[PATCH v9 2/2] drm/i915: Restrict qgv points which don't have enough bandwidth.

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According to BSpec 53998, we should try to
restrict qgv points, which can't provide
enough bandwidth for desired display configuration.

Currently we are just comparing against all of
those and take minimum(worst case).

v2: Fixed wrong PCode reply mask, removed hardcoded
    values.

v3: Forbid simultaneous legacy SAGV PCode requests and
    restricting qgv points. Put the actual restriction
    to commit function, added serialization(thanks to Ville)
    to prevent commit being applied out of order in case of
    nonblocking and/or nomodeset commits.

v4:
    - Minor code refactoring, fixed few typos(thanks to James Ausmus)
    - Change the naming of qgv point
      masking/unmasking functions(James Ausmus).
    - Simplify the masking/unmasking operation itself,
      as we don't need to mask only single point per request(James Ausmus)
    - Reject and stick to highest bandwidth point if SAGV
      can't be enabled(BSpec)

v5:
    - Add new mailbox reply codes, which seems to happen during boot
      time for TGL and indicate that QGV setting is not yet available.

v6:
    - Increase number of supported QGV points to be in sync with BSpec.

Reviewed-by: James Ausmus <james.ausmus@xxxxxxxxx>
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxx>
Cc: James Ausmus <james.ausmus@xxxxxxxxx>
---
 drivers/gpu/drm/i915/display/intel_atomic.c   |  16 +++
 drivers/gpu/drm/i915/display/intel_atomic.h   |   3 +
 drivers/gpu/drm/i915/display/intel_bw.c       | 111 ++++++++++++++----
 drivers/gpu/drm/i915/display/intel_bw.h       |   2 +
 drivers/gpu/drm/i915/display/intel_display.c  |  57 ++++++++-
 .../drm/i915/display/intel_display_types.h    |   3 +
 drivers/gpu/drm/i915/i915_drv.h               |   2 +
 drivers/gpu/drm/i915/i915_reg.h               |   5 +
 drivers/gpu/drm/i915/intel_sideband.c         |  27 ++++-
 9 files changed, 198 insertions(+), 28 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c b/drivers/gpu/drm/i915/display/intel_atomic.c
index c5a552a69752..b3f4f02f380b 100644
--- a/drivers/gpu/drm/i915/display/intel_atomic.c
+++ b/drivers/gpu/drm/i915/display/intel_atomic.c
@@ -207,6 +207,22 @@ intel_crtc_duplicate_state(struct drm_crtc *crtc)
 	return &crtc_state->base;
 }
 
+int intel_atomic_serialize_global_state(struct intel_atomic_state *state)
+{
+	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
+	struct intel_crtc *crtc;
+
+	for_each_intel_crtc(&dev_priv->drm, crtc) {
+		struct intel_crtc_state *crtc_state;
+
+		crtc_state = intel_atomic_get_crtc_state(&state->base, crtc);
+		if (IS_ERR(crtc_state))
+			return PTR_ERR(crtc_state);
+	}
+
+	return 0;
+}
+
 /**
  * intel_crtc_destroy_state - destroy crtc state
  * @crtc: drm crtc
diff --git a/drivers/gpu/drm/i915/display/intel_atomic.h b/drivers/gpu/drm/i915/display/intel_atomic.h
index 58065d3161a3..fd17b3ca257f 100644
--- a/drivers/gpu/drm/i915/display/intel_atomic.h
+++ b/drivers/gpu/drm/i915/display/intel_atomic.h
@@ -7,6 +7,7 @@
 #define __INTEL_ATOMIC_H__
 
 #include <linux/types.h>
+#include "intel_display_types.h"
 
 struct drm_atomic_state;
 struct drm_connector;
@@ -38,6 +39,8 @@ void intel_crtc_destroy_state(struct drm_crtc *crtc,
 struct drm_atomic_state *intel_atomic_state_alloc(struct drm_device *dev);
 void intel_atomic_state_clear(struct drm_atomic_state *state);
 
