// SPDX-License-Identifier: MIT
#include <linux/fb.h>
#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>
#include <drm/drm_fbdev_dma.h>
/*
* struct fb_ops
*/
static int drm_fbdev_dma_fb_open(struct fb_info *info, int user)
{
struct drm_fb_helper *fb_helper = info->par;
/* No need to take a ref for fbcon because it unbinds on unregister */
if (user && !try_module_get(fb_helper->dev->driver->fops->owner))
return -ENODEV;
return 0;
}
static int drm_fbdev_dma_fb_release(struct fb_info *info, int user)
{
struct drm_fb_helper *fb_helper = info->par;
if (user)
module_put(fb_helper->dev->driver->fops->owner);
return 0;
}
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 void drm_fbdev_dma_fb_destroy(struct fb_info *info)
{
struct drm_fb_helper *fb_helper = info->par;
if (!fb_helper->dev)
return;
fb_deferred_io_cleanup(info);
drm_fb_helper_fini(fb_helper);
drm_client_buffer_vunmap(fb_helper->buffer);
drm_client_framebuffer_delete(fb_helper->buffer);
drm_client_release(&fb_helper->client);
drm_fb_helper_unprepare(fb_helper);
kfree(fb_helper);
}
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,
DRM_FB_HELPER_DEFAULT_OPS,
__FB_DEFAULT_DMAMEM_OPS_DRAW,
.fb_mmap = drm_fbdev_dma_fb_mmap,
.fb_destroy = drm_fbdev_dma_fb_destroy,
};
FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(drm_fbdev_dma,
drm_fb_helper_damage_range,
drm_fb_helper_damage_area);
static int drm_fbdev_dma_deferred_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 const struct fb_ops drm_fbdev_dma_deferred_fb_ops = {
.owner = THIS_MODULE,
.fb_open = drm_fbdev_dma_fb_open,
.fb_release = drm_fbdev_dma_fb_release,
__FB_DEFAULT_DEFERRED_OPS_RDWR(drm_fbdev_dma),
DRM_FB_HELPER_DEFAULT_OPS,
__FB_DEFAULT_DEFERRED_OPS_DRAW(drm_fbdev_dma),
.fb_mmap = drm_fbdev_dma_deferred_fb_mmap,
.fb_destroy = drm_fbdev_dma_fb_destroy,
};
/*
* struct drm_fb_helper
*/
static int drm_fbdev_dma_helper_fb_probe(struct drm_fb_helper *fb_helper,
struct drm_fb_helper_surface_size *sizes)
{
struct drm_client_dev *client = &fb_helper->client;
struct drm_device *dev = fb_helper->dev;
bool use_deferred_io = false;
struct drm_client_buffer *buffer;
struct drm_gem_dma_object *dma_obj;
struct drm_framebuffer *fb;
struct fb_info *info;
u32 format;
struct iosys_map map;
int ret;
drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
sizes->surface_width, sizes->surface_height,
sizes->surface_bpp);
format = drm_driver_legacy_fb_format(dev, 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);
dma_obj = to_drm_gem_dma_obj(buffer->gem);
fb = buffer->fb;
/*
* Deferred I/O requires struct page for framebuffer memory,
* which is not guaranteed for all DMA ranges. We thus only
* install deferred I/O if we have a framebuffer that requires
* it.
*/
if (fb->funcs->dirty)
use_deferred_io = true;
ret = drm_client_buffer_vmap(buffer, &map);
if (ret) {
goto err_drm_client_buffer_delete;
} else if (drm_WARN_ON(dev, map.is_iomem)) {
ret = -ENODEV; /* I/O memory not supported; use generic emulation */
goto err_drm_client_buffer_delete;
}
fb_helper->buffer = buffer;
fb_helper->fb = fb;
info = drm_fb_helper_alloc_info(fb_helper);
if (IS_ERR(info)) {
ret = PTR_ERR(info);
goto err_drm_client_buffer_vunmap;
}
drm_fb_helper_fill_info(info, fb_helper, sizes);
if (use_deferred_io)
info->fbops = &drm_fbdev_dma_deferred_fb_ops;
else
info->fbops = &drm_fbdev_dma_fb_ops;
/* screen */
info->flags |= FBINFO_VIRTFB; /* system memory */
if (dma_obj->map_noncoherent)
info->flags |= FBINFO_READS_FAST; /* signal caching */
info->screen_size = sizes->surface_height * fb->pitches[0];
info->screen_buffer = map.vaddr;
if (!(info->flags & FBINFO_HIDE_SMEM_START)) {
if (!drm_WARN_ON(dev, is_vmalloc_addr(info->screen_buffer)))
info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer));
}
info->fix.smem_len = info->screen_size;
/*
* Only set up deferred I/O if the screen buffer supports
* it. If this disagrees with the previous test for ->dirty,
* mmap on the /dev/fb file might not work correctly.
