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drm/vkms: Implement CRC debugfs API

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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
This commit is contained in:
Haneen Mohammed 2018-08-02 04:10:26 +03:00 committed by Sean Paul
parent 3e77c4d022
commit 6c234fe37c
6 changed files with 197 additions and 10 deletions
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2
drivers/gpu/drm/vkms/Makefile
View File

@ -1,3 +1,3 @@
vkms-y := vkms_drv.o vkms_plane.o vkms_output.o vkms_crtc.o vkms_gem.o
vkms-y := vkms_drv.o vkms_plane.o vkms_output.o vkms_crtc.o vkms_gem.o vkms_crc.o
obj-$(CONFIG_DRM_VKMS) += vkms.o

95
drivers/gpu/drm/vkms/vkms_crc.c Normal file
View File

@ -0,0 +1,95 @@
// SPDX-License-Identifier: GPL-2.0
#include "vkms_drv.h"
#include <linux/crc32.h>
#include <drm/drm_gem_framebuffer_helper.h>
static uint32_t _vkms_get_crc(struct vkms_crc_data *crc_data)
{
struct drm_framebuffer *fb = &crc_data->fb;
struct drm_gem_object *gem_obj = drm_gem_fb_get_obj(fb, 0);
struct vkms_gem_object *vkms_obj = drm_gem_to_vkms_gem(gem_obj);
u32 crc = 0;
int i = 0;
unsigned int x = crc_data->src.x1 >> 16;
unsigned int y = crc_data->src.y1 >> 16;
unsigned int height = drm_rect_height(&crc_data->src) >> 16;
unsigned int width = drm_rect_width(&crc_data->src) >> 16;
unsigned int cpp = fb->format->cpp[0];
unsigned int src_offset;
unsigned int size_byte = width * cpp;
void *vaddr;
mutex_lock(&vkms_obj->pages_lock);
vaddr = vkms_obj->vaddr;
if (WARN_ON(!vaddr))
return crc;
for (i = y; i < y + height; i++) {
src_offset = fb->offsets[0] + (i * fb->pitches[0]) + (x * cpp);
crc = crc32_le(crc, vaddr + src_offset, size_byte);
}
mutex_unlock(&vkms_obj->pages_lock);
return crc;
}
void vkms_crc_work_handle(struct work_struct *work)
{
struct vkms_crtc_state *crtc_state = container_of(work,
struct vkms_crtc_state,
crc_work);
struct drm_crtc *crtc = crtc_state->base.crtc;
struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
struct vkms_device *vdev = container_of(out, struct vkms_device,
output);
struct vkms_crc_data *primary_crc = NULL;
struct drm_plane *plane;
u32 crc32 = 0;
drm_for_each_plane(plane, &vdev->drm) {
struct vkms_plane_state *vplane_state;
struct vkms_crc_data *crc_data;
vplane_state = to_vkms_plane_state(plane->state);
crc_data = vplane_state->crc_data;
if (drm_framebuffer_read_refcount(&crc_data->fb) == 0)
continue;
if (plane->type == DRM_PLANE_TYPE_PRIMARY) {
primary_crc = crc_data;
break;
}
}
if (primary_crc)
crc32 = _vkms_get_crc(primary_crc);
drm_crtc_add_crc_entry(crtc, true, crtc_state->n_frame, &crc32);
}
int vkms_set_crc_source(struct drm_crtc *crtc, const char *src_name,
size_t *values_cnt)
{
struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
bool enabled = false;
unsigned long flags;
int ret = 0;
if (src_name && strcmp(src_name, "auto") == 0)
enabled = true;
else if (src_name)
ret = -EINVAL;
*values_cnt = 1;
/* make sure nothing is scheduled on crtc workq */
flush_workqueue(out->crc_workq);
spin_lock_irqsave(&out->lock, flags);
out->crc_enabled = enabled;
spin_unlock_irqrestore(&out->lock, flags);
return ret;
}

