
+
+/*
+ * Read specified register from main NVRAM
+ */
+unsigned short ip22_nvram_read(int reg)
+{
+	if (ip22_is_fullhouse())
+		/* IP22 (Indigo2 aka FullHouse) stores env variables into
+		 * 93CS56 Microwire Bus EEPROM 2048 Bit (128x16) */
+		return ip22_eeprom_read(&hpc3c0->eeprom, reg);
+	else {
+		unsigned short tmp;
+		/* IP24 (Indy aka Guiness) uses DS1386 8K version */
+		reg <<= 1;
+		tmp = hpc3c0->bbram[reg++] & 0xff;
+		return (tmp << 8) | (hpc3c0->bbram[reg] & 0xff);
+	}
+}
+
+EXPORT_SYMBOL(ip22_nvram_read);
diff --git a/arch/mips/sgi-ip22/ip22-platform.c b/arch/mips/sgi-ip22/ip22-platform.c
new file mode 100644
index 0000000000..0b2002e02a
--- /dev/null
+++ b/arch/mips/sgi-ip22/ip22-platform.c
@@ -0,0 +1,223 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/init.h>
+#include <linux/if_ether.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+
+#include <asm/paccess.h>
+#include <asm/sgi/ip22.h>
+#include <asm/sgi/hpc3.h>
+#include <asm/sgi/mc.h>
+#include <asm/sgi/seeq.h>
+#include <asm/sgi/wd.h>
+
+static struct resource sgiwd93_0_resources[] = {
+	{
+		.name	= "eth0 irq",
+		.start	= SGI_WD93_0_IRQ,
+		.end	= SGI_WD93_0_IRQ,
+		.flags	= IORESOURCE_IRQ
+	}
+};
+
+static struct sgiwd93_platform_data sgiwd93_0_pd = {
+	.unit	= 0,
+	.irq	= SGI_WD93_0_IRQ,
+};
+
+static u64 sgiwd93_0_dma_mask = DMA_BIT_MASK(32);
+
+static struct platform_device sgiwd93_0_device = {
+	.name		= "sgiwd93",
+	.id		= 0,
+	.num_resources	= ARRAY_SIZE(sgiwd93_0_resources),
+	.resource	= sgiwd93_0_resources,
+	.dev = {
+		.platform_data = &sgiwd93_0_pd,
+		.dma_mask = &sgiwd93_0_dma_mask,
+		.coherent_dma_mask = DMA_BIT_MASK(32),
+	},
+};
+
+static struct resource sgiwd93_1_resources[] = {
+	{
+		.name	= "eth0 irq",
+		.start	= SGI_WD93_1_IRQ,
+		.end	= SGI_WD93_1_IRQ,
+		.flags	= IORESOURCE_IRQ
+	}
+};
+
+static struct sgiwd93_platform_data sgiwd93_1_pd = {
+	.unit	= 1,
+	.irq	= SGI_WD93_1_IRQ,
+};
+
+static u64 sgiwd93_1_dma_mask = DMA_BIT_MASK(32);
+
+static struct platform_device sgiwd93_1_device = {
+	.name		= "sgiwd93",
+	.id		= 1,
+	.num_resources	= ARRAY_SIZE(sgiwd93_1_resources),
+	.resource	= sgiwd93_1_resources,
+	.dev = {
+		.platform_data = &sgiwd93_1_pd,
+		.dma_mask = &sgiwd93_1_dma_mask,
+		.coherent_dma_mask = DMA_BIT_MASK(32),
+	},
+};
+
+/*
+ * Create a platform device for the GPI port that receives the
+ * image data from the embedded camera.
+ */
+static int __init sgiwd93_devinit(void)
+{
+	int res;
+
+	sgiwd93_0_pd.hregs	= &hpc3c0->scsi_chan0;
+	sgiwd93_0_pd.wdregs	= (unsigned char *) hpc3c0->scsi0_ext;
+
+	res = platform_device_register(&sgiwd93_0_device);
+	if (res)
+		return res;
+
+	if (!ip22_is_fullhouse())
+		return 0;
+
+	sgiwd93_1_pd.hregs	= &hpc3c0->scsi_chan1;
+	sgiwd93_1_pd.wdregs	= (unsigned char *) hpc3c0->scsi1_ext;
+
+	return platform_device_register(&sgiwd93_1_device);
+}
+
+device_initcall(sgiwd93_devinit);
+
+static struct resource sgiseeq_0_resources[] = {
+	{
+		.name	= "eth0 irq",
+		.start	= SGI_ENET_IRQ,
+		.end	= SGI_ENET_IRQ,
+		.flags	= IORESOURCE_IRQ
+	}
+};
+
+static struct sgiseeq_platform_data eth0_pd;
+
+static u64 sgiseeq_dma_mask = DMA_BIT_MASK(32);
+
+static struct platform_device eth0_device = {
+	.name		= "sgiseeq",
+	.id		= 0,
+	.num_resources	= ARRAY_SIZE(sgiseeq_0_resources),
+	.resource	= sgiseeq_0_resources,
+	.dev = {
+		.platform_data = &eth0_pd,
+		.dma_mask = &sgiseeq_dma_mask,
+		.coherent_dma_mask = DMA_BIT_MASK(32),
+	},
+};
+
+static struct resource sgiseeq_1_resources[] = {
+	{
+		.name	= "eth1 irq",
+		.start	= SGI_GIO_0_IRQ,
+		.end	= SGI_GIO_0_IRQ,
+		.flags	= IORESOURCE_IRQ
+	}
+};
+
+static struct sgiseeq_platform_data eth1_pd;
+
+static struct platform_device eth1_device = {
+	.name		= "sgiseeq",
+	.id		= 1,
+	.num_resources	= ARRAY_SIZE(sgiseeq_1_resources),
+	.resource	= sgiseeq_1_resources,
+	.dev = {
+		.platform_data = &eth1_pd,
+	},
+};
+
+/*
+ * Create a platform device for the GPI port that receives the
+ * image data from the embedded camera.
