uvesafb.c

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/*
 * A framebuffer driver for VBE 2.0+ compliant video cards
 *
 * (c) 2007 Michal Januszewski <[email protected]>
 *     Loosely based upon the vesafb driver.
 *
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/skbuff.h>
#include <linux/timer.h>
#include <linux/completion.h>
#include <linux/connector.h>
#include <linux/random.h>
#include <linux/platform_device.h>
#include <linux/limits.h>
#include <linux/fb.h>
#include <linux/io.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <video/edid.h>
#include <video/uvesafb.h>
#ifdef CONFIG_X86
#include <video/vga.h>
#endif
#ifdef CONFIG_MTRR
#include <asm/mtrr.h>
#endif
#include "edid.h"

static struct cb_id uvesafb_cn_id = {
    .idx = CN_IDX_V86D,
    .val = CN_VAL_V86D_UVESAFB
};
static char v86d_path[PATH_MAX] = "/sbin/v86d";
static char v86d_started;   /* has v86d been started by uvesafb? */

static struct fb_fix_screeninfo uvesafb_fix __devinitdata = {
    .id = "VESA VGA",
    .type   = FB_TYPE_PACKED_PIXELS,
    .accel  = FB_ACCEL_NONE,
    .visual = FB_VISUAL_TRUECOLOR,
};

static int mtrr     __devinitdata = 3; /* enable mtrr by default */
static bool blank   = 1;           /* enable blanking by default */
static int ypan     = 1;         /* 0: scroll, 1: ypan, 2: ywrap */
static bool pmi_setpal  __devinitdata = true; /* use PMI for palette changes */
static bool nocrtc  __devinitdata; /* ignore CRTC settings */
static bool noedid  __devinitdata; /* don't try DDC transfers */
static int vram_remap   __devinitdata; /* set amt. of memory to be used */
static int vram_total   __devinitdata; /* set total amount of memory */
static u16 maxclk   __devinitdata; /* maximum pixel clock */
static u16 maxvf    __devinitdata; /* maximum vertical frequency */
static u16 maxhf    __devinitdata; /* maximum horizontal frequency */
static u16 vbemode  __devinitdata; /* force use of a specific VBE mode */
static char *mode_option __devinitdata;
static u8  dac_width    = 6;

static struct uvesafb_ktask *uvfb_tasks[UVESAFB_TASKS_MAX];
static DEFINE_MUTEX(uvfb_lock);

/*
 * A handler for replies from userspace.
 *
 * Make sure each message passes consistency checks and if it does,
 * find the kernel part of the task struct, copy the registers and
 * the buffer contents and then complete the task.
 */
static void uvesafb_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
{
    struct uvesafb_task *utask;
    struct uvesafb_ktask *task;

    if (!capable(CAP_SYS_ADMIN))
        return;

    if (msg->seq >= UVESAFB_TASKS_MAX)
        return;

    mutex_lock(&uvfb_lock);
    task = uvfb_tasks[msg->seq];

    if (!task || msg->ack != task->ack) {
        mutex_unlock(&uvfb_lock);
        return;
    }

    utask = (struct uvesafb_task *)msg->data;

    /* Sanity checks for the buffer length. */
    if (task->t.buf_len < utask->buf_len ||
        utask->buf_len > msg->len - sizeof(*utask)) {
        mutex_unlock(&uvfb_lock);
        return;
    }

    uvfb_tasks[msg->seq] = NULL;
    mutex_unlock(&uvfb_lock);

    memcpy(&task->t, utask, sizeof(*utask));

    if (task->t.buf_len && task->buf)
        memcpy(task->buf, utask + 1, task->t.buf_len);

    complete(task->done);
    return;
}

static int uvesafb_helper_start(void)
{
    char *envp[] = {
        "HOME=/",
        "PATH=/sbin:/bin",
        NULL,
    };

    char *argv[] = {
        v86d_path,
        NULL,
    };

    return call_usermodehelper(v86d_path, argv, envp, UMH_WAIT_PROC);
}

/*
 * Execute a uvesafb task.
 *
 * Returns 0 if the task is executed successfully.
 *
 * A message sent to the userspace consists of the uvesafb_task
 * struct and (optionally) a buffer. The uvesafb_task struct is
 * a simplified version of uvesafb_ktask (its kernel counterpart)
 * containing only the register values, flags and the length of
 * the buffer.
 *
 * Each message is assigned a sequence number (increased linearly)
 * and a random ack number. The sequence number is used as a key
 * for the uvfb_tasks array which holds pointers to uvesafb_ktask
 * structs for all requests.
 */
static int uvesafb_exec(struct uvesafb_ktask *task)
{
    static int seq;
    struct cn_msg *m;
    int err;
    int len = sizeof(task->t) + task->t.buf_len;

    /*
     * Check whether the message isn't longer than the maximum
     * allowed by connector.
     */
    if (sizeof(*m) + len > CONNECTOR_MAX_MSG_SIZE) {
        printk(KERN_WARNING "uvesafb: message too long (%d), "
            "can't execute task\n", (int)(sizeof(*m) + len));
        return -E2BIG;
    }

    m = kzalloc(sizeof(*m) + len, GFP_KERNEL);
    if (!m)
        return -ENOMEM;

    init_completion(task->done);

    memcpy(&m->id, &uvesafb_cn_id, sizeof(m->id));
    m->seq = seq;
    m->len = len;
    m->ack = random32();

    /* uvesafb_task structure */
    memcpy(m + 1, &task->t, sizeof(task->t));

    /* Buffer */
    memcpy((u8 *)(m + 1) + sizeof(task->t), task->buf, task->t.buf_len);

    /*
     * Save the message ack number so that we can find the kernel
     * part of this task when a reply is received from userspace.
     */
    task->ack = m->ack;

    mutex_lock(&uvfb_lock);

    /* If all slots are taken -- bail out. */
    if (uvfb_tasks[seq]) {
        mutex_unlock(&uvfb_lock);
        err = -EBUSY;
        goto out;
    }

    /* Save a pointer to the kernel part of the task struct. */
    uvfb_tasks[seq] = task;
    mutex_unlock(&uvfb_lock);

    err = cn_netlink_send(m, 0, GFP_KERNEL);
    if (err == -ESRCH) {
        /*
         * Try to start the userspace helper if sending
         * the request failed the first time.
         */
        err = uvesafb_helper_start();
        if (err) {
            printk(KERN_ERR "uvesafb: failed to execute %s\n",
                    v86d_path);
            printk(KERN_ERR "uvesafb: make sure that the v86d "
                    "helper is installed and executable\n");
        } else {
            v86d_started = 1;
            err = cn_netlink_send(m, 0, gfp_any());
            if (err == -ENOBUFS)
                err = 0;
        }
    } else if (err == -ENOBUFS)
        err = 0;

    if (!err && !(task->t.flags & TF_EXIT))
        err = !wait_for_completion_timeout(task->done,
                msecs_to_jiffies(UVESAFB_TIMEOUT));

    mutex_lock(&uvfb_lock);
    uvfb_tasks[seq] = NULL;
    mutex_unlock(&uvfb_lock);

    seq++;
    if (seq >= UVESAFB_TASKS_MAX)
        seq = 0;
out:
    kfree(m);
    return err;
}

/*
 * Free a uvesafb_ktask struct.
 */
static void uvesafb_free(struct uvesafb_ktask *task)
{
    if (task) {
        if (task->done)
            kfree(task->done);
        kfree(task);
    }
}

