diff mbox

drm/vkms: Introduce basic VKMS driver

Message ID 20180514143346.GA21695@haneen-vb (mailing list archive)
State New, archived
Headers show

Commit Message

Haneen Mohammed May 14, 2018, 2:33 p.m. UTC 
This patch introduces Virtual Kernel Mode-Setting (VKMS) driver. It
creates a very basic kms driver with 1 crtc/encoder/connector/plane.

VKMS driver would be useful for testing, or for running X (or similar)
on headless machines and be able to still use the GPU. Thus it enables
a virtual display without the need for hardware display capability.

Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
---
 drivers/gpu/drm/Kconfig         |   6 ++
 drivers/gpu/drm/Makefile        |   1 +
 drivers/gpu/drm/vkms/Makefile   |   3 +
 drivers/gpu/drm/vkms/vkms_drv.c | 146 ++++++++++++++++++++++++++++++++
 drivers/gpu/drm/vkms/vkms_drv.h |  13 +++
 5 files changed, 169 insertions(+)
 create mode 100644 drivers/gpu/drm/vkms/Makefile
 create mode 100644 drivers/gpu/drm/vkms/vkms_drv.c
 create mode 100644 drivers/gpu/drm/vkms/vkms_drv.h

Comments

kernel test robot May 15, 2018, 11:30 a.m. UTC | #1 
Hi Haneen,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on drm/drm-next]
[also build test WARNING on v4.17-rc5 next-20180514]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Haneen-Mohammed/drm-vkms-Introduce-basic-VKMS-driver/20180515-165648
base:   git://people.freedesktop.org/~airlied/linux.git drm-next
reproduce:
        # apt-get install sparse
        make ARCH=x86_64 allmodconfig
        make C=1 CF=-D__CHECK_ENDIAN__


sparse warnings: (new ones prefixed by >>)

>> drivers/gpu/drm/vkms/vkms_drv.c:43:19: sparse: symbol 'vkms_driver' was not declared. Should it be static?

Please review and possibly fold the followup patch.

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
Daniel Vetter May 15, 2018, 11:32 a.m. UTC | #2 
On Mon, May 14, 2018 at 05:33:46PM +0300, Haneen Mohammed wrote:
> This patch introduces Virtual Kernel Mode-Setting (VKMS) driver. It
> creates a very basic kms driver with 1 crtc/encoder/connector/plane.
> 
> VKMS driver would be useful for testing, or for running X (or similar)
> on headless machines and be able to still use the GPU. Thus it enables
> a virtual display without the need for hardware display capability.
> 
> Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>

Created a new topic branch topic/vkms in drm-misc and pushed it there.