+ */
+static int __init sgiseeq_devinit(void)
+{
+	unsigned int pbdma __maybe_unused;
+	int res, i;
+
+	eth0_pd.hpc = hpc3c0;
+	eth0_pd.irq = SGI_ENET_IRQ;
+#define EADDR_NVOFS	250
+	for (i = 0; i < 3; i++) {
+		unsigned short tmp = ip22_nvram_read(EADDR_NVOFS / 2 + i);
+
+		eth0_pd.mac[2 * i]     = tmp >> 8;
+		eth0_pd.mac[2 * i + 1] = tmp & 0xff;
+	}
+
+	res = platform_device_register(&eth0_device);
+	if (res)
+		return res;
+
+	/* Second HPC is missing? */
+	if (ip22_is_fullhouse() ||
+	    get_dbe(pbdma, (unsigned int *)&hpc3c1->pbdma[1]))
+		return 0;
+
+	sgimc->giopar |= SGIMC_GIOPAR_MASTEREXP1 | SGIMC_GIOPAR_EXP164 |
+			 SGIMC_GIOPAR_HPC264;
+	hpc3c1->pbus_piocfg[0][0] = 0x3ffff;
+	/* interrupt/config register on Challenge S Mezz board */
+	hpc3c1->pbus_extregs[0][0] = 0x30;
+
+	eth1_pd.hpc = hpc3c1;
+	eth1_pd.irq = SGI_GIO_0_IRQ;
+#define EADDR_NVOFS	250
+	for (i = 0; i < 3; i++) {
+		unsigned short tmp = ip22_eeprom_read(&hpc3c1->eeprom,
+						      EADDR_NVOFS / 2 + i);
+
+		eth1_pd.mac[2 * i]     = tmp >> 8;
+		eth1_pd.mac[2 * i + 1] = tmp & 0xff;
+	}
+
+	return platform_device_register(&eth1_device);
+}
+
+device_initcall(sgiseeq_devinit);
+
+static int __init sgi_hal2_devinit(void)
+{
+	return IS_ERR(platform_device_register_simple("sgihal2", 0, NULL, 0));
+}
+
+device_initcall(sgi_hal2_devinit);
+
+static int __init sgi_button_devinit(void)
+{
+	if (ip22_is_fullhouse())
+		return 0; /* full house has no volume buttons */
+
+	return IS_ERR(platform_device_register_simple("sgibtns", -1, NULL, 0));
+}
+
+device_initcall(sgi_button_devinit);
+
+static int __init sgi_ds1286_devinit(void)
+{
+	struct resource res;
+
+	memset(&res, 0, sizeof(res));
+	res.start = HPC3_CHIP0_BASE + offsetof(struct hpc3_regs, rtcregs);
+	res.end = res.start + sizeof(hpc3c0->rtcregs) - 1;
+	res.flags = IORESOURCE_MEM;
+
+	return IS_ERR(platform_device_register_simple("rtc-ds1286", -1,
+						      &res, 1));
+}
+
+device_initcall(sgi_ds1286_devinit);
diff --git a/arch/mips/sgi-ip22/ip22-reset.c b/arch/mips/sgi-ip22/ip22-reset.c
new file mode 100644
index 0000000000..8f0861c580
--- /dev/null
+++ b/arch/mips/sgi-ip22/ip22-reset.c
@@ -0,0 +1,203 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1997, 1998, 2001, 03, 05, 06 by Ralf Baechle
+ */
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <linux/rtc/ds1286.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/sched/signal.h>
+#include <linux/panic_notifier.h>
+#include <linux/pm.h>
+#include <linux/timer.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/reboot.h>
+#include <asm/sgialib.h>
+#include <asm/sgi/ioc.h>
+#include <asm/sgi/hpc3.h>
+#include <asm/sgi/mc.h>
+#include <asm/sgi/ip22.h>
+
+/*
+ * Just powerdown if init hasn't done after POWERDOWN_TIMEOUT seconds.
+ * I'm not sure if this feature is a good idea, for now it's here just to
+ * make the power button make behave just like under IRIX.
+ */
+#define POWERDOWN_TIMEOUT	120
+
+/*
+ * Blink frequency during reboot grace period and when panicked.
