Merge branch 'x86/generalize-visws' into x86/core

6 files changed, 741 insertions, 3 deletions

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 4033d8dc745..55ff016e9f6 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -19,6 +19,7 @@ obj-y			:= process_$(BITS).o signal_$(BITS).o entry_$(BITS).o
 obj-y			+= traps_$(BITS).o irq_$(BITS).o
 obj-y			+= time_$(BITS).o ioport.o ldt.o
 obj-y			+= setup.o i8259.o irqinit_$(BITS).o setup_percpu.o
+obj-$(CONFIG_X86_VISWS)	+= visws_quirks.o
 obj-$(CONFIG_X86_32)	+= probe_roms_32.o
 obj-$(CONFIG_X86_32)	+= sys_i386_32.o i386_ksyms_32.o
 obj-$(CONFIG_X86_64)	+= sys_x86_64.o x8664_ksyms_64.o
diff --git a/arch/x86/kernel/apic_32.c b/arch/x86/kernel/apic_32.c
index 3e947208b9d..3e58b676d23 100644
--- a/arch/x86/kernel/apic_32.c
+++ b/arch/x86/kernel/apic_32.c
@@ -974,7 +974,7 @@ void __cpuinit setup_local_APIC(void)
 	 * Double-check whether this APIC is really registered.
 	 */
 	if (!apic_id_registered())
-		BUG();
+		WARN_ON_ONCE(1);
 
 	/*
 	 * Intel recommends to set DFR, LDR and TPR before enabling
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 9f5002e0b35..a5383ae2cbe 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -1313,6 +1313,11 @@ void __init e820_reserve_resources(void)
 	}
 }
 
+/*
+ * Non-standard memory setup can be specified via this quirk:
+ */
+char * (*arch_memory_setup_quirk)(void);
+
 char *__init default_machine_specific_memory_setup(void)
 {
 	char *who = "BIOS-e820";
@@ -1353,6 +1358,12 @@ char *__init default_machine_specific_memory_setup(void)
 
 char *__init __attribute__((weak)) machine_specific_memory_setup(void)
 {
+	if (arch_memory_setup_quirk) {
+		char *who = arch_memory_setup_quirk();
+
+		if (who)
+			return who;
+	}
 	return default_machine_specific_memory_setup();
 }
 
diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
index 8b6b1e05c30..3b25e49380c 100644
--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -726,12 +726,22 @@ static inline void __init construct_default_ISA_mptable(int mpc_default_type)
 static struct intel_mp_floating *mpf_found;
 
 /*
+ * Machine specific quirk for finding the SMP config before other setup
+ * activities destroy the table:
+ */
+int (*mach_get_smp_config_quirk)(unsigned int early);
+
+/*
  * Scan the memory blocks for an SMP configuration block.
  */
-static void __init __get_smp_config(unsigned early)
+static void __init __get_smp_config(unsigned int early)
 {
 	struct intel_mp_floating *mpf = mpf_found;
 
+	if (mach_get_smp_config_quirk) {
+		if (mach_get_smp_config_quirk(early))
+			return;
+	}
 	if (acpi_lapic && early)
 		return;
 	/*
@@ -889,10 +899,16 @@ static int __init smp_scan_config(unsigned long base, unsigned long length,
 	return 0;
 }
 
-static void __init __find_smp_config(unsigned reserve)
+int (*mach_find_smp_config_quirk)(unsigned int reserve);
+
+static void __init __find_smp_config(unsigned int reserve)
 {
 	unsigned int address;
 
+	if (mach_find_smp_config_quirk) {
+		if (mach_find_smp_config_quirk(reserve))
+			return;
+	}
 	/*
 	 * FIXME: Linux assumes you have 640K of base ram..
 	 * this continues the error...
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 86fc2d62427..987b6fde3a9 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -596,6 +596,7 @@ void __init setup_arch(char **cmdline_p)
 {
 #ifdef CONFIG_X86_32
 	memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
+	visws_early_detect();
 	pre_setup_arch_hook();
 	early_cpu_init();
 #else
diff --git a/arch/x86/kernel/visws_quirks.c b/arch/x86/kernel/visws_quirks.c
new file mode 100644
index 00000000000..e94bdb6add1
--- /dev/null
+++ b/arch/x86/kernel/visws_quirks.c
@@ -0,0 +1,709 @@
+/*
+ *  SGI Visual Workstation support and quirks, unmaintained.
