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[media] v4l2-dev/ioctl: determine the valid ioctls upfront
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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: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
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Hans Verkuil authored and Mauro Carvalho Chehab committed May 14, 2012
1 parent 8ab75e3 commit 48ea0be
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Showing 3 changed files with 296 additions and 276 deletions.
172 changes: 172 additions & 0 deletions drivers/media/video/v4l2-dev.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -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) {
Expand Down
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