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path: root/drivers/video/fbmem.c
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Diffstat (limited to 'drivers/video/fbmem.c')
-rw-r--r--drivers/video/fbmem.c223
1 files changed, 148 insertions, 75 deletions
diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index e0c22849..5aac00e 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(&registration_lock);
+ fb_info = registered_fb[idx];
+ if (fb_info)
+ atomic_inc(&fb_info->count);
+ mutex_unlock(&registration_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(&registration_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(&registration_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(&registration_lock);
+ do_remove_conflicting_framebuffers(a, name, primary);
+ mutex_unlock(&registration_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(&registration_lock);
+ ret = do_register_framebuffer(fb_info);
+ mutex_unlock(&registration_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(&registration_lock);
+ ret = do_unregister_framebuffer(fb_info);
+ mutex_unlock(&registration_lock);
+
return ret;
}
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