On Wed, May 20, 2020 at 12:25:25AM +0300, Stanislav Lisovskiy wrote:
> According to BSpec max BW per slice is calculated using formula
> Max BW = CDCLK * 64. Currently when calculating min CDCLK we
> account only per plane requirements, however in order to avoid
> FIFO underruns we need to estimate accumulated BW consumed by
> all planes(ddb entries basically) residing on that particular
> DBuf slice. This will allow us to put CDCLK lower and save power
> when we don't need that much bandwidth or gain additional
> performance once plane consumption grows.
>
> v2: - Fix long line warning
> - Limited new DBuf bw checks to only gens >= 11
>
> v3: - Lets track used Dbuf bw per slice and per crtc in bw state
> (or may be in DBuf state in future), that way we don't need
> to have all crtcs in state and those only if we detect if
> are actually going to change cdclk, just same way as we
> do with other stuff, i.e intel_atomic_serialize_global_state
> and co. Just as per Ville's paradigm.
> - Made dbuf bw calculation procedure look nicer by introducing
> for_each_dbuf_slice_in_mask - we often will now need to iterate
> slices using mask.
> - According to experimental results CDCLK * 64 accounts for
> overall bandwidth across all dbufs, not per dbuf.
>
> v4: - Fixed missing const(Ville)
> - Removed spurious whitespaces(Ville)
> - Fixed local variable init(reduced scope where not needed)
> - Added some comments about data rate for planar formats
> - Changed struct intel_crtc_bw to intel_dbuf_bw
> - Moved dbuf bw calculation to intel_compute_min_cdclk(Ville)
>
> v5: - Removed unneeded macro
>
> v6: - Prevent too frequent CDCLK switching back and forth:
> Always switch to higher CDCLK when needed to prevent bandwidth
> issues, however don't switch to lower CDCLK earlier than once
> in 30 minutes in order to prevent constant modeset blinking.
> We could of course not switch back at all, however this is
> bad from power consumption point of view.
>
> v7: - Fixed to track cdclk using bw_state, modeset will be now
> triggered only when CDCLK change is really needed.
>
> v8: - Lock global state if bw_state->min_cdclk is changed.
> - Try getting bw_state only if there are crtcs in the commit
> (need to have read-locked global state)
>
> v9: - Do not do Dbuf bw check for gens < 9 - triggers WARN
> as ddb_size is 0.
>
> v10: - Lock global state for older gens as well.
>
> v11: - Define new bw_calc_min_cdclk hook, instead of using
> a condition(Manasi Navare)
>
> v12: - Fixed rebase conflict
>
> Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
Looks good now with the hooks
Reviewed-by: Manasi Navare <manasi.d.navare@xxxxxxxxx>
Manasi
> ---
> drivers/gpu/drm/i915/display/intel_bw.c | 119 ++++++++++++++++++-
> drivers/gpu/drm/i915/display/intel_bw.h | 10 ++
> drivers/gpu/drm/i915/display/intel_cdclk.c | 28 ++++-
> drivers/gpu/drm/i915/display/intel_cdclk.h | 1 -
> drivers/gpu/drm/i915/display/intel_display.c | 39 +++++-
> drivers/gpu/drm/i915/i915_drv.h | 1 +
> drivers/gpu/drm/i915/intel_pm.c | 31 ++++-
> drivers/gpu/drm/i915/intel_pm.h | 4 +
> 8 files changed, 218 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_bw.c b/drivers/gpu/drm/i915/display/intel_bw.c
> index fef04e2d954e..cb614b624e20 100644
> --- a/drivers/gpu/drm/i915/display/intel_bw.c
> +++ b/drivers/gpu/drm/i915/display/intel_bw.c
> @@ -6,11 +6,12 @@
> #include <drm/drm_atomic_state_helper.h>
>
> #include "intel_bw.h"
> +#include "intel_pm.h"
> #include "intel_display_types.h"
> #include "intel_sideband.h"
> #include "intel_atomic.h"
> #include "intel_pm.h"
> -
> +#include "intel_cdclk.h"
>
> /* Parameters for Qclk Geyserville (QGV) */
> struct intel_qgv_point {
