root/drivers/video/fbdev/sbuslib.c
// SPDX-License-Identifier: GPL-2.0
/* sbuslib.c: Helper library for SBUS framebuffer drivers.
 *
 * Copyright (C) 2003 David S. Miller (davem@redhat.com)
 */

#include <linux/compat.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/fb.h>
#include <linux/mm.h>
#include <linux/uaccess.h>
#include <linux/of.h>

#include <asm/fbio.h>

#include "sbuslib.h"

void sbusfb_fill_var(struct fb_var_screeninfo *var, struct device_node *dp,
                     int bpp)
{
        memset(var, 0, sizeof(*var));

        var->xres = of_getintprop_default(dp, "width", 1152);
        var->yres = of_getintprop_default(dp, "height", 900);
        var->xres_virtual = var->xres;
        var->yres_virtual = var->yres;
        var->bits_per_pixel = bpp;
}

EXPORT_SYMBOL(sbusfb_fill_var);

static unsigned long sbusfb_mmapsize(long size, unsigned long fbsize)
{
        if (size == SBUS_MMAP_EMPTY) return 0;
        if (size >= 0) return size;
        return fbsize * (-size);
}

int sbusfb_mmap_helper(const struct sbus_mmap_map *map,
                       unsigned long physbase,
                       unsigned long fbsize,
                       unsigned long iospace,
                       struct vm_area_struct *vma)
{
        unsigned int size, page, r, map_size;
        unsigned long map_offset = 0;
        unsigned long off;
        int i;

        if (!(vma->vm_flags & (VM_SHARED | VM_MAYSHARE)))
                return -EINVAL;

        size = vma->vm_end - vma->vm_start;
        if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
                return -EINVAL;

        off = vma->vm_pgoff << PAGE_SHIFT;

        /* VM_IO | VM_DONTEXPAND | VM_DONTDUMP are set by remap_pfn_range() */

        vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
        vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);

        /* Each page, see which map applies */
        for (page = 0; page < size; ){
                map_size = 0;
                for (i = 0; map[i].size; i++)
                        if (map[i].voff == off+page) {
                                map_size = sbusfb_mmapsize(map[i].size, fbsize);
#ifdef __sparc_v9__
#define POFF_MASK       (PAGE_MASK|0x1UL)
#else
#define POFF_MASK       (PAGE_MASK)
#endif
                                map_offset = (physbase + map[i].poff) & POFF_MASK;
                                break;
                        }
                if (!map_size) {
                        page += PAGE_SIZE;
                        continue;
                }
                if (page + map_size > size)
                        map_size = size - page;
                r = io_remap_pfn_range(vma,
                                        vma->vm_start + page,
                                        MK_IOSPACE_PFN(iospace,
                                                map_offset >> PAGE_SHIFT),
                                        map_size,
                                        vma->vm_page_prot);
                if (r)
                        return -EAGAIN;
                page += map_size;
        }

        return 0;
}
EXPORT_SYMBOL(sbusfb_mmap_helper);

int sbusfb_ioctl_helper(unsigned long cmd, unsigned long arg,
                        struct fb_info *info,
                        int type, int fb_depth, unsigned long fb_size)
{
        switch(cmd) {
        case FBIOGTYPE: {
                struct fbtype __user *f = (struct fbtype __user *) arg;

                if (put_user(type, &f->fb_type) ||
                    put_user(info->var.yres, &f->fb_height) ||
                    put_user(info->var.xres, &f->fb_width) ||
                    put_user(fb_depth, &f->fb_depth) ||
                    put_user(0, &f->fb_cmsize) ||
                    put_user(fb_size, &f->fb_cmsize))
                        return -EFAULT;
                return 0;
        }
        case FBIOPUTCMAP_SPARC: {
                struct fbcmap __user *c = (struct fbcmap __user *) arg;
                struct fb_cmap cmap;
                u16 red, green, blue;
                u8 red8, green8, blue8;
                unsigned char __user *ured;
                unsigned char __user *ugreen;
                unsigned char __user *ublue;
                unsigned int index, count, i;

                if (get_user(index, &c->index) ||
                    get_user(count, &c->count) ||
                    get_user(ured, &c->red) ||
                    get_user(ugreen, &c->green) ||
                    get_user(ublue, &c->blue))
                        return -EFAULT;

                cmap.len = 1;
                cmap.red = &red;
                cmap.green = &green;
                cmap.blue = &blue;
                cmap.transp = NULL;
                for (i = 0; i < count; i++) {
                        int err;

