[Intel-gfx] [PATCH v9 4/4] drm/i915: Correctly map DBUF slices to pipes
Stanislav Lisovskiy
stanislav.lisovskiy at intel.com
Sun Dec 15 20:52:10 UTC 2019
Added proper DBuf slice mapping to correspondent
pipes, depending on pipe configuration as stated
in BSpec.
v2:
- Remove unneeded braces
- Stop using macro for DBuf assignments as
it seems to reduce readability.
v3: Start using enabled slices mask in dev_priv
v4: Renamed "enabled_slices" used in dev_priv
to "enabled_dbuf_slices_mask"(Matt Roper)
v5: - Removed redundant parameters from
intel_get_ddb_size function.(Matt Roper)
- Made i915_possible_dbuf_slices static(Matt Roper)
- Renamed total_width into total_width_in_range
so that it now reflects that this is not
a total pipe width but the one in current
dbuf slice allowed range for pipe.(Matt Roper)
- Removed 4th pipe for ICL in DBuf assignment
table(Matt Roper)
- Fixed wrong DBuf slice in DBuf table for TGL
(Matt Roper)
- Added comment regarding why we currently not
using pipe ratio for DBuf assignment for ICL
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
---
drivers/gpu/drm/i915/intel_pm.c | 252 +++++++++++++++++++++++++++++---
1 file changed, 234 insertions(+), 18 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 742aeb0b2a01..228921c83551 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3831,13 +3831,27 @@ bool intel_can_enable_sagv(struct intel_atomic_state *state)
return true;
}
-static u16 intel_get_ddb_size(struct drm_i915_private *dev_priv,
- const struct intel_crtc_state *crtc_state,
- const u64 total_data_rate,
- const int num_active)
+/*
+ * Calculate initial DBuf slice offset, based on slice size
+ * and mask(i.e if slice size is 1024 and second slice is enabled
+ * offset would be 1024)
+ */
+static u32 icl_get_first_dbuf_slice_offset(u32 dbuf_slice_mask,
+ u32 slice_size, u32 ddb_size)
+{
+ u32 offset = 0;
+
+ if (!dbuf_slice_mask)
+ return 0;
+
+ offset = (ffs(dbuf_slice_mask) - 1) * slice_size;
+
+ WARN_ON(offset >= ddb_size);
+ return offset;
+}
+
+static u16 intel_get_ddb_size(struct drm_i915_private *dev_priv)
{
- struct drm_atomic_state *state = crtc_state->uapi.state;
- struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
u16 ddb_size = INTEL_INFO(dev_priv)->ddb_size;
WARN_ON(ddb_size == 0);
@@ -3845,12 +3859,13 @@ static u16 intel_get_ddb_size(struct drm_i915_private *dev_priv,
if (INTEL_GEN(dev_priv) < 11)
return ddb_size - 4; /* 4 blocks for bypass path allocation */
- intel_state->enabled_dbuf_slices_mask = DBUF_S1_BIT;
- ddb_size /= 2;
-
return ddb_size;
}
+static u32 i915_possible_dbuf_slices(struct drm_i915_private *dev_priv,
+ int pipe, u32 active_pipes,
+ const struct intel_crtc_state *crtc_state);
+
static void
skl_ddb_get_pipe_allocation_limits(struct drm_i915_private *dev_priv,
const struct intel_crtc_state *crtc_state,
@@ -3862,10 +3877,17 @@ skl_ddb_get_pipe_allocation_limits(struct drm_i915_private *dev_priv,
struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
struct drm_crtc *for_crtc = crtc_state->uapi.crtc;
const struct intel_crtc *crtc;
- u32 pipe_width = 0, total_width = 0, width_before_pipe = 0;
+ u32 pipe_width = 0, total_width_in_range = 0, width_before_pipe = 0;
enum pipe for_pipe = to_intel_crtc(for_crtc)->pipe;
u16 ddb_size;
+ u32 ddb_range_size;
u32 i;
+ u32 dbuf_slice_mask;
+ u32 active_pipes;
+ u32 offset;
+ u32 slice_size;
+ u32 total_slice_mask;
+ u32 start, end;
if (WARN_ON(!state) || !crtc_state->hw.active) {
alloc->start = 0;
@@ -3875,12 +3897,15 @@ skl_ddb_get_pipe_allocation_limits(struct drm_i915_private *dev_priv,
}
if (intel_state->active_pipe_changes)
- *num_active = hweight8(intel_state->active_pipes);
+ active_pipes = intel_state->active_pipes;
else
- *num_active = hweight8(dev_priv->active_pipes);
+ active_pipes = dev_priv->active_pipes;
- ddb_size = intel_get_ddb_size(dev_priv, crtc_state, total_data_rate,
- *num_active);
+ *num_active = hweight8(active_pipes);
+
+ ddb_size = intel_get_ddb_size(dev_priv);
+
+ slice_size = ddb_size / INTEL_INFO(dev_priv)->num_supported_dbuf_slices;
/*
* If the state doesn't change the active CRTC's or there is no
@@ -3899,22 +3924,74 @@ skl_ddb_get_pipe_allocation_limits(struct drm_i915_private *dev_priv,
return;
}
+ /*
+ * Get allowed DBuf slices for correspondent pipe and platform.