+ *
+ *  Split out from setup.c by davej@suse.de
+ *
+ *	Copyright (C) 1999 Bent Hagemark, Ingo Molnar
+ *
+ *  SGI Visual Workstation interrupt controller
+ *
+ *  The Cobalt system ASIC in the Visual Workstation contains a "Cobalt" APIC
+ *  which serves as the main interrupt controller in the system.  Non-legacy
+ *  hardware in the system uses this controller directly.  Legacy devices
+ *  are connected to the PIIX4 which in turn has its 8259(s) connected to
+ *  a of the Cobalt APIC entry.
+ *
+ *  09/02/2000 - Updated for 2.4 by jbarnes@sgi.com
+ *
+ *  25/11/2002 - Updated for 2.5 by Andrey Panin <pazke@orbita1.ru>
+ */
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+
+#include <asm/visws/cobalt.h>
+#include <asm/visws/piix4.h>
+#include <asm/arch_hooks.h>
+#include <asm/fixmap.h>
+#include <asm/reboot.h>
+#include <asm/setup.h>
+#include <asm/e820.h>
+#include <asm/smp.h>
+#include <asm/io.h>
+
+#include <mach_ipi.h>
+
+#include "mach_apic.h"
+
+#include <linux/init.h>
+#include <linux/smp.h>
+
+#include <linux/kernel_stat.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+
+#include <asm/io.h>
+#include <asm/apic.h>
+#include <asm/i8259.h>
+#include <asm/irq_vectors.h>
+#include <asm/visws/cobalt.h>
+#include <asm/visws/lithium.h>
+#include <asm/visws/piix4.h>
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/pci_ids.h>
+
+extern int no_broadcast;
+
+#include <asm/io.h>
+#include <asm/apic.h>
+#include <asm/arch_hooks.h>
+#include <asm/visws/cobalt.h>
+#include <asm/visws/lithium.h>
+
+char visws_board_type	= -1;
+char visws_board_rev	= -1;
+
+int is_visws_box(void)
+{
+	return visws_board_type >= 0;
+}
+
+static int __init visws_time_init_quirk(void)
+{
+	printk(KERN_INFO "Starting Cobalt Timer system clock\n");
+
+	/* Set the countdown value */
+	co_cpu_write(CO_CPU_TIMEVAL, CO_TIME_HZ/HZ);
+
+	/* Start the timer */
+	co_cpu_write(CO_CPU_CTRL, co_cpu_read(CO_CPU_CTRL) | CO_CTRL_TIMERUN);
+
+	/* Enable (unmask) the timer interrupt */
+	co_cpu_write(CO_CPU_CTRL, co_cpu_read(CO_CPU_CTRL) & ~CO_CTRL_TIMEMASK);
+
+	/*
+	 * Zero return means the generic timer setup code will set up
+	 * the standard vector:
+	 */
+	return 0;
+}
+
+static int __init visws_pre_intr_init_quirk(void)
+{
+	init_VISWS_APIC_irqs();
+
+	/*
+	 * We dont want ISA irqs to be set up by the generic code:
+	 */
+	return 1;
+}
+
+/* Quirk for machine specific memory setup. */
+
+#define MB (1024 * 1024)
+
+unsigned long sgivwfb_mem_phys;
+unsigned long sgivwfb_mem_size;
+EXPORT_SYMBOL(sgivwfb_mem_phys);
+EXPORT_SYMBOL(sgivwfb_mem_size);
+
+long long mem_size __initdata = 0;
+
+static char * __init visws_memory_setup_quirk(void)
+{
+	long long gfx_mem_size = 8 * MB;
+
+	mem_size = boot_params.alt_mem_k;
+
+	if (!mem_size) {
+		printk(KERN_WARNING "Bootloader didn't set memory size, upgrade it !\n");
+		mem_size = 128 * MB;
+	}
+
+	/*
+	 * this hardcodes the graphics memory to 8 MB
