/*
 *  Written by Martin Kolinek, February 1996
 *
 * Changes:
 *
 *      Chris Beauregard July 28th, 1996
 *      - Fixed up integrated SCSI detection
 *
 *      Chris Beauregard August 3rd, 1996
 *      - Made mca_info local
 *      - Made integrated registers accessible through standard function calls
 *      - Added name field
 *      - More sanity checking
 *
 *      Chris Beauregard August 9th, 1996
 *      - Rewrote /proc/mca
 *
 *      Chris Beauregard January 7th, 1997
 *      - Added basic NMI-processing
 *      - Added more information to mca_info structure
 *
 *      David Weinehall October 12th, 1998
 *      - Made a lot of cleaning up in the source
 *      - Added use of save_flags / restore_flags
 *      - Added the 'driver_loaded' flag in MCA_adapter
 *      - Added an alternative implemention of ZP Gu's mca_find_unused_adapter
 *
 *      David Weinehall March 24th, 1999
 *      - Fixed the output of 'Driver Installed' in /proc/mca/pos
 *      - Made the Integrated Video & SCSI show up even if they have id 0000
 *
 *      Alexander Viro November 9th, 1999
 *      - Switched to regular procfs methods
 *
 *      Alfred Arnold & David Weinehall August 23rd, 2000
 *      - Added support for Planar POS-registers
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/mca.h>
#include <linux/kprobes.h>
#include <asm/system.h>
#include <asm/io.h>
#include <linux/proc_fs.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/ioport.h>
#include <asm/uaccess.h>
#include <linux/init.h>

static unsigned char which_scsi;

int MCA_bus;
EXPORT_SYMBOL(MCA_bus);

/*
 * Motherboard register spinlock. Untested on SMP at the moment, but
 * are there any MCA SMP boxes?
 *
 * Yes - Alan
 */
static DEFINE_SPINLOCK(mca_lock);

/* Build the status info for the adapter */

static void mca_configure_adapter_status(struct mca_device *mca_dev)
{
        mca_dev->status = MCA_ADAPTER_NONE;

        mca_dev->pos_id = mca_dev->pos[0]
                + (mca_dev->pos[1] << 8);

        if (!mca_dev->pos_id && mca_dev->slot < MCA_MAX_SLOT_NR) {

                /*
                 * id = 0x0000 usually indicates hardware failure,
                 * however, ZP Gu (zpg@castle.net> reports that his 9556
                 * has 0x0000 as id and everything still works. There
                 * also seem to be an adapter with id = 0x0000; the
                 * NCR Parallel Bus Memory Card. Until this is confirmed,
                 * however, this code will stay.
                 */

                mca_dev->status = MCA_ADAPTER_ERROR;

                return;
        } else if (mca_dev->pos_id != 0xffff) {

                /*
                 * 0xffff usually indicates that there's no adapter,
                 * however, some integrated adapters may have 0xffff as
                 * their id and still be valid. Examples are on-board
                 * VGA of the 55sx, the integrated SCSI of the 56 & 57,
                 * and possibly also the 95 ULTIMEDIA.
                 */

                mca_dev->status = MCA_ADAPTER_NORMAL;
        }

        if ((mca_dev->pos_id == 0xffff ||
            mca_dev->pos_id == 0x0000) && mca_dev->slot >= MCA_MAX_SLOT_NR) {
                int j;

                for (j = 2; j < 8; j++) {
                        if (mca_dev->pos[j] != 0xff) {
                                mca_dev->status = MCA_ADAPTER_NORMAL;
                                break;
                        }
                }
        }

        if (!(mca_dev->pos[2] & MCA_ENABLED)) {

                /* enabled bit is in POS 2 */

                mca_dev->status = MCA_ADAPTER_DISABLED;
        }
} /* mca_configure_adapter_status */