58
drivers/gpu/drm/vkms/vkms_crtc.c
View File

@ -10,17 +10,32 @@
#include <drm/drm_atomic_helper.h>
#include <drm/drm_crtc_helper.h>
static void _vblank_handle(struct vkms_output *output)
{
struct drm_crtc *crtc = &output->crtc;
struct vkms_crtc_state *state = to_vkms_crtc_state(crtc->state);
bool ret;
spin_lock(&output->lock);
ret = drm_crtc_handle_vblank(crtc);
if (!ret)
DRM_ERROR("vkms failure on handling vblank");
if (state && output->crc_enabled) {
state->n_frame = drm_crtc_accurate_vblank_count(crtc);
queue_work(output->crc_workq, &state->crc_work);
}
spin_unlock(&output->lock);
}
static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer)
{
struct vkms_output *output = container_of(timer, struct vkms_output,
vblank_hrtimer);
struct drm_crtc *crtc = &output->crtc;
int ret_overrun;
bool ret;
ret = drm_crtc_handle_vblank(crtc);
if (!ret)
DRM_ERROR("vkms failure on handling vblank");
_vblank_handle(output);
ret_overrun = hrtimer_forward_now(&output->vblank_hrtimer,
output->period_ns);
@ -97,18 +112,22 @@ vkms_atomic_crtc_duplicate_state(struct drm_crtc *crtc)
__drm_atomic_helper_crtc_duplicate_state(crtc, &vkms_state->base);
INIT_WORK(&vkms_state->crc_work, vkms_crc_work_handle);
return &vkms_state->base;
}
static void vkms_atomic_crtc_destroy_state(struct drm_crtc *crtc,
struct drm_crtc_state *state)
{
struct vkms_crtc_state *vkms_state;
vkms_state = to_vkms_crtc_state(state);
struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(state);
__drm_atomic_helper_crtc_destroy_state(state);
kfree(vkms_state);
if (vkms_state) {
flush_work(&vkms_state->crc_work);
kfree(vkms_state);
}
}
static const struct drm_crtc_funcs vkms_crtc_funcs = {
@ -120,6 +139,7 @@ static const struct drm_crtc_funcs vkms_crtc_funcs = {
.atomic_destroy_state = vkms_atomic_crtc_destroy_state,
.enable_vblank = vkms_enable_vblank,
.disable_vblank = vkms_disable_vblank,
.set_crc_source = vkms_set_crc_source,
};
static void vkms_crtc_atomic_enable(struct drm_crtc *crtc,
@ -134,9 +154,21 @@ static void vkms_crtc_atomic_disable(struct drm_crtc *crtc,
drm_crtc_vblank_off(crtc);
}
static void vkms_crtc_atomic_begin(struct drm_crtc *crtc,
struct drm_crtc_state *old_crtc_state)
{
struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
/* This lock is held across the atomic commit to block vblank timer
* from scheduling vkms_crc_work_handle until the crc_data is updated
*/
spin_lock_irq(&vkms_output->lock);
}
static void vkms_crtc_atomic_flush(struct drm_crtc *crtc,
struct drm_crtc_state *old_crtc_state)
{
struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
unsigned long flags;
if (crtc->state->event) {
@ -151,9 +183,12 @@ static void vkms_crtc_atomic_flush(struct drm_crtc *crtc,
crtc->state->event = NULL;
}
spin_unlock_irq(&vkms_output->lock);
}
static const struct drm_crtc_helper_funcs vkms_crtc_helper_funcs = {
.atomic_begin = vkms_crtc_atomic_begin,
.atomic_flush = vkms_crtc_atomic_flush,
.atomic_enable = vkms_crtc_atomic_enable,
.atomic_disable = vkms_crtc_atomic_disable,
@ -162,6 +197,7 @@ static const struct drm_crtc_helper_funcs vkms_crtc_helper_funcs = {
int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
struct drm_plane *primary, struct drm_plane *cursor)
{
struct vkms_output *vkms_out = drm_crtc_to_vkms_output(crtc);
int ret;
ret = drm_crtc_init_with_planes(dev, crtc, primary, cursor,
@ -173,5 +209,9 @@ int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs);
spin_lock_init(&vkms_out->lock);
vkms_out->crc_workq = alloc_ordered_workqueue("vkms_crc_workq", 0);
return ret;
}

1
drivers/gpu/drm/vkms/vkms_drv.c
View File

@ -46,6 +46,7 @@ static void vkms_release(struct drm_device *dev)
platform_device_unregister(vkms->platform);
drm_mode_config_cleanup(&vkms->drm);
drm_dev_fini(&vkms->drm);
destroy_workqueue(vkms->output.crc_workq);
}
static struct drm_driver vkms_driver = {

21
drivers/gpu/drm/vkms/vkms_drv.h
View File

@ -20,20 +20,31 @@ static const u32 vkms_formats[] = {
DRM_FORMAT_XRGB8888,
};
struct vkms_crc_data {
struct drm_rect src;
struct drm_framebuffer fb;
};
/**
* vkms_plane_state - Driver specific plane state
* @base: base plane state
* @crc_data: data required for CRC computation
*/
struct vkms_plane_state {
struct drm_plane_state base;
struct vkms_crc_data *crc_data;
};
/**
* vkms_crtc_state - Driver specific CRTC state
* @base: base CRTC state
* @crc_work: work struct to compute and add CRC entries
* @n_frame: frame number for computed CRC
*/
struct vkms_crtc_state {
struct drm_crtc_state base;
struct work_struct crc_work;
unsigned int n_frame;
};
struct vkms_output {
@ -43,6 +54,11 @@ struct vkms_output {
struct hrtimer vblank_hrtimer;
ktime_t period_ns;
struct drm_pending_vblank_event *event;
bool crc_enabled;
/* ordered wq for crc_work */
struct workqueue_struct *crc_workq;
/* protects concurrent access to crc_data */
spinlock_t lock;
};
struct vkms_device {
@ -106,4 +122,9 @@ int vkms_gem_vmap(struct drm_gem_object *obj);
void vkms_gem_vunmap(struct drm_gem_object *obj);
/* CRC Support */
int vkms_set_crc_source(struct drm_crtc *crtc, const char *src_name,
size_t *values_cnt);
void vkms_crc_work_handle(struct work_struct *work);
#endif /* _VKMS_DRV_H_ */

30
drivers/gpu/drm/vkms/vkms_plane.c
View File

@ -16,11 +16,18 @@ 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);
@ -31,6 +38,18 @@ 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);
@ -65,6 +84,17 @@ static const struct drm_plane_funcs vkms_plane_funcs = {
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,