+ */
+#define POWERDOWN_FREQ		(HZ / 4)
+#define PANIC_FREQ		(HZ / 8)
+
+static struct timer_list power_timer, blink_timer, debounce_timer;
+static unsigned long blink_timer_timeout;
+
+#define MACHINE_PANICKED		1
+#define MACHINE_SHUTTING_DOWN	2
+
+static int machine_state;
+
+static void __noreturn sgi_machine_power_off(void)
+{
+	unsigned int tmp;
+
+	local_irq_disable();
+
+	/* Disable watchdog */
+	tmp = hpc3c0->rtcregs[RTC_CMD] & 0xff;
+	hpc3c0->rtcregs[RTC_CMD] = tmp | RTC_WAM;
+	hpc3c0->rtcregs[RTC_WSEC] = 0;
+	hpc3c0->rtcregs[RTC_WHSEC] = 0;
+
+	while (1) {
+		sgioc->panel = ~SGIOC_PANEL_POWERON;
+		/* Good bye cruel world ...  */
+
+		/* If we're still running, we probably got sent an alarm
+		   interrupt.  Read the flag to clear it.  */
+		tmp = hpc3c0->rtcregs[RTC_HOURS_ALARM];
+	}
+}
+
+static void __noreturn sgi_machine_restart(char *command)
+{
+	if (machine_state & MACHINE_SHUTTING_DOWN)
+		sgi_machine_power_off();
+	sgimc->cpuctrl0 |= SGIMC_CCTRL0_SYSINIT;
+	while (1);
+}
+
+static void __noreturn sgi_machine_halt(void)
+{
+	if (machine_state & MACHINE_SHUTTING_DOWN)
+		sgi_machine_power_off();
+	ArcEnterInteractiveMode();
+}
+
+static void power_timeout(struct timer_list *unused)
+{
+	sgi_machine_power_off();
+}
+
+static void blink_timeout(struct timer_list *unused)
+{
+	/* XXX fix this for fullhouse  */
+	sgi_ioc_reset ^= (SGIOC_RESET_LC0OFF|SGIOC_RESET_LC1OFF);
+	sgioc->reset = sgi_ioc_reset;
+
+	mod_timer(&blink_timer, jiffies + blink_timer_timeout);
+}
+
+static void debounce(struct timer_list *unused)
+{
+	del_timer(&debounce_timer);
+	if (sgint->istat1 & SGINT_ISTAT1_PWR) {
+		/* Interrupt still being sent. */
+		debounce_timer.expires = jiffies + (HZ / 20); /* 0.05s	*/
+		add_timer(&debounce_timer);
+
+		sgioc->panel = SGIOC_PANEL_POWERON | SGIOC_PANEL_POWERINTR |
+			       SGIOC_PANEL_VOLDNINTR | SGIOC_PANEL_VOLDNHOLD |
+			       SGIOC_PANEL_VOLUPINTR | SGIOC_PANEL_VOLUPHOLD;
+
+		return;
+	}
+
+	if (machine_state & MACHINE_PANICKED)
+		sgimc->cpuctrl0 |= SGIMC_CCTRL0_SYSINIT;
+
+	enable_irq(SGI_PANEL_IRQ);
+}
+
+static inline void power_button(void)
+{
+	if (machine_state & MACHINE_PANICKED)
+		return;
+
+	if ((machine_state & MACHINE_SHUTTING_DOWN) ||
+			kill_cad_pid(SIGINT, 1)) {
+		/* No init process or button pressed twice.  */
+		sgi_machine_power_off();
+	}
+
+	machine_state |= MACHINE_SHUTTING_DOWN;
+	blink_timer_timeout = POWERDOWN_FREQ;
+	blink_timeout(&blink_timer);
+
+	timer_setup(&power_timer, power_timeout, 0);
+	power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
+	add_timer(&power_timer);
+}
+
+static irqreturn_t panel_int(int irq, void *dev_id)
+{
+	unsigned int buttons;
+
+	buttons = sgioc->panel;
+	sgioc->panel = SGIOC_PANEL_POWERON | SGIOC_PANEL_POWERINTR;
+
+	if (sgint->istat1 & SGINT_ISTAT1_PWR) {
+		/* Wait until interrupt goes away */
+		disable_irq_nosync(SGI_PANEL_IRQ);
+		timer_setup(&debounce_timer, debounce, 0);
+		debounce_timer.expires = jiffies + 5;
+		add_timer(&debounce_timer);
+	}
+
+	/* Power button was pressed
+	 * ioc.ps page 22: "The Panel Register is called Power Control by Full
+	 * House. Only lowest 2 bits are used. Guiness uses upper four bits
+	 * for volume control". This is not true, all bits are pulled high
+	 * on fullhouse */
+	if (!(buttons & SGIOC_PANEL_POWERINTR))
+		power_button();
+
+	return IRQ_HANDLED;
+}
+
+static int panic_event(struct notifier_block *this, unsigned long event,
+		      void *ptr)
+{
+	if (machine_state & MACHINE_PANICKED)
+		return NOTIFY_DONE;
+	machine_state |= MACHINE_PANICKED;
+
+	blink_timer_timeout = PANIC_FREQ;
+	blink_timeout(&blink_timer);
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block panic_block = {
+	.notifier_call	= panic_event,
+};
+
+static int __init reboot_setup(void)
+{
+	int res;
+
+	_machine_restart = sgi_machine_restart;
+	_machine_halt = sgi_machine_halt;
+	pm_power_off = sgi_machine_power_off;
+
+	res = request_irq(SGI_PANEL_IRQ, panel_int, 0, "Front Panel", NULL);
+	if (res) {
+		printk(KERN_ERR "Allocation of front panel IRQ failed\n");
+		return res;
+	}
+
+	timer_setup(&blink_timer, blink_timeout, 0);
+	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
+
+	return 0;
+}
+
+subsys_initcall(reboot_setup);
diff --git a/arch/mips/sgi-ip22/ip22-setup.c b/arch/mips/sgi-ip22/ip22-setup.c
new file mode 100644
index 0000000000..b69daa0240
--- /dev/null
+++ b/arch/mips/sgi-ip22/ip22-setup.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ip22-setup.c: SGI specific setup, including init of the feature struct.
+ *
+ * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
+ * Copyright (C) 1997, 1998 Ralf Baechle (ralf@gnu.org)
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/kdev_t.h>
+#include <linux/types.h>
+#include <linux/console.h>
+#include <linux/sched.h>
+#include <linux/tty.h>
+
+#include <asm/addrspace.h>
+#include <asm/bcache.h>
+#include <asm/bootinfo.h>
+#include <asm/irq.h>
+#include <asm/reboot.h>
+#include <asm/time.h>
+#include <asm/io.h>
+#include <asm/traps.h>
+#include <asm/sgialib.h>
+#include <asm/sgi/mc.h>
+#include <asm/sgi/hpc3.h>
+#include <asm/sgi/ip22.h>
+
+extern void ip22_be_init(void) __init;
+
+void __init plat_mem_setup(void)
+{
+	char *ctype;
+	char *cserial;
+
+	board_be_init = ip22_be_init;
+
+	/* Init the INDY HPC I/O controller.  Need to call this before
+	 * fucking with the memory controller because it needs to know the
+	 * boardID and whether this is a Guiness or a FullHouse machine.