Thanks, Daniel

> ---
>  drivers/gpu/drm/Kconfig         |   6 ++
>  drivers/gpu/drm/Makefile        |   1 +
>  drivers/gpu/drm/vkms/Makefile   |   3 +
>  drivers/gpu/drm/vkms/vkms_drv.c | 146 ++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/vkms/vkms_drv.h |  13 +++
>  5 files changed, 169 insertions(+)
>  create mode 100644 drivers/gpu/drm/vkms/Makefile
>  create mode 100644 drivers/gpu/drm/vkms/vkms_drv.c
>  create mode 100644 drivers/gpu/drm/vkms/vkms_drv.h
> 
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 2a72d2feb76d..7db3d82cbb27 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -213,6 +213,12 @@ config DRM_VGEM
>  	  as used by Mesa's software renderer for enhanced performance.
>  	  If M is selected the module will be called vgem.
>  
> +config DRM_VKMS
> +	tristate "Virtual KMS"
> +	depends on DRM
> +	help
> +	  Choose this option to get a virtual kernal mode-setting driver.
> +	  If M is selected the module will be called vkms.
>  
>  source "drivers/gpu/drm/exynos/Kconfig"
>  
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index ef9f3dab287f..8873d4769116 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -69,6 +69,7 @@ obj-$(CONFIG_DRM_SAVAGE)+= savage/
>  obj-$(CONFIG_DRM_VMWGFX)+= vmwgfx/
>  obj-$(CONFIG_DRM_VIA)	+=via/
>  obj-$(CONFIG_DRM_VGEM)	+= vgem/
> +obj-$(CONFIG_DRM_VKMS)	+= vkms/
>  obj-$(CONFIG_DRM_NOUVEAU) +=nouveau/
>  obj-$(CONFIG_DRM_EXYNOS) +=exynos/
>  obj-$(CONFIG_DRM_ROCKCHIP) +=rockchip/
> diff --git a/drivers/gpu/drm/vkms/Makefile b/drivers/gpu/drm/vkms/Makefile
> new file mode 100644
> index 000000000000..2aef948d3a34
> --- /dev/null
> +++ b/drivers/gpu/drm/vkms/Makefile
> @@ -0,0 +1,3 @@
> +vkms-y := vkms_drv.o
> +
> +obj-$(CONFIG_DRM_VKMS) += vkms.o
> diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
> new file mode 100644
> index 000000000000..b1df08ed23a0
> --- /dev/null
> +++ b/drivers/gpu/drm/vkms/vkms_drv.c
> @@ -0,0 +1,146 @@
> +/*
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#include <linux/module.h>
> +#include <drm/drmP.h>
> +#include <drm/drm_gem.h>
> +#include <drm/drm_crtc_helper.h>
> +#include "vkms_drv.h"
> +
> +#define DRIVER_NAME	"vkms"
> +#define DRIVER_DESC	"Virtual Kernel Mode Setting"
> +#define DRIVER_DATE	"20180514"
> +#define DRIVER_MAJOR	1
> +#define DRIVER_MINOR	0
> +
> +static struct vkms_device *vkms_device;
> +
> +static const struct file_operations vkms_driver_fops = {
> +	.owner		= THIS_MODULE,
> +	.open		= drm_open,
> +	.mmap		= drm_gem_mmap,
> +	.unlocked_ioctl	= drm_ioctl,
> +	.compat_ioctl	= drm_compat_ioctl,
> +	.poll		= drm_poll,
> +	.read		= drm_read,
> +	.llseek		= no_llseek,
> +	.release	= drm_release,
> +};
> +
> +static void vkms_release(struct drm_device *dev)
> +{
> +	struct vkms_device *vkms = container_of(dev, struct vkms_device, drm);
> +
> +	platform_device_unregister(vkms->platform);
> +	drm_mode_config_cleanup(&vkms->drm);
> +	drm_dev_fini(&vkms->drm);
> +}
> +
> +struct drm_driver vkms_driver = {