/*
 * Prepare a uvesafb_ktask struct to be used again.
 */
static void uvesafb_reset(struct uvesafb_ktask *task)
{
    struct completion *cpl = task->done;

    memset(task, 0, sizeof(*task));
    task->done = cpl;
}

/*
 * Allocate and prepare a uvesafb_ktask struct.
 */
static struct uvesafb_ktask *uvesafb_prep(void)
{
    struct uvesafb_ktask *task;

    task = kzalloc(sizeof(*task), GFP_KERNEL);
    if (task) {
        task->done = kzalloc(sizeof(*task->done), GFP_KERNEL);
        if (!task->done) {
            kfree(task);
            task = NULL;
        }
    }
    return task;
}

static void uvesafb_setup_var(struct fb_var_screeninfo *var,
        struct fb_info *info, struct vbe_mode_ib *mode)
{
    struct uvesafb_par *par = info->par;

    var->vmode = FB_VMODE_NONINTERLACED;
    var->sync = FB_SYNC_VERT_HIGH_ACT;

    var->xres = mode->x_res;
    var->yres = mode->y_res;
    var->xres_virtual = mode->x_res;
    var->yres_virtual = (par->ypan) ?
            info->fix.smem_len / mode->bytes_per_scan_line :
            mode->y_res;
    var->xoffset = 0;
    var->yoffset = 0;
    var->bits_per_pixel = mode->bits_per_pixel;

    if (var->bits_per_pixel == 15)
        var->bits_per_pixel = 16;

    if (var->bits_per_pixel > 8) {
        var->red.offset    = mode->red_off;
        var->red.length    = mode->red_len;
        var->green.offset  = mode->green_off;
        var->green.length  = mode->green_len;
        var->blue.offset   = mode->blue_off;
        var->blue.length   = mode->blue_len;
        var->transp.offset = mode->rsvd_off;
        var->transp.length = mode->rsvd_len;
    } else {
        var->red.offset    = 0;
        var->green.offset  = 0;
        var->blue.offset   = 0;
        var->transp.offset = 0;

        var->red.length    = 8;
        var->green.length  = 8;
        var->blue.length   = 8;
        var->transp.length = 0;
    }
}

static int uvesafb_vbe_find_mode(struct uvesafb_par *par,
        int xres, int yres, int depth, unsigned char flags)
{
    int i, match = -1, h = 0, d = 0x7fffffff;

    for (i = 0; i < par->vbe_modes_cnt; i++) {
        h = abs(par->vbe_modes[i].x_res - xres) +
            abs(par->vbe_modes[i].y_res - yres) +
            abs(depth - par->vbe_modes[i].depth);

        /*
         * We have an exact match in terms of resolution
         * and depth.
         */
        if (h == 0)
            return i;

        if (h < d || (h == d && par->vbe_modes[i].depth > depth)) {
            d = h;
            match = i;
        }
    }
    i = 1;

    if (flags & UVESAFB_EXACT_DEPTH &&
            par->vbe_modes[match].depth != depth)
        i = 0;

    if (flags & UVESAFB_EXACT_RES && d > 24)
        i = 0;

    if (i != 0)
        return match;
    else
        return -1;
}

static u8 *uvesafb_vbe_state_save(struct uvesafb_par *par)
{
    struct uvesafb_ktask *task;
    u8 *state;
    int err;

    if (!par->vbe_state_size)
        return NULL;

    state = kmalloc(par->vbe_state_size, GFP_KERNEL);
    if (!state)
        return ERR_PTR(-ENOMEM);

    task = uvesafb_prep();
    if (!task) {
        kfree(state);
        return NULL;
    }

    task->t.regs.eax = 0x4f04;
    task->t.regs.ecx = 0x000f;
    task->t.regs.edx = 0x0001;
    task->t.flags = TF_BUF_RET | TF_BUF_ESBX;
    task->t.buf_len = par->vbe_state_size;
    task->buf = state;
    err = uvesafb_exec(task);

    if (err || (task->t.regs.eax & 0xffff) != 0x004f) {
        printk(KERN_WARNING "uvesafb: VBE get state call "
                "failed (eax=0x%x, err=%d)\n",
                task->t.regs.eax, err);
        kfree(state);
        state = NULL;
    }

    uvesafb_free(task);
    return state;
}

static void uvesafb_vbe_state_restore(struct uvesafb_par *par, u8 *state_buf)
{
    struct uvesafb_ktask *task;
    int err;

    if (!state_buf)
        return;

    task = uvesafb_prep();
    if (!task)
        return;

    task->t.regs.eax = 0x4f04;
    task->t.regs.ecx = 0x000f;
    task->t.regs.edx = 0x0002;
    task->t.buf_len = par->vbe_state_size;
    task->t.flags = TF_BUF_ESBX;
    task->buf = state_buf;

    err = uvesafb_exec(task);
    if (err || (task->t.regs.eax & 0xffff) != 0x004f)
        printk(KERN_WARNING "uvesafb: VBE state restore call "
                "failed (eax=0x%x, err=%d)\n",
                task->t.regs.eax, err);

    uvesafb_free(task);
}

static int __devinit uvesafb_vbe_getinfo(struct uvesafb_ktask *task,
        struct uvesafb_par *par)
{
    int err;

    task->t.regs.eax = 0x4f00;
    task->t.flags = TF_VBEIB;
    task->t.buf_len = sizeof(struct vbe_ib);
    task->buf = &par->vbe_ib;
    strncpy(par->vbe_ib.vbe_signature, "VBE2", 4);

    err = uvesafb_exec(task);
    if (err || (task->t.regs.eax & 0xffff) != 0x004f) {
        printk(KERN_ERR "uvesafb: Getting VBE info block failed "
                "(eax=0x%x, err=%d)\n", (u32)task->t.regs.eax,
                err);
        return -EINVAL;
    }

    if (par->vbe_ib.vbe_version < 0x0200) {
        printk(KERN_ERR "uvesafb: Sorry, pre-VBE 2.0 cards are "
                "not supported.\n");
        return -EINVAL;
    }

    if (!par->vbe_ib.mode_list_ptr) {
        printk(KERN_ERR "uvesafb: Missing mode list!\n");
        return -EINVAL;
    }

    printk(KERN_INFO "uvesafb: ");

    /*
     * Convert string pointers and the mode list pointer into
     * usable addresses. Print informational messages about the
     * video adapter and its vendor.
     */
    if (par->vbe_ib.oem_vendor_name_ptr)
        printk("%s, ",
            ((char *)task->buf) + par->vbe_ib.oem_vendor_name_ptr);

    if (par->vbe_ib.oem_product_name_ptr)
        printk("%s, ",
            ((char *)task->buf) + par->vbe_ib.oem_product_name_ptr);

    if (par->vbe_ib.oem_product_rev_ptr)
        printk("%s, ",
            ((char *)task->buf) + par->vbe_ib.oem_product_rev_ptr);

    if (par->vbe_ib.oem_string_ptr)
        printk("OEM: %s, ",
            ((char *)task->buf) + par->vbe_ib.oem_string_ptr);

    printk("VBE v%d.%d\n", ((par->vbe_ib.vbe_version & 0xff00) >> 8),
            par->vbe_ib.vbe_version & 0xff);

    return 0;
}

static int __devinit uvesafb_vbe_getmodes(struct uvesafb_ktask *task,
        struct uvesafb_par *par)
{
    int off = 0, err;
    u16 *mode;

    par->vbe_modes_cnt = 0;

    /* Count available modes. */
    mode = (u16 *) (((u8 *)&par->vbe_ib) + par->vbe_ib.mode_list_ptr);
    while (*mode != 0xffff) {
        par->vbe_modes_cnt++;
        mode++;
    }

    par->vbe_modes = kzalloc(sizeof(struct vbe_mode_ib) *
                par->vbe_modes_cnt, GFP_KERNEL);
    if (!par->vbe_modes)
        return -ENOMEM;

    /* Get info about all available modes. */
    mode = (u16 *) (((u8 *)&par->vbe_ib) + par->vbe_ib.mode_list_ptr);
    while (*mode != 0xffff) {
        struct vbe_mode_ib *mib;

        uvesafb_reset(task);
        task->t.regs.eax = 0x4f01;
        task->t.regs.ecx = (u32) *mode;
        task->t.flags = TF_BUF_RET | TF_BUF_ESDI;
        task->t.buf_len = sizeof(struct vbe_mode_ib);
        task->buf = par->vbe_modes + off;

        err = uvesafb_exec(task);
        if (err || (task->t.regs.eax & 0xffff) != 0x004f) {
            printk(KERN_WARNING "uvesafb: Getting mode info block "
                "for mode 0x%x failed (eax=0x%x, err=%d)\n",
                *mode, (u32)task->t.regs.eax, err);
            mode++;
            par->vbe_modes_cnt--;
            continue;
        }

        mib = task->buf;
        mib->mode_id = *mode;

        /*
         * We only want modes that are supported with the current
         * hardware configuration, color, graphics and that have
         * support for the LFB.
         */
        if ((mib->mode_attr & VBE_MODE_MASK) == VBE_MODE_MASK &&
                 mib->bits_per_pixel >= 8)
            off++;
        else
            par->vbe_modes_cnt--;

        mode++;
        mib->depth = mib->red_len + mib->green_len + mib->blue_len;