+int intel_atomic_serialize_global_state(struct intel_atomic_state *state);
+
 struct intel_crtc_state *
 intel_atomic_get_crtc_state(struct drm_atomic_state *state,
 			    struct intel_crtc *crtc);
diff --git a/drivers/gpu/drm/i915/display/intel_bw.c b/drivers/gpu/drm/i915/display/intel_bw.c
index 22e83f857de8..60249d9776d1 100644
--- a/drivers/gpu/drm/i915/display/intel_bw.c
+++ b/drivers/gpu/drm/i915/display/intel_bw.c
@@ -8,14 +8,20 @@
 #include "intel_bw.h"
 #include "intel_display_types.h"
 #include "intel_sideband.h"
+#include "intel_atomic.h"
+#include "intel_pm.h"
 
 /* Parameters for Qclk Geyserville (QGV) */
 struct intel_qgv_point {
 	u16 dclk, t_rp, t_rdpre, t_rc, t_ras, t_rcd;
 };
 
+
+/* BSpec precisely defines this */
+#define NUM_SAGV_POINTS 4
+
 struct intel_qgv_info {
-	struct intel_qgv_point points[3];
+	struct intel_qgv_point points[NUM_SAGV_POINTS];
 	u8 num_points;
 	u8 num_channels;
 	u8 t_bl;
@@ -113,6 +119,27 @@ static int icl_pcode_read_qgv_point_info(struct drm_i915_private *dev_priv,
 	return 0;
 }
 
+int icl_pcode_restrict_qgv_points(struct drm_i915_private *dev_priv,
+				  u32 points_mask)
+{
+	int ret;
+
+	/* bspec says to keep retrying for at least 1 ms */
+	ret = skl_pcode_request(dev_priv, ICL_PCODE_SAGV_DE_MEM_SS_CONFIG,
+				points_mask,
+				GEN11_PCODE_POINTS_RESTRICTED_MASK,
+				GEN11_PCODE_POINTS_RESTRICTED,
+				1);
+
+	if (ret < 0) {
+		DRM_ERROR("Failed to disable qgv points (%d)\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+
 static int icl_get_qgv_points(struct drm_i915_private *dev_priv,
 			      struct intel_qgv_info *qi)
 {
@@ -270,22 +297,6 @@ void intel_bw_init_hw(struct drm_i915_private *dev_priv)
 		icl_get_bw_info(dev_priv, &icl_sa_info);
 }
 
-static unsigned int intel_max_data_rate(struct drm_i915_private *dev_priv,
-					int num_planes)
-{
-	if (INTEL_GEN(dev_priv) >= 11)
-		/*
-		 * FIXME with SAGV disabled maybe we can assume
-		 * point 1 will always be used? Seems to match
-		 * the behaviour observed in the wild.
-		 */
-		return min3(icl_max_bw(dev_priv, num_planes, 0),
-			    icl_max_bw(dev_priv, num_planes, 1),
-			    icl_max_bw(dev_priv, num_planes, 2));
-	else
-		return UINT_MAX;
-}
-
 static unsigned int intel_bw_crtc_num_active_planes(const struct intel_crtc_state *crtc_state)
 {
 	/*
@@ -377,7 +388,10 @@ int intel_bw_atomic_check(struct intel_atomic_state *state)
 	unsigned int data_rate, max_data_rate;
 	unsigned int num_active_planes;
 	struct intel_crtc *crtc;
-	int i;
+	int i, ret;
+	struct intel_qgv_info qi = {};
+	u32 allowed_points = 0;
+	unsigned int max_bw_point = 0, max_bw = 0;
 
