[PATCH v3] drm/i915/display: add platforms "is" member to struct intel_display

[Jani Nikula <jani.nikula@xxxxxxxxx>]

Facilitate using display->is.HASWELL and display->is.HASWELL_ULT
etc. for identifying platforms and subplatforms. Merge platform and
subplatform members together.

v3:
- Fix sanity check on display->is after merging subplatform members

v2:
- Use bitmap ops
- Add some sanity checks with warnings

Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
---
 .../gpu/drm/i915/display/intel_display_core.h |  3 ++
 .../drm/i915/display/intel_display_device.c   | 31 +++++++++++++++++--
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_core.h b/drivers/gpu/drm/i915/display/intel_display_core.h
index 0a711114ff2b..b2907894fa28 100644
--- a/drivers/gpu/drm/i915/display/intel_display_core.h
+++ b/drivers/gpu/drm/i915/display/intel_display_core.h
@@ -286,6 +286,9 @@ struct intel_display {
 	/* drm device backpointer */
 	struct drm_device *drm;
 
+	/* Platform (and subplatform, if any) identification */
+	struct intel_display_platforms is;
+
 	/* Display functions */
 	struct {
 		/* Top level crtc-ish functions */
diff --git a/drivers/gpu/drm/i915/display/intel_display_device.c b/drivers/gpu/drm/i915/display/intel_display_device.c
index 55ab1923c8b3..d0b7cf63bc9f 100644
--- a/drivers/gpu/drm/i915/display/intel_display_device.c
+++ b/drivers/gpu/drm/i915/display/intel_display_device.c
@@ -1269,8 +1269,28 @@ find_subplatform_desc(struct pci_dev *pdev, const struct platform_desc *desc)
 	return NULL;
 }
 
+/* Size of the entire bitmap, not the number of platforms */
+static unsigned int display_platforms_num_bits(void)
+{
+	return sizeof(((struct intel_display_platforms *)0)->bitmap) * BITS_PER_BYTE;
+}
+
+/* Number of platform bits set */
+static unsigned int display_platforms_weight(const struct intel_display_platforms *p)
+{
+	return bitmap_weight(p->bitmap, display_platforms_num_bits());
+}
+
+/* Merge the subplatform information from src to dst */
+static void display_platforms_or(struct intel_display_platforms *dst,
+				 const struct intel_display_platforms *src)
+{
+	bitmap_or(dst->bitmap, dst->bitmap, src->bitmap, display_platforms_num_bits());
+}
+
 void intel_display_device_probe(struct drm_i915_private *i915)
 {
+	struct intel_display *display = &i915->display;
 	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
 	const struct intel_display_device_info *info;
 	struct intel_display_ip_ver ip_ver = {};
@@ -1306,13 +1326,20 @@ void intel_display_device_probe(struct drm_i915_private *i915)
 	       &DISPLAY_INFO(i915)->__runtime_defaults,
 	       sizeof(*DISPLAY_RUNTIME_INFO(i915)));
 
-	drm_WARN_ON(&i915->drm, !desc->platform || !desc->name);
+	drm_WARN_ON(&i915->drm, !desc->platform || !desc->name ||
+		    display_platforms_weight(&desc->platforms) != 1);
 	DISPLAY_RUNTIME_INFO(i915)->platform = desc->platform;
+	display->is = desc->platforms;
 
 	subdesc = find_subplatform_desc(pdev, desc);
 	if (subdesc) {
-		drm_WARN_ON(&i915->drm, !subdesc->subplatform || !subdesc->name);
+		drm_WARN_ON(&i915->drm, !subdesc->subplatform || !subdesc->name ||
+			    display_platforms_weight(&subdesc->platforms) != 1);
 		DISPLAY_RUNTIME_INFO(i915)->subplatform = subdesc->subplatform;
+		display_platforms_or(&display->is, &subdesc->platforms);
+
+		/* Ensure platform and subplatform are distinct */
+		drm_WARN_ON(&i915->drm, display_platforms_weight(&display->is) == 1);
 	}
 
 	if (ip_ver.ver || ip_ver.rel || ip_ver.step)
-- 
2.39.2