                        if (get_user(red8, &ured[i]) ||
                            get_user(green8, &ugreen[i]) ||
                            get_user(blue8, &ublue[i]))
                                return -EFAULT;

                        red = red8 << 8;
                        green = green8 << 8;
                        blue = blue8 << 8;

                        cmap.start = index + i;
                        err = fb_set_cmap(&cmap, info);
                        if (err)
                                return err;
                }
                return 0;
        }
        case FBIOGETCMAP_SPARC: {
                struct fbcmap __user *c = (struct fbcmap __user *) arg;
                unsigned char __user *ured;
                unsigned char __user *ugreen;
                unsigned char __user *ublue;
                struct fb_cmap *cmap = &info->cmap;
                unsigned int index, count, i;
                u8 red, green, blue;

                if (get_user(index, &c->index) ||
                    get_user(count, &c->count) ||
                    get_user(ured, &c->red) ||
                    get_user(ugreen, &c->green) ||
                    get_user(ublue, &c->blue))
                        return -EFAULT;

                if (index > cmap->len || count > cmap->len - index)
                        return -EINVAL;

                for (i = 0; i < count; i++) {
                        red = cmap->red[index + i] >> 8;
                        green = cmap->green[index + i] >> 8;
                        blue = cmap->blue[index + i] >> 8;
                        if (put_user(red, &ured[i]) ||
                            put_user(green, &ugreen[i]) ||
                            put_user(blue, &ublue[i]))
                                return -EFAULT;
                }
                return 0;
        }
        default:
                return -EINVAL;
        }
}
EXPORT_SYMBOL(sbusfb_ioctl_helper);

#ifdef CONFIG_COMPAT
int sbusfb_compat_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg)
{
        switch (cmd) {
        case FBIOGTYPE:
        case FBIOSATTR:
        case FBIOGATTR:
        case FBIOSVIDEO:
        case FBIOGVIDEO:
        case FBIOSCURSOR32:
        case FBIOGCURSOR32:     /* This is not implemented yet.
                                   Later it should be converted... */
        case FBIOSCURPOS:
        case FBIOGCURPOS:
        case FBIOGCURMAX:
                return info->fbops->fb_ioctl(info, cmd, arg);
        case FBIOPUTCMAP32:
        case FBIOPUTCMAP_SPARC: {
                struct fbcmap32 c;
                struct fb_cmap cmap;
                u16 red, green, blue;
                u8 red8, green8, blue8;
                unsigned char __user *ured;
                unsigned char __user *ugreen;
                unsigned char __user *ublue;
                unsigned int i;

                if (copy_from_user(&c, compat_ptr(arg), sizeof(c)))
                        return -EFAULT;
                ured = compat_ptr(c.red);
                ugreen = compat_ptr(c.green);
                ublue = compat_ptr(c.blue);

                cmap.len = 1;
                cmap.red = &red;
                cmap.green = &green;
                cmap.blue = &blue;
                cmap.transp = NULL;
                for (i = 0; i < c.count; i++) {
                        int err;

                        if (get_user(red8, &ured[i]) ||
                            get_user(green8, &ugreen[i]) ||
                            get_user(blue8, &ublue[i]))
                                return -EFAULT;

                        red = red8 << 8;
                        green = green8 << 8;
                        blue = blue8 << 8;

                        cmap.start = c.index + i;
                        err = fb_set_cmap(&cmap, info);
                        if (err)
                                return err;
                }
                return 0;
        }
        case FBIOGETCMAP32: {
                struct fbcmap32 c;
                unsigned char __user *ured;
                unsigned char __user *ugreen;
                unsigned char __user *ublue;
                struct fb_cmap *cmap = &info->cmap;
                unsigned int index, i;
                u8 red, green, blue;

                if (copy_from_user(&c, compat_ptr(arg), sizeof(c)))
                        return -EFAULT;
                index = c.index;
                ured = compat_ptr(c.red);
                ugreen = compat_ptr(c.green);
                ublue = compat_ptr(c.blue);

                if (index > cmap->len || c.count > cmap->len - index)
                        return -EINVAL;

                for (i = 0; i < c.count; i++) {
                        red = cmap->red[index + i] >> 8;
                        green = cmap->green[index + i] >> 8;
                        blue = cmap->blue[index + i] >> 8;
                        if (put_user(red, &ured[i]) ||
                            put_user(green, &ugreen[i]) ||
                            put_user(blue, &ublue[i]))
                                return -EFAULT;
                }
                return 0;
        }
        default:
                return -ENOIOCTLCMD;
        }
}
EXPORT_SYMBOL(sbusfb_compat_ioctl);
#endif