[media] cpia2: convert .ioctl to .unlocked_ioctl

Implement core-assisted locking in cpia2.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

3 files changed, 50 insertions, 121 deletions

diff --git a/drivers/media/video/cpia2/cpia2.h b/drivers/media/video/cpia2/cpia2.h
index 916c13d5cf7d..6d6d1843791c 100644
--- a/drivers/media/video/cpia2/cpia2.h
+++ b/drivers/media/video/cpia2/cpia2.h
@@ -378,7 +378,7 @@ struct cpia2_fh {
 
 struct camera_data {
         /* locks */
-        struct mutex busy_lock; /* guard against SMP multithreading */
+        struct mutex v4l2_lock; /* serialize file operations */
         struct v4l2_prio_state prio;
 
         /* camera status */
diff --git a/drivers/media/video/cpia2/cpia2_core.c b/drivers/media/video/cpia2/cpia2_core.c
index 9606bc01b803..aaffca8e13fd 100644
--- a/drivers/media/video/cpia2/cpia2_core.c
+++ b/drivers/media/video/cpia2/cpia2_core.c
@@ -2247,7 +2247,7 @@ struct camera_data *cpia2_init_camera_struct(void)
 
 
         cam->present = 1;
-        mutex_init(&cam->busy_lock);
+        mutex_init(&cam->v4l2_lock);
         init_waitqueue_head(&cam->wq_stream);
 
         return cam;
@@ -2365,9 +2365,9 @@ long cpia2_read(struct camera_data *cam,
                 char __user *buf, unsigned long count, int noblock)
 {
         struct framebuf *frame;
-        if (!count) {
+
+        if (!count)
                 return 0;
-        }
 
         if (!buf) {
                 ERR("%s: buffer NULL\n",__func__);
@@ -2379,17 +2379,12 @@ long cpia2_read(struct camera_data *cam,
                 return -EINVAL;
         }
 
-        /* make this _really_ smp and multithread-safe */
-        if (mutex_lock_interruptible(&cam->busy_lock))
-                return -ERESTARTSYS;
-
         if (!cam->present) {
                 LOG("%s: camera removed\n",__func__);
-                mutex_unlock(&cam->busy_lock);
                 return 0;       /* EOF */
         }
 
-        if(!cam->streaming) {
+        if (!cam->streaming) {
                 /* Start streaming */
                 cpia2_usb_stream_start(cam,
                                        cam->params.camera_state.stream_mode);
@@ -2398,42 +2393,31 @@ long cpia2_read(struct camera_data *cam,
         /* Copy cam->curbuff in case it changes while we're processing */
         frame = cam->curbuff;
         if (noblock && frame->status != FRAME_READY) {
-                mutex_unlock(&cam->busy_lock);
                 return -EAGAIN;
         }
 
-        if(frame->status != FRAME_READY) {
-                mutex_unlock(&cam->busy_lock);
+        if (frame->status != FRAME_READY) {
+                mutex_unlock(&cam->v4l2_lock);
                 wait_event_interruptible(cam->wq_stream,
                                !cam->present ||
                                (frame = cam->curbuff)->status == FRAME_READY);
+                mutex_lock(&cam->v4l2_lock);
                 if (signal_pending(current))
                         return -ERESTARTSYS;
-                /* make this _really_ smp and multithread-safe */
-                if (mutex_lock_interruptible(&cam->busy_lock)) {
-                        return -ERESTARTSYS;
-                }
-                if(!cam->present) {
-                        mutex_unlock(&cam->busy_lock);
+                if (!cam->present)
                         return 0;
-                }
         }
 
         /* copy data to user space */
-        if (frame->length > count) {
-                mutex_unlock(&cam->busy_lock);
+        if (frame->length > count)
                 return -EFAULT;
-        }
-        if (copy_to_user(buf, frame->data, frame->length)) {
-                mutex_unlock(&cam->busy_lock);
+        if (copy_to_user(buf, frame->data, frame->length))
                 return -EFAULT;
-        }
 
         count = frame->length;
 
         frame->status = FRAME_EMPTY;
 
-        mutex_unlock(&cam->busy_lock);
         return count;
 }
 
@@ -2447,17 +2431,13 @@ unsigned int cpia2_poll(struct camera_data *cam, struct file *filp,
 {
         unsigned int status=0;
 
-        if(!cam) {
+        if (!cam) {
                 ERR("%s: Internal error, camera_data not found!\n",__func__);
                 return POLLERR;
         }
 
-        mutex_lock(&cam->busy_lock);
-
-        if(!cam->present) {
-                mutex_unlock(&cam->busy_lock);
+        if (!cam->present)
                 return POLLHUP;
-        }
 
         if(!cam->streaming) {
                 /* Start streaming */
@@ -2465,16 +2445,13 @@ unsigned int cpia2_poll(struct camera_data *cam, struct file *filp,
                                        cam->params.camera_state.stream_mode);
         }
 