+	 * it really should be sized dynamically (or at least
+	 * set as a boot param)
+	 */
+	if (!sgivwfb_mem_size) {
+		printk(KERN_WARNING "Defaulting to 8 MB framebuffer size\n");
+		sgivwfb_mem_size = 8 * MB;
+	}
+
+	/*
+	 * Trim to nearest MB
+	 */
+	sgivwfb_mem_size &= ~((1 << 20) - 1);
+	sgivwfb_mem_phys = mem_size - gfx_mem_size;
+
+	e820_add_region(0, LOWMEMSIZE(), E820_RAM);
+	e820_add_region(HIGH_MEMORY, mem_size - sgivwfb_mem_size - HIGH_MEMORY, E820_RAM);
+	e820_add_region(sgivwfb_mem_phys, sgivwfb_mem_size, E820_RESERVED);
+
+	return "PROM";
+}
+
+static void visws_machine_emergency_restart(void)
+{
+	/*
+	 * Visual Workstations restart after this
+	 * register is poked on the PIIX4
+	 */
+	outb(PIIX4_RESET_VAL, PIIX4_RESET_PORT);
+}
+
+static void visws_machine_power_off(void)
+{
+	unsigned short pm_status;
+/*	extern unsigned int pci_bus0; */
+
+	while ((pm_status = inw(PMSTS_PORT)) & 0x100)
+		outw(pm_status, PMSTS_PORT);
+
+	outw(PM_SUSPEND_ENABLE, PMCNTRL_PORT);
+
+	mdelay(10);
+
+#define PCI_CONF1_ADDRESS(bus, devfn, reg) \
+	(0x80000000 | (bus << 16) | (devfn << 8) | (reg & ~3))
+
+/*	outl(PCI_CONF1_ADDRESS(pci_bus0, SPECIAL_DEV, SPECIAL_REG), 0xCF8); */
+	outl(PIIX_SPECIAL_STOP, 0xCFC);
+}
+
+static int __init visws_get_smp_config_quirk(unsigned int early)
+{
+	/*
+	 * Prevent MP-table parsing by the generic code:
+	 */
+	return 1;
+}
+
+extern unsigned int __cpuinitdata maxcpus;
+
+/*
+ * The Visual Workstation is Intel MP compliant in the hardware
+ * sense, but it doesn't have a BIOS(-configuration table).
+ * No problem for Linux.
+ */
+
+static void __init MP_processor_info (struct mpc_config_processor *m)
+{
+	int ver, logical_apicid;
+	physid_mask_t apic_cpus;
+
+	if (!(m->mpc_cpuflag & CPU_ENABLED))
+		return;
+
+	logical_apicid = m->mpc_apicid;
+	printk(KERN_INFO "%sCPU #%d %u:%u APIC version %d\n",
+	       m->mpc_cpuflag & CPU_BOOTPROCESSOR ? "Bootup " : "",
+	       m->mpc_apicid,
+	       (m->mpc_cpufeature & CPU_FAMILY_MASK) >> 8,
+	       (m->mpc_cpufeature & CPU_MODEL_MASK) >> 4,
+	       m->mpc_apicver);
+
+	if (m->mpc_cpuflag & CPU_BOOTPROCESSOR)
+		boot_cpu_physical_apicid = m->mpc_apicid;
+
+	ver = m->mpc_apicver;
+	if ((ver >= 0x14 && m->mpc_apicid >= 0xff) || m->mpc_apicid >= 0xf) {
+		printk(KERN_ERR "Processor #%d INVALID. (Max ID: %d).\n",
+			m->mpc_apicid, MAX_APICS);
+		return;
+	}
+
+	apic_cpus = apicid_to_cpu_present(m->mpc_apicid);
+	physids_or(phys_cpu_present_map, phys_cpu_present_map, apic_cpus);
+	/*
+	 * Validate version
+	 */
+	if (ver == 0x0) {
+		printk(KERN_ERR "BIOS bug, APIC version is 0 for CPU#%d! "
+			"fixing up to 0x10. (tell your hw vendor)\n",
+			m->mpc_apicid);
+		ver = 0x10;
+	}
+	apic_version[m->mpc_apicid] = ver;
+}
+
+int __init visws_find_smp_config_quirk(unsigned int reserve)
+{
+	struct mpc_config_processor *mp = phys_to_virt(CO_CPU_TAB_PHYS);
+	unsigned short ncpus = readw(phys_to_virt(CO_CPU_NUM_PHYS));
+
