[PATCH v3] DRM: Add DRM kms/fb cma helper

Laurent Pinchart laurent.pinchart at ideasonboard.com
Wed Aug 8 07:43:30 PDT 2012


Hi Lars-Peter;

On Monday 02 July 2012 16:37:47 Lars-Peter Clausen wrote:
> This patchset introduces a set of helper function for implementing the KMS
> framebuffer layer for drivers which use the drm gem CMA helper function.
> 
> Signed-off-by: Lars-Peter Clausen <lars at metafoo.de>
> 
> ---
> Note: This patch depends on Sascha's "DRM: add drm gem CMA helper" patch
> 
> Changes since v2:
> 	* Adapt to changes in the GEM CMA helper
> 	* Add basic buffer size checking in drm_fb_cma_create
> Changes since v1:
> 	* Some spelling fixes
> 	* Add missing kfree in drm_fb_cma_alloc error path
> 	* Add multi-plane support
> ---
>  drivers/gpu/drm/Kconfig             |   10 +
>  drivers/gpu/drm/Makefile            |    1 +
>  drivers/gpu/drm/drm_fb_cma_helper.c |  393 ++++++++++++++++++++++++++++++++
>  include/drm/drm_fb_cma_helper.h     |   27 +++
>  4 files changed, 431 insertions(+)
>  create mode 100644 drivers/gpu/drm/drm_fb_cma_helper.c
>  create mode 100644 include/drm/drm_fb_cma_helper.h
> 
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 41bbd95..e511c9a 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -41,6 +41,16 @@ config DRM_GEM_CMA_HELPER
>  	help
>  	  Choose this if you need the GEM CMA helper functions
> 
> +config DRM_KMS_CMA_HELPER
> +	tristate
> +	select DRM_GEM_CMA_HELPER
> +	select DRM_KMS_HELPER
> +	select FB_SYS_FILLRECT
> +	select FB_SYS_COPYAREA
> +	select FB_SYS_IMAGEBLIT
> +	help
> +	  Choose this if you need the KMS cma helper functions
> +
>  config DRM_TDFX
>  	tristate "3dfx Banshee/Voodoo3+"
>  	depends on DRM && PCI
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 6e9e948..5dcb1a5 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -18,6 +18,7 @@ drm-$(CONFIG_COMPAT) += drm_ioc32.o
>  drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o
> 
>  drm_kms_helper-y := drm_fb_helper.o drm_crtc_helper.o drm_dp_i2c_helper.o
> +drm_kms_helper-$(CONFIG_DRM_KMS_CMA_HELPER) += drm_fb_cma_helper.o

This results in a built failure for me with

CONFIG_DRM=y
CONFIG_DRM_KMS_HELPER=m
# CONFIG_DRM_LOAD_EDID_FIRMWARE is not set
CONFIG_DRM_GEM_CMA_HELPER=m
CONFIG_DRM_KMS_CMA_HELPER=m

drm_fb_cma_helper.o isn't compiled at all. Can you reproduce the problem ?

