[PATCH v2 2/2] drm/vkms: Implement CRC debugfs API
Haneen Mohammed
hamohammed.sa at gmail.com
Thu Aug 2 01:10:26 UTC 2018
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 at gmail.com>
---
Changes in v2:
- remove vkms_crc_data for primary plane from vkms_output
and access it from vkms_plane_state instead.
- flush crc_workq in vkms_set_crc_source before changing out->enabled
value.
drivers/gpu/drm/vkms/Makefile | 2 +-
drivers/gpu/drm/vkms/vkms_crc.c | 95 +++++++++++++++++++++++++++++++
drivers/gpu/drm/vkms/vkms_crtc.c | 56 +++++++++++++++---
drivers/gpu/drm/vkms/vkms_drv.c | 1 +
drivers/gpu/drm/vkms/vkms_drv.h | 21 +++++++
drivers/gpu/drm/vkms/vkms_plane.c | 30 ++++++++++
6 files changed, 196 insertions(+), 9 deletions(-)
create mode 100644 drivers/gpu/drm/vkms/vkms_crc.c
diff --git a/drivers/gpu/drm/vkms/Makefile b/drivers/gpu/drm/vkms/Makefile
index 986297da51bf..37966914f70b 100644
--- a/drivers/gpu/drm/vkms/Makefile
+++ b/drivers/gpu/drm/vkms/Makefile
@@ -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
diff --git a/drivers/gpu/drm/vkms/vkms_crc.c b/drivers/gpu/drm/vkms/vkms_crc.c
new file mode 100644
index 000000000000..9b909221943f
--- /dev/null
+++ b/drivers/gpu/drm/vkms/vkms_crc.c
@@ -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;
+}
diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c
index 26babb85ca77..a6c080d7f7ae 100644
--- a/drivers/gpu/drm/vkms/vkms_crtc.c
+++ b/drivers/gpu/drm/vkms/vkms_crtc.c
@@ -10,18 +10,33 @@
#include <drm/drm_atomic_helper.h>
#include <drm/drm_crtc_helper.h>
-static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer)
+static void _vblank_handle(struct vkms_output *output)
{
- struct vkms_output *output = container_of(timer, struct vkms_output,
- vblank_hrtimer);
struct drm_crtc *crtc = &output->crtc;
- int ret_overrun;
+ 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);
+ int ret_overrun;
+
+ _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 vblamk 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;
}
diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
index e340aa128b61..519a353cd909 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.c
+++ b/drivers/gpu/drm/vkms/vkms_drv.c
@@ -79,6 +79,7 @@ static void vkms_release(struct drm_device *dev)
drm_atomic_helper_shutdown(&vkms->drm);
drm_mode_config_cleanup(&vkms->drm);
drm_dev_fini(&vkms->drm);
+ destroy_workqueue(vkms->output.crc_workq);
}
static struct drm_driver vkms_driver = {
diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
index a1b206643c10..de1ddf31341b 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.h
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -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_ */
diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
index 70fca22bc51b..c91661631c76 100644
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -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,
--
2.17.1
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