+	if (ncpus > CO_CPU_MAX) {
+		printk(KERN_WARNING "find_visws_smp: got cpu count of %d at %p\n",
+			ncpus, mp);
+
+		ncpus = CO_CPU_MAX;
+	}
+
+	if (ncpus > maxcpus)
+		ncpus = maxcpus;
+
+#ifdef CONFIG_X86_LOCAL_APIC
+	smp_found_config = 1;
+#endif
+	while (ncpus--)
+		MP_processor_info(mp++);
+
+	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
+
+	return 1;
+}
+
+extern int visws_trap_init_quirk(void);
+
+void __init visws_early_detect(void)
+{
+	int raw;
+
+	visws_board_type = (char)(inb_p(PIIX_GPI_BD_REG) & PIIX_GPI_BD_REG)
+							 >> PIIX_GPI_BD_SHIFT;
+
+	if (visws_board_type < 0)
+		return;
+
+	/*
+	 * Install special quirks for timer, interrupt and memory setup:
+	 */
+	arch_time_init_quirk		= visws_time_init_quirk;
+	arch_pre_intr_init_quirk	= visws_pre_intr_init_quirk;
+	arch_memory_setup_quirk		= visws_memory_setup_quirk;
+
+	/*
+	 * Fall back to generic behavior for traps:
+	 */
+	arch_intr_init_quirk		= NULL;
+	arch_trap_init_quirk		= visws_trap_init_quirk;
+
+	/*
+	 * Install reboot quirks:
+	 */
+	pm_power_off			= visws_machine_power_off;
+	machine_ops.emergency_restart	= visws_machine_emergency_restart;
+
+	/*
+	 * Do not use broadcast IPIs:
+	 */
+	no_broadcast = 0;
+
+	/*
+	 * Override generic MP-table parsing:
+	 */
+	mach_get_smp_config_quirk	= visws_get_smp_config_quirk;
+	mach_find_smp_config_quirk	= visws_find_smp_config_quirk;
+
+#ifdef CONFIG_X86_IO_APIC
+	/*
+	 * Turn off IO-APIC detection and initialization:
+	 */
+	skip_ioapic_setup		= 1;
+#endif
+
+	/*
+	 * Get Board rev.
+	 * First, we have to initialize the 307 part to allow us access
+	 * to the GPIO registers.  Let's map them at 0x0fc0 which is right
+	 * after the PIIX4 PM section.
+	 */
+	outb_p(SIO_DEV_SEL, SIO_INDEX);
+	outb_p(SIO_GP_DEV, SIO_DATA);	/* Talk to GPIO regs. */
+
+	outb_p(SIO_DEV_MSB, SIO_INDEX);
+	outb_p(SIO_GP_MSB, SIO_DATA);	/* MSB of GPIO base address */
+
+	outb_p(SIO_DEV_LSB, SIO_INDEX);
+	outb_p(SIO_GP_LSB, SIO_DATA);	/* LSB of GPIO base address */
+
+	outb_p(SIO_DEV_ENB, SIO_INDEX);
+	outb_p(1, SIO_DATA);		/* Enable GPIO registers. */
+
+	/*
+	 * Now, we have to map the power management section to write
+	 * a bit which enables access to the GPIO registers.
+	 * What lunatic came up with this shit?
+	 */
+	outb_p(SIO_DEV_SEL, SIO_INDEX);
+	outb_p(SIO_PM_DEV, SIO_DATA);	/* Talk to GPIO regs. */
+
+	outb_p(SIO_DEV_MSB, SIO_INDEX);
+	outb_p(SIO_PM_MSB, SIO_DATA);	/* MSB of PM base address */
+
+	outb_p(SIO_DEV_LSB, SIO_INDEX);
+	outb_p(SIO_PM_LSB, SIO_DATA);	/* LSB of PM base address */
+
+	outb_p(SIO_DEV_ENB, SIO_INDEX);
+	outb_p(1, SIO_DATA);		/* Enable PM registers. */
+
+	/*
+	 * Now, write the PM register which enables the GPIO registers.
+	 */
+	outb_p(SIO_PM_FER2, SIO_PM_INDEX);
+	outb_p(SIO_PM_GP_EN, SIO_PM_DATA);
+
+	/*
+	 * Now, initialize the GPIO registers.
+	 * We want them all to be inputs which is the
+	 * power on default, so let's leave them alone.
