[media] v4l2-dev/ioctl: determine the valid ioctls upfront

Rather than testing whether an ioctl is implemented in the driver or not
every time the ioctl is called, do it upfront when the device is registered.

This also allows a driver to disable certain ioctls based on the capabilities
of the detected board, something you can't do today without creating separate
v4l2_ioctl_ops structs for each new variation.

For the most part it is pretty straightforward, but for control ioctls a flag
is needed since it is possible that you have per-filehandle controls, and that
can't be determined upfront of course.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/v4l2-dev.c

@@ -516,6 +516,175 @@ static int get_index(struct video_device *vdev)
 	return find_first_zero_bit(used, VIDEO_NUM_DEVICES);
 }
 
+#define SET_VALID_IOCTL(ops, cmd, op)			\
+	if (ops->op)					\
+		set_bit(_IOC_NR(cmd), valid_ioctls)
+
+/* This determines which ioctls are actually implemented in the driver.
+   It's a one-time thing which simplifies video_ioctl2 as it can just do
+   a bit test.
+
+   Note that drivers can override this by setting bits to 1 in
+   vdev->valid_ioctls. If an ioctl is marked as 1 when this function is
+   called, then that ioctl will actually be marked as unimplemented.
+
+   It does that by first setting up the local valid_ioctls bitmap, and
+   at the end do a:
+
+   vdev->valid_ioctls = valid_ioctls & ~(vdev->valid_ioctls)
+ */
+static void determine_valid_ioctls(struct video_device *vdev)
+{
+	DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
+	const struct v4l2_ioctl_ops *ops = vdev->ioctl_ops;
+
+	bitmap_zero(valid_ioctls, BASE_VIDIOC_PRIVATE);
+
+	SET_VALID_IOCTL(ops, VIDIOC_QUERYCAP, vidioc_querycap);
+	if (ops->vidioc_g_priority ||
+			test_bit(V4L2_FL_USE_FH_PRIO, &vdev->flags))
+		set_bit(_IOC_NR(VIDIOC_G_PRIORITY), valid_ioctls);
+	if (ops->vidioc_s_priority ||
+			test_bit(V4L2_FL_USE_FH_PRIO, &vdev->flags))
+		set_bit(_IOC_NR(VIDIOC_S_PRIORITY), valid_ioctls);
+	if (ops->vidioc_enum_fmt_vid_cap ||
+	    ops->vidioc_enum_fmt_vid_out ||
+	    ops->vidioc_enum_fmt_vid_cap_mplane ||
+	    ops->vidioc_enum_fmt_vid_out_mplane ||
+	    ops->vidioc_enum_fmt_vid_overlay ||
+	    ops->vidioc_enum_fmt_type_private)
+		set_bit(_IOC_NR(VIDIOC_ENUM_FMT), valid_ioctls);
+	if (ops->vidioc_g_fmt_vid_cap ||
+	    ops->vidioc_g_fmt_vid_out ||
+	    ops->vidioc_g_fmt_vid_cap_mplane ||
+	    ops->vidioc_g_fmt_vid_out_mplane ||
+	    ops->vidioc_g_fmt_vid_overlay ||
+	    ops->vidioc_g_fmt_vbi_cap ||
+	    ops->vidioc_g_fmt_vid_out_overlay ||
+	    ops->vidioc_g_fmt_vbi_out ||
+	    ops->vidioc_g_fmt_sliced_vbi_cap ||
+	    ops->vidioc_g_fmt_sliced_vbi_out ||
+	    ops->vidioc_g_fmt_type_private)
+		set_bit(_IOC_NR(VIDIOC_G_FMT), valid_ioctls);
+	if (ops->vidioc_s_fmt_vid_cap ||
+	    ops->vidioc_s_fmt_vid_out ||
+	    ops->vidioc_s_fmt_vid_cap_mplane ||
+	    ops->vidioc_s_fmt_vid_out_mplane ||
+	    ops->vidioc_s_fmt_vid_overlay ||
+	    ops->vidioc_s_fmt_vbi_cap ||
+	    ops->vidioc_s_fmt_vid_out_overlay ||
+	    ops->vidioc_s_fmt_vbi_out ||
+	    ops->vidioc_s_fmt_sliced_vbi_cap ||
+	    ops->vidioc_s_fmt_sliced_vbi_out ||
