[Intel-gfx] [PATCH v4 2/2] drm/i915: Restrict qgv points which don't have enough bandwidth.
James Ausmus
james.ausmus at intel.com
Thu Oct 17 22:02:29 UTC 2019
On Tue, Oct 15, 2019 at 04:50:13PM +0300, Stanislav Lisovskiy wrote:
> 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)
>
> Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
> Cc: Ville Syrjälä <ville.syrjala at intel.com>
> Cc: James Ausmus <james.ausmus at intel.com>
> ---
> 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 | 105 ++++++++++++++----
> drivers/gpu/drm/i915/display/intel_bw.h | 2 +
> drivers/gpu/drm/i915/display/intel_display.c | 58 +++++++++-
> .../drm/i915/display/intel_display_types.h | 3 +
> drivers/gpu/drm/i915/i915_drv.h | 2 +
> drivers/gpu/drm/i915/i915_reg.h | 3 +
> 8 files changed, 166 insertions(+), 26 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..09f786cfdfaa 100644
> --- a/drivers/gpu/drm/i915/display/intel_bw.c
> +++ b/drivers/gpu/drm/i915/display/intel_bw.c
> @@ -8,6 +8,8 @@
> #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 {
> @@ -113,6 +115,27 @@ 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);
This could also be enabling qgv points, so this might better be "Failed
to set qgv point mask".
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +
> static int icl_get_qgv_points(struct drm_i915_private *dev_priv,
> struct intel_qgv_info *qi)
> {
> @@ -270,22 +293,6 @@ 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 +384,10 @@ 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 +431,67 @@ 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 a8168e2aacd5..4aaf66955149 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -14003,6 +14003,48 @@ 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",
Nit: "Could not mask unusable qgv points"
> + 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",
Nit: "Could not unmask allowed qgv points"
With those:
Reviewed-by: James Ausmus <james.ausmus at intel.com>
> + 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;
> @@ -14030,6 +14072,9 @@ 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 */
> @@ -14048,8 +14093,9 @@ 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);
> }
> @@ -14127,8 +14173,12 @@ 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 40390d855815..8750a34c3e28 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -512,6 +512,9 @@ 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 c46b339064c0..0b1b641a280f 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1335,6 +1335,8 @@ 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 e24991e54897..1f3402547ba5 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -8869,6 +8869,7 @@ 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
> @@ -8881,6 +8882,8 @@ 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
> --
> 2.17.1
>
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