+ */
+ dbuf_slice_mask = i915_possible_dbuf_slices(dev_priv, for_pipe,
+ active_pipes, crtc_state);
+
+ DRM_DEBUG_KMS("DBuf slice mask %x pipe %d active pipes %x\n",
+ dbuf_slice_mask,
+ for_pipe, active_pipes);
+
+ /*
+ * Figure out at which DBuf slice we start, i.e if we start at Dbuf S2
+ * and slice size is 1024, the offset would be 1024
+ */
+ offset = icl_get_first_dbuf_slice_offset(dbuf_slice_mask,
+ slice_size, ddb_size);
+
+ /*
+ * Figure out total size of allowed DBuf slices, which is basically
+ * a number of allowed slices for that pipe multiplied by slice size.
+ * Inside of this
+ * range ddb entries are still allocated in proportion to display width.
+ */
+ ddb_range_size = hweight8(dbuf_slice_mask) * slice_size;
+
/*
* Watermark/ddb requirement highly depends upon width of the
* framebuffer, So instead of allocating DDB equally among pipes
* distribute DDB based on resolution/width of the display.
*/
+ total_slice_mask = dbuf_slice_mask;
for_each_new_intel_crtc_in_state(intel_state, crtc, crtc_state, i) {
const struct drm_display_mode *adjusted_mode =
&crtc_state->hw.adjusted_mode;
enum pipe pipe = crtc->pipe;
int hdisplay, vdisplay;
+ u32 pipe_dbuf_slice_mask;
- if (!crtc_state->hw.enable)
+ if (!crtc_state->hw.active)
+ continue;
+
+ pipe_dbuf_slice_mask = i915_possible_dbuf_slices(dev_priv,
+ pipe,
+ active_pipes,
+ crtc_state);
+
+ /*
+ * According to BSpec pipe can share one dbuf slice with another
+ * pipes or pipe can use multiple dbufs, in both cases we
+ * account for other pipes only if they have exactly same mask.
+ * However we need to account how many slices we should enable
+ * in total.
+ */
+ total_slice_mask |= pipe_dbuf_slice_mask;
+
+ /*
+ * Do not account pipes using other slice sets
+ * luckily as of current BSpec slice sets do not partially
+ * intersect(pipes share either same one slice or same slice set
+ * i.e no partial intersection), so it is enough to check for
+ * equality for now.