+	 */
+	sgihpc_init();
+
+	/* Init INDY memory controller. */
+	sgimc_init();
+
+#ifdef CONFIG_BOARD_SCACHE
+	/* Now enable boardcaches, if any. */
+	indy_sc_init();
+#endif
+
+	/* Set EISA IO port base for Indigo2
+	 * ioremap cannot fail */
+	set_io_port_base((unsigned long)ioremap(0x00080000,
+						0x1fffffff - 0x00080000));
+	/* ARCS console environment variable is set to "g?" for
+	 * graphics console, it is set to "d" for the first serial
+	 * line and "d2" for the second serial line.
+	 *
+	 * Need to check if the case is 'g' but no keyboard:
+	 * (ConsoleIn/Out = serial)
+	 */
+	ctype = ArcGetEnvironmentVariable("console");
+	cserial = ArcGetEnvironmentVariable("ConsoleOut");
+
+	if ((ctype && *ctype == 'd') || (cserial && *cserial == 's')) {
+		static char options[8] __initdata;
+		char *baud = ArcGetEnvironmentVariable("dbaud");
+		if (baud)
+			strcpy(options, baud);
+		add_preferred_console("ttyS", *(ctype + 1) == '2' ? 1 : 0,
+				      baud ? options : NULL);
+	} else if (!ctype || *ctype != 'g') {
+		/* Use ARC if we don't want serial ('d') or graphics ('g'). */
+		prom_flags |= PROM_FLAG_USE_AS_CONSOLE;
+		add_preferred_console("arc", 0, NULL);
+	}
+}
diff --git a/arch/mips/sgi-ip22/ip22-time.c b/arch/mips/sgi-ip22/ip22-time.c
new file mode 100644
index 0000000000..045aa89f28
--- /dev/null
+++ b/arch/mips/sgi-ip22/ip22-time.c
@@ -0,0 +1,131 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Time operations for IP22 machines. Original code may come from
+ * Ralf Baechle or David S. Miller (sorry guys, i'm really not sure)
+ *
+ * Copyright (C) 2001 by Ladislav Michl
+ * Copyright (C) 2003, 06 Ralf Baechle (ralf@linux-mips.org)
+ */
+#include <linux/bcd.h>
+#include <linux/i8253.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+#include <linux/time.h>
+#include <linux/ftrace.h>
+
+#include <asm/cpu.h>
+#include <asm/mipsregs.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/time.h>
+#include <asm/sgialib.h>
+#include <asm/sgi/ioc.h>
+#include <asm/sgi/hpc3.h>
+#include <asm/sgi/ip22.h>
+
+static unsigned long dosample(void)
+{
+	u32 ct0, ct1;
+	u8 msb;
+
+	/* Start the counter. */
+	sgint->tcword = (SGINT_TCWORD_CNT2 | SGINT_TCWORD_CALL |
+			 SGINT_TCWORD_MRGEN);
+	sgint->tcnt2 = SGINT_TCSAMP_COUNTER & 0xff;
+	sgint->tcnt2 = SGINT_TCSAMP_COUNTER >> 8;
+
+	/* Get initial counter invariant */
+	ct0 = read_c0_count();
+
+	/* Latch and spin until top byte of counter2 is zero */
+	do {
+		writeb(SGINT_TCWORD_CNT2 | SGINT_TCWORD_CLAT, &sgint->tcword);
+		(void) readb(&sgint->tcnt2);
+		msb = readb(&sgint->tcnt2);
+		ct1 = read_c0_count();
+	} while (msb);
+
+	/* Stop the counter. */
+	writeb(SGINT_TCWORD_CNT2 | SGINT_TCWORD_CALL | SGINT_TCWORD_MSWST,
+	       &sgint->tcword);
+	/*
+	 * Return the difference, this is how far the r4k counter increments
+	 * for every 1/HZ seconds. We round off the nearest 1 MHz of master
+	 * clock (= 1000000 / HZ / 2).
+	 */
+
+	return (ct1 - ct0) / (500000/HZ) * (500000/HZ);
+}
+
+/*
+ * Here we need to calibrate the cycle counter to at least be close.
+ */
+__init void plat_time_init(void)
+{
+	unsigned long r4k_ticks[3];
+	unsigned long r4k_tick;
+
+	/*
+	 * Figure out the r4k offset, the algorithm is very simple and works in
+	 * _all_ cases as long as the 8254 counter register itself works ok (as
+	 * an interrupt driving timer it does not because of bug, this is why
+	 * we are using the onchip r4k counter/compare register to serve this
+	 * purpose, but for r4k_offset calculation it will work ok for us).
+	 * There are other very complicated ways of performing this calculation
+	 * but this one works just fine so I am not going to futz around. ;-)
+	 */
+	printk(KERN_INFO "Calibrating system timer... ");
+	dosample();	/* Prime cache. */
+	dosample();	/* Prime cache. */
+	/* Zero is NOT an option. */
+	do {
+		r4k_ticks[0] = dosample();
+	} while (!r4k_ticks[0]);
+	do {
+		r4k_ticks[1] = dosample();
+	} while (!r4k_ticks[1]);
+
+	if (r4k_ticks[0] != r4k_ticks[1]) {
+		printk("warning: timer counts differ, retrying... ");
+		r4k_ticks[2] = dosample();
+		if (r4k_ticks[2] == r4k_ticks[0]
+		    || r4k_ticks[2] == r4k_ticks[1])
+			r4k_tick = r4k_ticks[2];
+		else {
+			printk("disagreement, using average... ");
+			r4k_tick = (r4k_ticks[0] + r4k_ticks[1]
+				   + r4k_ticks[2]) / 3;
+		}
+	} else
+		r4k_tick = r4k_ticks[0];
+
+	printk("%d [%d.%04d MHz CPU]\n", (int) r4k_tick,
+		(int) (r4k_tick / (500000 / HZ)),
+		(int) (r4k_tick % (500000 / HZ)));
+
+	mips_hpt_frequency = r4k_tick * HZ;
+
+	if (ip22_is_fullhouse())
+		setup_pit_timer();
+}
+
+/* Generic SGI handler for (spurious) 8254 interrupts */
+void __irq_entry indy_8254timer_irq(void)
+{
+	int irq = SGI_8254_0_IRQ;
+	ULONG cnt;
+	char c;
+
+	irq_enter();
+	kstat_incr_irq_this_cpu(irq);
+	printk(KERN_ALERT "Oops, got 8254 interrupt.\n");
+	ArcRead(0, &c, 1, &cnt);
+	ArcEnterInteractiveMode();
+	irq_exit();
+}
diff --git a/arch/mips/sgi-ip22/ip28-berr.c b/arch/mips/sgi-ip22/ip28-berr.c
new file mode 100644
index 0000000000..16ca470deb
--- /dev/null
+++ b/arch/mips/sgi-ip22/ip28-berr.c
@@ -0,0 +1,488 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ip28-berr.c: Bus error handling.