+	    ops->vidioc_s_fmt_type_private)
+		set_bit(_IOC_NR(VIDIOC_S_FMT), valid_ioctls);
+	if (ops->vidioc_try_fmt_vid_cap ||
+	    ops->vidioc_try_fmt_vid_out ||
+	    ops->vidioc_try_fmt_vid_cap_mplane ||
+	    ops->vidioc_try_fmt_vid_out_mplane ||
+	    ops->vidioc_try_fmt_vid_overlay ||
+	    ops->vidioc_try_fmt_vbi_cap ||
+	    ops->vidioc_try_fmt_vid_out_overlay ||
+	    ops->vidioc_try_fmt_vbi_out ||
+	    ops->vidioc_try_fmt_sliced_vbi_cap ||
+	    ops->vidioc_try_fmt_sliced_vbi_out ||
+	    ops->vidioc_try_fmt_type_private)
+		set_bit(_IOC_NR(VIDIOC_TRY_FMT), valid_ioctls);
+	SET_VALID_IOCTL(ops, VIDIOC_REQBUFS, vidioc_reqbufs);
+	SET_VALID_IOCTL(ops, VIDIOC_QUERYBUF, vidioc_querybuf);
+	SET_VALID_IOCTL(ops, VIDIOC_QBUF, vidioc_qbuf);
+	SET_VALID_IOCTL(ops, VIDIOC_DQBUF, vidioc_dqbuf);
+	SET_VALID_IOCTL(ops, VIDIOC_OVERLAY, vidioc_overlay);
+	SET_VALID_IOCTL(ops, VIDIOC_G_FBUF, vidioc_g_fbuf);
+	SET_VALID_IOCTL(ops, VIDIOC_S_FBUF, vidioc_s_fbuf);
+	SET_VALID_IOCTL(ops, VIDIOC_STREAMON, vidioc_streamon);
+	SET_VALID_IOCTL(ops, VIDIOC_STREAMOFF, vidioc_streamoff);
+	if (vdev->tvnorms)
+		set_bit(_IOC_NR(VIDIOC_ENUMSTD), valid_ioctls);
+	if (ops->vidioc_g_std || vdev->current_norm)
+		set_bit(_IOC_NR(VIDIOC_G_STD), valid_ioctls);
+	SET_VALID_IOCTL(ops, VIDIOC_S_STD, vidioc_s_std);
+	SET_VALID_IOCTL(ops, VIDIOC_QUERYSTD, vidioc_querystd);
+	SET_VALID_IOCTL(ops, VIDIOC_ENUMINPUT, vidioc_enum_input);
+	SET_VALID_IOCTL(ops, VIDIOC_G_INPUT, vidioc_g_input);
+	SET_VALID_IOCTL(ops, VIDIOC_S_INPUT, vidioc_s_input);
+	SET_VALID_IOCTL(ops, VIDIOC_ENUMOUTPUT, vidioc_enum_output);
+	SET_VALID_IOCTL(ops, VIDIOC_G_OUTPUT, vidioc_g_output);
+	SET_VALID_IOCTL(ops, VIDIOC_S_OUTPUT, vidioc_s_output);
+	/* Note: the control handler can also be passed through the filehandle,
+	   and that can't be tested here. If the bit for these control ioctls
+	   is set, then the ioctl is valid. But if it is 0, then it can still
+	   be valid if the filehandle passed the control handler. */
+	if (vdev->ctrl_handler || ops->vidioc_queryctrl)
+		set_bit(_IOC_NR(VIDIOC_QUERYCTRL), valid_ioctls);
+	if (vdev->ctrl_handler || ops->vidioc_g_ctrl || ops->vidioc_g_ext_ctrls)
+		set_bit(_IOC_NR(VIDIOC_G_CTRL), valid_ioctls);
+	if (vdev->ctrl_handler || ops->vidioc_s_ctrl || ops->vidioc_s_ext_ctrls)
+		set_bit(_IOC_NR(VIDIOC_S_CTRL), valid_ioctls);
+	if (vdev->ctrl_handler || ops->vidioc_g_ext_ctrls)
+		set_bit(_IOC_NR(VIDIOC_G_EXT_CTRLS), valid_ioctls);
+	if (vdev->ctrl_handler || ops->vidioc_s_ext_ctrls)
+		set_bit(_IOC_NR(VIDIOC_S_EXT_CTRLS), valid_ioctls);
+	if (vdev->ctrl_handler || ops->vidioc_try_ext_ctrls)
+		set_bit(_IOC_NR(VIDIOC_TRY_EXT_CTRLS), valid_ioctls);
+	if (vdev->ctrl_handler || ops->vidioc_querymenu)
+		set_bit(_IOC_NR(VIDIOC_QUERYMENU), valid_ioctls);
+	SET_VALID_IOCTL(ops, VIDIOC_ENUMAUDIO, vidioc_enumaudio);
+	SET_VALID_IOCTL(ops, VIDIOC_G_AUDIO, vidioc_g_audio);
+	SET_VALID_IOCTL(ops, VIDIOC_S_AUDIO, vidioc_s_audio);
+	SET_VALID_IOCTL(ops, VIDIOC_ENUMAUDOUT, vidioc_enumaudout);
+	SET_VALID_IOCTL(ops, VIDIOC_G_AUDOUT, vidioc_g_audout);
+	SET_VALID_IOCTL(ops, VIDIOC_S_AUDOUT, vidioc_s_audout);
+	SET_VALID_IOCTL(ops, VIDIOC_G_MODULATOR, vidioc_g_modulator);
