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 --- 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,