+ *
+ * Copyright (C) 2002, 2003 Ladislav Michl (ladis@linux-mips.org)
+ * Copyright (C) 2005 Peter Fuerst (pf@net.alphadv.de) - IP28
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/signal.h>
+#include <linux/seq_file.h>
+
+#include <asm/addrspace.h>
+#include <asm/traps.h>
+#include <asm/branch.h>
+#include <asm/irq_regs.h>
+#include <asm/sgi/mc.h>
+#include <asm/sgi/hpc3.h>
+#include <asm/sgi/ioc.h>
+#include <asm/sgi/ip22.h>
+#include <asm/r4kcache.h>
+#include <linux/uaccess.h>
+#include <asm/bootinfo.h>
+
+static unsigned int count_be_is_fixup;
+static unsigned int count_be_handler;
+static unsigned int count_be_interrupt;
+static int debug_be_interrupt;
+
+static unsigned int cpu_err_stat;	/* Status reg for CPU */
+static unsigned int gio_err_stat;	/* Status reg for GIO */
+static unsigned int cpu_err_addr;	/* Error address reg for CPU */
+static unsigned int gio_err_addr;	/* Error address reg for GIO */
+static unsigned int extio_stat;
+static unsigned int hpc3_berr_stat;	/* Bus error interrupt status */
+
+struct hpc3_stat {
+	unsigned long addr;
+	unsigned int ctrl;
+	unsigned int cbp;
+	unsigned int ndptr;
+};
+
+static struct {
+	struct hpc3_stat pbdma[8];
+	struct hpc3_stat scsi[2];
+	struct hpc3_stat ethrx, ethtx;
+} hpc3;
+
+static struct {
+	unsigned long err_addr;
+	struct {
+		u32 lo;
+		u32 hi;
+	} tags[1][2], tagd[4][2], tagi[4][2]; /* Way 0/1 */
+} cache_tags;
+
+static inline void save_cache_tags(unsigned busaddr)
+{
+	unsigned long addr = CAC_BASE | busaddr;
+	int i;
+	cache_tags.err_addr = addr;
+
+	/*
+	 * Starting with a bus-address, save secondary cache (indexed by
+	 * PA[23..18:7..6]) tags first.
+	 */
+	addr &= ~1L;
+#define tag cache_tags.tags[0]
+	cache_op(Index_Load_Tag_S, addr);
+	tag[0].lo = read_c0_taglo();	/* PA[35:18], VA[13:12] */
+	tag[0].hi = read_c0_taghi();	/* PA[39:36] */
+	cache_op(Index_Load_Tag_S, addr | 1L);
+	tag[1].lo = read_c0_taglo();	/* PA[35:18], VA[13:12] */
+	tag[1].hi = read_c0_taghi();	/* PA[39:36] */
+#undef tag
+
+	/*
+	 * Save all primary data cache (indexed by VA[13:5]) tags which
+	 * might fit to this bus-address, knowing that VA[11:0] == PA[11:0].
+	 * Saving all tags and evaluating them later is easier and safer
+	 * than relying on VA[13:12] from the secondary cache tags to pick
+	 * matching primary tags here already.
+	 */
+	addr &= (0xffL << 56) | ((1 << 12) - 1);
+#define tag cache_tags.tagd[i]
+	for (i = 0; i < 4; ++i, addr += (1 << 12)) {
+		cache_op(Index_Load_Tag_D, addr);
+		tag[0].lo = read_c0_taglo();	/* PA[35:12] */
+		tag[0].hi = read_c0_taghi();	/* PA[39:36] */
+		cache_op(Index_Load_Tag_D, addr | 1L);
+		tag[1].lo = read_c0_taglo();	/* PA[35:12] */
+		tag[1].hi = read_c0_taghi();	/* PA[39:36] */
+	}
+#undef tag
+
+	/*
+	 * Save primary instruction cache (indexed by VA[13:6]) tags
+	 * the same way.
