drm/i915: split out intel_pch.[ch] from i915_drv.[ch]

Abstract the rather self-contained piece of code from i915_drv.[ch]. No
functional changes.

Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190807120415.17917-1-jani.nikula@intel.com

drivers/gpu/drm/i915/Makefile

@@ -50,6 +50,7 @@ i915-y += i915_drv.o \
 	  i915_sysfs.o \
 	  intel_csr.o \
 	  intel_device_info.o \
+	  intel_pch.o \
 	  intel_pm.o \
 	  intel_runtime_pm.o \
 	  intel_sideband.o \

drivers/gpu/drm/i915/i915_drv.c

@@ -145,200 +145,6 @@ __i915_printk(struct drm_i915_private *dev_priv, const char *level,
 	}
 }
 
-/* Map PCH device id to PCH type, or PCH_NONE if unknown. */
-static enum intel_pch
-intel_pch_type(const struct drm_i915_private *dev_priv, unsigned short id)
-{
-	switch (id) {
-	case INTEL_PCH_IBX_DEVICE_ID_TYPE:
-		DRM_DEBUG_KMS("Found Ibex Peak PCH\n");
-		WARN_ON(!IS_GEN(dev_priv, 5));
-		return PCH_IBX;
-	case INTEL_PCH_CPT_DEVICE_ID_TYPE:
-		DRM_DEBUG_KMS("Found CougarPoint PCH\n");
-		WARN_ON(!IS_GEN(dev_priv, 6) && !IS_IVYBRIDGE(dev_priv));
-		return PCH_CPT;
-	case INTEL_PCH_PPT_DEVICE_ID_TYPE:
-		DRM_DEBUG_KMS("Found PantherPoint PCH\n");
-		WARN_ON(!IS_GEN(dev_priv, 6) && !IS_IVYBRIDGE(dev_priv));
-		/* PantherPoint is CPT compatible */
-		return PCH_CPT;
-	case INTEL_PCH_LPT_DEVICE_ID_TYPE:
-		DRM_DEBUG_KMS("Found LynxPoint PCH\n");
-		WARN_ON(!IS_HASWELL(dev_priv) && !IS_BROADWELL(dev_priv));
-		WARN_ON(IS_HSW_ULT(dev_priv) || IS_BDW_ULT(dev_priv));
-		return PCH_LPT;
-	case INTEL_PCH_LPT_LP_DEVICE_ID_TYPE:
-		DRM_DEBUG_KMS("Found LynxPoint LP PCH\n");
-		WARN_ON(!IS_HASWELL(dev_priv) && !IS_BROADWELL(dev_priv));
-		WARN_ON(!IS_HSW_ULT(dev_priv) && !IS_BDW_ULT(dev_priv));
-		return PCH_LPT;
-	case INTEL_PCH_WPT_DEVICE_ID_TYPE:
-		DRM_DEBUG_KMS("Found WildcatPoint PCH\n");
-		WARN_ON(!IS_HASWELL(dev_priv) && !IS_BROADWELL(dev_priv));
-		WARN_ON(IS_HSW_ULT(dev_priv) || IS_BDW_ULT(dev_priv));
-		/* WildcatPoint is LPT compatible */
-		return PCH_LPT;
-	case INTEL_PCH_WPT_LP_DEVICE_ID_TYPE:
-		DRM_DEBUG_KMS("Found WildcatPoint LP PCH\n");
-		WARN_ON(!IS_HASWELL(dev_priv) && !IS_BROADWELL(dev_priv));
-		WARN_ON(!IS_HSW_ULT(dev_priv) && !IS_BDW_ULT(dev_priv));
-		/* WildcatPoint is LPT compatible */
-		return PCH_LPT;
-	case INTEL_PCH_SPT_DEVICE_ID_TYPE:
-		DRM_DEBUG_KMS("Found SunrisePoint PCH\n");
-		WARN_ON(!IS_SKYLAKE(dev_priv) && !IS_KABYLAKE(dev_priv));
-		return PCH_SPT;