> +	.driver_features	= DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
> +	.release		= vkms_release,
> +	.fops			= &vkms_driver_fops,
> +
> +	.name			= DRIVER_NAME,
> +	.desc			= DRIVER_DESC,
> +	.date			= DRIVER_DATE,
> +	.major			= DRIVER_MAJOR,
> +	.minor			= DRIVER_MINOR,
> +};
> +
> +static const u32 vkms_formats[] = {
> +	DRM_FORMAT_XRGB8888,
> +};
> +
> +static void vkms_connector_destroy(struct drm_connector *connector)
> +{
> +	drm_connector_unregister(connector);
> +	drm_connector_cleanup(connector);
> +}
> +
> +static const struct drm_connector_funcs vkms_connector_funcs = {
> +	.fill_modes = drm_helper_probe_single_connector_modes,
> +	.destroy = vkms_connector_destroy,
> +};
> +
> +static int __init vkms_init(void)
> +{
> +	int ret;
> +
> +	vkms_device = kzalloc(sizeof(*vkms_device), GFP_KERNEL);
> +	if (!vkms_device)
> +		return -ENOMEM;
> +
> +	ret = drm_dev_init(&vkms_device->drm, &vkms_driver, NULL);
> +	if (ret)
> +		goto out_free;
> +
> +	vkms_device->platform =
> +		platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
> +	if (IS_ERR(vkms_device->platform)) {
> +		ret = PTR_ERR(vkms_device->platform);
> +		goto out_fini;
> +	}
> +
> +	drm_mode_config_init(&vkms_device->drm);
> +
> +	ret = drm_connector_init(&vkms_device->drm, &vkms_device->connector,
> +				 &vkms_connector_funcs,
> +				 DRM_MODE_CONNECTOR_VIRTUAL);
> +	if (ret < 0) {
> +		DRM_ERROR("Failed to init connector\n");
> +		goto out_unregister;
> +	}
> +
> +	ret = drm_simple_display_pipe_init(&vkms_device->drm,
> +					   &vkms_device->pipe,
> +					   NULL,
> +					   vkms_formats,
> +					   ARRAY_SIZE(vkms_formats),
> +					   NULL,
> +					   &vkms_device->connector);
> +	if (ret < 0) {
> +		DRM_ERROR("Cannot setup simple display pipe\n");
> +		goto out_unregister;
> +	}
> +
> +	ret = drm_dev_register(&vkms_device->drm, 0);
> +	if (ret)
> +		goto out_unregister;
> +
> +	drm_connector_register(&vkms_device->connector);
> +
> +	return 0;
> +
> +out_unregister:
> +	platform_device_unregister(vkms_device->platform);
> +out_fini:
> +	drm_dev_fini(&vkms_device->drm);
> +out_free:
> +	kfree(vkms_device);
> +
> +	return ret;
> +}
> +
> +static void __exit vkms_exit(void)
> +{
> +	if (!vkms_device) {
> +		DRM_INFO("vkms_device is NULL.\n");
> +		return;
> +	}
> +
> +	drm_dev_unregister(&vkms_device->drm);
> +	drm_dev_put(&vkms_device->drm);
> +
> +	kfree(vkms_device);
> +}
> +
> +module_init(vkms_init);
> +module_exit(vkms_exit);
> +
> +MODULE_DESCRIPTION(DRIVER_DESC);
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
> new file mode 100644
> index 000000000000..c77c5bf5032a
> --- /dev/null
> +++ b/drivers/gpu/drm/vkms/vkms_drv.h
> @@ -0,0 +1,13 @@
> +#ifndef _VKMS_DRV_H_
> +#define _VKMS_DRV_H_
> +
> +#include <drm/drm_simple_kms_helper.h>
> +
> +struct vkms_device {
> +	struct drm_device drm;
> +	struct platform_device *platform;
> +	struct drm_simple_display_pipe pipe;
> +	struct drm_connector connector;
> +};
> +
> +#endif /* _VKMS_DRV_H_ */
> -- 
> 2.17.0
>
diff mbox