+	 */
+	addr &= (0xffL << 56) | ((1 << 12) - 1);
+#define tag cache_tags.tagi[i]
+	for (i = 0; i < 4; ++i, addr += (1 << 12)) {
+		cache_op(Index_Load_Tag_I, addr);
+		tag[0].lo = read_c0_taglo();	/* PA[35:12] */
+		tag[0].hi = read_c0_taghi();	/* PA[39:36] */
+		cache_op(Index_Load_Tag_I, addr | 1L);
+		tag[1].lo = read_c0_taglo();	/* PA[35:12] */
+		tag[1].hi = read_c0_taghi();	/* PA[39:36] */
+	}
+#undef tag
+}
+
+#define GIO_ERRMASK	0xff00
+#define CPU_ERRMASK	0x3f00
+
+static void save_and_clear_buserr(void)
+{
+	int i;
+
+	/* save status registers */
+	cpu_err_addr = sgimc->cerr;
+	cpu_err_stat = sgimc->cstat;
+	gio_err_addr = sgimc->gerr;
+	gio_err_stat = sgimc->gstat;
+	extio_stat = sgioc->extio;
+	hpc3_berr_stat = hpc3c0->bestat;
+
+	hpc3.scsi[0].addr  = (unsigned long)&hpc3c0->scsi_chan0;
+	hpc3.scsi[0].ctrl  = hpc3c0->scsi_chan0.ctrl; /* HPC3_SCTRL_ACTIVE ? */
+	hpc3.scsi[0].cbp   = hpc3c0->scsi_chan0.cbptr;
+	hpc3.scsi[0].ndptr = hpc3c0->scsi_chan0.ndptr;
+
+	hpc3.scsi[1].addr  = (unsigned long)&hpc3c0->scsi_chan1;
+	hpc3.scsi[1].ctrl  = hpc3c0->scsi_chan1.ctrl; /* HPC3_SCTRL_ACTIVE ? */
+	hpc3.scsi[1].cbp   = hpc3c0->scsi_chan1.cbptr;
+	hpc3.scsi[1].ndptr = hpc3c0->scsi_chan1.ndptr;
+
+	hpc3.ethrx.addr	 = (unsigned long)&hpc3c0->ethregs.rx_cbptr;
+	hpc3.ethrx.ctrl	 = hpc3c0->ethregs.rx_ctrl; /* HPC3_ERXCTRL_ACTIVE ? */
+	hpc3.ethrx.cbp	 = hpc3c0->ethregs.rx_cbptr;
+	hpc3.ethrx.ndptr = hpc3c0->ethregs.rx_ndptr;
+
+	hpc3.ethtx.addr	 = (unsigned long)&hpc3c0->ethregs.tx_cbptr;
+	hpc3.ethtx.ctrl	 = hpc3c0->ethregs.tx_ctrl; /* HPC3_ETXCTRL_ACTIVE ? */
+	hpc3.ethtx.cbp	 = hpc3c0->ethregs.tx_cbptr;
+	hpc3.ethtx.ndptr = hpc3c0->ethregs.tx_ndptr;
+
+	for (i = 0; i < 8; ++i) {
+		/* HPC3_PDMACTRL_ISACT ? */
+		hpc3.pbdma[i].addr  = (unsigned long)&hpc3c0->pbdma[i];
+		hpc3.pbdma[i].ctrl  = hpc3c0->pbdma[i].pbdma_ctrl;
+		hpc3.pbdma[i].cbp   = hpc3c0->pbdma[i].pbdma_bptr;
+		hpc3.pbdma[i].ndptr = hpc3c0->pbdma[i].pbdma_dptr;
+	}
+	i = 0;
+	if (gio_err_stat & CPU_ERRMASK)
+		i = gio_err_addr;
+	if (cpu_err_stat & CPU_ERRMASK)
+		i = cpu_err_addr;
+	save_cache_tags(i);
+
+	sgimc->cstat = sgimc->gstat = 0;
+}
+
+static void print_cache_tags(void)
+{
+	u32 scb, scw;
+	int i;
+
+	printk(KERN_ERR "Cache tags @ %08x:\n", (unsigned)cache_tags.err_addr);
+
+	/* PA[31:12] shifted to PTag0 (PA[35:12]) format */
+	scw = (cache_tags.err_addr >> 4) & 0x0fffff00;
+
+	scb = cache_tags.err_addr & ((1 << 12) - 1) & ~((1 << 5) - 1);
+	for (i = 0; i < 4; ++i) { /* for each possible VA[13:12] value */
+		if ((cache_tags.tagd[i][0].lo & 0x0fffff00) != scw &&
+		    (cache_tags.tagd[i][1].lo & 0x0fffff00) != scw)
+		    continue;
+		printk(KERN_ERR
+		       "D: 0: %08x %08x, 1: %08x %08x  (VA[13:5]  %04x)\n",
+			cache_tags.tagd[i][0].hi, cache_tags.tagd[i][0].lo,
+			cache_tags.tagd[i][1].hi, cache_tags.tagd[i][1].lo,
+			scb | (1 << 12)*i);
+	}
+	scb = cache_tags.err_addr & ((1 << 12) - 1) & ~((1 << 6) - 1);
+	for (i = 0; i < 4; ++i) { /* for each possible VA[13:12] value */
+		if ((cache_tags.tagi[i][0].lo & 0x0fffff00) != scw &&
+		    (cache_tags.tagi[i][1].lo & 0x0fffff00) != scw)
+		    continue;
+		printk(KERN_ERR
+		       "I: 0: %08x %08x, 1: %08x %08x  (VA[13:6]  %04x)\n",
+			cache_tags.tagi[i][0].hi, cache_tags.tagi[i][0].lo,
+			cache_tags.tagi[i][1].hi, cache_tags.tagi[i][1].lo,
+			scb | (1 << 12)*i);
+	}
+	i = read_c0_config();
+	scb = i & (1 << 13) ? 7:6;	/* scblksize = 2^[7..6] */
+	scw = ((i >> 16) & 7) + 19 - 1; /* scwaysize = 2^[24..19] / 2 */
+
+	i = ((1 << scw) - 1) & ~((1 << scb) - 1);
+	printk(KERN_ERR "S: 0: %08x %08x, 1: %08x %08x	(PA[%u:%u] %05x)\n",
+		cache_tags.tags[0][0].hi, cache_tags.tags[0][0].lo,
+		cache_tags.tags[0][1].hi, cache_tags.tags[0][1].lo,