        /*
         * Handle 8bpp modes and modes with broken color component
         * lengths.
         */
        if (mib->depth == 0 || (mib->depth == 24 &&
                    mib->bits_per_pixel == 32))
            mib->depth = mib->bits_per_pixel;
    }

    if (par->vbe_modes_cnt > 0)
        return 0;
    else
        return -EINVAL;
}

/*
 * The Protected Mode Interface is 32-bit x86 code, so we only run it on
 * x86 and not x86_64.
 */
#ifdef CONFIG_X86_32
static int __devinit uvesafb_vbe_getpmi(struct uvesafb_ktask *task,
        struct uvesafb_par *par)
{
    int i, err;

    uvesafb_reset(task);
    task->t.regs.eax = 0x4f0a;
    task->t.regs.ebx = 0x0;
    err = uvesafb_exec(task);

    if ((task->t.regs.eax & 0xffff) != 0x4f || task->t.regs.es < 0xc000) {
        par->pmi_setpal = par->ypan = 0;
    } else {
        par->pmi_base = (u16 *)phys_to_virt(((u32)task->t.regs.es << 4)
                        + task->t.regs.edi);
        par->pmi_start = (u8 *)par->pmi_base + par->pmi_base[1];
        par->pmi_pal = (u8 *)par->pmi_base + par->pmi_base[2];
        printk(KERN_INFO "uvesafb: protected mode interface info at "
                 "%04x:%04x\n",
                 (u16)task->t.regs.es, (u16)task->t.regs.edi);
        printk(KERN_INFO "uvesafb: pmi: set display start = %p, "
                 "set palette = %p\n", par->pmi_start,
                 par->pmi_pal);

        if (par->pmi_base[3]) {
            printk(KERN_INFO "uvesafb: pmi: ports = ");
            for (i = par->pmi_base[3]/2;
                    par->pmi_base[i] != 0xffff; i++)
                printk("%x ", par->pmi_base[i]);
            printk("\n");

            if (par->pmi_base[i] != 0xffff) {
                printk(KERN_INFO "uvesafb: can't handle memory"
                         " requests, pmi disabled\n");
                par->ypan = par->pmi_setpal = 0;
            }
        }
    }
    return 0;
}
#endif /* CONFIG_X86_32 */

/*
 * Check whether a video mode is supported by the Video BIOS and is
 * compatible with the monitor limits.
 */
static int __devinit uvesafb_is_valid_mode(struct fb_videomode *mode,
        struct fb_info *info)
{
    if (info->monspecs.gtf) {
        fb_videomode_to_var(&info->var, mode);
        if (fb_validate_mode(&info->var, info))
            return 0;
    }

    if (uvesafb_vbe_find_mode(info->par, mode->xres, mode->yres, 8,
                UVESAFB_EXACT_RES) == -1)
        return 0;

    return 1;
}

static int __devinit uvesafb_vbe_getedid(struct uvesafb_ktask *task,
        struct fb_info *info)
{
    struct uvesafb_par *par = info->par;
    int err = 0;

    if (noedid || par->vbe_ib.vbe_version < 0x0300)
        return -EINVAL;

    task->t.regs.eax = 0x4f15;
    task->t.regs.ebx = 0;
    task->t.regs.ecx = 0;
    task->t.buf_len = 0;
    task->t.flags = 0;

    err = uvesafb_exec(task);

    if ((task->t.regs.eax & 0xffff) != 0x004f || err)
        return -EINVAL;

    if ((task->t.regs.ebx & 0x3) == 3) {
        printk(KERN_INFO "uvesafb: VBIOS/hardware supports both "
                 "DDC1 and DDC2 transfers\n");
    } else if ((task->t.regs.ebx & 0x3) == 2) {
        printk(KERN_INFO "uvesafb: VBIOS/hardware supports DDC2 "
                 "transfers\n");
    } else if ((task->t.regs.ebx & 0x3) == 1) {
        printk(KERN_INFO "uvesafb: VBIOS/hardware supports DDC1 "
                 "transfers\n");
    } else {
        printk(KERN_INFO "uvesafb: VBIOS/hardware doesn't support "
                 "DDC transfers\n");
        return -EINVAL;
    }

    task->t.regs.eax = 0x4f15;
    task->t.regs.ebx = 1;
    task->t.regs.ecx = task->t.regs.edx = 0;
    task->t.flags = TF_BUF_RET | TF_BUF_ESDI;
    task->t.buf_len = EDID_LENGTH;
    task->buf = kzalloc(EDID_LENGTH, GFP_KERNEL);
    if (!task->buf)
        return -ENOMEM;

    err = uvesafb_exec(task);

    if ((task->t.regs.eax & 0xffff) == 0x004f && !err) {
        fb_edid_to_monspecs(task->buf, &info->monspecs);

        if (info->monspecs.vfmax && info->monspecs.hfmax) {
            /*
             * If the maximum pixel clock wasn't specified in
             * the EDID block, set it to 300 MHz.
             */
            if (info->monspecs.dclkmax == 0)
                info->monspecs.dclkmax = 300 * 1000000;
            info->monspecs.gtf = 1;
        }
    } else {
        err = -EINVAL;
    }

    kfree(task->buf);
    return err;
}

static void __devinit uvesafb_vbe_getmonspecs(struct uvesafb_ktask *task,
        struct fb_info *info)
{
    struct uvesafb_par *par = info->par;
    int i;

    memset(&info->monspecs, 0, sizeof(info->monspecs));

    /*
     * If we don't get all necessary data from the EDID block,
     * mark it as incompatible with the GTF and set nocrtc so
     * that we always use the default BIOS refresh rate.
     */
    if (uvesafb_vbe_getedid(task, info)) {
        info->monspecs.gtf = 0;
        par->nocrtc = 1;
    }

    /* Kernel command line overrides. */
    if (maxclk)
        info->monspecs.dclkmax = maxclk * 1000000;
    if (maxvf)
        info->monspecs.vfmax = maxvf;
    if (maxhf)
        info->monspecs.hfmax = maxhf * 1000;

    /*
     * In case DDC transfers are not supported, the user can provide
     * monitor limits manually. Lower limits are set to "safe" values.
     */
    if (info->monspecs.gtf == 0 && maxclk && maxvf && maxhf) {
        info->monspecs.dclkmin = 0;
        info->monspecs.vfmin = 60;
        info->monspecs.hfmin = 29000;
        info->monspecs.gtf = 1;
        par->nocrtc = 0;
    }

    if (info->monspecs.gtf)
        printk(KERN_INFO
            "uvesafb: monitor limits: vf = %d Hz, hf = %d kHz, "
            "clk = %d MHz\n", info->monspecs.vfmax,
            (int)(info->monspecs.hfmax / 1000),
            (int)(info->monspecs.dclkmax / 1000000));
    else
        printk(KERN_INFO "uvesafb: no monitor limits have been set, "
                 "default refresh rate will be used\n");

    /* Add VBE modes to the modelist. */
    for (i = 0; i < par->vbe_modes_cnt; i++) {
        struct fb_var_screeninfo var;
        struct vbe_mode_ib *mode;
        struct fb_videomode vmode;

        mode = &par->vbe_modes[i];
        memset(&var, 0, sizeof(var));

        var.xres = mode->x_res;
        var.yres = mode->y_res;

        fb_get_mode(FB_VSYNCTIMINGS | FB_IGNOREMON, 60, &var, info);
        fb_var_to_videomode(&vmode, &var);
        fb_add_videomode(&vmode, &info->modelist);
    }

    /* Add valid VESA modes to our modelist. */
    for (i = 0; i < VESA_MODEDB_SIZE; i++) {
        if (uvesafb_is_valid_mode((struct fb_videomode *)
                        &vesa_modes[i], info))
            fb_add_videomode(&vesa_modes[i], &info->modelist);
    }

    for (i = 0; i < info->monspecs.modedb_len; i++) {
        if (uvesafb_is_valid_mode(&info->monspecs.modedb[i], info))
            fb_add_videomode(&info->monspecs.modedb[i],
                    &info->modelist);
    }

    return;
}

static void __devinit uvesafb_vbe_getstatesize(struct uvesafb_ktask *task,
        struct uvesafb_par *par)
{
    int err;

    uvesafb_reset(task);

