drm/kms/radeon: Add support for precise vblank timestamping.

This patch adds new functions for use by the drm core:

.get_vblank_timestamp() provides a precise timestamp
for the end of the most recent (or current) vblank
interval of a given crtc, as needed for the DRI2
implementation of the OML_sync_control extension.

It is a thin wrapper around the drm function
drm_calc_vbltimestamp_from_scanoutpos() which does
almost all the work and is shared across drivers.

.get_scanout_position() provides the current horizontal
and vertical video scanout position and "in vblank"
status of a given crtc, as needed by the drm for use by
drm_calc_vbltimestamp_from_scanoutpos().

The function is also used by the dynamic gpu reclocking
code to determine when it is safe to reclock inside vblank.

For that purpose radeon_pm_in_vbl() is modified to
accomodate a small change in the function prototype of
the radeon_get_crtc_scanoutpos() which is hooked up to
.get_scanout_position().

This code has been tested on AVIVO hardware, a RV530
(ATI Mobility Radeon X1600) in a Intel Core-2 Duo MacBookPro
and some R600 variant (FireGL V7600) in a single cpu
AMD Athlon 64 PC.

Signed-off-by: Mario Kleiner <mario.kleiner@tuebingen.mpg.de>
Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_display.c

@@ -1019,7 +1019,7 @@ bool radeon_crtc_scaling_mode_fixup(struct drm_crtc *crtc,
 /*
  * Retrieve current video scanout position of crtc on a given gpu.
  *
- * \param rdev Device to query.
+ * \param dev Device to query.
  * \param crtc Crtc to query.
  * \param *vpos Location where vertical scanout position should be stored.
  * \param *hpos Location where horizontal scanout position should go.
@@ -1031,72 +1031,74 @@ bool radeon_crtc_scaling_mode_fixup(struct drm_crtc *crtc,
  *
  * \return Flags, or'ed together as follows:
  *
- * RADEON_SCANOUTPOS_VALID = Query successfull.
- * RADEON_SCANOUTPOS_INVBL = Inside vblank.
- * RADEON_SCANOUTPOS_ACCURATE = Returned position is accurate. A lack of
+ * DRM_SCANOUTPOS_VALID = Query successfull.
+ * DRM_SCANOUTPOS_INVBL = Inside vblank.
+ * DRM_SCANOUTPOS_ACCURATE = Returned position is accurate. A lack of
  * this flag means that returned position may be offset by a constant but
  * unknown small number of scanlines wrt. real scanout position.
  *
  */
-int radeon_get_crtc_scanoutpos(struct radeon_device *rdev, int crtc, int *vpos, int *hpos)
+int radeon_get_crtc_scanoutpos(struct drm_device *dev, int crtc, int *vpos, int *hpos)
 {
 	u32 stat_crtc = 0, vbl = 0, position = 0;
 	int vbl_start, vbl_end, vtotal, ret = 0;
 	bool in_vbl = true;
 