+		scw-1, scb, i & (unsigned)cache_tags.err_addr);
+}
+
+static inline const char *cause_excode_text(int cause)
+{
+	static const char *txt[32] =
+	{	"Interrupt",
+		"TLB modification",
+		"TLB (load or instruction fetch)",
+		"TLB (store)",
+		"Address error (load or instruction fetch)",
+		"Address error (store)",
+		"Bus error (instruction fetch)",
+		"Bus error (data: load or store)",
+		"Syscall",
+		"Breakpoint",
+		"Reserved instruction",
+		"Coprocessor unusable",
+		"Arithmetic Overflow",
+		"Trap",
+		"14",
+		"Floating-Point",
+		"16", "17", "18", "19", "20", "21", "22",
+		"Watch Hi/Lo",
+		"24", "25", "26", "27", "28", "29", "30", "31",
+	};
+	return txt[(cause & 0x7c) >> 2];
+}
+
+static void print_buserr(const struct pt_regs *regs)
+{
+	const int field = 2 * sizeof(unsigned long);
+	int error = 0;
+
+	if (extio_stat & EXTIO_MC_BUSERR) {
+		printk(KERN_ERR "MC Bus Error\n");
+		error |= 1;
+	}
+	if (extio_stat & EXTIO_HPC3_BUSERR) {
+		printk(KERN_ERR "HPC3 Bus Error 0x%x:<id=0x%x,%s,lane=0x%x>\n",
+			hpc3_berr_stat,
+			(hpc3_berr_stat & HPC3_BESTAT_PIDMASK) >>
+					  HPC3_BESTAT_PIDSHIFT,
+			(hpc3_berr_stat & HPC3_BESTAT_CTYPE) ? "PIO" : "DMA",
+			hpc3_berr_stat & HPC3_BESTAT_BLMASK);
+		error |= 2;
+	}
+	if (extio_stat & EXTIO_EISA_BUSERR) {
+		printk(KERN_ERR "EISA Bus Error\n");
+		error |= 4;
+	}
+	if (cpu_err_stat & CPU_ERRMASK) {
+		printk(KERN_ERR "CPU error 0x%x<%s%s%s%s%s%s> @ 0x%08x\n",
+			cpu_err_stat,
+			cpu_err_stat & SGIMC_CSTAT_RD ? "RD " : "",
+			cpu_err_stat & SGIMC_CSTAT_PAR ? "PAR " : "",
+			cpu_err_stat & SGIMC_CSTAT_ADDR ? "ADDR " : "",
+			cpu_err_stat & SGIMC_CSTAT_SYSAD_PAR ? "SYSAD " : "",
+			cpu_err_stat & SGIMC_CSTAT_SYSCMD_PAR ? "SYSCMD " : "",
+			cpu_err_stat & SGIMC_CSTAT_BAD_DATA ? "BAD_DATA " : "",
+			cpu_err_addr);
+		error |= 8;
+	}
+	if (gio_err_stat & GIO_ERRMASK) {
+		printk(KERN_ERR "GIO error 0x%x:<%s%s%s%s%s%s%s%s> @ 0x%08x\n",
+			gio_err_stat,
+			gio_err_stat & SGIMC_GSTAT_RD ? "RD " : "",
+			gio_err_stat & SGIMC_GSTAT_WR ? "WR " : "",
+			gio_err_stat & SGIMC_GSTAT_TIME ? "TIME " : "",
+			gio_err_stat & SGIMC_GSTAT_PROM ? "PROM " : "",
+			gio_err_stat & SGIMC_GSTAT_ADDR ? "ADDR " : "",
+			gio_err_stat & SGIMC_GSTAT_BC ? "BC " : "",
+			gio_err_stat & SGIMC_GSTAT_PIO_RD ? "PIO_RD " : "",
+			gio_err_stat & SGIMC_GSTAT_PIO_WR ? "PIO_WR " : "",
+			gio_err_addr);
+		error |= 16;
+	}
+	if (!error)
+		printk(KERN_ERR "MC: Hmm, didn't find any error condition.\n");
+	else {
+		printk(KERN_ERR "CP0: config %08x,  "
+			"MC: cpuctrl0/1: %08x/%05x, giopar: %04x\n"
+			"MC: cpu/gio_memacc: %08x/%05x, memcfg0/1: %08x/%08x\n",
+			read_c0_config(),
+			sgimc->cpuctrl0, sgimc->cpuctrl0, sgimc->giopar,
+			sgimc->cmacc, sgimc->gmacc,
+			sgimc->mconfig0, sgimc->mconfig1);
+		print_cache_tags();
+	}
+	printk(KERN_ALERT "%s, epc == %0*lx, ra == %0*lx\n",
+	       cause_excode_text(regs->cp0_cause),
+	       field, regs->cp0_epc, field, regs->regs[31]);
+}
+
+static int check_microtlb(u32 hi, u32 lo, unsigned long vaddr)
+{
+	/* This is likely rather similar to correct code ;-) */
+
+	vaddr &= 0x7fffffff; /* Doc. states that top bit is ignored */
+
+	/* If tlb-entry is valid and VPN-high (bits [30:21] ?) matches... */
+	if ((lo & 2) && (vaddr >> 21) == ((hi<<1) >> 22)) {
+		u32 ctl = sgimc->dma_ctrl;
+		if (ctl & 1) {
+			unsigned int pgsz = (ctl & 2) ? 14:12; /* 16k:4k */
+			/* PTEIndex is VPN-low (bits [22:14]/[20:12] ?) */
+			unsigned long pte = (lo >> 6) << 12; /* PTEBase */
+			pte += 8*((vaddr >> pgsz) & 0x1ff);
+			if (page_is_ram(PFN_DOWN(pte))) {
+				/*
+				 * Note: Since DMA hardware does look up
+				 * translation on its own, this PTE *must*
+				 * match the TLB/EntryLo-register format !