-	case INTEL_PCH_SPT_LP_DEVICE_ID_TYPE:
-		DRM_DEBUG_KMS("Found SunrisePoint LP PCH\n");
-		WARN_ON(!IS_SKYLAKE(dev_priv) && !IS_KABYLAKE(dev_priv));
-		return PCH_SPT;
-	case INTEL_PCH_KBP_DEVICE_ID_TYPE:
-		DRM_DEBUG_KMS("Found Kaby Lake PCH (KBP)\n");
-		WARN_ON(!IS_SKYLAKE(dev_priv) && !IS_KABYLAKE(dev_priv) &&
-			!IS_COFFEELAKE(dev_priv));
-		/* KBP is SPT compatible */
-		return PCH_SPT;
-	case INTEL_PCH_CNP_DEVICE_ID_TYPE:
-		DRM_DEBUG_KMS("Found Cannon Lake PCH (CNP)\n");
-		WARN_ON(!IS_CANNONLAKE(dev_priv) && !IS_COFFEELAKE(dev_priv));
-		return PCH_CNP;
-	case INTEL_PCH_CNP_LP_DEVICE_ID_TYPE:
-		DRM_DEBUG_KMS("Found Cannon Lake LP PCH (CNP-LP)\n");
-		WARN_ON(!IS_CANNONLAKE(dev_priv) && !IS_COFFEELAKE(dev_priv));
-		return PCH_CNP;
-	case INTEL_PCH_CMP_DEVICE_ID_TYPE:
-		DRM_DEBUG_KMS("Found Comet Lake PCH (CMP)\n");
-		WARN_ON(!IS_COFFEELAKE(dev_priv));
-		/* CometPoint is CNP Compatible */
-		return PCH_CNP;
-	case INTEL_PCH_ICP_DEVICE_ID_TYPE:
-		DRM_DEBUG_KMS("Found Ice Lake PCH\n");
-		WARN_ON(!IS_ICELAKE(dev_priv));
-		return PCH_ICP;
-	case INTEL_PCH_MCC_DEVICE_ID_TYPE:
-	case INTEL_PCH_MCC2_DEVICE_ID_TYPE:
-		DRM_DEBUG_KMS("Found Mule Creek Canyon PCH\n");
-		WARN_ON(!IS_ELKHARTLAKE(dev_priv));
-		return PCH_MCC;
-	case INTEL_PCH_TGP_DEVICE_ID_TYPE:
-		DRM_DEBUG_KMS("Found Tiger Lake LP PCH\n");
-		WARN_ON(!IS_TIGERLAKE(dev_priv));
-		return PCH_TGP;
-	default:
-		return PCH_NONE;
-	}
-}
-
-static bool intel_is_virt_pch(unsigned short id,
-			      unsigned short svendor, unsigned short sdevice)
-{
-	return (id == INTEL_PCH_P2X_DEVICE_ID_TYPE ||
-		id == INTEL_PCH_P3X_DEVICE_ID_TYPE ||
-		(id == INTEL_PCH_QEMU_DEVICE_ID_TYPE &&
-		 svendor == PCI_SUBVENDOR_ID_REDHAT_QUMRANET &&
-		 sdevice == PCI_SUBDEVICE_ID_QEMU));
-}
-
-static unsigned short
-intel_virt_detect_pch(const struct drm_i915_private *dev_priv)
-{
-	unsigned short id = 0;
-
-	/*
-	 * In a virtualized passthrough environment we can be in a
-	 * setup where the ISA bridge is not able to be passed through.
-	 * In this case, a south bridge can be emulated and we have to
-	 * make an educated guess as to which PCH is really there.
-	 */
-
-	if (IS_TIGERLAKE(dev_priv))
-		id = INTEL_PCH_TGP_DEVICE_ID_TYPE;
-	else if (IS_ELKHARTLAKE(dev_priv))
-		id = INTEL_PCH_MCC_DEVICE_ID_TYPE;
-	else if (IS_ICELAKE(dev_priv))
-		id = INTEL_PCH_ICP_DEVICE_ID_TYPE;
-	else if (IS_CANNONLAKE(dev_priv) || IS_COFFEELAKE(dev_priv))
-		id = INTEL_PCH_CNP_DEVICE_ID_TYPE;
