[PATCH v2 3/3] drm/vmwgfx: Convert to DRM vblank timers

[Thomas Zimmermann <tzimmermann@suse.de>]

Replace vmwgfx's vblank timer with DRM's common implementation. The
timer handling is almost identical with a few additional bug fixes in
the common code.

Replace most of vmwgfx's vmw_vkms_get_vblank_timestamp() with the
shared helper drm_crtc_vblank_get_vblank_timeout(). The common helper
also works in the presence of delayed vblank timeouts that modify the
vblank counter concurrently.

Set the timeout handler to vmw_vkms_handle_vblank_timeout(). In addition
to handling vblank events, this function also controls CRC generation.

Remove all the hrtimer-related code from vmwgfx. DRM vblank timers
provides this.

v2:
- only cancel vblank timer in CRTC cleanup if vkms_enabled (Zack)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_kms.h  |  2 -
 drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c  |  1 +
 drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c |  1 +
 drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c |  1 +
 drivers/gpu/drm/vmwgfx/vmwgfx_vkms.c | 65 ++++------------------------
 drivers/gpu/drm/vmwgfx/vmwgfx_vkms.h |  1 -
 6 files changed, 12 insertions(+), 59 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h
index 445471fe9be6..b5670ece90a9 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h
@@ -322,8 +322,6 @@ struct vmw_display_unit {
 
 	struct {
 		struct work_struct crc_generator_work;
-		struct hrtimer timer;
-		ktime_t period_ns;
 
 		/* protects concurrent access to the vblank handler */
 		atomic_t atomic_lock;
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c
index f07669b27fba..6f22d5f5c379 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c
@@ -402,6 +402,7 @@ static const struct drm_crtc_helper_funcs vmw_ldu_crtc_helper_funcs = {
 	.atomic_flush = vmw_vkms_crtc_atomic_flush,
 	.atomic_enable = vmw_vkms_crtc_atomic_enable,
 	.atomic_disable = vmw_vkms_crtc_atomic_disable,
+	.handle_vblank_timeout  = vmw_vkms_handle_vblank_timeout,
 };
 
 
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c b/drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c
index 605d037d18c6..cfb8ad3ebe43 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c
@@ -797,6 +797,7 @@ static const struct drm_crtc_helper_funcs vmw_sou_crtc_helper_funcs = {
 	.atomic_flush = vmw_vkms_crtc_atomic_flush,
 	.atomic_enable = vmw_vkms_crtc_atomic_enable,
 	.atomic_disable = vmw_sou_crtc_atomic_disable,
+	.handle_vblank_timeout  = vmw_vkms_handle_vblank_timeout,
 };
 
 
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c b/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
index dcbacee97f61..1f5497e2638a 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
@@ -1515,6 +1515,7 @@ static const struct drm_crtc_helper_funcs vmw_stdu_crtc_helper_funcs = {
 	.atomic_flush = vmw_stdu_crtc_atomic_flush,
 	.atomic_enable = vmw_vkms_crtc_atomic_enable,
 	.atomic_disable = vmw_stdu_crtc_atomic_disable,
+	.handle_vblank_timeout  = vmw_vkms_handle_vblank_timeout,
 };
 
 
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_vkms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_vkms.c
index 15439ddd4f22..1f98aa04c9f3 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_vkms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_vkms.c
@@ -195,27 +195,6 @@ vmw_vkms_handle_vblank_timeout(struct drm_crtc *crtc)
 	return true;
 }
 
