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 4033d8dc745b..55ff016e9f69 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 3e947208b9d9..3e58b676d23b 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 9f5002e0b35c..a5383ae2cbe3 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 8b6b1e05c306..3b25e49380c6 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 86fc2d624270..987b6fde3a99 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 000000000000..e94bdb6add1d
--- /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);
+}