-	else if (IS_KABYLAKE(dev_priv) || IS_SKYLAKE(dev_priv))
-		id = INTEL_PCH_SPT_DEVICE_ID_TYPE;
-	else if (IS_HSW_ULT(dev_priv) || IS_BDW_ULT(dev_priv))
-		id = INTEL_PCH_LPT_LP_DEVICE_ID_TYPE;
-	else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
-		id = INTEL_PCH_LPT_DEVICE_ID_TYPE;
-	else if (IS_GEN(dev_priv, 6) || IS_IVYBRIDGE(dev_priv))
-		id = INTEL_PCH_CPT_DEVICE_ID_TYPE;
-	else if (IS_GEN(dev_priv, 5))
-		id = INTEL_PCH_IBX_DEVICE_ID_TYPE;
-
-	if (id)
-		DRM_DEBUG_KMS("Assuming PCH ID %04x\n", id);
-	else
-		DRM_DEBUG_KMS("Assuming no PCH\n");
-
-	return id;
-}
-
-static void intel_detect_pch(struct drm_i915_private *dev_priv)
-{
-	struct pci_dev *pch = NULL;
-
-	/*
-	 * The reason to probe ISA bridge instead of Dev31:Fun0 is to
-	 * make graphics device passthrough work easy for VMM, that only
-	 * need to expose ISA bridge to let driver know the real hardware
-	 * underneath. This is a requirement from virtualization team.
-	 *
-	 * In some virtualized environments (e.g. XEN), there is irrelevant
-	 * ISA bridge in the system. To work reliably, we should scan trhough
-	 * all the ISA bridge devices and check for the first match, instead
-	 * of only checking the first one.
-	 */
-	while ((pch = pci_get_class(PCI_CLASS_BRIDGE_ISA << 8, pch))) {
-		unsigned short id;
-		enum intel_pch pch_type;
-
-		if (pch->vendor != PCI_VENDOR_ID_INTEL)
-			continue;
-
-		id = pch->device & INTEL_PCH_DEVICE_ID_MASK;
-
-		pch_type = intel_pch_type(dev_priv, id);
-		if (pch_type != PCH_NONE) {
-			dev_priv->pch_type = pch_type;
-			dev_priv->pch_id = id;
-			break;
-		} else if (intel_is_virt_pch(id, pch->subsystem_vendor,
-					 pch->subsystem_device)) {
-			id = intel_virt_detect_pch(dev_priv);
-			pch_type = intel_pch_type(dev_priv, id);
-
-			/* Sanity check virtual PCH id */
-			if (WARN_ON(id && pch_type == PCH_NONE))
-				id = 0;
-
-			dev_priv->pch_type = pch_type;
-			dev_priv->pch_id = id;
-			break;
-		}
-	}
-
-	/*
-	 * Use PCH_NOP (PCH but no South Display) for PCH platforms without
-	 * display.
-	 */
-	if (pch && !HAS_DISPLAY(dev_priv)) {
-		DRM_DEBUG_KMS("Display disabled, reverting to NOP PCH\n");
-		dev_priv->pch_type = PCH_NOP;
-		dev_priv->pch_id = 0;
-	}
-
-	if (!pch)
-		DRM_DEBUG_KMS("No PCH found.\n");
-
-	pci_dev_put(pch);
-}
-
 static int i915_get_bridge_dev(struct drm_i915_private *dev_priv)
 {
 	int domain = pci_domain_nr(dev_priv->drm.pdev->bus);