 	/* FIXME earlier gens need some checks too */
 	if (INTEL_GEN(dev_priv) < 11)
@@ -421,16 +435,67 @@ int intel_bw_atomic_check(struct intel_atomic_state *state)
 	data_rate = intel_bw_data_rate(dev_priv, bw_state);
 	num_active_planes = intel_bw_num_active_planes(dev_priv, bw_state);
 
-	max_data_rate = intel_max_data_rate(dev_priv, num_active_planes);
-
 	data_rate = DIV_ROUND_UP(data_rate, 1000);
 
-	if (data_rate > max_data_rate) {
-		DRM_DEBUG_KMS("Bandwidth %u MB/s exceeds max available %d MB/s (%d active planes)\n",
-			      data_rate, max_data_rate, num_active_planes);
+	ret = icl_get_qgv_points(dev_priv, &qi);
+	if (ret < 0)
+		return 0;
+
+	for (i = 0; i < qi.num_points; i++) {
+		max_data_rate = icl_max_bw(dev_priv, num_active_planes, i);
+		/*
+		 * We need to know which qgv point gives us
+		 * maximum bandwidth in order to disable SAGV
+		 * if we find that we exceed SAGV block time
+		 * with watermarks. By that moment we already
+		 * have those, as it is calculated earlier in
+		 * intel_atomic_check,
+		 */
+		if (max_data_rate > max_bw) {
+			max_bw_point = i;
+			max_bw = max_data_rate;
+		}
+		if (max_data_rate >= data_rate)
+			allowed_points |= 1 << i;
+		DRM_DEBUG_KMS("QGV point %d: max bw %d required %d\n",
+			      i, max_data_rate, data_rate);
+	}
+
+	/*
+	 * BSpec states that we always should have at least one allowed point
+	 * left, so if we couldn't - simply reject the configuration for obvious
+	 * reasons.
+	 */
+	if (allowed_points == 0) {
+		DRM_DEBUG_KMS("Could not find any suitable QGV points\n");
 		return -EINVAL;
 	}
 
+	/*
+	 * Leave only single point with highest bandwidth, if
+	 * we can't enable SAGV according to BSpec.
+	 */
+	if (!intel_can_enable_sagv(state))
+		allowed_points = 1 << max_bw_point;
+
+	/*
+	 * We store the ones which need to be masked as that is what PCode
+	 * actually accepts as a parameter.
+	 */
+	state->qgv_points_mask = (~allowed_points) & ((1 << qi.num_points) - 1);
+
+	/*
+	 * If the actual mask had changed we need to make sure that
+	 * the commits are serialized(in case this is a nomodeset, nonblocking)
+	 */
+	if (state->qgv_points_mask != dev_priv->qgv_points_mask) {
+		ret = intel_atomic_serialize_global_state(state);
+		if (ret) {
+			DRM_DEBUG_KMS("Could not serialize global state\n");
+			return ret;
+		}
+	}
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/i915/display/intel_bw.h b/drivers/gpu/drm/i915/display/intel_bw.h
index 9db10af012f4..66bf9bc10b73 100644
--- a/drivers/gpu/drm/i915/display/intel_bw.h
+++ b/drivers/gpu/drm/i915/display/intel_bw.h
@@ -28,5 +28,7 @@ int intel_bw_init(struct drm_i915_private *dev_priv);
 int intel_bw_atomic_check(struct intel_atomic_state *state);
 void intel_bw_crtc_update(struct intel_bw_state *bw_state,
 			  const struct intel_crtc_state *crtc_state);
+int icl_pcode_restrict_qgv_points(struct drm_i915_private *dev_priv,
+				  u32 points_mask);
 
 #endif /* __INTEL_BW_H__ */
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index d870ce1709ea..525eaefce6b8 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -14471,6 +14471,48 @@ static void intel_atomic_cleanup_work(struct work_struct *work)
 	intel_atomic_helper_free_state(i915);
 }
 
