[Intel-gfx] [PATCH] drm/i915: Implement PSF GV point support
Stanislav Lisovskiy
stanislav.lisovskiy at intel.com
Thu May 20 11:42:59 UTC 2021
PSF GV points are an additional factor that can limit the
bandwidth available to display, separate from the traditional
QGV points. Whereas traditional QGV points represent possible
memory clock frequencies, PSF GV points reflect possible
frequencies of the memory fabric.
Switching between PSF GV points has the advantage of incurring
almost no memory access block time and thus does not need to be
accounted for in watermark calculations.
This patch adds support for those on top of regular QGV points.
Those are supposed to be used simultaneously, i.e we are always
at some QGV and some PSF GV point, based on the current video
mode requirements.
Bspec: 64631, 53998
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
Cc: Matt Roper <matthew.d.roper at intel.com>
---
drivers/gpu/drm/i915/display/intel_bw.c | 100 +++++++++++++++++++++++-
drivers/gpu/drm/i915/i915_drv.h | 7 ++
drivers/gpu/drm/i915/i915_reg.h | 3 +
drivers/gpu/drm/i915/intel_dram.c | 1 +
4 files changed, 108 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_bw.c b/drivers/gpu/drm/i915/display/intel_bw.c
index 3a1ba52266a7..891e2f3c9739 100644
--- a/drivers/gpu/drm/i915/display/intel_bw.c
+++ b/drivers/gpu/drm/i915/display/intel_bw.c
@@ -17,9 +17,15 @@ struct intel_qgv_point {
u16 dclk, t_rp, t_rdpre, t_rc, t_ras, t_rcd;
};
+struct intel_psf_gv_point {
+ u8 clk; /* clock in multiples of 16.6666 MHz */
+};
+
struct intel_qgv_info {
struct intel_qgv_point points[I915_NUM_QGV_POINTS];
+ struct intel_psf_gv_point psf_points[I915_NUM_PSF_GV_POINTS];
u8 num_points;
+ u8 num_psf_points;
u8 t_bl;
};
@@ -49,6 +55,28 @@ static int icl_pcode_read_qgv_point_info(struct drm_i915_private *dev_priv,
return 0;
}
+static int adls_pcode_read_psf_gv_point_info(struct drm_i915_private *dev_priv,
+ struct intel_psf_gv_point *points)
+{
+ u32 val = 0, val2 = 0;
+ int ret;
+ int i;
+
+ ret = sandybridge_pcode_read(dev_priv,
+ ICL_PCODE_MEM_SUBSYSYSTEM_INFO |
+ ADL_PCODE_MEM_SS_READ_PSF_GV_INFO,
+ &val, &val2);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < I915_NUM_PSF_GV_POINTS; i++) {
+ points[i].clk = val & 0xff;
+ val >>= 8;
+ }
+
+ return 0;
+}
+
int icl_pcode_restrict_qgv_points(struct drm_i915_private *dev_priv,
u32 points_mask)
{
@@ -76,6 +104,7 @@ static int icl_get_qgv_points(struct drm_i915_private *dev_priv,
int i, ret;
qi->num_points = dram_info->num_qgv_points;
+ qi->num_psf_points = dram_info->num_psf_gv_points;
if (DISPLAY_VER(dev_priv) == 12)
switch (dram_info->type) {
@@ -109,6 +138,19 @@ static int icl_get_qgv_points(struct drm_i915_private *dev_priv,
sp->t_rcd, sp->t_rc);
}
+ if (qi->num_psf_points > 0) {
+ ret = adls_pcode_read_psf_gv_point_info(dev_priv, qi->psf_points);
+ if (ret) {
+ drm_err(&dev_priv->drm, "Failed to read PSF point data; PSF points will not be considered in bandwidth calculations.\n");
+ qi->num_psf_points = 0;
+ }
+
+ for (i = 0; i < qi->num_psf_points; i++)
+ drm_dbg_kms(&dev_priv->drm,
+ "PSF GV %d: CLK=%d \n",
+ i, qi->psf_points[i].clk);
+ }
+
return 0;
}
@@ -118,6 +160,16 @@ static int icl_calc_bw(int dclk, int num, int den)
return DIV_ROUND_CLOSEST(num * dclk * 100, den * 6);
}
+static int adl_calc_psf_bw(int clk)
+{
+ /*
+ * clk is multiples of 16.666MHz (100/6)
+ * According to BSpec PSF GV bandwidth is
+ * calculated as BW = 64 * clk * 16.666Mhz
+ */
+ return DIV_ROUND_CLOSEST(64 * clk * 100, 6);
+}
+
static int icl_sagv_max_dclk(const struct intel_qgv_info *qi)
{
u16 dclk = 0;
@@ -194,6 +246,7 @@ static int icl_get_bw_info(struct drm_i915_private *dev_priv, const struct intel
bi->num_planes = (ipqdepth - clpchgroup) / clpchgroup + 1;
bi->num_qgv_points = qi.num_points;
+ bi->num_psf_gv_points = qi.num_psf_points;
for (j = 0; j < qi.num_points; j++) {
const struct intel_qgv_point *sp = &qi.points[j];
@@ -217,6 +270,16 @@ static int icl_get_bw_info(struct drm_i915_private *dev_priv, const struct intel
i, j, bi->num_planes, bi->deratedbw[j]);
}
+ for (j = 0; j < qi.num_psf_points; j++) {
+ const struct intel_psf_gv_point *sp = &qi.psf_points[j];
+
+ bi->psf_bw[j] = adl_calc_psf_bw(sp->clk);
+
