drm/i915/display: allow to skip certain power wells

This allows us to skip power wells on a platform allowing it to re-use
the table from another one instead of having to create a new table from
scratch that is basically a copy with a few removals.

Cc: Imre Deak <imre.deak@intel.com>
Suggested-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Aditya Swarup <aditya.swarup@intel.com>
[ Adapt ignore logic to be based on pw id rather than adding a new
  field, as suggested by Imre ]
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201014191937.1266226-1-lucas.demarchi@intel.com

drivers/gpu/drm/i915/display/intel_display_power.c

@@ -4554,13 +4554,18 @@ static u32 get_allowed_dc_mask(const struct drm_i915_private *dev_priv,
 static int
 __set_power_wells(struct i915_power_domains *power_domains,
 		  const struct i915_power_well_desc *power_well_descs,
-		  int power_well_count)
+		  int power_well_descs_sz, u64 skip_mask)
 {
 	struct drm_i915_private *i915 = container_of(power_domains,
 						     struct drm_i915_private,
 						     power_domains);
 	u64 power_well_ids = 0;
-	int i;
+	int power_well_count = 0;
+	int i, plt_idx = 0;
+
+	for (i = 0; i < power_well_descs_sz; i++)
+		if (!(BIT_ULL(power_well_descs[i].id) & skip_mask))
+			power_well_count++;
 
 	power_domains->power_well_count = power_well_count;
 	power_domains->power_wells =
@@ -4570,10 +4575,14 @@ __set_power_wells(struct i915_power_domains *power_domains,
 	if (!power_domains->power_wells)
 		return -ENOMEM;
 
-	for (i = 0; i < power_well_count; i++) {
+	for (i = 0; i < power_well_descs_sz; i++) {
 		enum i915_power_well_id id = power_well_descs[i].id;
 
-		power_domains->power_wells[i].desc = &power_well_descs[i];
+		if (BIT_ULL(id) & skip_mask)
+			continue;
+
+		power_domains->power_wells[plt_idx++].desc =
+			&power_well_descs[i];
 
 		if (id == DISP_PW_ID_NONE)
 			continue;
@@ -4586,9 +4595,12 @@ __set_power_wells(struct i915_power_domains *power_domains,
 	return 0;
 }
 
-#define set_power_wells(power_domains, __power_well_descs) \
+#define set_power_wells_mask(power_domains, __power_well_descs, skip_mask) \
 	__set_power_wells(power_domains, __power_well_descs, \
-			  ARRAY_SIZE(__power_well_descs))
+			  ARRAY_SIZE(__power_well_descs), skip_mask)
+
+#define set_power_wells(power_domains, __power_well_descs) \
+	set_power_wells_mask(power_domains, __power_well_descs, 0)
 
 /**
  * intel_power_domains_init - initializes the power domain structures