Patch

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 2a72d2feb76d..7db3d82cbb27 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -213,6 +213,12 @@  config DRM_VGEM
 	  as used by Mesa's software renderer for enhanced performance.
 	  If M is selected the module will be called vgem.
 
+config DRM_VKMS
+	tristate "Virtual KMS"
+	depends on DRM
+	help
+	  Choose this option to get a virtual kernal mode-setting driver.
+	  If M is selected the module will be called vkms.
 
 source "drivers/gpu/drm/exynos/Kconfig"
 
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index ef9f3dab287f..8873d4769116 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -69,6 +69,7 @@  obj-$(CONFIG_DRM_SAVAGE)+= savage/
 obj-$(CONFIG_DRM_VMWGFX)+= vmwgfx/
 obj-$(CONFIG_DRM_VIA)	+=via/
 obj-$(CONFIG_DRM_VGEM)	+= vgem/
+obj-$(CONFIG_DRM_VKMS)	+= vkms/
 obj-$(CONFIG_DRM_NOUVEAU) +=nouveau/
 obj-$(CONFIG_DRM_EXYNOS) +=exynos/
 obj-$(CONFIG_DRM_ROCKCHIP) +=rockchip/
diff --git a/drivers/gpu/drm/vkms/Makefile b/drivers/gpu/drm/vkms/Makefile
new file mode 100644
index 000000000000..2aef948d3a34
--- /dev/null
+++ b/drivers/gpu/drm/vkms/Makefile
@@ -0,0 +1,3 @@ 
+vkms-y := vkms_drv.o
+
+obj-$(CONFIG_DRM_VKMS) += vkms.o
diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
new file mode 100644
index 000000000000..b1df08ed23a0
--- /dev/null
+++ b/drivers/gpu/drm/vkms/vkms_drv.c
@@ -0,0 +1,146 @@ 
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <drm/drmP.h>
+#include <drm/drm_gem.h>
+#include <drm/drm_crtc_helper.h>
+#include "vkms_drv.h"
+
+#define DRIVER_NAME	"vkms"
+#define DRIVER_DESC	"Virtual Kernel Mode Setting"
+#define DRIVER_DATE	"20180514"
+#define DRIVER_MAJOR	1
+#define DRIVER_MINOR	0
+
+static struct vkms_device *vkms_device;
+
+static const struct file_operations vkms_driver_fops = {
+	.owner		= THIS_MODULE,
+	.open		= drm_open,
+	.mmap		= drm_gem_mmap,
+	.unlocked_ioctl	= drm_ioctl,
+	.compat_ioctl	= drm_compat_ioctl,
+	.poll		= drm_poll,
+	.read		= drm_read,
+	.llseek		= no_llseek,
+	.release	= drm_release,
+};
+
+static void vkms_release(struct drm_device *dev)
+{
+	struct vkms_device *vkms = container_of(dev, struct vkms_device, drm);
+
+	platform_device_unregister(vkms->platform);
+	drm_mode_config_cleanup(&vkms->drm);
+	drm_dev_fini(&vkms->drm);
+}
+
+struct drm_driver vkms_driver = {
+	.driver_features	= DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
+	.release		= vkms_release,
+	.fops			= &vkms_driver_fops,
+
+	.name			= DRIVER_NAME,
+	.desc			= DRIVER_DESC,
+	.date			= DRIVER_DATE,
+	.major			= DRIVER_MAJOR,
+	.minor			= DRIVER_MINOR,
+};
+
+static const u32 vkms_formats[] = {
+	DRM_FORMAT_XRGB8888,
+};
+
+static void vkms_connector_destroy(struct drm_connector *connector)
+{
+	drm_connector_unregister(connector);
+	drm_connector_cleanup(connector);
+}
+
+static const struct drm_connector_funcs vkms_connector_funcs = {
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.destroy = vkms_connector_destroy,
+};
+
+static int __init vkms_init(void)
+{
+	int ret;
+
+	vkms_device = kzalloc(sizeof(*vkms_device), GFP_KERNEL);
+	if (!vkms_device)
+		return -ENOMEM;
+
+	ret = drm_dev_init(&vkms_device->drm, &vkms_driver, NULL);
+	if (ret)
+		goto out_free;
+
+	vkms_device->platform =
+		platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
+	if (IS_ERR(vkms_device->platform)) {
+		ret = PTR_ERR(vkms_device->platform);
+		goto out_fini;
+	}
+
+	drm_mode_config_init(&vkms_device->drm);
+
+	ret = drm_connector_init(&vkms_device->drm, &vkms_device->connector,
+				 &vkms_connector_funcs,
+				 DRM_MODE_CONNECTOR_VIRTUAL);
+	if (ret < 0) {
+		DRM_ERROR("Failed to init connector\n");
+		goto out_unregister;
+	}
+
+	ret = drm_simple_display_pipe_init(&vkms_device->drm,
+					   &vkms_device->pipe,
+					   NULL,
+					   vkms_formats,
+					   ARRAY_SIZE(vkms_formats),
+					   NULL,
+					   &vkms_device->connector);
+	if (ret < 0) {
+		DRM_ERROR("Cannot setup simple display pipe\n");
+		goto out_unregister;
+	}
+
+	ret = drm_dev_register(&vkms_device->drm, 0);
+	if (ret)
+		goto out_unregister;
+
+	drm_connector_register(&vkms_device->connector);
+
+	return 0;
+
+out_unregister:
+	platform_device_unregister(vkms_device->platform);
+out_fini:
+	drm_dev_fini(&vkms_device->drm);
+out_free:
+	kfree(vkms_device);
+
+	return ret;
+}
+
+static void __exit vkms_exit(void)
+{
+	if (!vkms_device) {
+		DRM_INFO("vkms_device is NULL.\n");
+		return;
+	}
+
+	drm_dev_unregister(&vkms_device->drm);
+	drm_dev_put(&vkms_device->drm);
+
+	kfree(vkms_device);
+}
+
+module_init(vkms_init);
+module_exit(vkms_exit);
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
new file mode 100644
index 000000000000..c77c5bf5032a
--- /dev/null
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -0,0 +1,13 @@ 
+#ifndef _VKMS_DRV_H_
+#define _VKMS_DRV_H_
+
+#include <drm/drm_simple_kms_helper.h>
+
+struct vkms_device {
+	struct drm_device drm;
+	struct platform_device *platform;
+	struct drm_simple_display_pipe pipe;
+	struct drm_connector connector;
+};
+
+#endif /* _VKMS_DRV_H_ */