drm/i915/dmc: allocate dmc structure dynamically

sizeof(struct intel_dmc) > 1024 bytes, allocated on all platforms as
part of struct drm_i915_private, whether they have DMC or not.

Allocate struct intel_dmc dynamically, and hide all the dmc details
behind an opaque pointer in intel_dmc.c.

Care must be taken to take into account all cases: DMC not supported on
the platform, DMC supported but not initialized, and DMC initialized but
not loaded. For the second case, we need to move the wakeref out of
struct intel_dmc.

v2:
- Rebase to kzalloc dmc after runtime pm get (Imre)

Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230301122944.1298929-4-jani.nikula@intel.com

drivers/gpu/drm/i915/display/intel_display_core.h

@@ -19,7 +19,6 @@
 #include "intel_cdclk.h"
 #include "intel_display_limits.h"
 #include "intel_display_power.h"
-#include "intel_dmc.h"
 #include "intel_dpll_mgr.h"
 #include "intel_fbc.h"
 #include "intel_global_state.h"
@@ -40,6 +39,7 @@ struct intel_cdclk_vals;
 struct intel_color_funcs;
 struct intel_crtc;
 struct intel_crtc_state;
+struct intel_dmc;
 struct intel_dpll_funcs;
 struct intel_dpll_mgr;
 struct intel_fbdev;
@@ -340,6 +340,11 @@ struct intel_display {
 		spinlock_t phy_lock;
 	} dkl;
 
+	struct {
+		struct intel_dmc *dmc;
+		intel_wakeref_t wakeref;
+	} dmc;
+
 	struct {
 		/* VLV/CHV/BXT/GLK DSI MMIO register base address */
 		u32 mmio_base;
@@ -467,7 +472,6 @@ struct intel_display {
 
 	/* Grouping using named structs. Keep sorted. */
 	struct intel_audio audio;
-	struct intel_dmc dmc;
 	struct intel_dpll dpll;
 	struct intel_fbc *fbc[I915_MAX_FBCS];
 	struct intel_frontbuffer_tracking fb_tracking;

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

@@ -38,9 +38,37 @@
  * low-power state and comes back to normal.
  */
 
+enum intel_dmc_id {
+	DMC_FW_MAIN = 0,
+	DMC_FW_PIPEA,
+	DMC_FW_PIPEB,
+	DMC_FW_PIPEC,
+	DMC_FW_PIPED,
+	DMC_FW_MAX
+};
+
+struct intel_dmc {
+	struct drm_i915_private *i915;
+	struct work_struct work;
+	const char *fw_path;
+	u32 max_fw_size; /* bytes */
+	u32 version;
+	struct dmc_fw_info {
+		u32 mmio_count;
+		i915_reg_t mmioaddr[20];
+		u32 mmiodata[20];
+		u32 dmc_offset;
+		u32 start_mmioaddr;
+		u32 dmc_fw_size; /*dwords */
+		u32 *payload;
+		bool present;
+	} dmc_info[DMC_FW_MAX];
+};
+
+/* Note: This may be NULL. */
 static struct intel_dmc *i915_to_dmc(struct drm_i915_private *i915)
 {
-	return &i915->display.dmc;
+	return i915->display.dmc.dmc;
 }
 
 #define DMC_VERSION(major, minor)	((major) << 16 | (minor))
@@ -947,7 +975,10 @@ void intel_dmc_init(struct drm_i915_private *dev_priv)
 	 */
 	intel_dmc_runtime_pm_get(dev_priv);
 
-	dmc = i915_to_dmc(dev_priv);
+	dmc = kzalloc(sizeof(*dmc), GFP_KERNEL);
+	if (!dmc)
+		return;
+
 	dmc->i915 = dev_priv;
 
 	INIT_WORK(&dmc->work, dmc_load_work_fn);
@@ -991,10 +1022,9 @@ void intel_dmc_init(struct drm_i915_private *dev_priv)
 
 	if (dev_priv->params.dmc_firmware_path) {
 		if (strlen(dev_priv->params.dmc_firmware_path) == 0) {
-			dmc->fw_path = NULL;
 			drm_info(&dev_priv->drm,
 				 "Disabling DMC firmware and runtime PM\n");
-			return;
+			goto out;
 		}
 
 		dmc->fw_path = dev_priv->params.dmc_firmware_path;
@@ -1003,11 +1033,18 @@ void intel_dmc_init(struct drm_i915_private *dev_priv)
 	if (!dmc->fw_path) {
 		drm_dbg_kms(&dev_priv->drm,
 			    "No known DMC firmware for platform, disabling runtime PM\n");
-		return;
+		goto out;
 	}
 
+	dev_priv->display.dmc.dmc = dmc;
+
 	drm_dbg_kms(&dev_priv->drm, "Loading %s\n", dmc->fw_path);
 	schedule_work(&dmc->work);
+
+	return;
+
+out:
+	kfree(dmc);
 }
 
 /**
@@ -1074,6 +1111,9 @@ void intel_dmc_fini(struct drm_i915_private *dev_priv)
 	if (dmc) {
 		for_each_dmc_id(dmc_id)
 			kfree(dmc->dmc_info[dmc_id].payload);
+
+		kfree(dmc);
+		dev_priv->display.dmc.dmc = NULL;
 	}
 }
 

drivers/gpu/drm/i915/display/intel_dmc.h

@@ -6,44 +6,12 @@
 #ifndef __INTEL_DMC_H__
 #define __INTEL_DMC_H__
 
-#include "i915_reg_defs.h"
-#include "intel_wakeref.h"
-#include <linux/workqueue.h>
+#include <linux/types.h>
 
 struct drm_i915_error_state_buf;
 struct drm_i915_private;
-
 enum pipe;
 
-enum intel_dmc_id {
-	DMC_FW_MAIN = 0,
-	DMC_FW_PIPEA,
-	DMC_FW_PIPEB,
-	DMC_FW_PIPEC,
-	DMC_FW_PIPED,
-	DMC_FW_MAX
-};
-
-struct intel_dmc {
-	struct drm_i915_private *i915;
-	struct work_struct work;
-	const char *fw_path;
-	u32 max_fw_size; /* bytes */
-	u32 version;
-	struct dmc_fw_info {
-		u32 mmio_count;
-		i915_reg_t mmioaddr[20];
-		u32 mmiodata[20];
-		u32 dmc_offset;
-		u32 start_mmioaddr;
-		u32 dmc_fw_size; /*dwords */
-		u32 *payload;
-		bool present;
-	} dmc_info[DMC_FW_MAX];
-
-	intel_wakeref_t wakeref;
-};
-
 void intel_dmc_init(struct drm_i915_private *i915);
 void intel_dmc_load_program(struct drm_i915_private *i915);
 void intel_dmc_disable_program(struct drm_i915_private *i915);

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

@@ -22,6 +22,7 @@
 #include "intel_display.h"
 #include "intel_display_power.h"
 #include "intel_display_types.h"
+#include "intel_dmc.h"
 #include "intel_fifo_underrun.h"
 #include "intel_modeset_setup.h"
 #include "intel_pch_display.h"