+	struct radeon_device *rdev = dev->dev_private;
+
 	if (ASIC_IS_DCE4(rdev)) {
 		if (crtc == 0) {
 			vbl = RREG32(EVERGREEN_CRTC_V_BLANK_START_END +
 				     EVERGREEN_CRTC0_REGISTER_OFFSET);
 			position = RREG32(EVERGREEN_CRTC_STATUS_POSITION +
 					  EVERGREEN_CRTC0_REGISTER_OFFSET);
-			ret |= RADEON_SCANOUTPOS_VALID;
+			ret |= DRM_SCANOUTPOS_VALID;
 		}
 		if (crtc == 1) {
 			vbl = RREG32(EVERGREEN_CRTC_V_BLANK_START_END +
 				     EVERGREEN_CRTC1_REGISTER_OFFSET);
 			position = RREG32(EVERGREEN_CRTC_STATUS_POSITION +
 					  EVERGREEN_CRTC1_REGISTER_OFFSET);
-			ret |= RADEON_SCANOUTPOS_VALID;
+			ret |= DRM_SCANOUTPOS_VALID;
 		}
 		if (crtc == 2) {
 			vbl = RREG32(EVERGREEN_CRTC_V_BLANK_START_END +
 				     EVERGREEN_CRTC2_REGISTER_OFFSET);
 			position = RREG32(EVERGREEN_CRTC_STATUS_POSITION +
 					  EVERGREEN_CRTC2_REGISTER_OFFSET);
-			ret |= RADEON_SCANOUTPOS_VALID;
+			ret |= DRM_SCANOUTPOS_VALID;
 		}
 		if (crtc == 3) {
 			vbl = RREG32(EVERGREEN_CRTC_V_BLANK_START_END +
 				     EVERGREEN_CRTC3_REGISTER_OFFSET);
 			position = RREG32(EVERGREEN_CRTC_STATUS_POSITION +
 					  EVERGREEN_CRTC3_REGISTER_OFFSET);
-			ret |= RADEON_SCANOUTPOS_VALID;
+			ret |= DRM_SCANOUTPOS_VALID;
 		}
 		if (crtc == 4) {
 			vbl = RREG32(EVERGREEN_CRTC_V_BLANK_START_END +
 				     EVERGREEN_CRTC4_REGISTER_OFFSET);
 			position = RREG32(EVERGREEN_CRTC_STATUS_POSITION +
 					  EVERGREEN_CRTC4_REGISTER_OFFSET);
-			ret |= RADEON_SCANOUTPOS_VALID;
+			ret |= DRM_SCANOUTPOS_VALID;
 		}
 		if (crtc == 5) {
 			vbl = RREG32(EVERGREEN_CRTC_V_BLANK_START_END +
 				     EVERGREEN_CRTC5_REGISTER_OFFSET);
 			position = RREG32(EVERGREEN_CRTC_STATUS_POSITION +
 					  EVERGREEN_CRTC5_REGISTER_OFFSET);
-			ret |= RADEON_SCANOUTPOS_VALID;
+			ret |= DRM_SCANOUTPOS_VALID;
 		}
 	} else if (ASIC_IS_AVIVO(rdev)) {
 		if (crtc == 0) {
 			vbl = RREG32(AVIVO_D1CRTC_V_BLANK_START_END);
 			position = RREG32(AVIVO_D1CRTC_STATUS_POSITION);
-			ret |= RADEON_SCANOUTPOS_VALID;
+			ret |= DRM_SCANOUTPOS_VALID;
 		}
 		if (crtc == 1) {
 			vbl = RREG32(AVIVO_D2CRTC_V_BLANK_START_END);
 			position = RREG32(AVIVO_D2CRTC_STATUS_POSITION);
-			ret |= RADEON_SCANOUTPOS_VALID;
+			ret |= DRM_SCANOUTPOS_VALID;
 		}
 	} else {
 		/* Pre-AVIVO: Different encoding of scanout pos and vblank interval. */
@@ -1112,7 +1114,7 @@ int radeon_get_crtc_scanoutpos(struct radeon_device *rdev, int crtc, int *vpos,
 			if (!(stat_crtc & 1))
 				in_vbl = false;
 
-			ret |= RADEON_SCANOUTPOS_VALID;
+			ret |= DRM_SCANOUTPOS_VALID;
 		}
 		if (crtc == 1) {
 			vbl = (RREG32(RADEON_CRTC2_V_TOTAL_DISP) &
@@ -1122,7 +1124,7 @@ int radeon_get_crtc_scanoutpos(struct radeon_device *rdev, int crtc, int *vpos,
 			if (!(stat_crtc & 1))
 				in_vbl = false;
 
-			ret |= RADEON_SCANOUTPOS_VALID;
+			ret |= DRM_SCANOUTPOS_VALID;
 		}
 	}
 
@@ -1133,13 +1135,13 @@ int radeon_get_crtc_scanoutpos(struct radeon_device *rdev, int crtc, int *vpos,
 	/* Valid vblank area boundaries from gpu retrieved? */
 	if (vbl > 0) {
 		/* Yes: Decode. */
-		ret |= RADEON_SCANOUTPOS_ACCURATE;
+		ret |= DRM_SCANOUTPOS_ACCURATE;
 		vbl_start = vbl & 0x1fff;
 		vbl_end = (vbl >> 16) & 0x1fff;
 	}
 	else {
 		/* No: Fake something reasonable which gives at least ok results. */
-		vbl_start = rdev->mode_info.crtcs[crtc]->base.mode.crtc_vdisplay;
+		vbl_start = rdev->mode_info.crtcs[crtc]->base.hwmode.crtc_vdisplay;
 		vbl_end = 0;
 	}
 
@@ -1155,7 +1157,7 @@ int radeon_get_crtc_scanoutpos(struct radeon_device *rdev, int crtc, int *vpos,
 
 	/* Inside "upper part" of vblank area? Apply corrective offset if so: */
 	if (in_vbl && (*vpos >= vbl_start)) {
-		vtotal = rdev->mode_info.crtcs[crtc]->base.mode.crtc_vtotal;
+		vtotal = rdev->mode_info.crtcs[crtc]->base.hwmode.crtc_vtotal;
 		*vpos = *vpos - vtotal;
 	}
 
@@ -1164,7 +1166,7 @@ int radeon_get_crtc_scanoutpos(struct radeon_device *rdev, int crtc, int *vpos,
 