+ drm_dbg_kms(&dev_priv->drm,
+ "BW%d / PSF GV %d: num_planes=%d bw=%u\n",
+ i, j, bi->num_planes, bi->psf_bw[j]);
+ }
+
if (bi->num_planes == 1)
break;
}
@@ -262,6 +325,15 @@ static unsigned int icl_max_bw(struct drm_i915_private *dev_priv,
return 0;
}
+static unsigned int adl_psf_bw(struct drm_i915_private *dev_priv,
+ int psf_gv_point)
+{
+ const struct intel_bw_info *bi =
+ &dev_priv->max_bw[0];
+
+ return bi->psf_bw[psf_gv_point];
+}
+
void intel_bw_init_hw(struct drm_i915_private *dev_priv)
{
if (!HAS_DISPLAY(dev_priv))
@@ -534,7 +606,8 @@ int intel_bw_atomic_check(struct intel_atomic_state *state)
u32 allowed_points = 0;
unsigned int max_bw_point = 0, max_bw = 0;
unsigned int num_qgv_points = dev_priv->max_bw[0].num_qgv_points;
- u32 mask = (1 << num_qgv_points) - 1;
+ unsigned int num_psf_gv_points = dev_priv->max_bw[0].num_psf_gv_points;
+ u32 mask = ADLS_QGV_PT_MASK | ADLS_PSF_PT_MASK;
/* FIXME earlier gens need some checks too */
if (DISPLAY_VER(dev_priv) < 11)
@@ -602,23 +675,44 @@ int intel_bw_atomic_check(struct intel_atomic_state *state)
max_bw = max_data_rate;
}
if (max_data_rate >= data_rate)
- allowed_points |= BIT(i);
+ allowed_points |= REG_FIELD_PREP(ADLS_QGV_PT_MASK, BIT(i));
+
drm_dbg_kms(&dev_priv->drm, "QGV point %d: max bw %d required %d\n",
i, max_data_rate, data_rate);
}
+ for (i = 0; i < num_psf_gv_points; i++) {
+ unsigned int max_data_rate = adl_psf_bw(dev_priv, i);
+
+ if (max_data_rate >= data_rate)
+ allowed_points |= REG_FIELD_PREP(ADLS_PSF_PT_MASK, BIT(i));
+
+ drm_dbg_kms(&dev_priv->drm, "PSF GV 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) {
+ if ((allowed_points & ADLS_QGV_PT_MASK) == 0) {
drm_dbg_kms(&dev_priv->drm, "No QGV points provide sufficient memory"
" bandwidth %d for display configuration(%d active planes).\n",
data_rate, num_active_planes);
return -EINVAL;
}
+ if (num_psf_gv_points > 0) {
+ if ((allowed_points & ADLS_PSF_PT_MASK) == 0) {
+ drm_dbg_kms(&dev_priv->drm, "No PSF GV points provide sufficient memory"
+ " bandwidth %d for display configuration(%d active planes).\n",
+ data_rate, num_active_planes);
+ return -EINVAL;
+ }
+ }
+
/*
* Leave only single point with highest bandwidth, if
* we can't enable SAGV due to the increased memory latency it may
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 9cb02618ba15..16938e268e25 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -591,6 +591,9 @@ i915_fence_timeout(const struct drm_i915_private *i915)
#define HAS_HW_SAGV_WM(i915) (DISPLAY_VER(i915) >= 13 && !IS_DGFX(i915))
+/* Amount of PSF GV points, BSpec precisely defines this */
+#define I915_NUM_PSF_GV_POINTS 3
+
struct ddi_vbt_port_info {
/* Non-NULL if port present. */
struct intel_bios_encoder_data *devdata;
@@ -1103,12 +1106,16 @@ struct drm_i915_private {
INTEL_DRAM_LPDDR5,
} type;
u8 num_qgv_points;
+ u8 num_psf_gv_points;
} dram_info;
struct intel_bw_info {
/* for each QGV point */
unsigned int deratedbw[I915_NUM_QGV_POINTS];
+ /* for each PSF GV point */
+ unsigned int psf_bw[I915_NUM_PSF_GV_POINTS];
u8 num_qgv_points;
+ u8 num_psf_gv_points;
u8 num_planes;
} max_bw[6];
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 4dbe79009c0e..c658b531d941 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -9336,9 +9336,12 @@ 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 ADL_PCODE_MEM_SS_READ_PSF_GV_INFO ((0) | (0x2 << 8))
#define ICL_PCODE_SAGV_DE_MEM_SS_CONFIG 0xe
#define ICL_PCODE_POINTS_RESTRICTED 0x0
#define ICL_PCODE_POINTS_RESTRICTED_MASK 0x1
+#define ADLS_QGV_PT_MASK REG_GENMASK(7, 0)
+#define ADLS_PSF_PT_MASK REG_GENMASK(10, 8)
#define GEN6_PCODE_READ_D_COMP 0x10
#define GEN6_PCODE_WRITE_D_COMP 0x11
#define ICL_PCODE_EXIT_TCCOLD 0x12
diff --git a/drivers/gpu/drm/i915/intel_dram.c b/drivers/gpu/drm/i915/intel_dram.c
index 1e53c017c30d..53ccd106785f 100644
--- a/drivers/gpu/drm/i915/intel_dram.c
+++ b/drivers/gpu/drm/i915/intel_dram.c
@@ -468,6 +468,7 @@ static int icl_pcode_read_mem_global_info(struct drm_i915_private *dev_priv)
dram_info->num_channels = (val & 0xf0) >> 4;
dram_info->num_qgv_points = (val & 0xf00) >> 8;
+ dram_info->num_psf_gv_points = (val & 0x3000) >> 12;
return 0;
}
--
2.24.1.485.gad05a3d8e5
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