*/
if (!is_vmalloc_addr(info->screen_buffer) && info->fix.smem_start) {
unsigned long pfn = info->fix.smem_start >> PAGE_SHIFT;
if (drm_WARN_ON(dev, !pfn_to_page(pfn)))
use_deferred_io = false;
}
/* deferred I/O */
if (use_deferred_io) {
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;
drm_client_buffer_vunmap(buffer);
err_drm_client_buffer_delete:
drm_client_framebuffer_delete(buffer);
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,
};
/*
* struct drm_client_funcs
*/
static void drm_fbdev_dma_client_unregister(struct drm_client_dev *client)
{
struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
if (fb_helper->info) {
drm_fb_helper_unregister_info(fb_helper);
} else {
drm_client_release(&fb_helper->client);
drm_fb_helper_unprepare(fb_helper);
kfree(fb_helper);
}
}
static int drm_fbdev_dma_client_restore(struct drm_client_dev *client)
{
drm_fb_helper_lastclose(client->dev);
return 0;
}
static int drm_fbdev_dma_client_hotplug(struct drm_client_dev *client)
{
struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
struct drm_device *dev = client->dev;
int ret;
if (dev->fb_helper)
return drm_fb_helper_hotplug_event(dev->fb_helper);
ret = drm_fb_helper_init(dev, fb_helper);
if (ret)
goto err_drm_err;
if (!drm_drv_uses_atomic_modeset(dev))
drm_helper_disable_unused_functions(dev);
ret = drm_fb_helper_initial_config(fb_helper);
if (ret)
goto err_drm_fb_helper_fini;
return 0;
err_drm_fb_helper_fini:
drm_fb_helper_fini(fb_helper);
err_drm_err:
drm_err(dev, "fbdev-dma: Failed to setup generic emulation (ret=%d)\n", ret);
return ret;
}
static const struct drm_client_funcs drm_fbdev_dma_client_funcs = {
.owner = THIS_MODULE,
.unregister = drm_fbdev_dma_client_unregister,
.restore = drm_fbdev_dma_client_restore,
.hotplug = drm_fbdev_dma_client_hotplug,
};
/**
* drm_fbdev_dma_setup() - Setup fbdev emulation for GEM DMA helpers
* @dev: DRM device
* @preferred_bpp: Preferred bits per pixel for the device.
* 32 is used if this is zero.
*
* This function sets up fbdev emulation for GEM DMA drivers that support
* dumb buffers with a virtual address and that can be mmap'ed.
* drm_fbdev_dma_setup() shall be called after the DRM driver registered
* the new DRM device with drm_dev_register().
*
* Restore, hotplug events and teardown are all taken care of. Drivers that do
* suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.
* Simple drivers might use drm_mode_config_helper_suspend().
*
* This function is safe to call even when there are no connectors present.
* Setup will be retried on the next hotplug event.
*
* The fbdev is destroyed by drm_dev_unregister().
*/
void drm_fbdev_dma_setup(struct drm_device *dev, unsigned int preferred_bpp)
{
struct drm_fb_helper *fb_helper;
int ret;
drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
if (!fb_helper)
return;
drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_dma_helper_funcs);
ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_dma_client_funcs);
if (ret) {
drm_err(dev, "Failed to register client: %d\n", ret);
goto err_drm_client_init;
}
drm_client_register(&fb_helper->client);
return;
err_drm_client_init:
drm_fb_helper_unprepare(fb_helper);
kfree(fb_helper);
}
EXPORT_SYMBOL(drm_fbdev_dma_setup);
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