drivers/gpu/drm/i915/i915_drv.h

@@ -77,6 +77,7 @@
 #include "gt/uc/intel_uc.h"
 
 #include "intel_device_info.h"
+#include "intel_pch.h"
 #include "intel_runtime_pm.h"
 #include "intel_uncore.h"
 #include "intel_wakeref.h"
@@ -528,25 +529,6 @@ struct i915_psr {
 	u16 su_x_granularity;
 };
 
-/*
- * Sorted by south display engine compatibility.
- * If the new PCH comes with a south display engine that is not
- * inherited from the latest item, please do not add it to the
- * end. Instead, add it right after its "parent" PCH.
- */
-enum intel_pch {
-	PCH_NOP = -1,	/* PCH without south display */
-	PCH_NONE = 0,	/* No PCH present */
-	PCH_IBX,	/* Ibexpeak PCH */
-	PCH_CPT,	/* Cougarpoint/Pantherpoint PCH */
-	PCH_LPT,	/* Lynxpoint/Wildcatpoint PCH */
-	PCH_SPT,        /* Sunrisepoint/Kaby Lake PCH */
-	PCH_CNP,        /* Cannon/Comet Lake PCH */
-	PCH_ICP,	/* Ice Lake PCH */
-	PCH_MCC,        /* Mule Creek Canyon PCH */
-	PCH_TGP,	/* Tiger Lake PCH */
-};
-
 #define QUIRK_LVDS_SSC_DISABLE (1<<1)
 #define QUIRK_INVERT_BRIGHTNESS (1<<2)
 #define QUIRK_BACKLIGHT_PRESENT (1<<3)
@@ -2281,46 +2263,6 @@ IS_SUBPLATFORM(const struct drm_i915_private *i915,
 
 #define HAS_GLOBAL_MOCS_REGISTERS(dev_priv)	(INTEL_INFO(dev_priv)->has_global_mocs)
 
-#define INTEL_PCH_DEVICE_ID_MASK		0xff80
-#define INTEL_PCH_IBX_DEVICE_ID_TYPE		0x3b00
-#define INTEL_PCH_CPT_DEVICE_ID_TYPE		0x1c00
-#define INTEL_PCH_PPT_DEVICE_ID_TYPE		0x1e00
-#define INTEL_PCH_LPT_DEVICE_ID_TYPE		0x8c00
-#define INTEL_PCH_LPT_LP_DEVICE_ID_TYPE		0x9c00
-#define INTEL_PCH_WPT_DEVICE_ID_TYPE		0x8c80
-#define INTEL_PCH_WPT_LP_DEVICE_ID_TYPE		0x9c80
-#define INTEL_PCH_SPT_DEVICE_ID_TYPE		0xA100
-#define INTEL_PCH_SPT_LP_DEVICE_ID_TYPE		0x9D00
-#define INTEL_PCH_KBP_DEVICE_ID_TYPE		0xA280
-#define INTEL_PCH_CNP_DEVICE_ID_TYPE		0xA300
-#define INTEL_PCH_CNP_LP_DEVICE_ID_TYPE		0x9D80
-#define INTEL_PCH_CMP_DEVICE_ID_TYPE		0x0280
-#define INTEL_PCH_ICP_DEVICE_ID_TYPE		0x3480
-#define INTEL_PCH_MCC_DEVICE_ID_TYPE		0x4B00
-#define INTEL_PCH_MCC2_DEVICE_ID_TYPE		0x3880
-#define INTEL_PCH_TGP_DEVICE_ID_TYPE		0xA080
-#define INTEL_PCH_P2X_DEVICE_ID_TYPE		0x7100
-#define INTEL_PCH_P3X_DEVICE_ID_TYPE		0x7000
-#define INTEL_PCH_QEMU_DEVICE_ID_TYPE		0x2900 /* qemu q35 has 2918 */
-
-#define INTEL_PCH_TYPE(dev_priv) ((dev_priv)->pch_type)
-#define INTEL_PCH_ID(dev_priv) ((dev_priv)->pch_id)
-#define HAS_PCH_MCC(dev_priv) (INTEL_PCH_TYPE(dev_priv) == PCH_MCC)
-#define HAS_PCH_TGP(dev_priv) (INTEL_PCH_TYPE(dev_priv) == PCH_TGP)
-#define HAS_PCH_ICP(dev_priv) (INTEL_PCH_TYPE(dev_priv) == PCH_ICP)
-#define HAS_PCH_CNP(dev_priv) (INTEL_PCH_TYPE(dev_priv) == PCH_CNP)
-#define HAS_PCH_SPT(dev_priv) (INTEL_PCH_TYPE(dev_priv) == PCH_SPT)
-#define HAS_PCH_LPT(dev_priv) (INTEL_PCH_TYPE(dev_priv) == PCH_LPT)
-#define HAS_PCH_LPT_LP(dev_priv) \
-	(INTEL_PCH_ID(dev_priv) == INTEL_PCH_LPT_LP_DEVICE_ID_TYPE || \
-	 INTEL_PCH_ID(dev_priv) == INTEL_PCH_WPT_LP_DEVICE_ID_TYPE)
-#define HAS_PCH_LPT_H(dev_priv) \
-	(INTEL_PCH_ID(dev_priv) == INTEL_PCH_LPT_DEVICE_ID_TYPE || \
-	 INTEL_PCH_ID(dev_priv) == INTEL_PCH_WPT_DEVICE_ID_TYPE)
-#define HAS_PCH_CPT(dev_priv) (INTEL_PCH_TYPE(dev_priv) == PCH_CPT)
-#define HAS_PCH_IBX(dev_priv) (INTEL_PCH_TYPE(dev_priv) == PCH_IBX)
-#define HAS_PCH_NOP(dev_priv) (INTEL_PCH_TYPE(dev_priv) == PCH_NOP)
-#define HAS_PCH_SPLIT(dev_priv) (INTEL_PCH_TYPE(dev_priv) != PCH_NONE)
 