> @@ -343,7 +344,6 @@ static unsigned int intel_bw_crtc_data_rate(const struct intel_crtc_state *crtc_
>
> return data_rate;
> }
> -
> void intel_bw_crtc_update(struct intel_bw_state *bw_state,
> const struct intel_crtc_state *crtc_state)
> {
> @@ -420,6 +420,121 @@ intel_atomic_get_bw_state(struct intel_atomic_state *state)
> return to_intel_bw_state(bw_state);
> }
>
> +int skl_bw_calc_min_cdclk(struct intel_atomic_state *state)
> +{
> + struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> + int i;
> + const struct intel_crtc_state *crtc_state;
> + struct intel_crtc *crtc;
> + int max_bw = 0;
> + int slice_id;
> + struct intel_bw_state *new_bw_state = NULL;
> + struct intel_bw_state *old_bw_state = NULL;
> +
> + for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i) {
> + enum plane_id plane_id;
> + struct intel_dbuf_bw *crtc_bw;
> +
> + new_bw_state = intel_atomic_get_bw_state(state);
> + if (IS_ERR(new_bw_state))
> + return PTR_ERR(new_bw_state);
> +
> + crtc_bw = &new_bw_state->dbuf_bw[crtc->pipe];
> +
> + memset(&crtc_bw->used_bw, 0, sizeof(crtc_bw->used_bw));
> +
> + for_each_plane_id_on_crtc(crtc, plane_id) {
> + const struct skl_ddb_entry *plane_alloc =
> + &crtc_state->wm.skl.plane_ddb_y[plane_id];
> + const struct skl_ddb_entry *uv_plane_alloc =
> + &crtc_state->wm.skl.plane_ddb_uv[plane_id];
> + unsigned int data_rate = crtc_state->data_rate[plane_id];
> + unsigned int dbuf_mask = 0;
> +
> + dbuf_mask |= skl_ddb_dbuf_slice_mask(dev_priv, plane_alloc);
> + dbuf_mask |= skl_ddb_dbuf_slice_mask(dev_priv, uv_plane_alloc);
> +
> + /*
> + * FIXME: To calculate that more properly we probably need to
> + * to split per plane data_rate into data_rate_y and data_rate_uv
> + * for multiplanar formats in order not to get accounted those twice
> + * if they happen to reside on different slices.
> + * However for pre-icl this would work anyway because we have only single
> + * slice and for icl+ uv plane has non-zero data rate.
> + * So in worst case those calculation are a bit pessimistic, which
> + * shouldn't pose any significant problem anyway.
> + */
> + for_each_dbuf_slice_in_mask(slice_id, dbuf_mask)
> + crtc_bw->used_bw[slice_id] += data_rate;
> + }
> +
> + for_each_dbuf_slice(slice_id) {
> + /*
> + * Current experimental observations show that contrary to BSpec
> + * we get underruns once we exceed 64 * CDCLK for slices in total.
> + * As a temporary measure in order not to keep CDCLK bumped up all the
> + * time we calculate CDCLK according to this formula for overall bw
> + * consumed by slices.
> + */
> + max_bw += crtc_bw->used_bw[slice_id];
> + }
> +
> + new_bw_state->min_cdclk = max_bw / 64;
> +
> + old_bw_state = intel_atomic_get_old_bw_state(state);
> + }
> +
> + if (!old_bw_state)
> + return 0;
> +
> + if (new_bw_state->min_cdclk != old_bw_state->min_cdclk) {
> + int ret = intel_atomic_lock_global_state(&new_bw_state->base);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +int intel_bw_calc_min_cdclk(struct intel_atomic_state *state)
> +{
> + int i;
> + const struct intel_crtc_state *crtc_state;
> + struct intel_crtc *crtc;
> + int min_cdclk = 0;
> + struct intel_bw_state *new_bw_state = NULL;
> + struct intel_bw_state *old_bw_state = NULL;
> +
> + for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i) {
> + struct intel_cdclk_state *cdclk_state;
> +
> + new_bw_state = intel_atomic_get_bw_state(state);
> + if (IS_ERR(new_bw_state))
> + return PTR_ERR(new_bw_state);
> +
> + cdclk_state = intel_atomic_get_cdclk_state(state);
> + if (IS_ERR(cdclk_state))
> + return PTR_ERR(cdclk_state);
> +
> + min_cdclk = max(cdclk_state->min_cdclk[crtc->pipe], min_cdclk);
> +
> + new_bw_state->min_cdclk = min_cdclk;
> +
