This is the first step in getting generic fbdev emulation.
A drm_fb_helper_funcs.fb_probe function is added which uses the
DRM client API to get a framebuffer backed by a dumb buffer.
A transitional hack for tinydrm is needed in order to switch over all
CMA helper drivers in a later patch. This hack will be removed when
tinydrm moves to vmalloc buffers.
Signed-off-by: Noralf Trønnes <noralf@xxxxxxxxxxx>
---
drivers/gpu/drm/drm_fb_helper.c | 164 ++++++++++++++++++++++++++++++++++++++++
include/drm/drm_fb_helper.h | 26 +++++++
2 files changed, 190 insertions(+)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 2ee1eaa66188..444c2b4040ea 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -30,11 +30,13 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/console.h>
+#include <linux/dma-buf.h>
#include <linux/kernel.h>
#include <linux/sysrq.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <drm/drmP.h>
+#include <drm/drm_client.h>
#include <drm/drm_crtc.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_crtc_helper.h>
@@ -2928,6 +2930,168 @@ void drm_fb_helper_output_poll_changed(struct drm_device *dev)
}
EXPORT_SYMBOL(drm_fb_helper_output_poll_changed);
+/* @user: 1=userspace, 0=fbcon */
+static int drm_fbdev_fb_open(struct fb_info *info, int user)
+{
+ struct drm_fb_helper *fb_helper = info->par;
+
+ if (!try_module_get(fb_helper->dev->driver->fops->owner))
+ return -ENODEV;
+
+ return 0;
+}
+
+static int drm_fbdev_fb_release(struct fb_info *info, int user)
+{
+ struct drm_fb_helper *fb_helper = info->par;
+
+ module_put(fb_helper->dev->driver->fops->owner);
+
+ return 0;
+}
+
+/*
+ * fb_ops.fb_destroy is called by the last put_fb_info() call at the end of
+ * unregister_framebuffer() or fb_release().
+ */
+static void drm_fbdev_fb_destroy(struct fb_info *info)
+{
+ struct drm_fb_helper *fb_helper = info->par;
+ struct fb_ops *fbops = NULL;
+
+ DRM_DEBUG("\n");
+
+ if (fb_helper->fbdev->fbdefio) {
+ fb_deferred_io_cleanup(fb_helper->fbdev);
+ fbops = fb_helper->fbdev->fbops;
+ }
+
+ drm_fb_helper_fini(fb_helper);
+ drm_client_framebuffer_delete(fb_helper->buffer);
+ drm_client_free(fb_helper->client);
+ kfree(fb_helper);
+ kfree(fbops);
+}
+
+static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
+{
+ struct drm_fb_helper *fb_helper = info->par;
+
+ if (fb_helper->dev->driver->gem_prime_mmap)
+ return fb_helper->dev->driver->gem_prime_mmap(fb_helper->buffer->gem, vma);
+ else
+ return -ENODEV;
+}
+
+static struct fb_ops drm_fbdev_fb_ops = {
+ /* No need to set owner, this module is already pinned by the driver. */
+ DRM_FB_HELPER_DEFAULT_OPS,
+ .fb_open = drm_fbdev_fb_open,
+ .fb_release = drm_fbdev_fb_release,
+ .fb_destroy = drm_fbdev_fb_destroy,
+ .fb_mmap = drm_fbdev_fb_mmap,
+ .fb_read = drm_fb_helper_sys_read,
+ .fb_write = drm_fb_helper_sys_write,
+ .fb_fillrect = drm_fb_helper_sys_fillrect,
+ .fb_copyarea = drm_fb_helper_sys_copyarea,
+ .fb_imageblit = drm_fb_helper_sys_imageblit,
+};
+
+static struct fb_deferred_io drm_fbdev_defio = {
+ .delay = HZ / 20,
+ .deferred_io = drm_fb_helper_deferred_io,
+};
+
+/*
+ * TODO: Remove this when tinydrm is converted to vmalloc buffers.