>  obj-$(CONFIG_DRM_KMS_HELPER) += drm_kms_helper.o
> 
> diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c
> b/drivers/gpu/drm/drm_fb_cma_helper.c new file mode 100644
> index 0000000..9042233
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_fb_cma_helper.c
> @@ -0,0 +1,393 @@
> +/*
> + * drm kms/fb cma (contiguous memory allocator) helper functions
> + *
> + * Copyright (C) 2012 Analog Device Inc.
> + *   Author: Lars-Peter Clausen <lars at metafoo.de>
> + *
> + * Based on udl_fbdev.c
> + *  Copyright (C) 2012 Red Hat
> + *
> + * 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.
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <drm/drmP.h>
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_fb_helper.h>
> +#include <drm/drm_crtc_helper.h>
> +#include <drm/drm_gem_cma_helper.h>
> +#include <drm/drm_fb_cma_helper.h>
> +#include <linux/module.h>
> +
> +struct drm_fb_cma {
> +	struct drm_framebuffer		fb;
> +	struct drm_gem_cma_object	*obj[4];
> +};
> +
> +struct drm_fbdev_cma {
> +	struct drm_fb_helper	fb_helper;
> +	struct drm_fb_cma	*fb;
> +};
> +
> +static inline struct drm_fbdev_cma *to_fbdev_cma(struct drm_fb_helper
> *helper) +{
> +	return container_of(helper, struct drm_fbdev_cma, fb_helper);
> +}
> +
> +static inline struct drm_fb_cma *to_fb_cma(struct drm_framebuffer *fb)
> +{
> +	return container_of(fb, struct drm_fb_cma, fb);
> +}
> +
> +static void drm_fb_cma_destroy(struct drm_framebuffer *fb)
> +{
> +	struct drm_fb_cma *fb_cma = to_fb_cma(fb);
> +	int i;
> +
> +	for (i = 0; i < 4; i++) {
> +		if (fb_cma->obj[i])
> +			drm_gem_object_unreference_unlocked(&fb_cma->obj[i]->base);
> +	}
> +
> +	drm_framebuffer_cleanup(fb);
> +	kfree(fb_cma);
> +}
> +
> +static int drm_fb_cma_create_handle(struct drm_framebuffer *fb,
> +	struct drm_file *file_priv, unsigned int *handle)
> +{
> +	struct drm_fb_cma *fb_cma = to_fb_cma(fb);
> +
> +	return drm_gem_handle_create(file_priv,
> +			&fb_cma->obj[0]->base, handle);
> +}
> +
> +static struct drm_framebuffer_funcs drm_fb_cma_funcs = {
> +	.destroy	= drm_fb_cma_destroy,
> +	.create_handle	= drm_fb_cma_create_handle,
> +};
> +
> +static struct drm_fb_cma *drm_fb_cma_alloc(struct drm_device *dev,
> +	struct drm_mode_fb_cmd2 *mode_cmd, struct drm_gem_cma_object **obj,
> +	unsigned int num_planes)
> +{
> +	struct drm_fb_cma *fb_cma;
> +	int ret;
> +	int i;
> +
> +	fb_cma = kzalloc(sizeof(*fb_cma), GFP_KERNEL);
> +	if (!fb_cma)
> +		return ERR_PTR(-ENOMEM);
> +
> +	ret = drm_framebuffer_init(dev, &fb_cma->fb, &drm_fb_cma_funcs);
> +	if (ret) {
> +		dev_err(dev->dev, "Failed to initalize framebuffer: %d\n", ret);
> +		kfree(fb_cma);
> +		return ERR_PTR(ret);
> +	}
> +
> +	drm_helper_mode_fill_fb_struct(&fb_cma->fb, mode_cmd);
> +
> +	for (i = 0; i < num_planes; i++)
> +		fb_cma->obj[i] = obj[i];
> +
> +	return fb_cma;
> +}
> +
> +/**
> + * drm_fb_cma_create() - (struct drm_mode_config_funcs *)->fb_create
> callback function + *
> + * If your hardware has special alignment or pitch requirements these
> should be + * checked before calling this function.
> + */
> +struct drm_framebuffer *drm_fb_cma_create(struct drm_device *dev,