+static void intel_qgv_points_mask(struct intel_atomic_state *state)
+{
+	struct drm_device *dev = state->base.dev;
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	int ret;
+	u32 new_mask = dev_priv->qgv_points_mask | state->qgv_points_mask;
+
+	/*
+	 * Restrict required qgv points before updating the configuration.
+	 * According to BSpec we can't mask and unmask qgv points at the same
+	 * time. Also masking should be done before updating the configuration
+	 * and unmasking afterwards.
+	 */
+	ret = icl_pcode_restrict_qgv_points(dev_priv, new_mask);
+	if (ret < 0)
+		DRM_DEBUG_KMS("Could not restrict required qgv points(%d)\n",
+			      ret);
+	else
+		dev_priv->qgv_points_mask = new_mask;
+}
+
+static void intel_qgv_points_unmask(struct intel_atomic_state *state)
+{
+	struct drm_device *dev = state->base.dev;
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	int ret;
+	u32 new_mask = dev_priv->qgv_points_mask & state->qgv_points_mask;
+
+	/*
+	 * Allow required qgv points after updating the configuration.
+	 * According to BSpec we can't mask and unmask qgv points at the same
+	 * time. Also masking should be done before updating the configuration
+	 * and unmasking afterwards.
+	 */
+	ret = icl_pcode_restrict_qgv_points(dev_priv, new_mask);
+	if (ret < 0)
+		DRM_DEBUG_KMS("Could not restrict required qgv points(%d)\n",
+			      ret);
+	else
+		dev_priv->qgv_points_mask = new_mask;
+}
+
 static void intel_atomic_commit_tail(struct intel_atomic_state *state)
 {
 	struct drm_device *dev = state->base.dev;
@@ -14498,6 +14540,9 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
 		}
 	}
 
+	if ((INTEL_GEN(dev_priv) >= 11))
+		intel_qgv_points_mask(state);
+
 	intel_commit_modeset_disables(state);
 
 	/* FIXME: Eventually get rid of our crtc->config pointer */
@@ -14516,8 +14561,9 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
 		 * SKL workaround: bspec recommends we disable the SAGV when we
 		 * have more then one pipe enabled
 		 */
-		if (!intel_can_enable_sagv(state))
-			intel_disable_sagv(dev_priv);
+		if (INTEL_GEN(dev_priv) < 11)
+			if (!intel_can_enable_sagv(state))
+				intel_disable_sagv(dev_priv);
 
 		intel_modeset_verify_disabled(dev_priv, state);
 	}
@@ -14599,8 +14645,11 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
 	if (state->modeset)
 		intel_verify_planes(state);
 
-	if (state->modeset && intel_can_enable_sagv(state))
-		intel_enable_sagv(dev_priv);
+	if (INTEL_GEN(dev_priv) < 11) {
+		if (state->modeset && intel_can_enable_sagv(state))
+			intel_enable_sagv(dev_priv);
+	} else
+		intel_qgv_points_unmask(state);
 
 	drm_atomic_helper_commit_hw_done(&state->base);
 
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index f87f98b7ef0d..c6975d9b4696 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -520,6 +520,9 @@ struct intel_atomic_state {
 	struct i915_sw_fence commit_ready;
 
 	struct llist_node freed;
+
+	/* Gen11+ only */
+	u32 qgv_points_mask;
 };
 
 struct intel_plane_state {
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index aa8babe6b77d..fe7dd6213e5c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1333,6 +1333,8 @@ struct drm_i915_private {
 		u8 num_planes;
 	} max_bw[6];
 