+ */
+static int drm_fbdev_cma_deferred_io_mmap(struct fb_info *info,
+ struct vm_area_struct *vma)
+{
+ fb_deferred_io_mmap(info, vma);
+ vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
+
+ return 0;
+}
+
+int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
+ struct drm_fb_helper_surface_size *sizes)
+{
+ struct drm_client_dev *client = fb_helper->client;
+ struct drm_client_buffer *buffer;
+ struct drm_framebuffer *fb;
+ struct fb_info *fbi;
+ u32 format;
+ int ret;
+
+ DRM_DEBUG_KMS("surface width(%d), height(%d) and bpp(%d)\n",
+ sizes->surface_width, sizes->surface_height,
+ sizes->surface_bpp);
+
+ format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
+ buffer = drm_client_framebuffer_create(client, sizes->surface_width,
+ sizes->surface_height, format);
+ if (IS_ERR(buffer))
+ return PTR_ERR(buffer);
+
+ fb_helper->buffer = buffer;
+ fb_helper->fb = buffer->fb;
+ fb = buffer->fb;
+
+ fbi = drm_fb_helper_alloc_fbi(fb_helper);
+ if (IS_ERR(fbi)) {
+ ret = PTR_ERR(fbi);
+ goto err_free_buffer;
+ }
+
+ fbi->par = fb_helper;
+ fbi->fbops = &drm_fbdev_fb_ops;
+ fbi->screen_size = fb->height * fb->pitches[0];
+ fbi->fix.smem_len = fbi->screen_size;
+ fbi->screen_buffer = buffer->vaddr;
+ strcpy(fbi->fix.id, "DRM emulated");
+
+ drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->format->depth);
+ drm_fb_helper_fill_var(fbi, fb_helper, sizes->fb_width, sizes->fb_height);
+
+ if (fb->funcs->dirty) {
+ struct fb_ops *fbops;
+
+ /*
+ * fb_deferred_io_cleanup() clears &fbops->fb_mmap so a per
+ * instance version is necessary.
+ */
+ fbops = kzalloc(sizeof(*fbops), GFP_KERNEL);
+ if (!fbops) {
+ ret = -ENOMEM;
+ goto err_fb_info_destroy;
+ }
+
+ *fbops = *fbi->fbops;
+ fbi->fbops = fbops;
+
+ fbi->fbdefio = &drm_fbdev_defio;
+
+ /* TODO: Remove this when tinydrm is converted to vmalloc buffers. */
+ fbi->fix.smem_start = page_to_phys(virt_to_page(buffer->vaddr));
+
+ fb_deferred_io_init(fbi);
+
+ /* TODO: Remove this when tinydrm is converted to vmalloc buffers. */
+ fbi->fbops->fb_mmap = drm_fbdev_cma_deferred_io_mmap;
+ }
+
+ return 0;
+
+err_fb_info_destroy:
+ drm_fb_helper_fini(fb_helper);
+err_free_buffer:
+ drm_client_framebuffer_delete(buffer);
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_fb_helper_generic_probe);
+
/* The Kconfig DRM_KMS_HELPER selects FRAMEBUFFER_CONSOLE (if !EXPERT)
* but the module doesn't depend on any fb console symbols. At least
* attempt to load fbcon to avoid leaving the system without a usable console.
diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index b069433e7fc1..bb38469a9502 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -30,6 +30,8 @@
#ifndef DRM_FB_HELPER_H
#define DRM_FB_HELPER_H
+struct drm_client_buffer;
+struct drm_client_dev;
struct drm_fb_helper;
#include <drm/drm_crtc.h>
@@ -232,6 +234,20 @@ struct drm_fb_helper {
* See also: @deferred_setup
*/
int preferred_bpp;
+
+ /**
+ * @client:
+ *
+ * DRM client used by the generic fbdev emulation.
+ */
+ struct drm_client_dev *client;
+
+ /**
+ * @buffer:
+ *
+ * Framebuffer used by the generic fbdev emulation.
+ */
+ struct drm_client_buffer *buffer;
};
/**
@@ -330,6 +346,9 @@ void drm_fb_helper_fbdev_teardown(struct drm_device *dev);
void drm_fb_helper_lastclose(struct drm_device *dev);
void drm_fb_helper_output_poll_changed(struct drm_device *dev);
+
+int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
+ struct drm_fb_helper_surface_size *sizes);
#else
static inline void drm_fb_helper_prepare(struct drm_device *dev,
struct drm_fb_helper *helper,
@@ -564,6 +583,13 @@ static inline void drm_fb_helper_output_poll_changed(struct drm_device *dev)
{
}
+static inline int
+drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
+ struct drm_fb_helper_surface_size *sizes)
+{
+ return 0;
+}
+
#endif
static inline int
--
2.15.1
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