    /*
     * Get the VBE state buffer size. We want all available
     * hardware state data (CL = 0x0f).
     */
    task->t.regs.eax = 0x4f04;
    task->t.regs.ecx = 0x000f;
    task->t.regs.edx = 0x0000;
    task->t.flags = 0;

    err = uvesafb_exec(task);

    if (err || (task->t.regs.eax & 0xffff) != 0x004f) {
        printk(KERN_WARNING "uvesafb: VBE state buffer size "
            "cannot be determined (eax=0x%x, err=%d)\n",
            task->t.regs.eax, err);
        par->vbe_state_size = 0;
        return;
    }

    par->vbe_state_size = 64 * (task->t.regs.ebx & 0xffff);
}

static int __devinit uvesafb_vbe_init(struct fb_info *info)
{
    struct uvesafb_ktask *task = NULL;
    struct uvesafb_par *par = info->par;
    int err;

    task = uvesafb_prep();
    if (!task)
        return -ENOMEM;

    err = uvesafb_vbe_getinfo(task, par);
    if (err)
        goto out;

    err = uvesafb_vbe_getmodes(task, par);
    if (err)
        goto out;

    par->nocrtc = nocrtc;
#ifdef CONFIG_X86_32
    par->pmi_setpal = pmi_setpal;
    par->ypan = ypan;

    if (par->pmi_setpal || par->ypan) {
        if (__supported_pte_mask & _PAGE_NX) {
            par->pmi_setpal = par->ypan = 0;
            printk(KERN_WARNING "uvesafb: NX protection is actively."
                "We have better not to use the PMI.\n");
        } else {
            uvesafb_vbe_getpmi(task, par);
        }
    }
#else
    /* The protected mode interface is not available on non-x86. */
    par->pmi_setpal = par->ypan = 0;
#endif

    INIT_LIST_HEAD(&info->modelist);
    uvesafb_vbe_getmonspecs(task, info);
    uvesafb_vbe_getstatesize(task, par);

out:    uvesafb_free(task);
    return err;
}

static int __devinit uvesafb_vbe_init_mode(struct fb_info *info)
{
    struct list_head *pos;
    struct fb_modelist *modelist;
    struct fb_videomode *mode;
    struct uvesafb_par *par = info->par;
    int i, modeid;

    /* Has the user requested a specific VESA mode? */
    if (vbemode) {
        for (i = 0; i < par->vbe_modes_cnt; i++) {
            if (par->vbe_modes[i].mode_id == vbemode) {
                modeid = i;
                uvesafb_setup_var(&info->var, info,
                        &par->vbe_modes[modeid]);
                fb_get_mode(FB_VSYNCTIMINGS | FB_IGNOREMON, 60,
                        &info->var, info);
                /*
                 * With pixclock set to 0, the default BIOS
                 * timings will be used in set_par().
                 */
                info->var.pixclock = 0;
                goto gotmode;
            }
        }
        printk(KERN_INFO "uvesafb: requested VBE mode 0x%x is "
                 "unavailable\n", vbemode);
        vbemode = 0;
    }

    /* Count the modes in the modelist */
    i = 0;
    list_for_each(pos, &info->modelist)
        i++;

    /*
     * Convert the modelist into a modedb so that we can use it with
     * fb_find_mode().
     */
    mode = kzalloc(i * sizeof(*mode), GFP_KERNEL);
    if (mode) {
        i = 0;
        list_for_each(pos, &info->modelist) {
            modelist = list_entry(pos, struct fb_modelist, list);
            mode[i] = modelist->mode;
            i++;
        }

        if (!mode_option)
            mode_option = UVESAFB_DEFAULT_MODE;

        i = fb_find_mode(&info->var, info, mode_option, mode, i,
            NULL, 8);

        kfree(mode);
    }

    /* fb_find_mode() failed */
    if (i == 0) {
        info->var.xres = 640;
        info->var.yres = 480;
        mode = (struct fb_videomode *)
                fb_find_best_mode(&info->var, &info->modelist);

        if (mode) {
            fb_videomode_to_var(&info->var, mode);
        } else {
            modeid = par->vbe_modes[0].mode_id;
            uvesafb_setup_var(&info->var, info,
                    &par->vbe_modes[modeid]);
            fb_get_mode(FB_VSYNCTIMINGS | FB_IGNOREMON, 60,
                    &info->var, info);

            goto gotmode;
        }
    }

    /* Look for a matching VBE mode. */
    modeid = uvesafb_vbe_find_mode(par, info->var.xres, info->var.yres,
            info->var.bits_per_pixel, UVESAFB_EXACT_RES);

    if (modeid == -1)
        return -EINVAL;

    uvesafb_setup_var(&info->var, info, &par->vbe_modes[modeid]);

gotmode:
    /*
     * If we are not VBE3.0+ compliant, we're done -- the BIOS will
     * ignore our timings anyway.
     */
    if (par->vbe_ib.vbe_version < 0x0300 || par->nocrtc)
        fb_get_mode(FB_VSYNCTIMINGS | FB_IGNOREMON, 60,
                    &info->var, info);

    return modeid;
}

static int uvesafb_setpalette(struct uvesafb_pal_entry *entries, int count,
        int start, struct fb_info *info)
{
    struct uvesafb_ktask *task;
#ifdef CONFIG_X86
    struct uvesafb_par *par = info->par;
    int i = par->mode_idx;
#endif
    int err = 0;

    /*
     * We support palette modifications for 8 bpp modes only, so
     * there can never be more than 256 entries.
     */
    if (start + count > 256)
        return -EINVAL;

#ifdef CONFIG_X86
    /* Use VGA registers if mode is VGA-compatible. */
    if (i >= 0 && i < par->vbe_modes_cnt &&
        par->vbe_modes[i].mode_attr & VBE_MODE_VGACOMPAT) {
        for (i = 0; i < count; i++) {
            outb_p(start + i,        dac_reg);
            outb_p(entries[i].red,   dac_val);
            outb_p(entries[i].green, dac_val);
            outb_p(entries[i].blue,  dac_val);
        }
    }
#ifdef CONFIG_X86_32
    else if (par->pmi_setpal) {
        __asm__ __volatile__(
        "call *(%%esi)"
        : /* no return value */
        : "a" (0x4f09),         /* EAX */
          "b" (0),              /* EBX */
          "c" (count),          /* ECX */
          "d" (start),          /* EDX */
          "D" (entries),        /* EDI */
          "S" (&par->pmi_pal)); /* ESI */
    }
#endif /* CONFIG_X86_32 */
    else
#endif /* CONFIG_X86 */
    {
        task = uvesafb_prep();
        if (!task)
            return -ENOMEM;

        task->t.regs.eax = 0x4f09;
        task->t.regs.ebx = 0x0;
        task->t.regs.ecx = count;
        task->t.regs.edx = start;
        task->t.flags = TF_BUF_ESDI;
        task->t.buf_len = sizeof(struct uvesafb_pal_entry) * count;
        task->buf = entries;

        err = uvesafb_exec(task);
        if ((task->t.regs.eax & 0xffff) != 0x004f)
            err = 1;

        uvesafb_free(task);
    }
    return err;
}

static int uvesafb_setcolreg(unsigned regno, unsigned red, unsigned green,
        unsigned blue, unsigned transp,
        struct fb_info *info)
{
    struct uvesafb_pal_entry entry;
    int shift = 16 - dac_width;
    int err = 0;

    if (regno >= info->cmap.len)
        return -EINVAL;

    if (info->var.bits_per_pixel == 8) {
        entry.red   = red   >> shift;
        entry.green = green >> shift;
        entry.blue  = blue  >> shift;
        entry.pad   = 0;

        err = uvesafb_setpalette(&entry, 1, regno, info);
    } else if (regno < 16) {
        switch (info->var.bits_per_pixel) {
        case 16:
            if (info->var.red.offset == 10) {
                /* 1:5:5:5 */
                ((u32 *) (info->pseudo_palette))[regno] =
                        ((red   & 0xf800) >>  1) |
                        ((green & 0xf800) >>  6) |
                        ((blue  & 0xf800) >> 11);
            } else {
                /* 0:5:6:5 */
                ((u32 *) (info->pseudo_palette))[regno] =
                        ((red   & 0xf800)      ) |
                        ((green & 0xfc00) >>  5) |
                        ((blue  & 0xf800) >> 11);
            }
            break;

        case 24:
        case 32:
            red   >>= 8;
            green >>= 8;
            blue  >>= 8;
            ((u32 *)(info->pseudo_palette))[regno] =
                (red   << info->var.red.offset)   |
                (green << info->var.green.offset) |
                (blue  << info->var.blue.offset);
            break;
        }
    }
    return err;
}

static int uvesafb_setcmap(struct fb_cmap *cmap, struct fb_info *info)
{
    struct uvesafb_pal_entry *entries;
    int shift = 16 - dac_width;
    int i, err = 0;

    if (info->var.bits_per_pixel == 8) {
        if (cmap->start + cmap->len > info->cmap.start +
            info->cmap.len || cmap->start < info->cmap.start)
            return -EINVAL;

        entries = kmalloc(sizeof(*entries) * cmap->len, GFP_KERNEL);
        if (!entries)
            return -ENOMEM;

        for (i = 0; i < cmap->len; i++) {
            entries[i].red   = cmap->red[i]   >> shift;
            entries[i].green = cmap->green[i] >> shift;
            entries[i].blue  = cmap->blue[i]  >> shift;
            entries[i].pad   = 0;
        }
        err = uvesafb_setpalette(entries, cmap->len, cmap->start, info);
        kfree(entries);
    } else {
        /*
         * For modes with bpp > 8, we only set the pseudo palette in
         * the fb_info struct. We rely on uvesafb_setcolreg to do all
         * sanity checking.
         */
        for (i = 0; i < cmap->len; i++) {
            err |= uvesafb_setcolreg(cmap->start + i, cmap->red[i],
                        cmap->green[i], cmap->blue[i],
                        0, info);
        }
    }
    return err;
}

static int uvesafb_pan_display(struct fb_var_screeninfo *var,
        struct fb_info *info)
{
#ifdef CONFIG_X86_32
    int offset;
    struct uvesafb_par *par = info->par;

    offset = (var->yoffset * info->fix.line_length + var->xoffset) / 4;