+	u32 qgv_points_mask;
+
 	struct drm_private_obj bw_obj;
 
 	struct intel_runtime_pm runtime_pm;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 855db888516c..93823443036f 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -8858,6 +8858,8 @@ enum {
 #define     GEN6_PCODE_UNIMPLEMENTED_CMD	0xFF
 #define     GEN7_PCODE_TIMEOUT			0x2
 #define     GEN7_PCODE_ILLEGAL_DATA		0x3
+#define     GEN11_PCODE_MAIL_BOX_LOCKED		0x6
+#define     GEN11_PCODE_REJECTED		0x11
 #define     GEN7_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE 0x10
 #define   GEN6_PCODE_WRITE_RC6VIDS		0x4
 #define   GEN6_PCODE_READ_RC6VIDS		0x5
@@ -8879,6 +8881,7 @@ enum {
 #define   ICL_PCODE_MEM_SUBSYSYSTEM_INFO	0xd
 #define     ICL_PCODE_MEM_SS_READ_GLOBAL_INFO	(0x0 << 8)
 #define     ICL_PCODE_MEM_SS_READ_QGV_POINT_INFO(point)	(((point) << 16) | (0x1 << 8))
+#define   ICL_PCODE_SAGV_DE_MEM_SS_CONFIG	0xe
 #define   GEN6_PCODE_READ_D_COMP		0x10
 #define   GEN6_PCODE_WRITE_D_COMP		0x11
 #define   HSW_PCODE_DE_WRITE_FREQ_REQ		0x17
@@ -8891,6 +8894,8 @@ enum {
 #define     GEN9_SAGV_IS_DISABLED		0x1
 #define     GEN9_SAGV_ENABLE			0x3
 #define GEN12_PCODE_READ_SAGV_BLOCK_TIME_US	0x23
+#define GEN11_PCODE_POINTS_RESTRICTED		0x0
+#define GEN11_PCODE_POINTS_RESTRICTED_MASK	0x1
 #define GEN6_PCODE_DATA				_MMIO(0x138128)
 #define   GEN6_PCODE_FREQ_IA_RATIO_SHIFT	8
 #define   GEN6_PCODE_FREQ_RING_RATIO_SHIFT	16
diff --git a/drivers/gpu/drm/i915/intel_sideband.c b/drivers/gpu/drm/i915/intel_sideband.c
index e06b35b844a0..ff9dbed094d8 100644
--- a/drivers/gpu/drm/i915/intel_sideband.c
+++ b/drivers/gpu/drm/i915/intel_sideband.c
@@ -371,6 +371,29 @@ static inline int gen7_check_mailbox_status(u32 mbox)
 	}
 }
 
+static inline int gen11_check_mailbox_status(u32 mbox)
+{
+	switch (mbox & GEN6_PCODE_ERROR_MASK) {
+	case GEN6_PCODE_SUCCESS:
+		return 0;
+	case GEN6_PCODE_ILLEGAL_CMD:
+		return -ENXIO;
+	case GEN7_PCODE_TIMEOUT:
+		return -ETIMEDOUT;
+	case GEN7_PCODE_ILLEGAL_DATA:
+		return -EINVAL;
+	case GEN7_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE:
+		return -EOVERFLOW;
+	case GEN11_PCODE_MAIL_BOX_LOCKED:
+		return -EAGAIN;
+	case GEN11_PCODE_REJECTED:
+		return -EACCES;
+	default:
+		MISSING_CASE(mbox & GEN6_PCODE_ERROR_MASK);
+		return 0;
+	}
+}
+
 static int __sandybridge_pcode_rw(struct drm_i915_private *i915,
 				  u32 mbox, u32 *val, u32 *val1,
 				  int fast_timeout_us,
@@ -408,7 +431,9 @@ static int __sandybridge_pcode_rw(struct drm_i915_private *i915,
 	if (is_read && val1)
 		*val1 = intel_uncore_read_fw(uncore, GEN6_PCODE_DATA1);
 
-	if (INTEL_GEN(i915) > 6)
+	if (INTEL_GEN(i915) >= 11)
+		return gen11_check_mailbox_status(mbox);
+	else if (INTEL_GEN(i915) > 6)
 		return gen7_check_mailbox_status(mbox);
 	else
 		return gen6_check_mailbox_status(mbox);
-- 
2.17.1

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