-        mutex_unlock(&cam->busy_lock);
         poll_wait(filp, &cam->wq_stream, wait);
-        mutex_lock(&cam->busy_lock);
 
         if(!cam->present)
                 status = POLLHUP;
         else if(cam->curbuff->status == FRAME_READY)
                 status = POLLIN | POLLRDNORM;
 
-        mutex_unlock(&cam->busy_lock);
         return status;
 }
 
@@ -2496,29 +2473,19 @@ int cpia2_remap_buffer(struct camera_data *cam, struct vm_area_struct *vma)
 
         DBG("mmap offset:%ld size:%ld\n", start_offset, size);
 
-        /* make this _really_ smp-safe */
-        if (mutex_lock_interruptible(&cam->busy_lock))
-                return -ERESTARTSYS;
-
-        if (!cam->present) {
-                mutex_unlock(&cam->busy_lock);
+        if (!cam->present)
                 return -ENODEV;
-        }
 
         if (size > cam->frame_size*cam->num_frames  ||
             (start_offset % cam->frame_size) != 0 ||
-            (start_offset+size > cam->frame_size*cam->num_frames)) {
-                mutex_unlock(&cam->busy_lock);
+            (start_offset+size > cam->frame_size*cam->num_frames))
                 return -EINVAL;
-        }
 
         pos = ((unsigned long) (cam->frame_buffer)) + start_offset;
         while (size > 0) {
                 page = kvirt_to_pa(pos);
-                if (remap_pfn_range(vma, start, page >> PAGE_SHIFT, PAGE_SIZE, PAGE_SHARED)) {
-                        mutex_unlock(&cam->busy_lock);
+                if (remap_pfn_range(vma, start, page >> PAGE_SHIFT, PAGE_SIZE, PAGE_SHARED))
                         return -EAGAIN;
-                }
                 start += PAGE_SIZE;
                 pos += PAGE_SIZE;
                 if (size > PAGE_SIZE)
@@ -2528,7 +2495,5 @@ int cpia2_remap_buffer(struct camera_data *cam, struct vm_area_struct *vma)
         }
 
         cam->mmapped = true;
-        mutex_unlock(&cam->busy_lock);
         return 0;
 }
-
diff --git a/drivers/media/video/cpia2/cpia2_v4l.c b/drivers/media/video/cpia2/cpia2_v4l.c
index 7edf80b0d01a..9bad39842936 100644
--- a/drivers/media/video/cpia2/cpia2_v4l.c
+++ b/drivers/media/video/cpia2/cpia2_v4l.c
@@ -238,59 +238,40 @@ static struct v4l2_queryctrl controls[] = {
 static int cpia2_open(struct file *file)
 {
         struct camera_data *cam = video_drvdata(file);
-        int retval = 0;
+        struct cpia2_fh *fh;
 
         if (!cam) {
                 ERR("Internal error, camera_data not found!\n");
                 return -ENODEV;
         }
 
-        if(mutex_lock_interruptible(&cam->busy_lock))
-                return -ERESTARTSYS;
-
-        if(!cam->present) {
-                retval = -ENODEV;
-                goto err_return;
-        }
+        if (!cam->present)
+                return -ENODEV;
 
-        if (cam->open_count > 0) {
-                goto skip_init;
-        }
+        if (cam->open_count == 0) {
+                if (cpia2_allocate_buffers(cam))
+                        return -ENOMEM;
 
-        if (cpia2_allocate_buffers(cam)) {
-                retval = -ENOMEM;
-                goto err_return;
-        }
+                /* reset the camera */
+                if (cpia2_reset_camera(cam) < 0)
+                        return -EIO;
 
-        /* reset the camera */
-        if (cpia2_reset_camera(cam) < 0) {
-                retval = -EIO;
-                goto err_return;
+                cam->APP_len = 0;
+                cam->COM_len = 0;
         }
 
-        cam->APP_len = 0;
-        cam->COM_len = 0;
-
-skip_init:
-        {
-                struct cpia2_fh *fh = kmalloc(sizeof(*fh),GFP_KERNEL);
-                if(!fh) {
-                        retval = -ENOMEM;
-                        goto err_return;
-                }
-                file->private_data = fh;
-                fh->prio = V4L2_PRIORITY_UNSET;
-                v4l2_prio_open(&cam->prio, &fh->prio);
-                fh->mmapped = 0;
-        }
+        fh = kmalloc(sizeof(*fh), GFP_KERNEL);
+        if (!fh)
+                return -ENOMEM;
+        file->private_data = fh;
+        fh->prio = V4L2_PRIORITY_UNSET;
+        v4l2_prio_open(&cam->prio, &fh->prio);
+        fh->mmapped = 0;
 