/*--------------------------------------------------------------------*/

static struct resource mca_standard_resources[] = {
        { .start = 0x60, .end = 0x60, .name = "system control port B (MCA)" },
        { .start = 0x90, .end = 0x90, .name = "arbitration (MCA)" },
        { .start = 0x91, .end = 0x91, .name = "card Select Feedback (MCA)" },
        { .start = 0x92, .end = 0x92, .name = "system Control port A (MCA)" },
        { .start = 0x94, .end = 0x94, .name = "system board setup (MCA)" },
        { .start = 0x96, .end = 0x97, .name = "POS (MCA)" },
        { .start = 0x100, .end = 0x107, .name = "POS (MCA)" }
};

#define MCA_STANDARD_RESOURCES  ARRAY_SIZE(mca_standard_resources)

/*
 *      mca_read_and_store_pos - read the POS registers into a memory buffer
 *      @pos: a char pointer to 8 bytes, contains the POS register value on
 *            successful return
 *
 *      Returns 1 if a card actually exists (i.e. the pos isn't
 *      all 0xff) or 0 otherwise
 */
static int mca_read_and_store_pos(unsigned char *pos)
{
        int j;
        int found = 0;

        for (j = 0; j < 8; j++) {
                pos[j] = inb_p(MCA_POS_REG(j));
                if (pos[j] != 0xff) {
                        /* 0xff all across means no device. 0x00 means
                         * something's broken, but a device is
                         * probably there.  However, if you get 0x00
                         * from a motherboard register it won't matter
                         * what we find.  For the record, on the
                         * 57SLC, the integrated SCSI adapter has
                         * 0xffff for the adapter ID, but nonzero for
                         * other registers.  */

                        found = 1;
                }
        }
        return found;
}

static unsigned char mca_pc_read_pos(struct mca_device *mca_dev, int reg)
{
        unsigned char byte;
        unsigned long flags;

        if (reg < 0 || reg >= 8)
                return 0;

        spin_lock_irqsave(&mca_lock, flags);
        if (mca_dev->pos_register) {
                /* Disable adapter setup, enable motherboard setup */

                outb_p(0, MCA_ADAPTER_SETUP_REG);
                outb_p(mca_dev->pos_register, MCA_MOTHERBOARD_SETUP_REG);

                byte = inb_p(MCA_POS_REG(reg));
                outb_p(0xff, MCA_MOTHERBOARD_SETUP_REG);
        } else {

                /* Make sure motherboard setup is off */

                outb_p(0xff, MCA_MOTHERBOARD_SETUP_REG);

                /* Read the appropriate register */

                outb_p(0x8|(mca_dev->slot & 0xf), MCA_ADAPTER_SETUP_REG);
                byte = inb_p(MCA_POS_REG(reg));
                outb_p(0, MCA_ADAPTER_SETUP_REG);
        }
        spin_unlock_irqrestore(&mca_lock, flags);

        mca_dev->pos[reg] = byte;

        return byte;
}

static void mca_pc_write_pos(struct mca_device *mca_dev, int reg,
                             unsigned char byte)
{
        unsigned long flags;

        if (reg < 0 || reg >= 8)
                return;

        spin_lock_irqsave(&mca_lock, flags);

        /* Make sure motherboard setup is off */

        outb_p(0xff, MCA_MOTHERBOARD_SETUP_REG);

        /* Read in the appropriate register */

        outb_p(0x8|(mca_dev->slot&0xf), MCA_ADAPTER_SETUP_REG);
        outb_p(byte, MCA_POS_REG(reg));
        outb_p(0, MCA_ADAPTER_SETUP_REG);

        spin_unlock_irqrestore(&mca_lock, flags);

        /* Update the global register list, while we have the byte */

        mca_dev->pos[reg] = byte;

}

/* for the primary MCA bus, we have identity transforms */
static int mca_dummy_transform_irq(struct mca_device *mca_dev, int irq)
{
        return irq;
}

static int mca_dummy_transform_ioport(struct mca_device *mca_dev, int port)
{
        return port;
}

static void *mca_dummy_transform_memory(struct mca_device *mca_dev, void *mem)
{
        return mem;
}


static int __init mca_init(void)
{
        unsigned int i, j;
        struct mca_device *mca_dev;
        unsigned char pos[8];
        short mca_builtin_scsi_ports[] = {0xf7, 0xfd, 0x00};
        struct mca_bus *bus;