 #define HAS_GMCH(dev_priv) (INTEL_INFO(dev_priv)->display.has_gmch)
 

drivers/gpu/drm/i915/intel_pch.c

+// SPDX-License-Identifier: MIT
+/*
+ * Copyright 2019 Intel Corporation.
+ */
+
+#include "i915_drv.h"
+#include "intel_pch.h"
+
+/* Map PCH device id to PCH type, or PCH_NONE if unknown. */
+static enum intel_pch
+intel_pch_type(const struct drm_i915_private *dev_priv, unsigned short id)
+{
+	switch (id) {
+	case INTEL_PCH_IBX_DEVICE_ID_TYPE:
+		DRM_DEBUG_KMS("Found Ibex Peak PCH\n");
+		WARN_ON(!IS_GEN(dev_priv, 5));
+		return PCH_IBX;
+	case INTEL_PCH_CPT_DEVICE_ID_TYPE:
+		DRM_DEBUG_KMS("Found CougarPoint PCH\n");
+		WARN_ON(!IS_GEN(dev_priv, 6) && !IS_IVYBRIDGE(dev_priv));
+		return PCH_CPT;
+	case INTEL_PCH_PPT_DEVICE_ID_TYPE:
+		DRM_DEBUG_KMS("Found PantherPoint PCH\n");
+		WARN_ON(!IS_GEN(dev_priv, 6) && !IS_IVYBRIDGE(dev_priv));
+		/* PantherPoint is CPT compatible */
+		return PCH_CPT;
+	case INTEL_PCH_LPT_DEVICE_ID_TYPE:
+		DRM_DEBUG_KMS("Found LynxPoint PCH\n");
+		WARN_ON(!IS_HASWELL(dev_priv) && !IS_BROADWELL(dev_priv));
+		WARN_ON(IS_HSW_ULT(dev_priv) || IS_BDW_ULT(dev_priv));
+		return PCH_LPT;
+	case INTEL_PCH_LPT_LP_DEVICE_ID_TYPE:
+		DRM_DEBUG_KMS("Found LynxPoint LP PCH\n");
+		WARN_ON(!IS_HASWELL(dev_priv) && !IS_BROADWELL(dev_priv));
+		WARN_ON(!IS_HSW_ULT(dev_priv) && !IS_BDW_ULT(dev_priv));
+		return PCH_LPT;
+	case INTEL_PCH_WPT_DEVICE_ID_TYPE:
+		DRM_DEBUG_KMS("Found WildcatPoint PCH\n");
+		WARN_ON(!IS_HASWELL(dev_priv) && !IS_BROADWELL(dev_priv));
+		WARN_ON(IS_HSW_ULT(dev_priv) || IS_BDW_ULT(dev_priv));
+		/* WildcatPoint is LPT compatible */
+		return PCH_LPT;
+	case INTEL_PCH_WPT_LP_DEVICE_ID_TYPE:
+		DRM_DEBUG_KMS("Found WildcatPoint LP PCH\n");
+		WARN_ON(!IS_HASWELL(dev_priv) && !IS_BROADWELL(dev_priv));
+		WARN_ON(!IS_HSW_ULT(dev_priv) && !IS_BDW_ULT(dev_priv));
+		/* WildcatPoint is LPT compatible */
+		return PCH_LPT;
+	case INTEL_PCH_SPT_DEVICE_ID_TYPE:
+		DRM_DEBUG_KMS("Found SunrisePoint PCH\n");
+		WARN_ON(!IS_SKYLAKE(dev_priv) && !IS_KABYLAKE(dev_priv));
+		return PCH_SPT;
+	case INTEL_PCH_SPT_LP_DEVICE_ID_TYPE:
+		DRM_DEBUG_KMS("Found SunrisePoint LP PCH\n");
+		WARN_ON(!IS_SKYLAKE(dev_priv) && !IS_KABYLAKE(dev_priv));
+		return PCH_SPT;
+	case INTEL_PCH_KBP_DEVICE_ID_TYPE:
