linux_dsm_epyc7002/drivers/gpu/drm/vkms/vkms_plane.c
Haneen Mohammed 6c234fe37c drm/vkms: Implement CRC debugfs API
This patch implement the necessary functions to compute and add CRCs
entries:

- Implement the set_crc_source() callback.
- Compute CRC using crc32 on the visible part of the framebuffer.
- Use ordered workqueue per output to compute and add CRC at the end
  of a vblank.
- Use appropriate synchronization methods since the CRC computation must
  be atomic wrt the generated vblank event for a given atomic update, by
  using spinlock across atomic_begin/atomic_flush to wrap the event
  handling code completely and match the flip event with the CRC.

Since vkms_crc_work_handle() can sleep, spinlock can't be acquired
while accessing vkms_output->primary_crc to compute CRC.
To make sure the data is updated and released without conflict with
the vkms_crc_work_handle(), the work_struct is flushed @crtc_destroy
and the data is updated before scheduling the work handle again, as
follow:

* CRC data update:
1- store vkms_crc_data {fb, src} per plane_state
2- @plane_duplicate_state -> allocate vkms_crc_data
3- during atomic commit (@atomic_update) ->
	a) copy {fb, src} to plane_state->crc_data
	b) get reference to fb,
3- @plane_destroy_state -> a) if (fb refcount) remove reference to fb
			   b) deallocate crc_data

* Atomic Commit:
1- vkms_plane_atomic_check
2- vkms_prepare_fb -> vmap vkms_gem_obj->vaddr
3- atomic_begin -> hold crc spinlock
4- atomic_plane_update -> a) update vkms_output->primary_crc
			  b) get reference to fb
5- atomic_flush -> a) send vblank event while holding event_lock
		   b) release crc spinlock

* hrtimer regular callback:
1- hold crc spinlock
2- drm_crtc_handle_vblank()
3- queue vkms_crc_work_handle
4- release crc spinlock

* cleanup:
1- @cleanup_fb ->vunmap vkms_gem_obj->vaddr
2- @crtc_destroy -> flush work struct
3- @plane_destroy -> a) if (fb refcount) remove reference to fb
		     b) deallocate crc_data

Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
[seanpaul fixed typo in vkms_crtc s/vblamk/vblank/]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/b948327f48c3e70ab232b4a0848ee6d033b26484.1533171495.git.hamohammed.sa@gmail.com
2018-08-03 14:52:58 -04:00