        /*
         * WARNING: Be careful when making changes here. Putting an adapter
         * and the motherboard simultaneously into setup mode may result in
         * damage to chips (according to The Indispensible PC Hardware Book
         * by Hans-Peter Messmer). Also, we disable system interrupts (so
         * that we are not disturbed in the middle of this).
         */

        /* Make sure the MCA bus is present */

        if (mca_system_init()) {
                printk(KERN_ERR "MCA bus system initialisation failed\n");
                return -ENODEV;
        }

        if (!MCA_bus)
                return -ENODEV;

        printk(KERN_INFO "Micro Channel bus detected.\n");

        /* All MCA systems have at least a primary bus */
        bus = mca_attach_bus(MCA_PRIMARY_BUS);
        if (!bus)
                goto out_nomem;
        bus->default_dma_mask = 0xffffffffLL;
        bus->f.mca_write_pos = mca_pc_write_pos;
        bus->f.mca_read_pos = mca_pc_read_pos;
        bus->f.mca_transform_irq = mca_dummy_transform_irq;
        bus->f.mca_transform_ioport = mca_dummy_transform_ioport;
        bus->f.mca_transform_memory = mca_dummy_transform_memory;

        /* get the motherboard device */
        mca_dev = kzalloc(sizeof(struct mca_device), GFP_KERNEL);
        if (unlikely(!mca_dev))
                goto out_nomem;

        /*
         * We do not expect many MCA interrupts during initialization,
         * but let us be safe:
         */
        spin_lock_irq(&mca_lock);

        /* Make sure adapter setup is off */

        outb_p(0, MCA_ADAPTER_SETUP_REG);

        /* Read motherboard POS registers */

        mca_dev->pos_register = 0x7f;
        outb_p(mca_dev->pos_register, MCA_MOTHERBOARD_SETUP_REG);
        mca_dev->name[0] = 0;
        mca_read_and_store_pos(mca_dev->pos);
        mca_configure_adapter_status(mca_dev);
        /* fake POS and slot for a motherboard */
        mca_dev->pos_id = MCA_MOTHERBOARD_POS;
        mca_dev->slot = MCA_MOTHERBOARD;
        mca_register_device(MCA_PRIMARY_BUS, mca_dev);

        mca_dev = kzalloc(sizeof(struct mca_device), GFP_ATOMIC);
        if (unlikely(!mca_dev))
                goto out_unlock_nomem;

        /* Put motherboard into video setup mode, read integrated video
         * POS registers, and turn motherboard setup off.
         */

        mca_dev->pos_register = 0xdf;
        outb_p(mca_dev->pos_register, MCA_MOTHERBOARD_SETUP_REG);
        mca_dev->name[0] = 0;
        mca_read_and_store_pos(mca_dev->pos);
        mca_configure_adapter_status(mca_dev);
        /* fake POS and slot for the integrated video */
        mca_dev->pos_id = MCA_INTEGVIDEO_POS;
        mca_dev->slot = MCA_INTEGVIDEO;
        mca_register_device(MCA_PRIMARY_BUS, mca_dev);

        /*
         * Put motherboard into scsi setup mode, read integrated scsi
         * POS registers, and turn motherboard setup off.
         *
         * It seems there are two possible SCSI registers. Martin says that
         * for the 56,57, 0xf7 is the one, but fails on the 76.
         * Alfredo (apena@vnet.ibm.com) says
         * 0xfd works on his machine. We'll try both of them. I figure it's
         * a good bet that only one could be valid at a time. This could
         * screw up though if one is used for something else on the other
         * machine.
         */

        for (i = 0; (which_scsi = mca_builtin_scsi_ports[i]) != 0; i++) {
                outb_p(which_scsi, MCA_MOTHERBOARD_SETUP_REG);
                if (mca_read_and_store_pos(pos))
                        break;
        }
        if (which_scsi) {
                /* found a scsi card */
                mca_dev = kzalloc(sizeof(struct mca_device), GFP_ATOMIC);
                if (unlikely(!mca_dev))
                        goto out_unlock_nomem;

                for (j = 0; j < 8; j++)
                        mca_dev->pos[j] = pos[j];

                mca_configure_adapter_status(mca_dev);
                /* fake POS and slot for integrated SCSI controller */
                mca_dev->pos_id = MCA_INTEGSCSI_POS;
                mca_dev->slot = MCA_INTEGSCSI;
                mca_dev->pos_register = which_scsi;
                mca_register_device(MCA_PRIMARY_BUS, mca_dev);
        }