+	 * So, let's just read the board rev!
+	 */
+	raw = inb_p(SIO_GP_DATA1);
+	raw &= 0x7f;	/* 7 bits of valid board revision ID. */
+
+	if (visws_board_type == VISWS_320) {
+		if (raw < 0x6) {
+			visws_board_rev = 4;
+		} else if (raw < 0xc) {
+			visws_board_rev = 5;
+		} else {
+			visws_board_rev = 6;
+		}
+	} else if (visws_board_type == VISWS_540) {
+			visws_board_rev = 2;
+		} else {
+			visws_board_rev = raw;
+		}
+
+	printk(KERN_INFO "Silicon Graphics Visual Workstation %s (rev %d) detected\n",
+	       (visws_board_type == VISWS_320 ? "320" :
+	       (visws_board_type == VISWS_540 ? "540" :
+		"unknown")), visws_board_rev);
+}
+
+#define A01234 (LI_INTA_0 | LI_INTA_1 | LI_INTA_2 | LI_INTA_3 | LI_INTA_4)
+#define BCD (LI_INTB | LI_INTC | LI_INTD)
+#define ALLDEVS (A01234 | BCD)
+
+static __init void lithium_init(void)
+{
+	set_fixmap(FIX_LI_PCIA, LI_PCI_A_PHYS);
+	set_fixmap(FIX_LI_PCIB, LI_PCI_B_PHYS);
+
+	if ((li_pcia_read16(PCI_VENDOR_ID) != PCI_VENDOR_ID_SGI) ||
+	    (li_pcia_read16(PCI_DEVICE_ID) != PCI_DEVICE_ID_SGI_LITHIUM)) {
+		printk(KERN_EMERG "Lithium hostbridge %c not found\n", 'A');
+/*		panic("This machine is not SGI Visual Workstation 320/540"); */
+	}
+
+	if ((li_pcib_read16(PCI_VENDOR_ID) != PCI_VENDOR_ID_SGI) ||
+	    (li_pcib_read16(PCI_DEVICE_ID) != PCI_DEVICE_ID_SGI_LITHIUM)) {
+		printk(KERN_EMERG "Lithium hostbridge %c not found\n", 'B');
+/*		panic("This machine is not SGI Visual Workstation 320/540"); */
+	}
+
+	li_pcia_write16(LI_PCI_INTEN, ALLDEVS);
+	li_pcib_write16(LI_PCI_INTEN, ALLDEVS);
+}
+
+static __init void cobalt_init(void)
+{
+	/*
+	 * On normal SMP PC this is used only with SMP, but we have to
+	 * use it and set it up here to start the Cobalt clock
+	 */
+	set_fixmap(FIX_APIC_BASE, APIC_DEFAULT_PHYS_BASE);
+	setup_local_APIC();
+	printk(KERN_INFO "Local APIC Version %#x, ID %#x\n",
+		(unsigned int)apic_read(APIC_LVR),
+		(unsigned int)apic_read(APIC_ID));
+
+	set_fixmap(FIX_CO_CPU, CO_CPU_PHYS);
+	set_fixmap(FIX_CO_APIC, CO_APIC_PHYS);
+	printk(KERN_INFO "Cobalt Revision %#lx, APIC ID %#lx\n",
+		co_cpu_read(CO_CPU_REV), co_apic_read(CO_APIC_ID));
+
+	/* Enable Cobalt APIC being careful to NOT change the ID! */
+	co_apic_write(CO_APIC_ID, co_apic_read(CO_APIC_ID) | CO_APIC_ENABLE);
+
+	printk(KERN_INFO "Cobalt APIC enabled: ID reg %#lx\n",
+		co_apic_read(CO_APIC_ID));
+}
+
+int __init visws_trap_init_quirk(void)
+{
+	lithium_init();
+	cobalt_init();
+
+	return 1;
+}
+
+/*
+ * IRQ controller / APIC support:
+ */
+
+static DEFINE_SPINLOCK(cobalt_lock);
+
+/*
+ * Set the given Cobalt APIC Redirection Table entry to point
+ * to the given IDT vector/index.
+ */
+static inline void co_apic_set(int entry, int irq)
+{
+	co_apic_write(CO_APIC_LO(entry), CO_APIC_LEVEL | (irq + FIRST_EXTERNAL_VECTOR));
+	co_apic_write(CO_APIC_HI(entry), 0);
+}
+
+/*
+ * Cobalt (IO)-APIC functions to handle PCI devices.