+	SET_VALID_IOCTL(ops, VIDIOC_S_MODULATOR, vidioc_s_modulator);
+	if (ops->vidioc_g_crop || ops->vidioc_g_selection)
+		set_bit(_IOC_NR(VIDIOC_G_CROP), valid_ioctls);
+	if (ops->vidioc_s_crop || ops->vidioc_s_selection)
+		set_bit(_IOC_NR(VIDIOC_S_CROP), valid_ioctls);
+	SET_VALID_IOCTL(ops, VIDIOC_G_SELECTION, vidioc_g_selection);
+	SET_VALID_IOCTL(ops, VIDIOC_S_SELECTION, vidioc_s_selection);
+	if (ops->vidioc_cropcap || ops->vidioc_g_selection)
+		set_bit(_IOC_NR(VIDIOC_CROPCAP), valid_ioctls);
+	SET_VALID_IOCTL(ops, VIDIOC_G_JPEGCOMP, vidioc_g_jpegcomp);
+	SET_VALID_IOCTL(ops, VIDIOC_S_JPEGCOMP, vidioc_s_jpegcomp);
+	SET_VALID_IOCTL(ops, VIDIOC_G_ENC_INDEX, vidioc_g_enc_index);
+	SET_VALID_IOCTL(ops, VIDIOC_ENCODER_CMD, vidioc_encoder_cmd);
+	SET_VALID_IOCTL(ops, VIDIOC_TRY_ENCODER_CMD, vidioc_try_encoder_cmd);
+	SET_VALID_IOCTL(ops, VIDIOC_DECODER_CMD, vidioc_decoder_cmd);
+	SET_VALID_IOCTL(ops, VIDIOC_TRY_DECODER_CMD, vidioc_try_decoder_cmd);
+	if (ops->vidioc_g_parm || vdev->current_norm)
+		set_bit(_IOC_NR(VIDIOC_G_PARM), valid_ioctls);
+	SET_VALID_IOCTL(ops, VIDIOC_S_PARM, vidioc_s_parm);
+	SET_VALID_IOCTL(ops, VIDIOC_G_TUNER, vidioc_g_tuner);
+	SET_VALID_IOCTL(ops, VIDIOC_S_TUNER, vidioc_s_tuner);
+	SET_VALID_IOCTL(ops, VIDIOC_G_FREQUENCY, vidioc_g_frequency);
+	SET_VALID_IOCTL(ops, VIDIOC_S_FREQUENCY, vidioc_s_frequency);
+	SET_VALID_IOCTL(ops, VIDIOC_G_SLICED_VBI_CAP, vidioc_g_sliced_vbi_cap);
+	SET_VALID_IOCTL(ops, VIDIOC_LOG_STATUS, vidioc_log_status);
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+	SET_VALID_IOCTL(ops, VIDIOC_DBG_G_REGISTER, vidioc_g_register);
+	SET_VALID_IOCTL(ops, VIDIOC_DBG_S_REGISTER, vidioc_s_register);
+#endif
+	SET_VALID_IOCTL(ops, VIDIOC_DBG_G_CHIP_IDENT, vidioc_g_chip_ident);
+	SET_VALID_IOCTL(ops, VIDIOC_S_HW_FREQ_SEEK, vidioc_s_hw_freq_seek);
+	SET_VALID_IOCTL(ops, VIDIOC_ENUM_FRAMESIZES, vidioc_enum_framesizes);
+	SET_VALID_IOCTL(ops, VIDIOC_ENUM_FRAMEINTERVALS, vidioc_enum_frameintervals);
+	SET_VALID_IOCTL(ops, VIDIOC_ENUM_DV_PRESETS, vidioc_enum_dv_presets);
+	SET_VALID_IOCTL(ops, VIDIOC_S_DV_PRESET, vidioc_s_dv_preset);
+	SET_VALID_IOCTL(ops, VIDIOC_G_DV_PRESET, vidioc_g_dv_preset);
+	SET_VALID_IOCTL(ops, VIDIOC_QUERY_DV_PRESET, vidioc_query_dv_preset);
+	SET_VALID_IOCTL(ops, VIDIOC_S_DV_TIMINGS, vidioc_s_dv_timings);
+	SET_VALID_IOCTL(ops, VIDIOC_G_DV_TIMINGS, vidioc_g_dv_timings);
+	/* yes, really vidioc_subscribe_event */
+	SET_VALID_IOCTL(ops, VIDIOC_DQEVENT, vidioc_subscribe_event);
+	SET_VALID_IOCTL(ops, VIDIOC_SUBSCRIBE_EVENT, vidioc_subscribe_event);
+	SET_VALID_IOCTL(ops, VIDIOC_UNSUBSCRIBE_EVENT, vidioc_unsubscribe_event);
+	SET_VALID_IOCTL(ops, VIDIOC_CREATE_BUFS, vidioc_create_bufs);
+	SET_VALID_IOCTL(ops, VIDIOC_PREPARE_BUF, vidioc_prepare_buf);
+	bitmap_andnot(vdev->valid_ioctls, valid_ioctls, vdev->valid_ioctls,
+			BASE_VIDIOC_PRIVATE);
+}
+
 /**
  *	__video_register_device - register video4linux devices
  *	@vdev: video device structure we want to register
@@ -663,6 +832,9 @@ int __video_register_device(struct video_device *vdev, int type, int nr,
 	vdev->index = get_index(vdev);
 	mutex_unlock(&videodev_lock);
 