         ++cam->open_count;
 
         cpia2_dbg_dump_registers(cam);
-
-err_return:
-        mutex_unlock(&cam->busy_lock);
-        return retval;
+        return 0;
 }
 
 /******************************************************************************
@@ -304,15 +285,11 @@ static int cpia2_close(struct file *file)
         struct camera_data *cam = video_get_drvdata(dev);
         struct cpia2_fh *fh = file->private_data;
 
-        mutex_lock(&cam->busy_lock);
-
         if (cam->present &&
-            (cam->open_count == 1
-             || fh->prio == V4L2_PRIORITY_RECORD
-            )) {
+            (cam->open_count == 1 || fh->prio == V4L2_PRIORITY_RECORD)) {
                 cpia2_usb_stream_stop(cam);
 
-                if(cam->open_count == 1) {
+                if (cam->open_count == 1) {
                         /* save camera state for later open */
                         cpia2_save_camera_state(cam);
 
@@ -321,26 +298,21 @@ static int cpia2_close(struct file *file)
                 }
         }
 
-        {
-                if(fh->mmapped)
-                        cam->mmapped = 0;
-                v4l2_prio_close(&cam->prio, fh->prio);
-                file->private_data = NULL;
-                kfree(fh);
-        }
+        if (fh->mmapped)
+                cam->mmapped = 0;
+        v4l2_prio_close(&cam->prio, fh->prio);
+        file->private_data = NULL;
+        kfree(fh);
 
         if (--cam->open_count == 0) {
                 cpia2_free_buffers(cam);
                 if (!cam->present) {
                         video_unregister_device(dev);
-                        mutex_unlock(&cam->busy_lock);
                         kfree(cam);
                         return 0;
                 }
         }
 
-        mutex_unlock(&cam->busy_lock);
-
         return 0;
 }
 
@@ -405,11 +377,11 @@ static int sync(struct camera_data *cam, int frame_nr)
                         return 0;
                 }
 
-                mutex_unlock(&cam->busy_lock);
+                mutex_unlock(&cam->v4l2_lock);
                 wait_event_interruptible(cam->wq_stream,
                                          !cam->streaming ||
                                          frame->status == FRAME_READY);
-                mutex_lock(&cam->busy_lock);
+                mutex_lock(&cam->v4l2_lock);
                 if (signal_pending(current))
                         return -ERESTARTSYS;
                 if(!cam->present)
@@ -1293,11 +1265,11 @@ static int ioctl_dqbuf(void *arg,struct camera_data *cam, struct file *file)
         if(frame < 0) {
                 /* Wait for a frame to become available */
                 struct framebuf *cb=cam->curbuff;
-                mutex_unlock(&cam->busy_lock);
+                mutex_unlock(&cam->v4l2_lock);
                 wait_event_interruptible(cam->wq_stream,
                                          !cam->present ||
                                          (cb=cam->curbuff)->status == FRAME_READY);
-                mutex_lock(&cam->busy_lock);
+                mutex_lock(&cam->v4l2_lock);
                 if (signal_pending(current))
                         return -ERESTARTSYS;
                 if(!cam->present)
@@ -1337,14 +1309,8 @@ static long cpia2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
         if (!cam)
                 return -ENOTTY;
 
-        /* make this _really_ smp-safe */
-        if (mutex_lock_interruptible(&cam->busy_lock))
-                return -ERESTARTSYS;
-
-        if (!cam->present) {
-                mutex_unlock(&cam->busy_lock);
+        if (!cam->present)
                 return -ENODEV;
-        }
 
         /* Priority check */
         switch (cmd) {
@@ -1352,10 +1318,8 @@ static long cpia2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
         {
                 struct cpia2_fh *fh = file->private_data;
                 retval = v4l2_prio_check(&cam->prio, fh->prio);
-                if(retval) {
-                        mutex_unlock(&cam->busy_lock);
+                if (retval)
                         return retval;
-                }
                 break;
         }
         default:
@@ -1529,7 +1493,6 @@ static long cpia2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
                 break;
         }
 
-        mutex_unlock(&cam->busy_lock);
         return retval;
 }
 
@@ -1596,7 +1559,7 @@ static const struct v4l2_file_operations cpia2_fops = {
         .release        = cpia2_close,
         .read           = cpia2_v4l_read,
         .poll           = cpia2_v4l_poll,
-        .ioctl          = cpia2_ioctl,
+        .unlocked_ioctl = cpia2_ioctl,
         .mmap           = cpia2_mmap,
 };
 
@@ -1620,6 +1583,7 @@ int cpia2_register_camera(struct camera_data *cam)
 
         memcpy(cam->vdev, &cpia2_template, sizeof(cpia2_template));
         video_set_drvdata(cam->vdev, cam);
+        cam->vdev->lock = &cam->v4l2_lock;
 
         reset_camera_struct_v4l(cam);