> + old_bw_state = intel_atomic_get_old_bw_state(state);
> + }
> +
> + if (!old_bw_state)
> + return 0;
> +
> + if (new_bw_state->min_cdclk != old_bw_state->min_cdclk) {
> + int ret = intel_atomic_lock_global_state(&new_bw_state->base);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> int intel_bw_atomic_check(struct intel_atomic_state *state)
> {
> struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> diff --git a/drivers/gpu/drm/i915/display/intel_bw.h b/drivers/gpu/drm/i915/display/intel_bw.h
> index bbcaaa73ec1b..af1a981dec84 100644
> --- a/drivers/gpu/drm/i915/display/intel_bw.h
> +++ b/drivers/gpu/drm/i915/display/intel_bw.h
> @@ -10,13 +10,19 @@
>
> #include "intel_display.h"
> #include "intel_global_state.h"
> +#include "intel_display_power.h"
>
> struct drm_i915_private;
> struct intel_atomic_state;
> struct intel_crtc_state;
>
> +struct intel_dbuf_bw {
> + int used_bw[I915_MAX_DBUF_SLICES];
> +};
> +
> struct intel_bw_state {
> struct intel_global_state base;
> + struct intel_dbuf_bw dbuf_bw[I915_MAX_PIPES];
>
> /*
> * Contains a bit mask, used to determine, whether correspondent
> @@ -36,6 +42,8 @@ struct intel_bw_state {
>
> /* bitmask of active pipes */
> u8 active_pipes;
> +
> + int min_cdclk;
> };
>
> #define to_intel_bw_state(x) container_of((x), struct intel_bw_state, base)
> @@ -56,5 +64,7 @@ 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);
> +int intel_bw_calc_min_cdclk(struct intel_atomic_state *state);
> +int skl_bw_calc_min_cdclk(struct intel_atomic_state *state);
>
> #endif /* __INTEL_BW_H__ */
> diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
> index 9419a4724357..4c38d20db9c3 100644
> --- a/drivers/gpu/drm/i915/display/intel_cdclk.c
> +++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
> @@ -21,10 +21,12 @@
> * DEALINGS IN THE SOFTWARE.
> */
>
> +#include <linux/time.h>
> #include "intel_atomic.h"
> #include "intel_cdclk.h"
> #include "intel_display_types.h"
> #include "intel_sideband.h"
> +#include "intel_bw.h"
>
> /**
> * DOC: CDCLK / RAWCLK
> @@ -2093,11 +2095,9 @@ int intel_crtc_compute_min_cdclk(const struct intel_crtc_state *crtc_state)
> static int intel_compute_min_cdclk(struct intel_cdclk_state *cdclk_state)
> {
> struct intel_atomic_state *state = cdclk_state->base.state;
> - struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> struct intel_crtc *crtc;
> struct intel_crtc_state *crtc_state;
> int min_cdclk, i;
> - enum pipe pipe;
>
> for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i) {
> int ret;
> @@ -2117,8 +2117,18 @@ static int intel_compute_min_cdclk(struct intel_cdclk_state *cdclk_state)
> }
>
> min_cdclk = cdclk_state->force_min_cdclk;
> - for_each_pipe(dev_priv, pipe)
> - min_cdclk = max(cdclk_state->min_cdclk[pipe], min_cdclk);
> +
> + for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i) {
> + struct intel_bw_state *bw_state;
> +
> + min_cdclk = max(cdclk_state->min_cdclk[crtc->pipe], min_cdclk);
> +
> + bw_state = intel_atomic_get_bw_state(state);
> + if (IS_ERR(bw_state))
> + return PTR_ERR(bw_state);
> +
> + min_cdclk = max(bw_state->min_cdclk, min_cdclk);
> + }
>
> return min_cdclk;
> }
> @@ -2790,25 +2800,30 @@ void intel_init_cdclk_hooks(struct drm_i915_private *dev_priv)
> {
> if (INTEL_GEN(dev_priv) >= 12) {
> dev_priv->display.set_cdclk = bxt_set_cdclk;
> + dev_priv->display.bw_calc_min_cdclk = skl_bw_calc_min_cdclk;
> dev_priv->display.modeset_calc_cdclk = bxt_modeset_calc_cdclk;
> dev_priv->display.calc_voltage_level = tgl_calc_voltage_level;
> dev_priv->cdclk.table = icl_cdclk_table;
> } else if (IS_ELKHARTLAKE(dev_priv)) {
> dev_priv->display.set_cdclk = bxt_set_cdclk;
> + dev_priv->display.bw_calc_min_cdclk = skl_bw_calc_min_cdclk;