-static enum hrtimer_restart
-vmw_vkms_vblank_simulate(struct hrtimer *timer)
-{
-	struct vmw_display_unit *du = container_of(timer, struct vmw_display_unit, vkms.timer);
-	struct drm_crtc *crtc = &du->crtc;
-	u64 ret_overrun;
-	bool success;
-
-	ret_overrun = hrtimer_forward_now(&du->vkms.timer,
-					  du->vkms.period_ns);
-	if (ret_overrun != 1)
-		drm_dbg_driver(crtc->dev, "vblank timer missed %lld frames.\n",
-			       ret_overrun - 1);
-
-	success = vmw_vkms_handle_vblank_timeout(crtc);
-	if (!success)
-		return HRTIMER_NORESTART;
-
-	return HRTIMER_RESTART;
-}
-
 void
 vmw_vkms_init(struct vmw_private *vmw)
 {
@@ -258,32 +237,12 @@ vmw_vkms_get_vblank_timestamp(struct drm_crtc *crtc,
 			      ktime_t *vblank_time,
 			      bool in_vblank_irq)
 {
-	struct drm_device *dev = crtc->dev;
-	struct vmw_private *vmw = vmw_priv(dev);
-	struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
-	struct drm_vblank_crtc *vblank = drm_crtc_vblank_crtc(crtc);
+	struct vmw_private *vmw = vmw_priv(crtc->dev);
 
 	if (!vmw->vkms_enabled)
 		return false;
 
-	if (!READ_ONCE(vblank->enabled)) {
-		*vblank_time = ktime_get();
-		return true;
-	}
-
-	*vblank_time = READ_ONCE(du->vkms.timer.node.expires);
-
-	if (WARN_ON(*vblank_time == vblank->time))
-		return true;
-
-	/*
-	 * To prevent races we roll the hrtimer forward before we do any
-	 * interrupt processing - this is how real hw works (the interrupt is
-	 * only generated after all the vblank registers are updated) and what
-	 * the vblank core expects. Therefore we need to always correct the
-	 * timestampe by one frame.
-	 */
-	*vblank_time -= du->vkms.period_ns;
+	drm_crtc_vblank_get_vblank_timeout(crtc, vblank_time);
 
 	return true;
 }
@@ -293,20 +252,11 @@ vmw_vkms_enable_vblank(struct drm_crtc *crtc)
 {
 	struct drm_device *dev = crtc->dev;
 	struct vmw_private *vmw = vmw_priv(dev);
-	struct drm_vblank_crtc *vblank = drm_crtc_vblank_crtc(crtc);
-	struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
 
 	if (!vmw->vkms_enabled)
 		return -EINVAL;
 
-	drm_calc_timestamping_constants(crtc, &crtc->mode);
-
-	hrtimer_setup(&du->vkms.timer, &vmw_vkms_vblank_simulate, CLOCK_MONOTONIC,
-		      HRTIMER_MODE_REL);
-	du->vkms.period_ns = ktime_set(0, vblank->framedur_ns);
-	hrtimer_start(&du->vkms.timer, du->vkms.period_ns, HRTIMER_MODE_REL);
-
-	return 0;
+	return drm_crtc_vblank_start_timer(crtc);
 }
 
 void
@@ -318,9 +268,9 @@ vmw_vkms_disable_vblank(struct drm_crtc *crtc)
 	if (!vmw->vkms_enabled)
 		return;
 
-	hrtimer_cancel(&du->vkms.timer);
+	drm_crtc_vblank_cancel_timer(crtc);
+
 	du->vkms.surface = NULL;
-	du->vkms.period_ns = ktime_set(0, 0);
 }
 
 enum vmw_vkms_lock_state {
@@ -344,12 +294,15 @@ vmw_vkms_crtc_init(struct drm_crtc *crtc)
 void
 vmw_vkms_crtc_cleanup(struct drm_crtc *crtc)
 {
+	struct vmw_private *vmw = vmw_priv(crtc->dev);
 	struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
 
+	if (vmw->vkms_enabled)
+		drm_crtc_vblank_cancel_timer(crtc);
+
 	if (du->vkms.surface)
 		vmw_surface_unreference(&du->vkms.surface);
 	WARN_ON(work_pending(&du->vkms.crc_generator_work));
-	hrtimer_cancel(&du->vkms.timer);
 }
 
 void
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_vkms.h b/drivers/gpu/drm/vmwgfx/vmwgfx_vkms.h
index 0b6bbf7c4487..40c679f59db2 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_vkms.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_vkms.h
@@ -29,7 +29,6 @@
 #ifndef VMWGFX_VKMS_H_
 #define VMWGFX_VKMS_H_
 
-#include <linux/hrtimer_types.h>
 #include <linux/types.h>
 
 struct drm_atomic_state;
-- 
2.54.0