+	if (vdev->ioctl_ops)
+		determine_valid_ioctls(vdev);
+
 	/* Part 3: Initialize the character device */
 	vdev->cdev = cdev_alloc();
 	if (vdev->cdev == NULL) {

include/media/v4l2-dev.h

@@ -126,6 +126,7 @@ struct video_device
 
 	/* ioctl callbacks */
 	const struct v4l2_ioctl_ops *ioctl_ops;
+	DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
 
 	/* serialization lock */
 	DECLARE_BITMAP(dont_use_lock, BASE_VIDIOC_PRIVATE);
@@ -184,6 +185,16 @@ static inline void v4l2_dont_use_lock(struct video_device *vdev, unsigned int cm
 		set_bit(_IOC_NR(cmd), vdev->dont_use_lock);
 }
 
+/* Mark that this command isn't implemented, must be called before
+   video_device_register. See also the comments in determine_valid_ioctls().
+   This function allows drivers to provide just one v4l2_ioctl_ops struct, but
+   disable ioctls based on the specific card that is actually found. */
+static inline void v4l2_dont_use_cmd(struct video_device *vdev, unsigned int cmd)
+{
+	if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
+		set_bit(_IOC_NR(cmd), vdev->valid_ioctls);
+}
+
 /* helper functions to access driver private data. */
 static inline void *video_get_drvdata(struct video_device *vdev)
 {