> dev_priv->display.modeset_calc_cdclk = bxt_modeset_calc_cdclk;
> dev_priv->display.calc_voltage_level = ehl_calc_voltage_level;
> dev_priv->cdclk.table = icl_cdclk_table;
> } else if (INTEL_GEN(dev_priv) >= 11) {
> dev_priv->display.set_cdclk = bxt_set_cdclk;
> + dev_priv->display.bw_calc_min_cdclk = skl_bw_calc_min_cdclk;
> dev_priv->display.modeset_calc_cdclk = bxt_modeset_calc_cdclk;
> dev_priv->display.calc_voltage_level = icl_calc_voltage_level;
> dev_priv->cdclk.table = icl_cdclk_table;
> } else if (IS_CANNONLAKE(dev_priv)) {
> + dev_priv->display.bw_calc_min_cdclk = skl_bw_calc_min_cdclk;
> dev_priv->display.set_cdclk = bxt_set_cdclk;
> dev_priv->display.modeset_calc_cdclk = bxt_modeset_calc_cdclk;
> dev_priv->display.calc_voltage_level = cnl_calc_voltage_level;
> dev_priv->cdclk.table = cnl_cdclk_table;
> } else if (IS_GEN9_LP(dev_priv)) {
> + dev_priv->display.bw_calc_min_cdclk = skl_bw_calc_min_cdclk;
> dev_priv->display.set_cdclk = bxt_set_cdclk;
> dev_priv->display.modeset_calc_cdclk = bxt_modeset_calc_cdclk;
> dev_priv->display.calc_voltage_level = bxt_calc_voltage_level;
> @@ -2817,18 +2832,23 @@ void intel_init_cdclk_hooks(struct drm_i915_private *dev_priv)
> else
> dev_priv->cdclk.table = bxt_cdclk_table;
> } else if (IS_GEN9_BC(dev_priv)) {
> + dev_priv->display.bw_calc_min_cdclk = skl_bw_calc_min_cdclk;
> dev_priv->display.set_cdclk = skl_set_cdclk;
> dev_priv->display.modeset_calc_cdclk = skl_modeset_calc_cdclk;
> } else if (IS_BROADWELL(dev_priv)) {
> + dev_priv->display.bw_calc_min_cdclk = intel_bw_calc_min_cdclk;
> dev_priv->display.set_cdclk = bdw_set_cdclk;
> dev_priv->display.modeset_calc_cdclk = bdw_modeset_calc_cdclk;
> } else if (IS_CHERRYVIEW(dev_priv)) {
> + dev_priv->display.bw_calc_min_cdclk = intel_bw_calc_min_cdclk;
> dev_priv->display.set_cdclk = chv_set_cdclk;
> dev_priv->display.modeset_calc_cdclk = vlv_modeset_calc_cdclk;
> } else if (IS_VALLEYVIEW(dev_priv)) {
> + dev_priv->display.bw_calc_min_cdclk = intel_bw_calc_min_cdclk;
> dev_priv->display.set_cdclk = vlv_set_cdclk;
> dev_priv->display.modeset_calc_cdclk = vlv_modeset_calc_cdclk;
> } else {
> + dev_priv->display.bw_calc_min_cdclk = intel_bw_calc_min_cdclk;
> dev_priv->display.modeset_calc_cdclk = fixed_modeset_calc_cdclk;
> }
>
> diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.h b/drivers/gpu/drm/i915/display/intel_cdclk.h
> index 5731806e4cee..d62e11d620c0 100644
> --- a/drivers/gpu/drm/i915/display/intel_cdclk.h
> +++ b/drivers/gpu/drm/i915/display/intel_cdclk.h
> @@ -7,7 +7,6 @@
> #define __INTEL_CDCLK_H__
>
> #include <linux/types.h>
> -
> #include "i915_drv.h"
> #include "intel_display.h"
> #include "intel_global_state.h"
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 8068dc96d5aa..c9f93036ff44 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -14703,16 +14703,14 @@ static int intel_atomic_check_planes(struct intel_atomic_state *state)
> static int intel_atomic_check_cdclk(struct intel_atomic_state *state,
> bool *need_cdclk_calc)
> {
> - struct intel_cdclk_state *new_cdclk_state;
> + struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> int i;
> struct intel_plane_state *plane_state;
> struct intel_plane *plane;
> int ret;
> -
> - new_cdclk_state = intel_atomic_get_new_cdclk_state(state);
> - if (new_cdclk_state && new_cdclk_state->force_min_cdclk_changed)
> - *need_cdclk_calc = true;
> -
> + struct intel_cdclk_state *new_cdclk_state;
> + struct intel_crtc_state *new_crtc_state;
> + struct intel_crtc *crtc;
> /*
> * active_planes bitmask has been updated, and potentially
> * affected planes are part of the state. We can now
> @@ -14724,6 +14722,35 @@ static int intel_atomic_check_cdclk(struct intel_atomic_state *state,