+ */
+ if (dbuf_slice_mask != pipe_dbuf_slice_mask)
continue;
drm_mode_get_hv_timing(adjusted_mode, &hdisplay, &vdisplay);
- total_width += hdisplay;
+
+ total_width_in_range += hdisplay;
if (pipe < for_pipe)
width_before_pipe += hdisplay;
@@ -3922,8 +3999,20 @@ skl_ddb_get_pipe_allocation_limits(struct drm_i915_private *dev_priv,
pipe_width = hdisplay;
}
- alloc->start = ddb_size * width_before_pipe / total_width;
- alloc->end = ddb_size * (width_before_pipe + pipe_width) / total_width;
+ intel_state->enabled_dbuf_slices_mask = total_slice_mask;
+
+ start = ddb_range_size * width_before_pipe / total_width_in_range;
+ end = ddb_range_size *
+ (width_before_pipe + pipe_width) / total_width_in_range;
+
+ alloc->start = offset + start;
+ alloc->end = offset + end;
+
+ DRM_DEBUG_KMS("Pipe %d ddb %d-%d\n", for_pipe,
+ alloc->start, alloc->end);
+ DRM_DEBUG_KMS("Enabled ddb slices mask %x num supported %d\n",
+ intel_state->enabled_dbuf_slices_mask,
+ INTEL_INFO(dev_priv)->num_supported_dbuf_slices);
}
static int skl_compute_wm_params(const struct intel_crtc_state *crtc_state,
@@ -4094,6 +4183,133 @@ skl_plane_downscale_amount(const struct intel_crtc_state *crtc_state,
return mul_fixed16(downscale_w, downscale_h);
}
+struct dbuf_slice_conf_entry {
+ u32 active_pipes;
+ u32 dbuf_mask[I915_MAX_PIPES];
+};
+
+/*
+ * Table taken from Bspec 12716
+ * Pipes do have some preferred DBuf slice affinity,
+ * plus there are some hardcoded requirements on how
+ * those should be distributed for multipipe scenarios.
+ * For more DBuf slices algorithm can get even more messy
+ * and less readable, so decided to use a table almost
+ * as is from BSpec itself - that way it is at least easier
+ * to compare, change and check.
+ */
+static struct dbuf_slice_conf_entry icl_allowed_dbufs[] = {
+ { BIT(PIPE_A), { DBUF_S1_BIT, 0, 0 } },
+ { BIT(PIPE_B), { 0, DBUF_S1_BIT, 0 } },
+ { BIT(PIPE_C), { 0, 0, DBUF_S2_BIT } },
+ { BIT(PIPE_A) | BIT(PIPE_B), { DBUF_S1_BIT, DBUF_S2_BIT, 0} },
+ { BIT(PIPE_A) | BIT(PIPE_C), { DBUF_S1_BIT, 0, DBUF_S2_BIT } },
+ { BIT(PIPE_B) | BIT(PIPE_C), { 0, DBUF_S1_BIT, DBUF_S2_BIT } },
+ { BIT(PIPE_A) | BIT(PIPE_B) | BIT(PIPE_C),
+ { DBUF_S1_BIT, DBUF_S1_BIT, DBUF_S2_BIT } }
+};
+
+/*
+ * Table taken from Bspec 49255
+ * Pipes do have some preferred DBuf slice affinity,
+ * plus there are some hardcoded requirements on how
+ * those should be distributed for multipipe scenarios.
+ * For more DBuf slices algorithm can get even more messy
+ * and less readable, so decided to use a table almost
+ * as is from BSpec itself - that way it is at least easier
+ * to compare, change and check.