+		DRM_DEBUG_KMS("Found Kaby Lake PCH (KBP)\n");
+		WARN_ON(!IS_SKYLAKE(dev_priv) && !IS_KABYLAKE(dev_priv) &&
+			!IS_COFFEELAKE(dev_priv));
+		/* KBP is SPT compatible */
+		return PCH_SPT;
+	case INTEL_PCH_CNP_DEVICE_ID_TYPE:
+		DRM_DEBUG_KMS("Found Cannon Lake PCH (CNP)\n");
+		WARN_ON(!IS_CANNONLAKE(dev_priv) && !IS_COFFEELAKE(dev_priv));
+		return PCH_CNP;
+	case INTEL_PCH_CNP_LP_DEVICE_ID_TYPE:
+		DRM_DEBUG_KMS("Found Cannon Lake LP PCH (CNP-LP)\n");
+		WARN_ON(!IS_CANNONLAKE(dev_priv) && !IS_COFFEELAKE(dev_priv));
+		return PCH_CNP;
+	case INTEL_PCH_CMP_DEVICE_ID_TYPE:
+		DRM_DEBUG_KMS("Found Comet Lake PCH (CMP)\n");
+		WARN_ON(!IS_COFFEELAKE(dev_priv));
+		/* CometPoint is CNP Compatible */
+		return PCH_CNP;
+	case INTEL_PCH_ICP_DEVICE_ID_TYPE:
+		DRM_DEBUG_KMS("Found Ice Lake PCH\n");
+		WARN_ON(!IS_ICELAKE(dev_priv));
+		return PCH_ICP;
+	case INTEL_PCH_MCC_DEVICE_ID_TYPE:
+	case INTEL_PCH_MCC2_DEVICE_ID_TYPE:
+		DRM_DEBUG_KMS("Found Mule Creek Canyon PCH\n");
+		WARN_ON(!IS_ELKHARTLAKE(dev_priv));
+		return PCH_MCC;
+	case INTEL_PCH_TGP_DEVICE_ID_TYPE:
+		DRM_DEBUG_KMS("Found Tiger Lake LP PCH\n");
+		WARN_ON(!IS_TIGERLAKE(dev_priv));
+		return PCH_TGP;
+	default:
+		return PCH_NONE;
+	}
+}
+
+static bool intel_is_virt_pch(unsigned short id,
+			      unsigned short svendor, unsigned short sdevice)
+{
+	return (id == INTEL_PCH_P2X_DEVICE_ID_TYPE ||
+		id == INTEL_PCH_P3X_DEVICE_ID_TYPE ||
+		(id == INTEL_PCH_QEMU_DEVICE_ID_TYPE &&
+		 svendor == PCI_SUBVENDOR_ID_REDHAT_QUMRANET &&
+		 sdevice == PCI_SUBDEVICE_ID_QEMU));
+}
+
+static unsigned short
+intel_virt_detect_pch(const struct drm_i915_private *dev_priv)
+{
+	unsigned short id = 0;
+
+	/*
+	 * In a virtualized passthrough environment we can be in a
+	 * setup where the ISA bridge is not able to be passed through.
+	 * In this case, a south bridge can be emulated and we have to
+	 * make an educated guess as to which PCH is really there.
+	 */
+
+	if (IS_TIGERLAKE(dev_priv))
+		id = INTEL_PCH_TGP_DEVICE_ID_TYPE;
+	else if (IS_ELKHARTLAKE(dev_priv))
+		id = INTEL_PCH_MCC_DEVICE_ID_TYPE;
+	else if (IS_ICELAKE(dev_priv))
+		id = INTEL_PCH_ICP_DEVICE_ID_TYPE;
+	else if (IS_CANNONLAKE(dev_priv) || IS_COFFEELAKE(dev_priv))
+		id = INTEL_PCH_CNP_DEVICE_ID_TYPE;