    /*
     * It turns out it's not the best idea to do panning via vm86,
     * so we only allow it if we have a PMI.
     */
    if (par->pmi_start) {
        __asm__ __volatile__(
            "call *(%%edi)"
            : /* no return value */
            : "a" (0x4f07),         /* EAX */
              "b" (0),              /* EBX */
              "c" (offset),         /* ECX */
              "d" (offset >> 16),   /* EDX */
              "D" (&par->pmi_start));    /* EDI */
    }
#endif
    return 0;
}

static int uvesafb_blank(int blank, struct fb_info *info)
{
    struct uvesafb_ktask *task;
    int err = 1;
#ifdef CONFIG_X86
    struct uvesafb_par *par = info->par;

    if (par->vbe_ib.capabilities & VBE_CAP_VGACOMPAT) {
        int loop = 10000;
        u8 seq = 0, crtc17 = 0;

        if (blank == FB_BLANK_POWERDOWN) {
            seq = 0x20;
            crtc17 = 0x00;
            err = 0;
        } else {
            seq = 0x00;
            crtc17 = 0x80;
            err = (blank == FB_BLANK_UNBLANK) ? 0 : -EINVAL;
        }

        vga_wseq(NULL, 0x00, 0x01);
        seq |= vga_rseq(NULL, 0x01) & ~0x20;
        vga_wseq(NULL, 0x00, seq);

        crtc17 |= vga_rcrt(NULL, 0x17) & ~0x80;
        while (loop--);
        vga_wcrt(NULL, 0x17, crtc17);
        vga_wseq(NULL, 0x00, 0x03);
    } else
#endif /* CONFIG_X86 */
    {
        task = uvesafb_prep();
        if (!task)
            return -ENOMEM;

        task->t.regs.eax = 0x4f10;
        switch (blank) {
        case FB_BLANK_UNBLANK:
            task->t.regs.ebx = 0x0001;
            break;
        case FB_BLANK_NORMAL:
            task->t.regs.ebx = 0x0101;  /* standby */
            break;
        case FB_BLANK_POWERDOWN:
            task->t.regs.ebx = 0x0401;  /* powerdown */
            break;
        default:
            goto out;
        }

        err = uvesafb_exec(task);
        if (err || (task->t.regs.eax & 0xffff) != 0x004f)
            err = 1;
out:        uvesafb_free(task);
    }
    return err;
}

static int uvesafb_open(struct fb_info *info, int user)
{
    struct uvesafb_par *par = info->par;
    int cnt = atomic_read(&par->ref_count);
    u8 *buf = NULL;

    if (!cnt && par->vbe_state_size) {
        buf =  uvesafb_vbe_state_save(par);
        if (IS_ERR(buf)) {
            printk(KERN_WARNING "uvesafb: save hardware state"
                "failed, error code is %ld!\n", PTR_ERR(buf));
        } else {
            par->vbe_state_orig = buf;
        }
    }

    atomic_inc(&par->ref_count);
    return 0;
}

static int uvesafb_release(struct fb_info *info, int user)
{
    struct uvesafb_ktask *task = NULL;
    struct uvesafb_par *par = info->par;
    int cnt = atomic_read(&par->ref_count);

    if (!cnt)
        return -EINVAL;

    if (cnt != 1)
        goto out;

    task = uvesafb_prep();
    if (!task)
        goto out;

    /* First, try to set the standard 80x25 text mode. */
    task->t.regs.eax = 0x0003;
    uvesafb_exec(task);

    /*
     * Now try to restore whatever hardware state we might have
     * saved when the fb device was first opened.
     */
    uvesafb_vbe_state_restore(par, par->vbe_state_orig);
out:
    atomic_dec(&par->ref_count);
    if (task)
        uvesafb_free(task);
    return 0;
}

static int uvesafb_set_par(struct fb_info *info)
{
    struct uvesafb_par *par = info->par;
    struct uvesafb_ktask *task = NULL;
    struct vbe_crtc_ib *crtc = NULL;
    struct vbe_mode_ib *mode = NULL;
    int i, err = 0, depth = info->var.bits_per_pixel;

    if (depth > 8 && depth != 32)
        depth = info->var.red.length + info->var.green.length +
            info->var.blue.length;

    i = uvesafb_vbe_find_mode(par, info->var.xres, info->var.yres, depth,
                 UVESAFB_EXACT_RES | UVESAFB_EXACT_DEPTH);
    if (i >= 0)
        mode = &par->vbe_modes[i];
    else
        return -EINVAL;

    task = uvesafb_prep();
    if (!task)
        return -ENOMEM;
setmode:
    task->t.regs.eax = 0x4f02;
    task->t.regs.ebx = mode->mode_id | 0x4000;  /* use LFB */

    if (par->vbe_ib.vbe_version >= 0x0300 && !par->nocrtc &&
        info->var.pixclock != 0) {
        task->t.regs.ebx |= 0x0800;     /* use CRTC data */
        task->t.flags = TF_BUF_ESDI;
        crtc = kzalloc(sizeof(struct vbe_crtc_ib), GFP_KERNEL);
        if (!crtc) {
            err = -ENOMEM;
            goto out;
        }
        crtc->horiz_start = info->var.xres + info->var.right_margin;
        crtc->horiz_end   = crtc->horiz_start + info->var.hsync_len;
        crtc->horiz_total = crtc->horiz_end + info->var.left_margin;

        crtc->vert_start  = info->var.yres + info->var.lower_margin;
        crtc->vert_end    = crtc->vert_start + info->var.vsync_len;
        crtc->vert_total  = crtc->vert_end + info->var.upper_margin;

        crtc->pixel_clock = PICOS2KHZ(info->var.pixclock) * 1000;
        crtc->refresh_rate = (u16)(100 * (crtc->pixel_clock /
                (crtc->vert_total * crtc->horiz_total)));

        if (info->var.vmode & FB_VMODE_DOUBLE)
            crtc->flags |= 0x1;
        if (info->var.vmode & FB_VMODE_INTERLACED)
            crtc->flags |= 0x2;
        if (!(info->var.sync & FB_SYNC_HOR_HIGH_ACT))
            crtc->flags |= 0x4;
        if (!(info->var.sync & FB_SYNC_VERT_HIGH_ACT))
            crtc->flags |= 0x8;
        memcpy(&par->crtc, crtc, sizeof(*crtc));
    } else {
        memset(&par->crtc, 0, sizeof(*crtc));
    }

    task->t.buf_len = sizeof(struct vbe_crtc_ib);
    task->buf = &par->crtc;

    err = uvesafb_exec(task);
    if (err || (task->t.regs.eax & 0xffff) != 0x004f) {
        /*
         * The mode switch might have failed because we tried to
         * use our own timings.  Try again with the default timings.
         */
        if (crtc != NULL) {
            printk(KERN_WARNING "uvesafb: mode switch failed "
                "(eax=0x%x, err=%d). Trying again with "
                "default timings.\n", task->t.regs.eax, err);
            uvesafb_reset(task);
            kfree(crtc);
            crtc = NULL;
            info->var.pixclock = 0;
            goto setmode;
        } else {
            printk(KERN_ERR "uvesafb: mode switch failed (eax="
                "0x%x, err=%d)\n", task->t.regs.eax, err);
            err = -EINVAL;
            goto out;
        }
    }
    par->mode_idx = i;