        /* Turn off motherboard setup */

        outb_p(0xff, MCA_MOTHERBOARD_SETUP_REG);

        /*
         * Now loop over MCA slots: put each adapter into setup mode, and
         * read its POS registers. Then put adapter setup off.
         */

        for (i = 0; i < MCA_MAX_SLOT_NR; i++) {
                outb_p(0x8|(i&0xf), MCA_ADAPTER_SETUP_REG);
                if (!mca_read_and_store_pos(pos))
                        continue;

                mca_dev = kzalloc(sizeof(struct mca_device), GFP_ATOMIC);
                if (unlikely(!mca_dev))
                        goto out_unlock_nomem;

                for (j = 0; j < 8; j++)
                        mca_dev->pos[j] = pos[j];

                mca_dev->driver_loaded = 0;
                mca_dev->slot = i;
                mca_dev->pos_register = 0;
                mca_configure_adapter_status(mca_dev);
                mca_register_device(MCA_PRIMARY_BUS, mca_dev);
        }
        outb_p(0, MCA_ADAPTER_SETUP_REG);

        /* Enable interrupts and return memory start */
        spin_unlock_irq(&mca_lock);

        for (i = 0; i < MCA_STANDARD_RESOURCES; i++)
                request_resource(&ioport_resource, mca_standard_resources + i);

        mca_do_proc_init();

        return 0;

 out_unlock_nomem:
        spin_unlock_irq(&mca_lock);
 out_nomem:
        printk(KERN_EMERG "Failed memory allocation in MCA setup!\n");
        return -ENOMEM;
}

subsys_initcall(mca_init);

/*--------------------------------------------------------------------*/

static __kprobes void
mca_handle_nmi_device(struct mca_device *mca_dev, int check_flag)
{
        int slot = mca_dev->slot;

        if (slot == MCA_INTEGSCSI) {
                printk(KERN_CRIT "NMI: caused by MCA integrated SCSI adapter (%s)\n",
                        mca_dev->name);
        } else if (slot == MCA_INTEGVIDEO) {
                printk(KERN_CRIT "NMI: caused by MCA integrated video adapter (%s)\n",
                        mca_dev->name);
        } else if (slot == MCA_MOTHERBOARD) {
                printk(KERN_CRIT "NMI: caused by motherboard (%s)\n",
                        mca_dev->name);
        }

        /* More info available in POS 6 and 7? */

        if (check_flag) {
                unsigned char pos6, pos7;

                pos6 = mca_device_read_pos(mca_dev, 6);
                pos7 = mca_device_read_pos(mca_dev, 7);

                printk(KERN_CRIT "NMI: POS 6 = 0x%x, POS 7 = 0x%x\n", pos6, pos7);
        }

} /* mca_handle_nmi_slot */

/*--------------------------------------------------------------------*/

static int __kprobes mca_handle_nmi_callback(struct device *dev, void *data)
{
        struct mca_device *mca_dev = to_mca_device(dev);
        unsigned char pos5;

        pos5 = mca_device_read_pos(mca_dev, 5);

        if (!(pos5 & 0x80)) {
                /*
                 *  Bit 7 of POS 5 is reset when this adapter has a hardware
                 * error. Bit 7 it reset if there's error information
                 * available in POS 6 and 7.
                 */
                mca_handle_nmi_device(mca_dev, !(pos5 & 0x40));
                return 1;
        }
        return 0;
}

void __kprobes mca_handle_nmi(void)
{
        /*
         *  First try - scan the various adapters and see if a specific
         * adapter was responsible for the error.
         */
        bus_for_each_dev(&mca_bus_type, NULL, NULL, mca_handle_nmi_callback);
}