+	else if (IS_KABYLAKE(dev_priv) || IS_SKYLAKE(dev_priv))
+		id = INTEL_PCH_SPT_DEVICE_ID_TYPE;
+	else if (IS_HSW_ULT(dev_priv) || IS_BDW_ULT(dev_priv))
+		id = INTEL_PCH_LPT_LP_DEVICE_ID_TYPE;
+	else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
+		id = INTEL_PCH_LPT_DEVICE_ID_TYPE;
+	else if (IS_GEN(dev_priv, 6) || IS_IVYBRIDGE(dev_priv))
+		id = INTEL_PCH_CPT_DEVICE_ID_TYPE;
+	else if (IS_GEN(dev_priv, 5))
+		id = INTEL_PCH_IBX_DEVICE_ID_TYPE;
+
+	if (id)
+		DRM_DEBUG_KMS("Assuming PCH ID %04x\n", id);
+	else
+		DRM_DEBUG_KMS("Assuming no PCH\n");
+
+	return id;
+}
+
+void intel_detect_pch(struct drm_i915_private *dev_priv)
+{
+	struct pci_dev *pch = NULL;
+
+	/*
+	 * The reason to probe ISA bridge instead of Dev31:Fun0 is to
+	 * make graphics device passthrough work easy for VMM, that only
+	 * need to expose ISA bridge to let driver know the real hardware
+	 * underneath. This is a requirement from virtualization team.
+	 *
+	 * In some virtualized environments (e.g. XEN), there is irrelevant
+	 * ISA bridge in the system. To work reliably, we should scan trhough
+	 * all the ISA bridge devices and check for the first match, instead
+	 * of only checking the first one.
+	 */
+	while ((pch = pci_get_class(PCI_CLASS_BRIDGE_ISA << 8, pch))) {
+		unsigned short id;
+		enum intel_pch pch_type;
+
+		if (pch->vendor != PCI_VENDOR_ID_INTEL)
+			continue;
+
+		id = pch->device & INTEL_PCH_DEVICE_ID_MASK;
+
+		pch_type = intel_pch_type(dev_priv, id);
+		if (pch_type != PCH_NONE) {
+			dev_priv->pch_type = pch_type;
+			dev_priv->pch_id = id;
+			break;
+		} else if (intel_is_virt_pch(id, pch->subsystem_vendor,
+					     pch->subsystem_device)) {
+			id = intel_virt_detect_pch(dev_priv);
+			pch_type = intel_pch_type(dev_priv, id);
+
+			/* Sanity check virtual PCH id */
+			if (WARN_ON(id && pch_type == PCH_NONE))
+				id = 0;
+
+			dev_priv->pch_type = pch_type;
+			dev_priv->pch_id = id;
+			break;
+		}
+	}
+
+	/*
+	 * Use PCH_NOP (PCH but no South Display) for PCH platforms without
+	 * display.
+	 */
+	if (pch && !HAS_DISPLAY(dev_priv)) {
+		DRM_DEBUG_KMS("Display disabled, reverting to NOP PCH\n");
+		dev_priv->pch_type = PCH_NOP;
+		dev_priv->pch_id = 0;
+	}
+
+	if (!pch)
+		DRM_DEBUG_KMS("No PCH found.\n");
+
+	pci_dev_put(pch);
+}