    /* For 8bpp modes, always try to set the DAC to 8 bits. */
    if (par->vbe_ib.capabilities & VBE_CAP_CAN_SWITCH_DAC &&
        mode->bits_per_pixel <= 8) {
        uvesafb_reset(task);
        task->t.regs.eax = 0x4f08;
        task->t.regs.ebx = 0x0800;

        err = uvesafb_exec(task);
        if (err || (task->t.regs.eax & 0xffff) != 0x004f ||
            ((task->t.regs.ebx & 0xff00) >> 8) != 8) {
            dac_width = 6;
        } else {
            dac_width = 8;
        }
    }

    info->fix.visual = (info->var.bits_per_pixel == 8) ?
                FB_VISUAL_PSEUDOCOLOR : FB_VISUAL_TRUECOLOR;
    info->fix.line_length = mode->bytes_per_scan_line;

out:    if (crtc != NULL)
        kfree(crtc);
    uvesafb_free(task);

    return err;
}

static void uvesafb_check_limits(struct fb_var_screeninfo *var,
        struct fb_info *info)
{
    const struct fb_videomode *mode;
    struct uvesafb_par *par = info->par;

    /*
     * If pixclock is set to 0, then we're using default BIOS timings
     * and thus don't have to perform any checks here.
     */
    if (!var->pixclock)
        return;

    if (par->vbe_ib.vbe_version < 0x0300) {
        fb_get_mode(FB_VSYNCTIMINGS | FB_IGNOREMON, 60, var, info);
        return;
    }

    if (!fb_validate_mode(var, info))
        return;

    mode = fb_find_best_mode(var, &info->modelist);
    if (mode) {
        if (mode->xres == var->xres && mode->yres == var->yres &&
            !(mode->vmode & (FB_VMODE_INTERLACED | FB_VMODE_DOUBLE))) {
            fb_videomode_to_var(var, mode);
            return;
        }
    }

    if (info->monspecs.gtf && !fb_get_mode(FB_MAXTIMINGS, 0, var, info))
        return;
    /* Use default refresh rate */
    var->pixclock = 0;
}

static int uvesafb_check_var(struct fb_var_screeninfo *var,
        struct fb_info *info)
{
    struct uvesafb_par *par = info->par;
    struct vbe_mode_ib *mode = NULL;
    int match = -1;
    int depth = var->red.length + var->green.length + var->blue.length;

    /*
     * Various apps will use bits_per_pixel to set the color depth,
     * which is theoretically incorrect, but which we'll try to handle
     * here.
     */
    if (depth == 0 || abs(depth - var->bits_per_pixel) >= 8)
        depth = var->bits_per_pixel;

    match = uvesafb_vbe_find_mode(par, var->xres, var->yres, depth,
                        UVESAFB_EXACT_RES);
    if (match == -1)
        return -EINVAL;

    mode = &par->vbe_modes[match];
    uvesafb_setup_var(var, info, mode);

    /*
     * Check whether we have remapped enough memory for this mode.
     * We might be called at an early stage, when we haven't remapped
     * any memory yet, in which case we simply skip the check.
     */
    if (var->yres * mode->bytes_per_scan_line > info->fix.smem_len
                        && info->fix.smem_len)
        return -EINVAL;

    if ((var->vmode & FB_VMODE_DOUBLE) &&
                !(par->vbe_modes[match].mode_attr & 0x100))
        var->vmode &= ~FB_VMODE_DOUBLE;

    if ((var->vmode & FB_VMODE_INTERLACED) &&
                !(par->vbe_modes[match].mode_attr & 0x200))
        var->vmode &= ~FB_VMODE_INTERLACED;

    uvesafb_check_limits(var, info);

    var->xres_virtual = var->xres;
    var->yres_virtual = (par->ypan) ?
                info->fix.smem_len / mode->bytes_per_scan_line :
                var->yres;
    return 0;
}

static struct fb_ops uvesafb_ops = {
    .owner      = THIS_MODULE,
    .fb_open    = uvesafb_open,
    .fb_release = uvesafb_release,
    .fb_setcolreg   = uvesafb_setcolreg,
    .fb_setcmap = uvesafb_setcmap,
    .fb_pan_display = uvesafb_pan_display,
    .fb_blank   = uvesafb_blank,
    .fb_fillrect    = cfb_fillrect,
    .fb_copyarea    = cfb_copyarea,
    .fb_imageblit   = cfb_imageblit,
    .fb_check_var   = uvesafb_check_var,
    .fb_set_par = uvesafb_set_par,
};

static void __devinit uvesafb_init_info(struct fb_info *info,
        struct vbe_mode_ib *mode)
{
    unsigned int size_vmode;
    unsigned int size_remap;
    unsigned int size_total;
    struct uvesafb_par *par = info->par;
    int i, h;

    info->pseudo_palette = ((u8 *)info->par + sizeof(struct uvesafb_par));
    info->fix = uvesafb_fix;
    info->fix.ypanstep = par->ypan ? 1 : 0;
    info->fix.ywrapstep = (par->ypan > 1) ? 1 : 0;

    /* Disable blanking if the user requested so. */
    if (!blank)
        info->fbops->fb_blank = NULL;

    /*
     * Find out how much IO memory is required for the mode with
     * the highest resolution.
     */
    size_remap = 0;
    for (i = 0; i < par->vbe_modes_cnt; i++) {
        h = par->vbe_modes[i].bytes_per_scan_line *
                    par->vbe_modes[i].y_res;
        if (h > size_remap)
            size_remap = h;
    }
    size_remap *= 2;

    /*
     *   size_vmode -- that is the amount of memory needed for the
     *                 used video mode, i.e. the minimum amount of
     *                 memory we need.
     */
    if (mode != NULL) {
        size_vmode = info->var.yres * mode->bytes_per_scan_line;
    } else {
        size_vmode = info->var.yres * info->var.xres *
                 ((info->var.bits_per_pixel + 7) >> 3);
    }

    /*
     *   size_total -- all video memory we have. Used for mtrr
     *                 entries, resource allocation and bounds
     *                 checking.
     */
    size_total = par->vbe_ib.total_memory * 65536;
    if (vram_total)
        size_total = vram_total * 1024 * 1024;
    if (size_total < size_vmode)
        size_total = size_vmode;

    /*
     *   size_remap -- the amount of video memory we are going to
     *                 use for vesafb.  With modern cards it is no
     *                 option to simply use size_total as th
     *                 wastes plenty of kernel address space.
     */
    if (vram_remap)
        size_remap = vram_remap * 1024 * 1024;
    if (size_remap < size_vmode)
        size_remap = size_vmode;
    if (size_remap > size_total)
        size_remap = size_total;

    info->fix.smem_len = size_remap;
    info->fix.smem_start = mode->phys_base_ptr;

    /*
     * We have to set yres_virtual here because when setup_var() was
     * called, smem_len wasn't defined yet.
     */
    info->var.yres_virtual = info->fix.smem_len /
                 mode->bytes_per_scan_line;

    if (par->ypan && info->var.yres_virtual > info->var.yres) {
        printk(KERN_INFO "uvesafb: scrolling: %s "
            "using protected mode interface, "
            "yres_virtual=%d\n",
            (par->ypan > 1) ? "ywrap" : "ypan",
            info->var.yres_virtual);
    } else {
        printk(KERN_INFO "uvesafb: scrolling: redraw\n");
        info->var.yres_virtual = info->var.yres;
        par->ypan = 0;
    }

    info->flags = FBINFO_FLAG_DEFAULT |
            (par->ypan ? FBINFO_HWACCEL_YPAN : 0);

    if (!par->ypan)
        info->fbops->fb_pan_display = NULL;
}

static void __devinit uvesafb_init_mtrr(struct fb_info *info)
{
#ifdef CONFIG_MTRR
    if (mtrr && !(info->fix.smem_start & (PAGE_SIZE - 1))) {
        int temp_size = info->fix.smem_len;
        unsigned int type = 0;

        switch (mtrr) {
        case 1:
            type = MTRR_TYPE_UNCACHABLE;
            break;
        case 2:
            type = MTRR_TYPE_WRBACK;
            break;
        case 3:
            type = MTRR_TYPE_WRCOMB;
            break;
        case 4:
            type = MTRR_TYPE_WRTHROUGH;
            break;
        default:
            type = 0;
            break;
        }

        if (type) {
            int rc;

            /* Find the largest power-of-two */
            temp_size = roundup_pow_of_two(temp_size);

