diff options
Diffstat (limited to 'drivers/video/fbmem.c')
| -rw-r--r-- | drivers/video/fbmem.c | 223 |
1 files changed, 148 insertions, 75 deletions
diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c index e0c2284924b..5aac00eb183 100644 --- a/drivers/video/fbmem.c +++ b/drivers/video/fbmem.c @@ -42,9 +42,34 @@ #define FBPIXMAPSIZE (1024 * 8) +static DEFINE_MUTEX(registration_lock); struct fb_info *registered_fb[FB_MAX] __read_mostly; int num_registered_fb __read_mostly; +static struct fb_info *get_fb_info(unsigned int idx) +{ + struct fb_info *fb_info; + + if (idx >= FB_MAX) + return ERR_PTR(-ENODEV); + + mutex_lock(®istration_lock); + fb_info = registered_fb[idx]; + if (fb_info) + atomic_inc(&fb_info->count); + mutex_unlock(®istration_lock); + + return fb_info; +} + +static void put_fb_info(struct fb_info *fb_info) +{ + if (!atomic_dec_and_test(&fb_info->count)) + return; + if (fb_info->fbops->fb_destroy) + fb_info->fbops->fb_destroy(fb_info); +} + int lock_fb_info(struct fb_info *info) { mutex_lock(&info->lock); @@ -647,6 +672,7 @@ int fb_show_logo(struct fb_info *info, int rotate) { return 0; } static void *fb_seq_start(struct seq_file *m, loff_t *pos) { + mutex_lock(®istration_lock); return (*pos < FB_MAX) ? pos : NULL; } @@ -658,6 +684,7 @@ static void *fb_seq_next(struct seq_file *m, void *v, loff_t *pos) static void fb_seq_stop(struct seq_file *m, void *v) { + mutex_unlock(®istration_lock); } static int fb_seq_show(struct seq_file *m, void *v) @@ -690,13 +717,30 @@ static const struct file_operations fb_proc_fops = { .release = seq_release, }; -static ssize_t -fb_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) +/* + * We hold a reference to the fb_info in file->private_data, + * but if the current registered fb has changed, we don't + * actually want to use it. + * + * So look up the fb_info using the inode minor number, + * and just verify it against the reference we have. + */ +static struct fb_info *file_fb_info(struct file *file) { - unsigned long p = *ppos; struct inode *inode = file->f_path.dentry->d_inode; int fbidx = iminor(inode); struct fb_info *info = registered_fb[fbidx]; + + if (info != file->private_data) + info = NULL; + return info; +} + +static ssize_t +fb_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) +{ + unsigned long p = *ppos; + struct fb_info *info = file_fb_info(file); u8 *buffer, *dst; u8 __iomem *src; int c, cnt = 0, err = 0; @@ -761,9 +805,7 @@ static ssize_t fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { unsigned long p = *ppos; - struct inode *inode = file->f_path.dentry->d_inode; - int fbidx = iminor(inode); - struct fb_info *info = registered_fb[fbidx]; + struct fb_info *info = file_fb_info(file); u8 *buffer, *src; u8 __iomem *dst; int c, cnt = 0, err = 0; @@ -1141,10 +1183,10 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, static long fb_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { - struct inode *inode = file->f_path.dentry->d_inode; - int fbidx = iminor(inode); - struct fb_info *info = registered_fb[fbidx]; + struct fb_info *info = file_fb_info(file); + if (!info) + return -ENODEV; return do_fb_ioctl(info, cmd, arg); } @@ -1265,12 +1307,13 @@ static int fb_get_fscreeninfo(struct fb_info *info, unsigned int cmd, static long fb_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { - struct inode *inode = file->f_path.dentry->d_inode; - int fbidx = iminor(inode); - struct fb_info *info = registered_fb[fbidx]; - struct fb_ops *fb = info->fbops; + struct fb_info *info = file_fb_info(file); + struct fb_ops *fb; long ret = -ENOIOCTLCMD; + if (!info) + return -ENODEV; + fb = info->fbops; switch(cmd) { case FBIOGET_VSCREENINFO: case FBIOPUT_VSCREENINFO: @@ -1303,16 +1346,18 @@ static long fb_compat_ioctl(struct file *file, unsigned int cmd, static int fb_mmap(struct file *file, struct vm_area_struct * vma) { - int fbidx = iminor(file->f_path.dentry->d_inode); - struct fb_info *info = registered_fb[fbidx]; - struct fb_ops *fb = info->fbops; + struct fb_info *info = file_fb_info(file); + struct fb_ops *fb; unsigned long off; unsigned long start; u32 len; + if (!info) + return -ENODEV; if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT)) return -EINVAL; off = vma->vm_pgoff << PAGE_SHIFT; + fb = info->fbops; if (!fb) return -ENODEV; mutex_lock(&info->mm_lock); @@ -1361,14 +1406,16 @@ __releases(&info->lock) struct fb_info *info; int res = 0; - if (fbidx >= FB_MAX) - return -ENODEV; - info = registered_fb[fbidx]; - if (!info) + info = get_fb_info(fbidx); + if (!info) { request_module("fb%d", fbidx); - info = registered_fb[fbidx]; - if (!info) - return -ENODEV; + info = get_fb_info(fbidx); + if (!info) + return -ENODEV; + } + if (IS_ERR(info)) + return PTR_ERR(info); + mutex_lock(&info->lock); if (!try_module_get(info->fbops->owner)) { res = -ENODEV; @@ -1386,6 +1433,8 @@ __releases(&info->lock) #endif out: mutex_unlock(&info->lock); + if (res) + put_fb_info(info); return res; } @@ -1401,6 +1450,7 @@ __releases(&info->lock) info->fbops->fb_release(info,1); module_put(info->fbops->owner); mutex_unlock(&info->lock); + put_fb_info(info); return 0; } @@ -1487,8 +1537,10 @@ static bool fb_do_apertures_overlap(struct apertures_struct *gena, return false; } +static int do_unregister_framebuffer(struct fb_info *fb_info); + #define VGA_FB_PHYS 0xA0000 -void remove_conflicting_framebuffers(struct apertures_struct *a, +static void do_remove_conflicting_framebuffers(struct apertures_struct *a, const char *name, bool primary) { int i; @@ -1510,43 +1562,32 @@ void remove_conflicting_framebuffers(struct apertures_struct *a, printk(KERN_INFO "fb: conflicting fb hw usage " "%s vs %s - removing generic driver\n", name, registered_fb[i]->fix.id); - unregister_framebuffer(registered_fb[i]); + do_unregister_framebuffer(registered_fb[i]); } } } -EXPORT_SYMBOL(remove_conflicting_framebuffers); -/** - * register_framebuffer - registers a frame buffer device - * @fb_info: frame buffer info structure - * - * Registers a frame buffer device @fb_info. - * - * Returns negative errno on error, or zero for success. - * - */ - -int -register_framebuffer(struct fb_info *fb_info) +static int do_register_framebuffer(struct fb_info *fb_info) { int i; struct fb_event event; struct fb_videomode mode; - if (num_registered_fb == FB_MAX) - return -ENXIO; - if (fb_check_foreignness(fb_info)) return -ENOSYS; - remove_conflicting_framebuffers(fb_info->apertures, fb_info->fix.id, + do_remove_conflicting_framebuffers(fb_info->apertures, fb_info->fix.id, fb_is_primary_device(fb_info)); + if (num_registered_fb == FB_MAX) + return -ENXIO; + num_registered_fb++; for (i = 0 ; i < FB_MAX; i++) if (!registered_fb[i]) break; fb_info->node = i; + atomic_set(&fb_info->count, 1); mutex_init(&fb_info->lock); mutex_init(&fb_info->mm_lock); @@ -1592,36 +1633,14 @@ register_framebuffer(struct fb_info *fb_info) return 0; } - -/** - * unregister_framebuffer - releases a frame buffer device - * @fb_info: frame buffer info structure - * - * Unregisters a frame buffer device @fb_info. - * - * Returns negative errno on error, or zero for success. - * - * This function will also notify the framebuffer console - * to release the driver. - * - * This is meant to be called within a driver's module_exit() - * function. If this is called outside module_exit(), ensure - * that the driver implements fb_open() and fb_release() to - * check that no processes are using the device. - */ - -int -unregister_framebuffer(struct fb_info *fb_info) +static int do_unregister_framebuffer(struct fb_info *fb_info) { struct fb_event event; int i, ret = 0; i = fb_info->node; - if (!registered_fb[i]) { - ret = -EINVAL; - goto done; - } - + if (i < 0 || i >= FB_MAX || registered_fb[i] != fb_info) + return -EINVAL; if (!lock_fb_info(fb_info)) return -ENODEV; @@ -1629,16 +1648,14 @@ unregister_framebuffer(struct fb_info *fb_info) ret = fb_notifier_call_chain(FB_EVENT_FB_UNBIND, &event); unlock_fb_info(fb_info); - if (ret) { - ret = -EINVAL; - goto done; - } + if (ret) + return -EINVAL; if (fb_info->pixmap.addr && (fb_info->pixmap.flags & FB_PIXMAP_DEFAULT)) kfree(fb_info->pixmap.addr); fb_destroy_modelist(&fb_info->modelist); - registered_fb[i]=NULL; + registered_fb[i] = NULL; num_registered_fb--; fb_cleanup_device(fb_info); device_destroy(fb_class, MKDEV(FB_MAJOR, i)); @@ -1646,9 +1663,65 @@ unregister_framebuffer(struct fb_info *fb_info) fb_notifier_call_chain(FB_EVENT_FB_UNREGISTERED, &event); /* this may free fb info */ - if (fb_info->fbops->fb_destroy) - fb_info->fbops->fb_destroy(fb_info); -done: + put_fb_info(fb_info); + return 0; +} + +void remove_conflicting_framebuffers(struct apertures_struct *a, + const char *name, bool primary) +{ + mutex_lock(®istration_lock); + do_remove_conflicting_framebuffers(a, name, primary); + mutex_unlock(®istration_lock); +} +EXPORT_SYMBOL(remove_conflicting_framebuffers); + +/** + * register_framebuffer - registers a frame buffer device + * @fb_info: frame buffer info structure + * + * Registers a frame buffer device @fb_info. + * + * Returns negative errno on error, or zero for success. + * + */ +int +register_framebuffer(struct fb_info *fb_info) +{ + int ret; + + mutex_lock(®istration_lock); + ret = do_register_framebuffer(fb_info); + mutex_unlock(®istration_lock); + + return ret; +} + +/** + * unregister_framebuffer - releases a frame buffer device + * @fb_info: frame buffer info structure + * + * Unregisters a frame buffer device @fb_info. + * + * Returns negative errno on error, or zero for success. + * + * This function will also notify the framebuffer console + * to release the driver. + * + * This is meant to be called within a driver's module_exit() + * function. If this is called outside module_exit(), ensure + * that the driver implements fb_open() and fb_release() to + * check that no processes are using the device. + */ +int +unregister_framebuffer(struct fb_info *fb_info) +{ + int ret; + + mutex_lock(®istration_lock); + ret = do_unregister_framebuffer(fb_info); + mutex_unlock(®istration_lock); + return ret; } |