192 lines
4.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* 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 "vkms_drv.h"
#include <drm/drm_plane_helper.h>
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
static struct drm_plane_state *
vkms_plane_duplicate_state(struct drm_plane *plane)
{
struct vkms_plane_state *vkms_state;
struct vkms_crc_data *crc_data;
vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
if (!vkms_state)
return NULL;
crc_data = kzalloc(sizeof(*crc_data), GFP_KERNEL);
if (WARN_ON(!crc_data))
DRM_INFO("Couldn't allocate crc_data");
vkms_state->crc_data = crc_data;
__drm_atomic_helper_plane_duplicate_state(plane,
&vkms_state->base);
return &vkms_state->base;
}
static void vkms_plane_destroy_state(struct drm_plane *plane,
struct drm_plane_state *old_state)
{
struct vkms_plane_state *vkms_state = to_vkms_plane_state(old_state);
struct drm_crtc *crtc = vkms_state->base.crtc;
if (crtc) {
/* dropping the reference we acquired in
* vkms_primary_plane_update()
*/
if (drm_framebuffer_read_refcount(&vkms_state->crc_data->fb))
drm_framebuffer_put(&vkms_state->crc_data->fb);
}
kfree(vkms_state->crc_data);
vkms_state->crc_data = NULL;
__drm_atomic_helper_plane_destroy_state(old_state);
kfree(vkms_state);
}
static void vkms_plane_reset(struct drm_plane *plane)
{
struct vkms_plane_state *vkms_state;
if (plane->state)
vkms_plane_destroy_state(plane, plane->state);
vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
if (!vkms_state) {
DRM_ERROR("Cannot allocate vkms_plane_state\n");
return;
}
plane->state = &vkms_state->base;
plane->state->plane = plane;
}
static const struct drm_plane_funcs vkms_plane_funcs = {
.update_plane = drm_atomic_helper_update_plane,
.disable_plane = drm_atomic_helper_disable_plane,
.destroy = drm_plane_cleanup,
.reset = vkms_plane_reset,
.atomic_duplicate_state = vkms_plane_duplicate_state,
.atomic_destroy_state = vkms_plane_destroy_state,
};
static void vkms_primary_plane_update(struct drm_plane *plane,
struct drm_plane_state *old_state)
{
struct vkms_plane_state *vkms_plane_state;
struct vkms_crc_data *crc_data;
if (!plane->state->crtc || !plane->state->fb)
return;
vkms_plane_state = to_vkms_plane_state(plane->state);
crc_data = vkms_plane_state->crc_data;
memcpy(&crc_data->src, &plane->state->src, sizeof(struct drm_rect));
memcpy(&crc_data->fb, plane->state->fb, sizeof(struct drm_framebuffer));
drm_framebuffer_get(&crc_data->fb);
}
static int vkms_plane_atomic_check(struct drm_plane *plane,
struct drm_plane_state *state)
{
struct drm_crtc_state *crtc_state;
int ret;
if (!state->fb | !state->crtc)
return 0;
crtc_state = drm_atomic_get_crtc_state(state->state, state->crtc);
if (IS_ERR(crtc_state))
return PTR_ERR(crtc_state);
ret = drm_atomic_helper_check_plane_state(state, crtc_state,
DRM_PLANE_HELPER_NO_SCALING,
DRM_PLANE_HELPER_NO_SCALING,
false, true);
if (ret != 0)
return ret;
/* for now primary plane must be visible and full screen */
if (!state->visible)
return -EINVAL;
return 0;
}
static int vkms_prepare_fb(struct drm_plane *plane,
struct drm_plane_state *state)
{
struct drm_gem_object *gem_obj;
struct vkms_gem_object *vkms_obj;
int ret;
if (!state->fb)
return 0;
gem_obj = drm_gem_fb_get_obj(state->fb, 0);
vkms_obj = drm_gem_to_vkms_gem(gem_obj);
ret = vkms_gem_vmap(gem_obj);
if (ret)
DRM_ERROR("vmap failed: %d\n", ret);
return drm_gem_fb_prepare_fb(plane, state);
}
static void vkms_cleanup_fb(struct drm_plane *plane,
struct drm_plane_state *old_state)
{
struct drm_gem_object *gem_obj;
if (!old_state->fb)
return;
gem_obj = drm_gem_fb_get_obj(old_state->fb, 0);
vkms_gem_vunmap(gem_obj);
}
static const struct drm_plane_helper_funcs vkms_primary_helper_funcs = {
.atomic_update = vkms_primary_plane_update,
.atomic_check = vkms_plane_atomic_check,
.prepare_fb = vkms_prepare_fb,
.cleanup_fb = vkms_cleanup_fb,
};
struct drm_plane *vkms_plane_init(struct vkms_device *vkmsdev)
{
struct drm_device *dev = &vkmsdev->drm;
struct drm_plane *plane;
const u32 *formats;
int ret, nformats;
plane = kzalloc(sizeof(*plane), GFP_KERNEL);
if (!plane)
return ERR_PTR(-ENOMEM);
formats = vkms_formats;
nformats = ARRAY_SIZE(vkms_formats);
ret = drm_universal_plane_init(dev, plane, 0,
&vkms_plane_funcs,
formats, nformats,
NULL, DRM_PLANE_TYPE_PRIMARY, NULL);
if (ret) {
kfree(plane);
return ERR_PTR(ret);
}
drm_plane_helper_add(plane, &vkms_primary_helper_funcs);
return plane;
}