+ */
+static inline int co_apic_ide0_hack(void)
+{
+	extern char visws_board_type;
+	extern char visws_board_rev;
+
+	if (visws_board_type == VISWS_320 && visws_board_rev == 5)
+		return 5;
+	return CO_APIC_IDE0;
+}
+
+static int is_co_apic(unsigned int irq)
+{
+	if (IS_CO_APIC(irq))
+		return CO_APIC(irq);
+
+	switch (irq) {
+		case 0: return CO_APIC_CPU;
+		case CO_IRQ_IDE0: return co_apic_ide0_hack();
+		case CO_IRQ_IDE1: return CO_APIC_IDE1;
+		default: return -1;
+	}
+}
+
+
+/*
+ * This is the SGI Cobalt (IO-)APIC:
+ */
+
+static void enable_cobalt_irq(unsigned int irq)
+{
+	co_apic_set(is_co_apic(irq), irq);
+}
+
+static void disable_cobalt_irq(unsigned int irq)
+{
+	int entry = is_co_apic(irq);
+
+	co_apic_write(CO_APIC_LO(entry), CO_APIC_MASK);
+	co_apic_read(CO_APIC_LO(entry));
+}
+
+/*
+ * "irq" really just serves to identify the device.  Here is where we
+ * map this to the Cobalt APIC entry where it's physically wired.
+ * This is called via request_irq -> setup_irq -> irq_desc->startup()
+ */
+static unsigned int startup_cobalt_irq(unsigned int irq)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&cobalt_lock, flags);
+	if ((irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS | IRQ_WAITING)))
+		irq_desc[irq].status &= ~(IRQ_DISABLED | IRQ_INPROGRESS | IRQ_WAITING);
+	enable_cobalt_irq(irq);
+	spin_unlock_irqrestore(&cobalt_lock, flags);
+	return 0;
+}
+
+static void ack_cobalt_irq(unsigned int irq)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&cobalt_lock, flags);
+	disable_cobalt_irq(irq);
+	apic_write(APIC_EOI, APIC_EIO_ACK);
+	spin_unlock_irqrestore(&cobalt_lock, flags);
+}
+
+static void end_cobalt_irq(unsigned int irq)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&cobalt_lock, flags);
+	if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS)))
+		enable_cobalt_irq(irq);
+	spin_unlock_irqrestore(&cobalt_lock, flags);
+}
+
+static struct irq_chip cobalt_irq_type = {
+	.typename =	"Cobalt-APIC",
+	.startup =	startup_cobalt_irq,
+	.shutdown =	disable_cobalt_irq,
+	.enable =	enable_cobalt_irq,
+	.disable =	disable_cobalt_irq,
+	.ack =		ack_cobalt_irq,
+	.end =		end_cobalt_irq,
+};
+
+
+/*
+ * This is the PIIX4-based 8259 that is wired up indirectly to Cobalt
+ * -- not the manner expected by the code in i8259.c.
+ *
+ * there is a 'master' physical interrupt source that gets sent to
+ * the CPU. But in the chipset there are various 'virtual' interrupts
+ * waiting to be handled. We represent this to Linux through a 'master'
+ * interrupt controller type, and through a special virtual interrupt-
+ * controller. Device drivers only see the virtual interrupt sources.
+ */
+static unsigned int startup_piix4_master_irq(unsigned int irq)
+{
+	init_8259A(0);
+
+	return startup_cobalt_irq(irq);
+}
+
+static void end_piix4_master_irq(unsigned int irq)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&cobalt_lock, flags);
+	enable_cobalt_irq(irq);
+	spin_unlock_irqrestore(&cobalt_lock, flags);
+}
+
+static struct irq_chip piix4_master_irq_type = {
+	.typename =	"PIIX4-master",
+	.startup =	startup_piix4_master_irq,
+	.ack =		ack_cobalt_irq,
+	.end =		end_piix4_master_irq,
+};
+
+
+static struct irq_chip piix4_virtual_irq_type = {
+	.typename =	"PIIX4-virtual",
+	.shutdown =	disable_8259A_irq,
+	.enable =	enable_8259A_irq,
+	.disable =	disable_8259A_irq,
+};
+
+
+/*
+ * PIIX4-8259 master/virtual functions to handle interrupt requests
+ * from legacy devices: floppy, parallel, serial, rtc.