            /* Try and find a power of two to add */
            do {
                rc = mtrr_add(info->fix.smem_start,
                          temp_size, type, 1);
                temp_size >>= 1;
            } while (temp_size >= PAGE_SIZE && rc == -EINVAL);
        }
    }
#endif /* CONFIG_MTRR */
}

static void __devinit uvesafb_ioremap(struct fb_info *info)
{
#ifdef CONFIG_X86
    switch (mtrr) {
    case 1: /* uncachable */
        info->screen_base = ioremap_nocache(info->fix.smem_start, info->fix.smem_len);
        break;
    case 2: /* write-back */
        info->screen_base = ioremap_cache(info->fix.smem_start, info->fix.smem_len);
        break;
    case 3: /* write-combining */
        info->screen_base = ioremap_wc(info->fix.smem_start, info->fix.smem_len);
        break;
    case 4: /* write-through */
    default:
        info->screen_base = ioremap(info->fix.smem_start, info->fix.smem_len);
        break;
    }
#else
    info->screen_base = ioremap(info->fix.smem_start, info->fix.smem_len);
#endif /* CONFIG_X86 */
}

static ssize_t uvesafb_show_vbe_ver(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    struct fb_info *info = platform_get_drvdata(to_platform_device(dev));
    struct uvesafb_par *par = info->par;

    return snprintf(buf, PAGE_SIZE, "%.4x\n", par->vbe_ib.vbe_version);
}

static DEVICE_ATTR(vbe_version, S_IRUGO, uvesafb_show_vbe_ver, NULL);

static ssize_t uvesafb_show_vbe_modes(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    struct fb_info *info = platform_get_drvdata(to_platform_device(dev));
    struct uvesafb_par *par = info->par;
    int ret = 0, i;

    for (i = 0; i < par->vbe_modes_cnt && ret < PAGE_SIZE; i++) {
        ret += snprintf(buf + ret, PAGE_SIZE - ret,
            "%dx%d-%d, 0x%.4x\n",
            par->vbe_modes[i].x_res, par->vbe_modes[i].y_res,
            par->vbe_modes[i].depth, par->vbe_modes[i].mode_id);
    }

    return ret;
}

static DEVICE_ATTR(vbe_modes, S_IRUGO, uvesafb_show_vbe_modes, NULL);

static ssize_t uvesafb_show_vendor(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    struct fb_info *info = platform_get_drvdata(to_platform_device(dev));
    struct uvesafb_par *par = info->par;

    if (par->vbe_ib.oem_vendor_name_ptr)
        return snprintf(buf, PAGE_SIZE, "%s\n", (char *)
            (&par->vbe_ib) + par->vbe_ib.oem_vendor_name_ptr);
    else
        return 0;
}

static DEVICE_ATTR(oem_vendor, S_IRUGO, uvesafb_show_vendor, NULL);

static ssize_t uvesafb_show_product_name(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    struct fb_info *info = platform_get_drvdata(to_platform_device(dev));
    struct uvesafb_par *par = info->par;

    if (par->vbe_ib.oem_product_name_ptr)
        return snprintf(buf, PAGE_SIZE, "%s\n", (char *)
            (&par->vbe_ib) + par->vbe_ib.oem_product_name_ptr);
    else
        return 0;
}

static DEVICE_ATTR(oem_product_name, S_IRUGO, uvesafb_show_product_name, NULL);

static ssize_t uvesafb_show_product_rev(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    struct fb_info *info = platform_get_drvdata(to_platform_device(dev));
    struct uvesafb_par *par = info->par;

    if (par->vbe_ib.oem_product_rev_ptr)
        return snprintf(buf, PAGE_SIZE, "%s\n", (char *)
            (&par->vbe_ib) + par->vbe_ib.oem_product_rev_ptr);
    else
        return 0;
}

static DEVICE_ATTR(oem_product_rev, S_IRUGO, uvesafb_show_product_rev, NULL);

static ssize_t uvesafb_show_oem_string(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    struct fb_info *info = platform_get_drvdata(to_platform_device(dev));
    struct uvesafb_par *par = info->par;

    if (par->vbe_ib.oem_string_ptr)
        return snprintf(buf, PAGE_SIZE, "%s\n",
            (char *)(&par->vbe_ib) + par->vbe_ib.oem_string_ptr);
    else
        return 0;
}

static DEVICE_ATTR(oem_string, S_IRUGO, uvesafb_show_oem_string, NULL);

static ssize_t uvesafb_show_nocrtc(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    struct fb_info *info = platform_get_drvdata(to_platform_device(dev));
    struct uvesafb_par *par = info->par;

    return snprintf(buf, PAGE_SIZE, "%d\n", par->nocrtc);
}

static ssize_t uvesafb_store_nocrtc(struct device *dev,
        struct device_attribute *attr, const char *buf, size_t count)
{
    struct fb_info *info = platform_get_drvdata(to_platform_device(dev));
    struct uvesafb_par *par = info->par;

    if (count > 0) {
        if (buf[0] == '0')
            par->nocrtc = 0;
        else
            par->nocrtc = 1;
    }
    return count;
}

static DEVICE_ATTR(nocrtc, S_IRUGO | S_IWUSR, uvesafb_show_nocrtc,
            uvesafb_store_nocrtc);

static struct attribute *uvesafb_dev_attrs[] = {
    &dev_attr_vbe_version.attr,
    &dev_attr_vbe_modes.attr,
    &dev_attr_oem_vendor.attr,
    &dev_attr_oem_product_name.attr,
    &dev_attr_oem_product_rev.attr,
    &dev_attr_oem_string.attr,
    &dev_attr_nocrtc.attr,
    NULL,
};

static struct attribute_group uvesafb_dev_attgrp = {
    .name = NULL,
    .attrs = uvesafb_dev_attrs,
};

static int __devinit uvesafb_probe(struct platform_device *dev)
{
    struct fb_info *info;
    struct vbe_mode_ib *mode = NULL;
    struct uvesafb_par *par;
    int err = 0, i;

    info = framebuffer_alloc(sizeof(*par) + sizeof(u32) * 256, &dev->dev);
    if (!info)
        return -ENOMEM;

    par = info->par;

    err = uvesafb_vbe_init(info);
    if (err) {
        printk(KERN_ERR "uvesafb: vbe_init() failed with %d\n", err);
        goto out;
    }

    info->fbops = &uvesafb_ops;

    i = uvesafb_vbe_init_mode(info);
    if (i < 0) {
        err = -EINVAL;
        goto out;
    } else {
        mode = &par->vbe_modes[i];
    }

    if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
        err = -ENXIO;
        goto out;
    }

    uvesafb_init_info(info, mode);

    if (!request_region(0x3c0, 32, "uvesafb")) {
        printk(KERN_ERR "uvesafb: request region 0x3c0-0x3e0 failed\n");
        err = -EIO;
        goto out_mode;
    }

    if (!request_mem_region(info->fix.smem_start, info->fix.smem_len,
                "uvesafb")) {
        printk(KERN_ERR "uvesafb: cannot reserve video memory at "
                "0x%lx\n", info->fix.smem_start);
        err = -EIO;
        goto out_reg;
    }

    uvesafb_init_mtrr(info);
    uvesafb_ioremap(info);

    if (!info->screen_base) {
        printk(KERN_ERR
            "uvesafb: abort, cannot ioremap 0x%x bytes of video "
            "memory at 0x%lx\n",
            info->fix.smem_len, info->fix.smem_start);
        err = -EIO;
        goto out_mem;
    }

    platform_set_drvdata(dev, info);

    if (register_framebuffer(info) < 0) {
        printk(KERN_ERR
            "uvesafb: failed to register framebuffer device\n");
        err = -EINVAL;
        goto out_unmap;
    }

    printk(KERN_INFO "uvesafb: framebuffer at 0x%lx, mapped to 0x%p, "
            "using %dk, total %dk\n", info->fix.smem_start,
            info->screen_base, info->fix.smem_len/1024,
            par->vbe_ib.total_memory * 64);
    printk(KERN_INFO "fb%d: %s frame buffer device\n", info->node,
            info->fix.id);

    err = sysfs_create_group(&dev->dev.kobj, &uvesafb_dev_attgrp);
    if (err != 0)
        printk(KERN_WARNING "fb%d: failed to register attributes\n",
            info->node);

    return 0;

out_unmap:
    iounmap(info->screen_base);
out_mem:
    release_mem_region(info->fix.smem_start, info->fix.smem_len);
out_reg:
    release_region(0x3c0, 32);
out_mode:
    if (!list_empty(&info->modelist))
        fb_destroy_modelist(&info->modelist);
    fb_destroy_modedb(info->monspecs.modedb);
    fb_dealloc_cmap(&info->cmap);
out:
    if (par->vbe_modes)
        kfree(par->vbe_modes);