> +	struct drm_file *file_priv, struct drm_mode_fb_cmd2 *mode_cmd)
> +{
> +	struct drm_fb_cma *fb_cma;
> +	struct drm_gem_cma_object *objs[4];
> +	struct drm_gem_object *obj;
> +	int ret;
> +	int i;
> +
> +	for (i = 0; i < drm_format_num_planes(mode_cmd->pixel_format); i++) {
> +		obj = drm_gem_object_lookup(dev, file_priv, mode_cmd->handles[i]);
> +		if (!obj) {
> +			dev_err(dev->dev, "Failed to lookup GEM object\n");
> +			ret = -ENXIO;
> +			goto err_gem_object_unreference;
> +		}
> +
> +		if (obj->size < mode_cmd->height * mode_cmd->pitches[i]) {
> +			drm_gem_object_unreference_unlocked(obj);
> +			ret = -EINVAL;
> +			goto err_gem_object_unreference;
> +		}
> +		objs[i] = to_drm_gem_cma_obj(obj);
> +	}
> +
> +	fb_cma = drm_fb_cma_alloc(dev, mode_cmd, objs, i);
> +	if (IS_ERR(fb_cma)) {
> +		ret = PTR_ERR(fb_cma);
> +		goto err_gem_object_unreference;
> +	}
> +
> +	return &fb_cma->fb;
> +
> +err_gem_object_unreference:
> +	for (i--; i >= 0; i--)
> +		drm_gem_object_unreference_unlocked(&objs[i]->base);
> +	return ERR_PTR(ret);
> +}
> +EXPORT_SYMBOL_GPL(drm_fb_cma_create);
> +
> +/**
> + * drm_fb_cma_get_gem_obj() - Get CMA GEM object for framebuffer
> + * @fb: The framebuffer
> + * @plane: Which plane
> + *
> + * Return the CMA GEM object for given framebuffer.
> + *
> + * This function will usually be called from the CRTC callback functions.
> + */
> +struct drm_gem_cma_object *drm_fb_cma_get_gem_obj(struct drm_framebuffer
> *fb, +	unsigned int plane)
> +{
> +	struct drm_fb_cma *fb_cma = to_fb_cma(fb);
> +
> +	if (plane >= 4)
> +		return NULL;
> +
> +	return fb_cma->obj[plane];
> +}
> +EXPORT_SYMBOL_GPL(drm_fb_cma_get_gem_obj);
> +
> +static struct fb_ops drm_fbdev_cma_ops = {
> +	.owner		= THIS_MODULE,
> +	.fb_fillrect	= sys_fillrect,
> +	.fb_copyarea	= sys_copyarea,
> +	.fb_imageblit	= sys_imageblit,
> +	.fb_check_var	= drm_fb_helper_check_var,
> +	.fb_set_par	= drm_fb_helper_set_par,
> +	.fb_blank	= drm_fb_helper_blank,
> +	.fb_pan_display	= drm_fb_helper_pan_display,
> +	.fb_setcmap	= drm_fb_helper_setcmap,
> +};
> +
> +static int drm_fbdev_cma_create(struct drm_fb_helper *helper,
> +	struct drm_fb_helper_surface_size *sizes)
> +{
> +	struct drm_fbdev_cma *fbdev_cma = to_fbdev_cma(helper);
> +	struct drm_mode_fb_cmd2 mode_cmd = { 0 };
> +	struct drm_device *dev = helper->dev;
> +	struct drm_gem_cma_object *obj;
> +	struct drm_framebuffer *fb;
> +	unsigned int bytes_per_pixel;
> +	unsigned long offset;
> +	struct fb_info *fbi;
> +	size_t size;
> +	int ret;
> +
> +	DRM_DEBUG_KMS("surface width(%d), height(%d) and bpp(%d\n",
> +			sizes->surface_width, sizes->surface_height,
> +			sizes->surface_bpp);
> +
> +	bytes_per_pixel = DIV_ROUND_UP(sizes->surface_bpp, 8);
> +
> +	mode_cmd.width = sizes->surface_width;
> +	mode_cmd.height = sizes->surface_height;
> +	mode_cmd.pitches[0] = sizes->surface_width * bytes_per_pixel;
> +	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
> +		sizes->surface_depth);
> +
> +	size = mode_cmd.pitches[0] * mode_cmd.height;
> +	obj = drm_gem_cma_create(dev, size);
> +	if (!obj)
> +		return -ENOMEM;
> +