+ *
+ * None of these get Cobalt APIC entries, neither do they have IDT
+ * entries. These interrupts are purely virtual and distributed from
+ * the 'master' interrupt source: CO_IRQ_8259.
+ *
+ * When the 8259 interrupts its handler figures out which of these
+ * devices is interrupting and dispatches to its handler.
+ *
+ * CAREFUL: devices see the 'virtual' interrupt only. Thus disable/
+ * enable_irq gets the right irq. This 'master' irq is never directly
+ * manipulated by any driver.
+ */
+static irqreturn_t piix4_master_intr(int irq, void *dev_id)
+{
+	int realirq;
+	irq_desc_t *desc;
+	unsigned long flags;
+
+	spin_lock_irqsave(&i8259A_lock, flags);
+
+	/* Find out what's interrupting in the PIIX4 master 8259 */
+	outb(0x0c, 0x20);		/* OCW3 Poll command */
+	realirq = inb(0x20);
+
+	/*
+	 * Bit 7 == 0 means invalid/spurious
+	 */
+	if (unlikely(!(realirq & 0x80)))
+		goto out_unlock;
+
+	realirq &= 7;
+
+	if (unlikely(realirq == 2)) {
+		outb(0x0c, 0xa0);
+		realirq = inb(0xa0);
+
+		if (unlikely(!(realirq & 0x80)))
+			goto out_unlock;
+
+		realirq = (realirq & 7) + 8;
+	}
+
+	/* mask and ack interrupt */
+	cached_irq_mask |= 1 << realirq;
+	if (unlikely(realirq > 7)) {
+		inb(0xa1);
+		outb(cached_slave_mask, 0xa1);
+		outb(0x60 + (realirq & 7), 0xa0);
+		outb(0x60 + 2, 0x20);
+	} else {
+		inb(0x21);
+		outb(cached_master_mask, 0x21);
+		outb(0x60 + realirq, 0x20);
+	}
+
+	spin_unlock_irqrestore(&i8259A_lock, flags);
+
+	desc = irq_desc + realirq;
+
+	/*
+	 * handle this 'virtual interrupt' as a Cobalt one now.
+	 */
+	kstat_cpu(smp_processor_id()).irqs[realirq]++;
+
+	if (likely(desc->action != NULL))
+		handle_IRQ_event(realirq, desc->action);
+
+	if (!(desc->status & IRQ_DISABLED))
+		enable_8259A_irq(realirq);
+
+	return IRQ_HANDLED;
+
+out_unlock:
+	spin_unlock_irqrestore(&i8259A_lock, flags);
+	return IRQ_NONE;
+}
+
+static struct irqaction master_action = {
+	.handler =	piix4_master_intr,
+	.name =		"PIIX4-8259",
+};
+
+static struct irqaction cascade_action = {
+	.handler = 	no_action,
+	.name =		"cascade",
+};
+
+
+void init_VISWS_APIC_irqs(void)
+{
+	int i;
+
+	for (i = 0; i < CO_IRQ_APIC0 + CO_APIC_LAST + 1; i++) {
+		irq_desc[i].status = IRQ_DISABLED;
+		irq_desc[i].action = 0;
+		irq_desc[i].depth = 1;
+
+		if (i == 0) {
+			irq_desc[i].chip = &cobalt_irq_type;
+		}
+		else if (i == CO_IRQ_IDE0) {
+			irq_desc[i].chip = &cobalt_irq_type;
+		}
+		else if (i == CO_IRQ_IDE1) {
+			irq_desc[i].chip = &cobalt_irq_type;
+		}
+		else if (i == CO_IRQ_8259) {
+			irq_desc[i].chip = &piix4_master_irq_type;
+		}
+		else if (i < CO_IRQ_APIC0) {
+			irq_desc[i].chip = &piix4_virtual_irq_type;
+		}
+		else if (IS_CO_APIC(i)) {
+			irq_desc[i].chip = &cobalt_irq_type;
+		}
+	}
+
+	setup_irq(CO_IRQ_8259, &master_action);
+	setup_irq(2, &cascade_action);
+}