> return ret;
> }
>
> + new_cdclk_state = intel_atomic_get_new_cdclk_state(state);
> +
> + if (new_cdclk_state && new_cdclk_state->force_min_cdclk_changed)
> + *need_cdclk_calc = true;
> +
> + ret = dev_priv->display.bw_calc_min_cdclk(state);
> + if (ret)
> + return ret;
> +
> + if (!new_cdclk_state)
> + return 0;
> +
> + for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) {
> + struct intel_bw_state *bw_state;
> + int min_cdclk = 0;
> +
> + min_cdclk = max(new_cdclk_state->min_cdclk[crtc->pipe], min_cdclk);
> +
> + bw_state = intel_atomic_get_bw_state(state);
> + if (IS_ERR(bw_state))
> + return PTR_ERR(bw_state);
> +
> + /*
> + * Currently do this change only if we need to increase
> + */
> + if (bw_state->min_cdclk > min_cdclk)
> + *need_cdclk_calc = true;
> + }
> +
> return 0;
> }
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 825a54b521d9..a4fdd2e0a8f4 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -273,6 +273,7 @@ struct drm_i915_display_funcs {
> void (*set_cdclk)(struct drm_i915_private *dev_priv,
> const struct intel_cdclk_config *cdclk_config,
> enum pipe pipe);
> + int (*bw_calc_min_cdclk)(struct intel_atomic_state *state);
> int (*get_fifo_size)(struct drm_i915_private *dev_priv,
> enum i9xx_plane_id i9xx_plane);
> int (*compute_pipe_wm)(struct intel_crtc_state *crtc_state);
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 4d885ef0bac5..937d91c28de9 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -4031,10 +4031,9 @@ icl_get_first_dbuf_slice_offset(u32 dbuf_slice_mask,
> return offset;
> }
>
> -static u16 intel_get_ddb_size(struct drm_i915_private *dev_priv)
> +u16 intel_get_ddb_size(struct drm_i915_private *dev_priv)
> {
> u16 ddb_size = INTEL_INFO(dev_priv)->ddb_size;
> -
> drm_WARN_ON(&dev_priv->drm, ddb_size == 0);
>
> if (INTEL_GEN(dev_priv) < 11)
> @@ -4043,6 +4042,34 @@ static u16 intel_get_ddb_size(struct drm_i915_private *dev_priv)
> return ddb_size;
> }
>
> +u32 skl_ddb_dbuf_slice_mask(struct drm_i915_private *dev_priv,
> + const struct skl_ddb_entry *entry)
> +{
> + u32 slice_mask = 0;
> + u16 ddb_size = intel_get_ddb_size(dev_priv);
> + u16 num_supported_slices = INTEL_INFO(dev_priv)->num_supported_dbuf_slices;
> + u16 slice_size = ddb_size / num_supported_slices;
> + u16 start_slice;
> + u16 end_slice;
> +
> + if (!skl_ddb_entry_size(entry))
> + return 0;
> +
> + start_slice = entry->start / slice_size;
> + end_slice = (entry->end - 1) / slice_size;
> +
> + /*
> + * Per plane DDB entry can in a really worst case be on multiple slices
> + * but single entry is anyway contigious.
> + */
> + while (start_slice <= end_slice) {
> + slice_mask |= BIT(start_slice);
> + start_slice++;
> + }
> +
> + return slice_mask;
> +}
> +
> static u8 skl_compute_dbuf_slices(const struct intel_crtc_state *crtc_state,
> u8 active_pipes);
>
> diff --git a/drivers/gpu/drm/i915/intel_pm.h b/drivers/gpu/drm/i915/intel_pm.h
> index 6636d2a057cd..d665bf77ae80 100644
> --- a/drivers/gpu/drm/i915/intel_pm.h
> +++ b/drivers/gpu/drm/i915/intel_pm.h
> @@ -39,6 +39,10 @@ u8 intel_enabled_dbuf_slices_mask(struct drm_i915_private *dev_priv);
> void skl_pipe_ddb_get_hw_state(struct intel_crtc *crtc,
> struct skl_ddb_entry *ddb_y,
> struct skl_ddb_entry *ddb_uv);
> +void skl_ddb_get_hw_state(struct drm_i915_private *dev_priv);
> +u16 intel_get_ddb_size(struct drm_i915_private *dev_priv);
> +u32 skl_ddb_dbuf_slice_mask(struct drm_i915_private *dev_priv,
> + const struct skl_ddb_entry *entry);
> void skl_pipe_wm_get_hw_state(struct intel_crtc *crtc,
> struct skl_pipe_wm *out);
> void g4x_wm_sanitize(struct drm_i915_private *dev_priv);
> --
> 2.24.1.485.gad05a3d8e5
>
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