> +	fbi = framebuffer_alloc(0, dev->dev);
> +	if (!fbi) {
> +		dev_err(dev->dev, "Failed to allocate framebuffer info.\n");
> +		ret = -ENOMEM;
> +		goto err_drm_gem_cma_free_object;
> +	}
> +
> +	fbdev_cma->fb = drm_fb_cma_alloc(dev, &mode_cmd, &obj, 1);
> +	if (IS_ERR(fbdev_cma->fb)) {
> +		dev_err(dev->dev, "Failed to allocate DRM framebuffer.\n");
> +		ret = PTR_ERR(fbdev_cma->fb);
> +		goto err_framebuffer_release;
> +	}
> +
> +	fb = &fbdev_cma->fb->fb;
> +	helper->fb = fb;
> +	helper->fbdev = fbi;
> +
> +	fbi->par = helper;
> +	fbi->flags = FBINFO_FLAG_DEFAULT;
> +	fbi->fbops = &drm_fbdev_cma_ops;
> +
> +	ret = fb_alloc_cmap(&fbi->cmap, 256, 0);
> +	if (ret) {
> +		dev_err(dev->dev, "Failed to allocate color map.\n");
> +		goto err_drm_fb_cma_destroy;
> +	}
> +
> +	drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->depth);
> +	drm_fb_helper_fill_var(fbi, helper, fb->width, fb->height);
> +
> +	offset = fbi->var.xoffset * bytes_per_pixel;
> +	offset += fbi->var.yoffset * fb->pitches[0];
> +
> +	dev->mode_config.fb_base = (resource_size_t)obj->paddr;
> +	fbi->screen_base = obj->vaddr + offset;
> +	fbi->fix.smem_start = (unsigned long)(obj->paddr + offset);
> +	fbi->screen_size = size;
> +	fbi->fix.smem_len = size;
> +
> +	return 0;
> +
> +err_drm_fb_cma_destroy:
> +	drm_fb_cma_destroy(fb);
> +err_framebuffer_release:
> +	framebuffer_release(fbi);
> +err_drm_gem_cma_free_object:
> +	drm_gem_cma_free_object(&obj->base);
> +	return ret;
> +}
> +
> +static int drm_fbdev_cma_probe(struct drm_fb_helper *helper,
> +	struct drm_fb_helper_surface_size *sizes)
> +{
> +	int ret = 0;
> +
> +	if (!helper->fb) {
> +		ret = drm_fbdev_cma_create(helper, sizes);
> +		if (ret < 0)
> +			return ret;
> +		ret = 1;
> +	}
> +
> +	return ret;
> +}
> +
> +static struct drm_fb_helper_funcs drm_fb_cma_helper_funcs = {
> +	.fb_probe = drm_fbdev_cma_probe,
> +};
> +
> +/**
> + * drm_fbdev_cma_init() - Allocate and initializes a drm_fbdev_cma struct
> + * @dev: DRM device
> + * @preferred_bpp: Preferred bits per pixel for the device
> + * @num_crtc: Number of CRTCs
> + * @max_conn_count: Maximum number of connectors
> + *
> + * Returns a newly allocated drm_fbdev_cma struct or a ERR_PTR.
> + */
> +struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,
> +	unsigned int preferred_bpp, unsigned int num_crtc,
> +	unsigned int max_conn_count)
> +{
> +	struct drm_fbdev_cma *fbdev_cma;
> +	struct drm_fb_helper *helper;
> +	int ret;
> +
> +	fbdev_cma = kzalloc(sizeof(*fbdev_cma), GFP_KERNEL);
> +	if (!fbdev_cma) {
> +		dev_err(dev->dev, "Failed to allocate drm fbdev.\n");
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	fbdev_cma->fb_helper.funcs = &drm_fb_cma_helper_funcs;
> +	helper = &fbdev_cma->fb_helper;
> +
> +	ret = drm_fb_helper_init(dev, helper, num_crtc, max_conn_count);
> +	if (ret < 0) {
> +		dev_err(dev->dev, "Failed to initialize drm fb helper.\n");
> +		goto err_free;
> +	}
> +
> +	ret = drm_fb_helper_single_add_all_connectors(helper);
> +	if (ret < 0) {
> +		dev_err(dev->dev, "Failed to add connectors.\n");
> +		goto err_drm_fb_helper_fini;
> +
> +	}
> +
