1 files changed, 44 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_edram.c b/drivers/gpu/drm/i915/i915_edram.c
new file mode 100644
index 000000000000..5818ec396d1e
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_edram.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: MIT
+/* Copyright © 2025 Intel Corporation */
+
+#include <drm/drm_print.h>
+
+#include "i915_drv.h"
+#include "i915_edram.h"
+#include "i915_reg.h"
+
+static u32 gen9_edram_size_mb(struct drm_i915_private *i915, u32 cap)
+{
+	static const u8 ways[8] = { 4, 8, 12, 16, 16, 16, 16, 16 };
+	static const u8 sets[4] = { 1, 1, 2, 2 };
+
+	return EDRAM_NUM_BANKS(cap) *
+		ways[EDRAM_WAYS_IDX(cap)] *
+		sets[EDRAM_SETS_IDX(cap)];
+}
+
+void i915_edram_detect(struct drm_i915_private *i915)
+{
+	u32 edram_cap = 0;
+
+	if (!(IS_HASWELL(i915) || IS_BROADWELL(i915) || GRAPHICS_VER(i915) >= 9))
+		return;
+
+	edram_cap = intel_uncore_read_fw(&i915->uncore, HSW_EDRAM_CAP);
+
+	/* NB: We can't write IDICR yet because we don't have gt funcs set up */
+
+	if (!(edram_cap & EDRAM_ENABLED))
+		return;
+
+	/*
+	 * The needed capability bits for size calculation are not there with
+	 * pre gen9 so return 128MB always.
+	 */
+	if (GRAPHICS_VER(i915) < 9)
+		i915->edram_size_mb = 128;
+	else
+		i915->edram_size_mb = gen9_edram_size_mb(i915, edram_cap);
+
+	drm_info(&i915->drm, "Found %uMB of eDRAM\n", i915->edram_size_mb);
+}