+				 */
+				unsigned long a = *(unsigned long *)
+						PHYS_TO_XKSEG_UNCACHED(pte);
+				a = (a & 0x3f) << 6; /* PFN */
+				a += vaddr & ((1 << pgsz) - 1);
+				return cpu_err_addr == a;
+			}
+		}
+	}
+	return 0;
+}
+
+static int check_vdma_memaddr(void)
+{
+	if (cpu_err_stat & CPU_ERRMASK) {
+		u32 a = sgimc->maddronly;
+
+		if (!(sgimc->dma_ctrl & 0x100)) /* Xlate-bit clear ? */
+			return cpu_err_addr == a;
+
+		if (check_microtlb(sgimc->dtlb_hi0, sgimc->dtlb_lo0, a) ||
+		    check_microtlb(sgimc->dtlb_hi1, sgimc->dtlb_lo1, a) ||
+		    check_microtlb(sgimc->dtlb_hi2, sgimc->dtlb_lo2, a) ||
+		    check_microtlb(sgimc->dtlb_hi3, sgimc->dtlb_lo3, a))
+			return 1;
+	}
+	return 0;
+}
+
+static int check_vdma_gioaddr(void)
+{
+	if (gio_err_stat & GIO_ERRMASK) {
+		u32 a = sgimc->gio_dma_trans;
+		a = (sgimc->gmaddronly & ~a) | (sgimc->gio_dma_sbits & a);
+		return gio_err_addr == a;
+	}
+	return 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.
+ */
+
+static int ip28_be_interrupt(const struct pt_regs *regs)
+{
+	int i;
+
+	save_and_clear_buserr();
+	/*
+	 * Try to find out, whether we got here by a mispredicted speculative
+	 * load/store operation.  If so, it's not fatal, we can go on.
+	 */
+	/* Any cause other than "Interrupt" (ExcCode 0) is fatal. */
+	if (regs->cp0_cause & CAUSEF_EXCCODE)
+		goto mips_be_fatal;
+
+	/* Any cause other than "Bus error interrupt" (IP6) is weird. */
+	if ((regs->cp0_cause & CAUSEF_IP6) != CAUSEF_IP6)
+		goto mips_be_fatal;
+
+	if (extio_stat & (EXTIO_HPC3_BUSERR | EXTIO_EISA_BUSERR))
+		goto mips_be_fatal;
+
+	/* Any state other than "Memory bus error" is fatal. */
+	if (cpu_err_stat & CPU_ERRMASK & ~SGIMC_CSTAT_ADDR)
+		goto mips_be_fatal;
+
+	/* GIO errors other than timeouts are fatal */
+	if (gio_err_stat & GIO_ERRMASK & ~SGIMC_GSTAT_TIME)
+		goto mips_be_fatal;
+
+	/*
+	 * Now we have an asynchronous bus error, speculatively or DMA caused.
+	 * Need to search all DMA descriptors for the error address.
+	 */
+	for (i = 0; i < sizeof(hpc3)/sizeof(struct hpc3_stat); ++i) {
+		struct hpc3_stat *hp = (struct hpc3_stat *)&hpc3 + i;
+		if ((cpu_err_stat & CPU_ERRMASK) &&
+		    (cpu_err_addr == hp->ndptr || cpu_err_addr == hp->cbp))
+			break;
+		if ((gio_err_stat & GIO_ERRMASK) &&
+		    (gio_err_addr == hp->ndptr || gio_err_addr == hp->cbp))
+			break;
+	}
+	if (i < sizeof(hpc3)/sizeof(struct hpc3_stat)) {
+		struct hpc3_stat *hp = (struct hpc3_stat *)&hpc3 + i;
+		printk(KERN_ERR "at DMA addresses: HPC3 @ %08lx:"
+		       " ctl %08x, ndp %08x, cbp %08x\n",
+		       CPHYSADDR(hp->addr), hp->ctrl, hp->ndptr, hp->cbp);
+		goto mips_be_fatal;
+	}
+	/* Check MC's virtual DMA stuff. */
+	if (check_vdma_memaddr()) {
+		printk(KERN_ERR "at GIO DMA: mem address 0x%08x.\n",
+			sgimc->maddronly);
+		goto mips_be_fatal;
+	}
+	if (check_vdma_gioaddr()) {
+		printk(KERN_ERR "at GIO DMA: gio address 0x%08x.\n",
+			sgimc->gmaddronly);
+		goto mips_be_fatal;
+	}
+	/* A speculative bus error... */
+	if (debug_be_interrupt) {
+		print_buserr(regs);
+		printk(KERN_ERR "discarded!\n");
+	}
+	return MIPS_BE_DISCARD;
+
+mips_be_fatal:
+	print_buserr(regs);
+	return MIPS_BE_FATAL;
+}
+
+void ip22_be_interrupt(int irq)
+{
+	struct pt_regs *regs = get_irq_regs();
+
+	count_be_interrupt++;
+
+	if (ip28_be_interrupt(regs) != MIPS_BE_DISCARD) {
+		/* Assume it would be too dangerous to continue ... */
+		die_if_kernel("Oops", regs);
+		force_sig(SIGBUS);
+	} else if (debug_be_interrupt)
+		show_regs(regs);
+}
+
+static int ip28_be_handler(struct pt_regs *regs, int is_fixup)
+{
+	/*
+	 * We arrive here only in the unusual case of do_be() invocation,
+	 * i.e. by a bus error exception without a bus error interrupt.
+	 */
+	if (is_fixup) {
+		count_be_is_fixup++;
+		save_and_clear_buserr();
+		return MIPS_BE_FIXUP;
+	}
+	count_be_handler++;
+	return ip28_be_interrupt(regs);
+}
+
+void __init ip22_be_init(void)
+{
+	mips_set_be_handler(ip28_be_handler);
+}
+
+int ip28_show_be_info(struct seq_file *m)
+{
+	seq_printf(m, "IP28 be fixups\t\t: %u\n", count_be_is_fixup);
+	seq_printf(m, "IP28 be interrupts\t: %u\n", count_be_interrupt);
+	seq_printf(m, "IP28 be handler\t\t: %u\n", count_be_handler);
+
+	return 0;
+}
+
+static int __init debug_be_setup(char *str)
+{
+	debug_be_interrupt++;
+	return 1;
+}
+__setup("ip28_debug_be", debug_be_setup);