> +	ret = drm_fb_helper_initial_config(helper, preferred_bpp);
> +	if (ret < 0) {
> +		dev_err(dev->dev, "Failed to set inital hw configuration.\n");
> +		goto err_drm_fb_helper_fini;
> +	}
> +
> +	return fbdev_cma;
> +
> +err_drm_fb_helper_fini:
> +	drm_fb_helper_fini(helper);
> +err_free:
> +	kfree(fbdev_cma);
> +
> +	return ERR_PTR(ret);
> +}
> +EXPORT_SYMBOL_GPL(drm_fbdev_cma_init);
> +
> +/**
> + * drm_fbdev_cma_fini() - Free drm_fbdev_cma struct
> + * @fbdev_cma: The drm_fbdev_cma struct
> + */
> +void drm_fbdev_cma_fini(struct drm_fbdev_cma *fbdev_cma)
> +{
> +	if (fbdev_cma->fb_helper.fbdev) {
> +		struct fb_info *info;
> +		int ret;
> +
> +		info = fbdev_cma->fb_helper.fbdev;
> +		ret = unregister_framebuffer(info);
> +		if (ret < 0)
> +			DRM_DEBUG_KMS("failed unregister_framebuffer()\n");
> +
> +		if (info->cmap.len)
> +			fb_dealloc_cmap(&info->cmap);
> +
> +		framebuffer_release(info);
> +	}
> +
> +	if (fbdev_cma->fb)
> +		drm_fb_cma_destroy(&fbdev_cma->fb->fb);
> +
> +	drm_fb_helper_fini(&fbdev_cma->fb_helper);
> +	kfree(fbdev_cma);
> +}
> +EXPORT_SYMBOL_GPL(drm_fbdev_cma_fini);
> +
> +/**
> + * drm_fbdev_cma_restore_mode() - Restores initial framebuffer mode
> + * @fbdev_cma: The drm_fbdev_cma struct, may be NULL
> + *
> + * This function is usually called from the DRM drivers lastclose callback.
> + */
> +void drm_fbdev_cma_restore_mode(struct drm_fbdev_cma *fbdev_cma)
> +{
> +	if (fbdev_cma)
> +		drm_fb_helper_restore_fbdev_mode(&fbdev_cma->fb_helper);
> +}
> +EXPORT_SYMBOL_GPL(drm_fbdev_cma_restore_mode);
> +
> +/**
> + * drm_fbdev_cma_hotplug_event() - Poll for hotpulug events
> + * @fbdev_cma: The drm_fbdev_cma struct, may be NULL
> + *
> + * This function is usually called from the DRM drivers output_poll_changed
> + * callback.
> + */
> +void drm_fbdev_cma_hotplug_event(struct drm_fbdev_cma *fbdev_cma)
> +{
> +	if (fbdev_cma)
> +		drm_fb_helper_hotplug_event(&fbdev_cma->fb_helper);
> +}
> +EXPORT_SYMBOL_GPL(drm_fbdev_cma_hotplug_event);
> diff --git a/include/drm/drm_fb_cma_helper.h
> b/include/drm/drm_fb_cma_helper.h new file mode 100644
> index 0000000..76c7098
> --- /dev/null
> +++ b/include/drm/drm_fb_cma_helper.h
> @@ -0,0 +1,27 @@
> +#ifndef __DRM_FB_CMA_HELPER_H__
> +#define __DRM_FB_CMA_HELPER_H__
> +
> +struct drm_fbdev_cma;
> +struct drm_gem_cma_object;
> +
> +struct drm_framebuffer;
> +struct drm_device;
> +struct drm_file;
> +struct drm_mode_fb_cmd2;
> +
> +struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,
> +	unsigned int preferred_bpp, unsigned int num_crtc,
> +	unsigned int max_conn_count);
> +void drm_fbdev_cma_fini(struct drm_fbdev_cma *fbdev_cma);
> +
> +void drm_fbdev_cma_restore_mode(struct drm_fbdev_cma *fbdev_cma);
> +void drm_fbdev_cma_hotplug_event(struct drm_fbdev_cma *fbdev_cma);
> +
> +struct drm_framebuffer *drm_fb_cma_create(struct drm_device *dev,
> +	struct drm_file *file_priv, struct drm_mode_fb_cmd2 *mode_cmd);
> +
> +struct drm_gem_cma_object *drm_fb_cma_get_gem_obj(struct drm_framebuffer
> *fb, +	unsigned int plane);
> +
> +#endif
> +
-- 
Regards,

Laurent Pinchart



More information about the dri-devel mailing list