+ */
+static struct dbuf_slice_conf_entry tgl_allowed_dbufs[] = {
+ { BIT(PIPE_A), { DBUF_S1_BIT | DBUF_S2_BIT, 0, 0, 0 } },
+ { BIT(PIPE_B), { 0, DBUF_S1_BIT | DBUF_S2_BIT, 0, 0 } },
+ { BIT(PIPE_C), { 0, 0, DBUF_S1_BIT | DBUF_S2_BIT, 0 } },
+ { BIT(PIPE_D), { 0, 0, 0, DBUF_S1_BIT | DBUF_S2_BIT } },
+ { BIT(PIPE_A) | BIT(PIPE_B), { DBUF_S2_BIT, DBUF_S1_BIT, 0, 0 } },
+ { BIT(PIPE_A) | BIT(PIPE_C), { DBUF_S1_BIT, 0, DBUF_S2_BIT, 0 } },
+ { BIT(PIPE_A) | BIT(PIPE_D), { DBUF_S1_BIT, 0, 0, DBUF_S2_BIT } },
+ { BIT(PIPE_B) | BIT(PIPE_C), { 0, DBUF_S1_BIT, DBUF_S2_BIT, 0 } },
+ { BIT(PIPE_B) | BIT(PIPE_D), { 0, DBUF_S1_BIT, 0, DBUF_S2_BIT } },
+ { BIT(PIPE_C) | BIT(PIPE_D), { 0, 0, DBUF_S1_BIT, DBUF_S2_BIT } },
+ { BIT(PIPE_A) | BIT(PIPE_B) | BIT(PIPE_C),
+ { DBUF_S1_BIT, DBUF_S1_BIT, DBUF_S2_BIT, 0 } },
+ { BIT(PIPE_A) | BIT(PIPE_B) | BIT(PIPE_D),
+ { DBUF_S1_BIT, DBUF_S1_BIT, 0, DBUF_S2_BIT } },
+ { BIT(PIPE_A) | BIT(PIPE_C) | BIT(PIPE_D),
+ { DBUF_S1_BIT, 0, DBUF_S2_BIT, DBUF_S2_BIT } },
+ { BIT(PIPE_B) | BIT(PIPE_C) | BIT(PIPE_D),
+ { 0, DBUF_S1_BIT, DBUF_S2_BIT, DBUF_S2_BIT } },
+ { BIT(PIPE_A) | BIT(PIPE_B) | BIT(PIPE_C) | BIT(PIPE_D),
+ { DBUF_S1_BIT, DBUF_S1_BIT, DBUF_S2_BIT, DBUF_S2_BIT } },
+};
+
+static u32 i915_find_pipe_conf(int pipe,
+ u32 active_pipes,
+ const struct dbuf_slice_conf_entry *dbuf_slices,
+ int size)
+{
+ int i;
+
+ for (i = 0; i < size; i++) {
+ if (dbuf_slices[i].active_pipes == active_pipes)
+ return dbuf_slices[i].dbuf_mask[pipe];
+ }
+ return 0;
+}
+
+/*
+ * This function finds an entry with same enabled pipe configuration and
+ * returns correspondent DBuf slice mask as stated in BSpec for particular
+ * platform.
+ */
+static u32 icl_possible_dbuf_slices(int pipe,
+ u32 active_pipes,
+ const struct intel_crtc_state *crtc_state)
+{
+ /*
+ * FIXME: For ICL this is still a bit unclear as prev BSpec revision
+ * required calculating "pipe ratio" in order to determine
+ * if one or two slices can be used for single pipe configurations
+ * as additional constraint to the existing table.
+ * However based on recent info, it should be not "pipe ratio"
+ * but rather ratio between pixel_rate and cdclk with additional
+ * constants, so for now we are using only table until this is
+ * clarified. Also this is the reason why crtc_state param is
+ * still here - we will need it once those additional constraints
+ * pop up.
+ */
+ return i915_find_pipe_conf(pipe, active_pipes,
+ icl_allowed_dbufs,
+ ARRAY_SIZE(icl_allowed_dbufs));
+}
+
+static u32 tgl_possible_dbuf_slices(int pipe,
+ u32 active_pipes,
+ const struct intel_crtc_state *crtc_state)
+{
+ return i915_find_pipe_conf(pipe, active_pipes,
+ tgl_allowed_dbufs,
+ ARRAY_SIZE(tgl_allowed_dbufs));
+}
+
+u32 i915_possible_dbuf_slices(struct drm_i915_private *dev_priv,
+ int pipe, u32 active_pipes,
+ const struct intel_crtc_state *crtc_state)
+{
+ if (IS_GEN(dev_priv, 11))
+ return icl_possible_dbuf_slices(pipe,
+ active_pipes,
+ crtc_state);
+ else if (IS_GEN(dev_priv, 12))
+ return tgl_possible_dbuf_slices(pipe,
+ active_pipes,
+ crtc_state);
+ /*
+ * For anything else just return one slice yet.
+ * Should be extended for other platforms.
+ */
+ return DBUF_S1_BIT;
+}
+
static u64
skl_plane_relative_data_rate(const struct intel_crtc_state *crtc_state,
const struct intel_plane_state *plane_state,
--
2.17.1
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