On Sun, Oct 23, 2022 at 12:46:21AM +0300, Oded Gabbay wrote:
> The accelerator devices will be exposed to the user space with a new,
> dedicated major number - 261.
>
> The drm core registers the new major number as a char device and create
> corresponding sysfs and debugfs root entries, same as for the drm major.
>
> In case CONFIG_ACCEL is not selected, this code is not compiled in.
>
> Signed-off-by: Oded Gabbay <ogabbay@xxxxxxxxxx>
> ---
> Documentation/admin-guide/devices.txt | 5 +++
> drivers/gpu/drm/drm_drv.c | 45 +++++++++++++++++++++++
> drivers/gpu/drm/drm_internal.h | 3 ++
> drivers/gpu/drm/drm_sysfs.c | 52 +++++++++++++++++++++++++++
> include/drm/drm_ioctl.h | 1 +
> 5 files changed, 106 insertions(+)
>
> diff --git a/Documentation/admin-guide/devices.txt b/Documentation/admin-guide/devices.txt
> index 9764d6edb189..06c525e01ea5 100644
> --- a/Documentation/admin-guide/devices.txt
> +++ b/Documentation/admin-guide/devices.txt
> @@ -3080,6 +3080,11 @@
> ...
> 255 = /dev/osd255 256th OSD Device
>
> + 261 char Compute Acceleration Devices
> + 0 = /dev/accel/accel0 First acceleration device
> + 1 = /dev/accel/accel1 Second acceleration device
> + ...
> +
> 384-511 char RESERVED FOR DYNAMIC ASSIGNMENT
> Character devices that request a dynamic allocation of major
> number will take numbers starting from 511 and downward,
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 8214a0b1ab7f..b58ffb1433d6 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -67,6 +67,10 @@ static bool drm_core_init_complete;
>
> static struct dentry *drm_debugfs_root;
>
> +#ifdef CONFIG_ACCEL
> +static struct dentry *accel_debugfs_root;
> +#endif
> +
> DEFINE_STATIC_SRCU(drm_unplug_srcu);
>
> /*
> @@ -1031,9 +1035,19 @@ static const struct file_operations drm_stub_fops = {
> .llseek = noop_llseek,
> };
>
> +static void accel_core_exit(void)
> +{
> +#ifdef CONFIG_ACCEL
> + unregister_chrdev(ACCEL_MAJOR, "accel");
> + debugfs_remove(accel_debugfs_root);
> + accel_sysfs_destroy();
> +#endif
> +}
Why is all of this in drm_drv.c?
Why not put it in drm/accel/accel.c or something like that? Then put
the proper stuff into a .h file and then you have no #ifdef in the .c
files.
Keeping #ifdef out of C files is key, please do not do things like you
have here. Especially as it ends up with this kind of mess:
> +static int __init accel_core_init(void)
> +{
> +#ifdef CONFIG_ACCEL
> + int ret;
> +
> + ret = accel_sysfs_init();
> + if (ret < 0) {
> + DRM_ERROR("Cannot create ACCEL class: %d\n", ret);
> + goto error;
> + }
> +
> + accel_debugfs_root = debugfs_create_dir("accel", NULL);
> +
> + ret = register_chrdev(ACCEL_MAJOR, "accel", &drm_stub_fops);
> + if (ret < 0)
> + goto error;
> +
> +error:
> + /* Any cleanup will be done in drm_core_exit() that will call
> + * to accel_core_exit()
> + */
> + return ret;
> +#else
> + return 0;
> +#endif
> +}
That's just a mess.
thanks,
greg k-h