    framebuffer_release(info);
    return err;
}

static int uvesafb_remove(struct platform_device *dev)
{
    struct fb_info *info = platform_get_drvdata(dev);

    if (info) {
        struct uvesafb_par *par = info->par;

        sysfs_remove_group(&dev->dev.kobj, &uvesafb_dev_attgrp);
        unregister_framebuffer(info);
        release_region(0x3c0, 32);
        iounmap(info->screen_base);
        release_mem_region(info->fix.smem_start, info->fix.smem_len);
        fb_destroy_modedb(info->monspecs.modedb);
        fb_dealloc_cmap(&info->cmap);

        if (par) {
            if (par->vbe_modes)
                kfree(par->vbe_modes);
            if (par->vbe_state_orig)
                kfree(par->vbe_state_orig);
            if (par->vbe_state_saved)
                kfree(par->vbe_state_saved);
        }

        framebuffer_release(info);
    }
    return 0;
}

static struct platform_driver uvesafb_driver = {
    .probe  = uvesafb_probe,
    .remove = uvesafb_remove,
    .driver = {
        .name = "uvesafb",
    },
};

static struct platform_device *uvesafb_device;

#ifndef MODULE
static int __devinit uvesafb_setup(char *options)
{
    char *this_opt;

    if (!options || !*options)
        return 0;

    while ((this_opt = strsep(&options, ",")) != NULL) {
        if (!*this_opt) continue;

        if (!strcmp(this_opt, "redraw"))
            ypan = 0;
        else if (!strcmp(this_opt, "ypan"))
            ypan = 1;
        else if (!strcmp(this_opt, "ywrap"))
            ypan = 2;
        else if (!strcmp(this_opt, "vgapal"))
            pmi_setpal = 0;
        else if (!strcmp(this_opt, "pmipal"))
            pmi_setpal = 1;
        else if (!strncmp(this_opt, "mtrr:", 5))
            mtrr = simple_strtoul(this_opt+5, NULL, 0);
        else if (!strcmp(this_opt, "nomtrr"))
            mtrr = 0;
        else if (!strcmp(this_opt, "nocrtc"))
            nocrtc = 1;
        else if (!strcmp(this_opt, "noedid"))
            noedid = 1;
        else if (!strcmp(this_opt, "noblank"))
            blank = 0;
        else if (!strncmp(this_opt, "vtotal:", 7))
            vram_total = simple_strtoul(this_opt + 7, NULL, 0);
        else if (!strncmp(this_opt, "vremap:", 7))
            vram_remap = simple_strtoul(this_opt + 7, NULL, 0);
        else if (!strncmp(this_opt, "maxhf:", 6))
            maxhf = simple_strtoul(this_opt + 6, NULL, 0);
        else if (!strncmp(this_opt, "maxvf:", 6))
            maxvf = simple_strtoul(this_opt + 6, NULL, 0);
        else if (!strncmp(this_opt, "maxclk:", 7))
            maxclk = simple_strtoul(this_opt + 7, NULL, 0);
        else if (!strncmp(this_opt, "vbemode:", 8))
            vbemode = simple_strtoul(this_opt + 8, NULL, 0);
        else if (this_opt[0] >= '0' && this_opt[0] <= '9') {
            mode_option = this_opt;
        } else {
            printk(KERN_WARNING
                "uvesafb: unrecognized option %s\n", this_opt);
        }
    }

    return 0;
}
#endif /* !MODULE */

static ssize_t show_v86d(struct device_driver *dev, char *buf)
{
    return snprintf(buf, PAGE_SIZE, "%s\n", v86d_path);
}

static ssize_t store_v86d(struct device_driver *dev, const char *buf,
        size_t count)
{
    strncpy(v86d_path, buf, PATH_MAX);
    return count;
}

static DRIVER_ATTR(v86d, S_IRUGO | S_IWUSR, show_v86d, store_v86d);

static int __devinit uvesafb_init(void)
{
    int err;

#ifndef MODULE
    char *option = NULL;

    if (fb_get_options("uvesafb", &option))
        return -ENODEV;
    uvesafb_setup(option);
#endif
    err = cn_add_callback(&uvesafb_cn_id, "uvesafb", uvesafb_cn_callback);
    if (err)
        return err;

    err = platform_driver_register(&uvesafb_driver);

    if (!err) {
        uvesafb_device = platform_device_alloc("uvesafb", 0);
        if (uvesafb_device)
            err = platform_device_add(uvesafb_device);
        else
            err = -ENOMEM;

        if (err) {
            platform_device_put(uvesafb_device);
            platform_driver_unregister(&uvesafb_driver);
            cn_del_callback(&uvesafb_cn_id);
            return err;
        }

        err = driver_create_file(&uvesafb_driver.driver,
                &driver_attr_v86d);
        if (err) {
            printk(KERN_WARNING "uvesafb: failed to register "
                    "attributes\n");
            err = 0;
        }
    }
    return err;
}

module_init(uvesafb_init);

static void __devexit uvesafb_exit(void)
{
    struct uvesafb_ktask *task;

    if (v86d_started) {
        task = uvesafb_prep();
        if (task) {
            task->t.flags = TF_EXIT;
            uvesafb_exec(task);
            uvesafb_free(task);
        }
    }

    cn_del_callback(&uvesafb_cn_id);
    driver_remove_file(&uvesafb_driver.driver, &driver_attr_v86d);
    platform_device_unregister(uvesafb_device);
    platform_driver_unregister(&uvesafb_driver);
}

module_exit(uvesafb_exit);

static int param_set_scroll(const char *val, const struct kernel_param *kp)
{
    ypan = 0;

    if (!strcmp(val, "redraw"))
        ypan = 0;
    else if (!strcmp(val, "ypan"))
        ypan = 1;
    else if (!strcmp(val, "ywrap"))
        ypan = 2;
    else
        return -EINVAL;

    return 0;
}
static struct kernel_param_ops param_ops_scroll = {
    .set = param_set_scroll,
};
#define param_check_scroll(name, p) __param_check(name, p, void)

module_param_named(scroll, ypan, scroll, 0);
MODULE_PARM_DESC(scroll,
    "Scrolling mode, set to 'redraw', 'ypan', or 'ywrap'");
module_param_named(vgapal, pmi_setpal, invbool, 0);
MODULE_PARM_DESC(vgapal, "Set palette using VGA registers");
module_param_named(pmipal, pmi_setpal, bool, 0);
MODULE_PARM_DESC(pmipal, "Set palette using PMI calls");
module_param(mtrr, uint, 0);
MODULE_PARM_DESC(mtrr,
    "Memory Type Range Registers setting. Use 0 to disable.");
module_param(blank, bool, 0);
MODULE_PARM_DESC(blank, "Enable hardware blanking");
module_param(nocrtc, bool, 0);
MODULE_PARM_DESC(nocrtc, "Ignore CRTC timings when setting modes");
module_param(noedid, bool, 0);
MODULE_PARM_DESC(noedid,
    "Ignore EDID-provided monitor limits when setting modes");
module_param(vram_remap, uint, 0);
MODULE_PARM_DESC(vram_remap, "Set amount of video memory to be used [MiB]");
module_param(vram_total, uint, 0);
MODULE_PARM_DESC(vram_total, "Set total amount of video memoery [MiB]");
module_param(maxclk, ushort, 0);
MODULE_PARM_DESC(maxclk, "Maximum pixelclock [MHz], overrides EDID data");
module_param(maxhf, ushort, 0);
MODULE_PARM_DESC(maxhf,
    "Maximum horizontal frequency [kHz], overrides EDID data");
module_param(maxvf, ushort, 0);
MODULE_PARM_DESC(maxvf,
    "Maximum vertical frequency [Hz], overrides EDID data");
module_param(mode_option, charp, 0);
MODULE_PARM_DESC(mode_option,
    "Specify initial video mode as \"<xres>x<yres>[-<bpp>][@<refresh>]\"");
module_param(vbemode, ushort, 0);
MODULE_PARM_DESC(vbemode,
    "VBE mode number to set, overrides the 'mode' option");
module_param_string(v86d, v86d_path, PATH_MAX, 0660);
MODULE_PARM_DESC(v86d, "Path to the v86d userspace helper.");

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Michal Januszewski <[email protected]>");
MODULE_DESCRIPTION("Framebuffer driver for VBE2.0+ compliant graphics boards");