Commit 808a40b6 authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

drm/fbdev-dma: Implement damage handling and deferred I/O 



Add support for damage handling and deferred I/O to fbdev-dma. This
enables fbdev-dma to support all DMA-memory-based DRM drivers, even
such with a dirty callback in their framebuffers.

The patch adds the code for deferred I/O and also sets a dedicated
helper for struct fb_ops.fb_mmap that support coherent mappings.

v3:
- init fb_ops with FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS() (Javier)

Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240419083331.7761-22-tzimmermann@suse.de
parent d2b42634

drivers/gpu/drm/drm_fbdev_dma.c

+51 −14
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 


#include <drm/drm_crtc_helper.h>

#include <drm/drm_drv.h>

#include <drm/drm_fb_dma_helper.h>

#include <drm/drm_fb_helper.h>

#include <drm/drm_framebuffer.h>

#include <drm/drm_gem_dma_helper.h>
@@ -35,6 +36,22 @@ static int drm_fbdev_dma_fb_release(struct fb_info *info, int user) 
	return 0;

}



FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(drm_fbdev_dma,

				   drm_fb_helper_damage_range,

				   drm_fb_helper_damage_area);



static int drm_fbdev_dma_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)

{

	struct drm_fb_helper *fb_helper = info->par;

	struct drm_framebuffer *fb = fb_helper->fb;

	struct drm_gem_dma_object *dma = drm_fb_dma_get_gem_obj(fb, 0);



	if (!dma->map_noncoherent)

		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);



	return fb_deferred_io_mmap(info, vma);

}



static void drm_fbdev_dma_fb_destroy(struct fb_info *info)

{

	struct drm_fb_helper *fb_helper = info->par;
@@ -51,20 +68,13 @@ static void drm_fbdev_dma_fb_destroy(struct fb_info *info) 
	kfree(fb_helper);

}



static int drm_fbdev_dma_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)

{

	struct drm_fb_helper *fb_helper = info->par;



	return drm_gem_prime_mmap(fb_helper->buffer->gem, vma);

}



static const struct fb_ops drm_fbdev_dma_fb_ops = {

	.owner = THIS_MODULE,

	.fb_open = drm_fbdev_dma_fb_open,

	.fb_release = drm_fbdev_dma_fb_release,

	__FB_DEFAULT_DMAMEM_OPS_RDWR,

	__FB_DEFAULT_DEFERRED_OPS_RDWR(drm_fbdev_dma),

	DRM_FB_HELPER_DEFAULT_OPS,

	__FB_DEFAULT_DMAMEM_OPS_DRAW,

	__FB_DEFAULT_DEFERRED_OPS_DRAW(drm_fbdev_dma),

	.fb_mmap = drm_fbdev_dma_fb_mmap,

	.fb_destroy = drm_fbdev_dma_fb_destroy,

};
@@ -98,10 +108,6 @@ static int drm_fbdev_dma_helper_fb_probe(struct drm_fb_helper *fb_helper, 
	dma_obj = to_drm_gem_dma_obj(buffer->gem);



	fb = buffer->fb;

	if (drm_WARN_ON(dev, fb->funcs->dirty)) {

		ret = -ENODEV; /* damage handling not supported; use generic emulation */

		goto err_drm_client_buffer_delete;

	}



	ret = drm_client_buffer_vmap(buffer, &map);

	if (ret) {
@@ -112,7 +118,7 @@ static int drm_fbdev_dma_helper_fb_probe(struct drm_fb_helper *fb_helper, 
	}



	fb_helper->buffer = buffer;

	fb_helper->fb = buffer->fb;

	fb_helper->fb = fb;



	info = drm_fb_helper_alloc_info(fb_helper);

	if (IS_ERR(info)) {
@@ -133,8 +139,19 @@ static int drm_fbdev_dma_helper_fb_probe(struct drm_fb_helper *fb_helper, 
	info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer));

	info->fix.smem_len = info->screen_size;



	/* deferred I/O */

	fb_helper->fbdefio.delay = HZ / 20;

	fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;



	info->fbdefio = &fb_helper->fbdefio;

	ret = fb_deferred_io_init(info);

	if (ret)

		goto err_drm_fb_helper_release_info;



	return 0;



err_drm_fb_helper_release_info:

	drm_fb_helper_release_info(fb_helper);

err_drm_client_buffer_vunmap:

	fb_helper->fb = NULL;

	fb_helper->buffer = NULL;
@@ -144,8 +161,28 @@ static int drm_fbdev_dma_helper_fb_probe(struct drm_fb_helper *fb_helper, 
	return ret;

}



static int drm_fbdev_dma_helper_fb_dirty(struct drm_fb_helper *helper,

					 struct drm_clip_rect *clip)

{

	struct drm_device *dev = helper->dev;

	int ret;



	/* Call damage handlers only if necessary */

	if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))

		return 0;



	if (helper->fb->funcs->dirty) {

		ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);

		if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))

			return ret;

	}



	return 0;

}



static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = {

	.fb_probe = drm_fbdev_dma_helper_fb_probe,

	.fb_dirty = drm_fbdev_dma_helper_fb_dirty,

};



/*