Added bandwidth calculation algorithm and checks,
similar way as it was done for ICL, some constants
were corrected according to BSpec.

Signed-off-by: Stanislav Lisovskiy <stanislav.lisovs...@intel.com>

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=111600
---
 drivers/gpu/drm/i915/display/intel_bw.c | 108 +++++++++++++++++++++++-
 1 file changed, 107 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_bw.c 
b/drivers/gpu/drm/i915/display/intel_bw.c
index 688858ebe4d0..e97d083f4f2a 100644
--- a/drivers/gpu/drm/i915/display/intel_bw.c
+++ b/drivers/gpu/drm/i915/display/intel_bw.c
@@ -132,7 +132,8 @@ static int icl_sagv_max_dclk(const struct intel_qgv_info 
*qi)
 }
 
 struct intel_sa_info {
-       u8 deburst, mpagesize, deprogbwlimit, displayrtids;
+       u8 deburst, mpagesize, deprogbwlimit;
+       u16 displayrtids;
 };
 
 static const struct intel_sa_info icl_sa_info = {
@@ -142,6 +143,14 @@ static const struct intel_sa_info icl_sa_info = {
        .displayrtids = 128,
 };
 
+static const struct intel_sa_info tgl_sa_info = {
+       .deburst = 16,
+       .mpagesize = 16,
+       .deprogbwlimit = 34, /* GB/s */
+       .displayrtids = 256,
+};
+
+
 static int icl_get_bw_info(struct drm_i915_private *dev_priv)
 {
        struct intel_qgv_info qi = {};
@@ -208,6 +217,74 @@ static int icl_get_bw_info(struct drm_i915_private 
*dev_priv)
        return 0;
 }
 
+static int tgl_get_bw_info(struct drm_i915_private *dev_priv)
+{
+       struct intel_qgv_info qi = {};
+       const struct intel_sa_info *sa = &tgl_sa_info;
+       bool is_y_tile = true; /* assume y tile may be used */
+       int num_channels;
+       int deinterleave;
+       int ipqdepth, ipqdepthpch;
+       int dclk_max;
+       int maxdebw;
+       int c3_derating = 10;
+       int c25_deprogbwpclimit = 60;
+       int i, ret;
+
+       ret = icl_get_qgv_points(dev_priv, &qi);
+       if (ret) {
+               DRM_DEBUG_KMS("Failed to get memory subsystem information, 
ignoring bandwidth limits");
+               return ret;
+       }
+       num_channels = qi.num_channels;
+
+       deinterleave = DIV_ROUND_UP(num_channels, is_y_tile ? 4 : 2);
+       dclk_max = icl_sagv_max_dclk(&qi);
+
+       ipqdepthpch = 16;
+
+       maxdebw = min(sa->deprogbwlimit * 1000,
+                     icl_calc_bw(dclk_max, 16 * c25_deprogbwpclimit, 100)); /* 
60% */
+       ipqdepth = min(ipqdepthpch, sa->displayrtids / num_channels);
+
+       for (i = 0; i < ARRAY_SIZE(dev_priv->max_bw); i++) {
+               struct intel_bw_info *bi = &dev_priv->max_bw[i];
+               int clpchgroup;
+               int j;
+
+               clpchgroup = (sa->deburst * deinterleave / num_channels) << i;
+               bi->num_planes = (ipqdepth - clpchgroup) / clpchgroup;
+
+               bi->num_qgv_points = qi.num_points;
+
+               for (j = 0; j < qi.num_points; j++) {
+                       const struct intel_qgv_point *sp = &qi.points[j];
+                       int ct, bw;
+
+                       /*
+                        * Max row cycle time
+                        *
+                        * FIXME what is the logic behind the
+                        * assumed burst length?
+                        */
+                       ct = max_t(int, sp->t_rc, sp->t_rp + sp->t_rcd +
+                                  (clpchgroup - 1) * qi.t_bl + sp->t_rdpre);
+                       bw = icl_calc_bw(sp->dclk, clpchgroup * 32 * 
num_channels, ct);
+
+                       bi->deratedbw[j] = min(maxdebw,
+                                              bw * (100 - c3_derating) / 100); 
/* 90% */
+
+                       DRM_DEBUG_KMS("BW%d / QGV %d: num_planes=%d 
deratedbw=%u\n",
+                                     i, j, bi->num_planes, bi->deratedbw[j]);
+               }
+
+               if (bi->num_planes == 1)
+                       break;
+       }
+
+       return 0;
+}
+
 static unsigned int icl_max_bw(struct drm_i915_private *dev_priv,
                               int num_planes, int qgv_point)
 {
@@ -231,10 +308,35 @@ static unsigned int icl_max_bw(struct drm_i915_private 
*dev_priv,
        return 0;
 }
 
+static unsigned int tgl_max_bw(struct drm_i915_private *dev_priv,
+                              int num_planes, int qgv_point)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(dev_priv->max_bw); i++) {
+               const struct intel_bw_info *bi =
+                       &dev_priv->max_bw[i];
+
+               /*
+                * Pcode will not expose all QGV points when
+                * SAGV is forced to off/min/med/max.
+                */
+               if (qgv_point >= bi->num_qgv_points)
+                       return UINT_MAX;
+
+               if (num_planes >= bi->num_planes)
+                       return bi->deratedbw[qgv_point];
+       }
+
+       return 0;
+}
+
 void intel_bw_init_hw(struct drm_i915_private *dev_priv)
 {
        if (IS_GEN(dev_priv, 11))
                icl_get_bw_info(dev_priv);
+       else if (IS_GEN(dev_priv, 12))
+               tgl_get_bw_info(dev_priv);
 }
 
 static unsigned int intel_max_data_rate(struct drm_i915_private *dev_priv,
@@ -249,6 +351,10 @@ static unsigned int intel_max_data_rate(struct 
drm_i915_private *dev_priv,
                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 if (IS_GEN(dev_priv, 12))
+               return min3(tgl_max_bw(dev_priv, num_planes, 0),
+                           tgl_max_bw(dev_priv, num_planes, 1),
+                           tgl_max_bw(dev_priv, num_planes, 2));
        else
                return UINT_MAX;
 }
-- 
2.17.1

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