 	/* In vblank? */
 	if (in_vbl)
-		ret |= RADEON_SCANOUTPOS_INVBL;
+		ret |= DRM_SCANOUTPOS_INVBL;
 
 	return ret;
 }

drivers/gpu/drm/radeon/radeon_drv.c

@@ -66,6 +66,10 @@ int radeon_resume_kms(struct drm_device *dev);
 u32 radeon_get_vblank_counter_kms(struct drm_device *dev, int crtc);
 int radeon_enable_vblank_kms(struct drm_device *dev, int crtc);
 void radeon_disable_vblank_kms(struct drm_device *dev, int crtc);
+int radeon_get_vblank_timestamp_kms(struct drm_device *dev, int crtc,
+				    int *max_error,
+				    struct timeval *vblank_time,
+				    unsigned flags);
 void radeon_driver_irq_preinstall_kms(struct drm_device *dev);
 int radeon_driver_irq_postinstall_kms(struct drm_device *dev);
 void radeon_driver_irq_uninstall_kms(struct drm_device *dev);
@@ -74,6 +78,8 @@ int radeon_dma_ioctl_kms(struct drm_device *dev, void *data,
 			 struct drm_file *file_priv);
 int radeon_gem_object_init(struct drm_gem_object *obj);
 void radeon_gem_object_free(struct drm_gem_object *obj);
+extern int radeon_get_crtc_scanoutpos(struct drm_device *dev, int crtc,
+				      int *vpos, int *hpos);
 extern struct drm_ioctl_desc radeon_ioctls_kms[];
 extern int radeon_max_kms_ioctl;
 int radeon_mmap(struct file *filp, struct vm_area_struct *vma);
@@ -277,6 +283,8 @@ static struct drm_driver kms_driver = {
 	.get_vblank_counter = radeon_get_vblank_counter_kms,
 	.enable_vblank = radeon_enable_vblank_kms,
 	.disable_vblank = radeon_disable_vblank_kms,
+	.get_vblank_timestamp = radeon_get_vblank_timestamp_kms,
+	.get_scanout_position = radeon_get_crtc_scanoutpos,
 #if defined(CONFIG_DEBUG_FS)
 	.debugfs_init = radeon_debugfs_init,
 	.debugfs_cleanup = radeon_debugfs_cleanup,

drivers/gpu/drm/radeon/radeon_kms.c

@@ -277,6 +277,27 @@ void radeon_disable_vblank_kms(struct drm_device *dev, int crtc)
 	radeon_irq_set(rdev);
 }
 
+int radeon_get_vblank_timestamp_kms(struct drm_device *dev, int crtc,
+				    int *max_error,
+				    struct timeval *vblank_time,
+				    unsigned flags)
+{
+	struct drm_crtc *drmcrtc;
+	struct radeon_device *rdev = dev->dev_private;
+
+	if (crtc < 0 || crtc >= dev->num_crtcs) {
+		DRM_ERROR("Invalid crtc %d\n", crtc);
+		return -EINVAL;
+	}
+
+	/* Get associated drm_crtc: */
+	drmcrtc = &rdev->mode_info.crtcs[crtc]->base;
+
+	/* Helper routine in DRM core does all the work: */
+	return drm_calc_vbltimestamp_from_scanoutpos(dev, crtc, max_error,
+						     vblank_time, flags,
+						     drmcrtc);
+}
 
 /*
  * IOCTL.

drivers/gpu/drm/radeon/radeon_mode.h

@@ -442,10 +442,6 @@ struct radeon_framebuffer {
 	struct drm_gem_object *obj;
 };
 
-/* radeon_get_crtc_scanoutpos() return flags */
-#define RADEON_SCANOUTPOS_VALID        (1 << 0)
-#define RADEON_SCANOUTPOS_INVBL        (1 << 1)
-#define RADEON_SCANOUTPOS_ACCURATE     (1 << 2)
 
 extern enum radeon_tv_std
 radeon_combios_get_tv_info(struct radeon_device *rdev);
@@ -562,7 +558,8 @@ extern int radeon_crtc_cursor_set(struct drm_crtc *crtc,
 extern int radeon_crtc_cursor_move(struct drm_crtc *crtc,
 				   int x, int y);
 
-extern int radeon_get_crtc_scanoutpos(struct radeon_device *rdev, int crtc, int *vpos, int *hpos);
+extern int radeon_get_crtc_scanoutpos(struct drm_device *dev, int crtc,
+				      int *vpos, int *hpos);
 
 extern bool radeon_combios_check_hardcoded_edid(struct radeon_device *rdev);
 extern struct edid *

drivers/gpu/drm/radeon/radeon_pm.c

@@ -720,9 +720,9 @@ static bool radeon_pm_in_vbl(struct radeon_device *rdev)
 	 */
 	for (crtc = 0; (crtc < rdev->num_crtc) && in_vbl; crtc++) {
 		if (rdev->pm.active_crtcs & (1 << crtc)) {
-			vbl_status = radeon_get_crtc_scanoutpos(rdev, crtc, &vpos, &hpos);
-			if ((vbl_status & RADEON_SCANOUTPOS_VALID) &&
-			    !(vbl_status & RADEON_SCANOUTPOS_INVBL))
+			vbl_status = radeon_get_crtc_scanoutpos(rdev->ddev, crtc, &vpos, &hpos);
+			if ((vbl_status & DRM_SCANOUTPOS_VALID) &&
+			    !(vbl_status & DRM_SCANOUTPOS_INVBL))
 				in_vbl = false;
 		}
 	}