drivers/gpu/drm/i915/intel_pch.h

+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright 2019 Intel Corporation.
+ */
+
+#ifndef __INTEL_PCH__
+#define __INTEL_PCH__
+
+struct drm_i915_private;
+
+/*
+ * Sorted by south display engine compatibility.
+ * If the new PCH comes with a south display engine that is not
+ * inherited from the latest item, please do not add it to the
+ * end. Instead, add it right after its "parent" PCH.
+ */
+enum intel_pch {
+	PCH_NOP = -1,	/* PCH without south display */
+	PCH_NONE = 0,	/* No PCH present */
+	PCH_IBX,	/* Ibexpeak PCH */
+	PCH_CPT,	/* Cougarpoint/Pantherpoint PCH */
+	PCH_LPT,	/* Lynxpoint/Wildcatpoint PCH */
+	PCH_SPT,        /* Sunrisepoint/Kaby Lake PCH */
+	PCH_CNP,        /* Cannon/Comet Lake PCH */
+	PCH_ICP,	/* Ice Lake PCH */
+	PCH_MCC,        /* Mule Creek Canyon PCH */
+	PCH_TGP,	/* Tiger Lake PCH */
+};
+
+#define INTEL_PCH_DEVICE_ID_MASK		0xff80
+#define INTEL_PCH_IBX_DEVICE_ID_TYPE		0x3b00
+#define INTEL_PCH_CPT_DEVICE_ID_TYPE		0x1c00
+#define INTEL_PCH_PPT_DEVICE_ID_TYPE		0x1e00
+#define INTEL_PCH_LPT_DEVICE_ID_TYPE		0x8c00
+#define INTEL_PCH_LPT_LP_DEVICE_ID_TYPE		0x9c00
+#define INTEL_PCH_WPT_DEVICE_ID_TYPE		0x8c80
+#define INTEL_PCH_WPT_LP_DEVICE_ID_TYPE		0x9c80
+#define INTEL_PCH_SPT_DEVICE_ID_TYPE		0xA100
+#define INTEL_PCH_SPT_LP_DEVICE_ID_TYPE		0x9D00
+#define INTEL_PCH_KBP_DEVICE_ID_TYPE		0xA280
+#define INTEL_PCH_CNP_DEVICE_ID_TYPE		0xA300
+#define INTEL_PCH_CNP_LP_DEVICE_ID_TYPE		0x9D80
+#define INTEL_PCH_CMP_DEVICE_ID_TYPE		0x0280
+#define INTEL_PCH_ICP_DEVICE_ID_TYPE		0x3480
+#define INTEL_PCH_MCC_DEVICE_ID_TYPE		0x4B00
+#define INTEL_PCH_MCC2_DEVICE_ID_TYPE		0x3880
+#define INTEL_PCH_TGP_DEVICE_ID_TYPE		0xA080
+#define INTEL_PCH_P2X_DEVICE_ID_TYPE		0x7100
+#define INTEL_PCH_P3X_DEVICE_ID_TYPE		0x7000
+#define INTEL_PCH_QEMU_DEVICE_ID_TYPE		0x2900 /* qemu q35 has 2918 */
+
+#define INTEL_PCH_TYPE(dev_priv)		((dev_priv)->pch_type)
+#define INTEL_PCH_ID(dev_priv)			((dev_priv)->pch_id)
+#define HAS_PCH_MCC(dev_priv)			(INTEL_PCH_TYPE(dev_priv) == PCH_MCC)
+#define HAS_PCH_TGP(dev_priv)			(INTEL_PCH_TYPE(dev_priv) == PCH_TGP)
+#define HAS_PCH_ICP(dev_priv)			(INTEL_PCH_TYPE(dev_priv) == PCH_ICP)
+#define HAS_PCH_CNP(dev_priv)			(INTEL_PCH_TYPE(dev_priv) == PCH_CNP)
+#define HAS_PCH_SPT(dev_priv)			(INTEL_PCH_TYPE(dev_priv) == PCH_SPT)
+#define HAS_PCH_LPT(dev_priv)			(INTEL_PCH_TYPE(dev_priv) == PCH_LPT)
+#define HAS_PCH_LPT_LP(dev_priv) \
+	(INTEL_PCH_ID(dev_priv) == INTEL_PCH_LPT_LP_DEVICE_ID_TYPE || \
+	 INTEL_PCH_ID(dev_priv) == INTEL_PCH_WPT_LP_DEVICE_ID_TYPE)
+#define HAS_PCH_LPT_H(dev_priv) \
+	(INTEL_PCH_ID(dev_priv) == INTEL_PCH_LPT_DEVICE_ID_TYPE || \
+	 INTEL_PCH_ID(dev_priv) == INTEL_PCH_WPT_DEVICE_ID_TYPE)
+#define HAS_PCH_CPT(dev_priv)			(INTEL_PCH_TYPE(dev_priv) == PCH_CPT)
+#define HAS_PCH_IBX(dev_priv)			(INTEL_PCH_TYPE(dev_priv) == PCH_IBX)
+#define HAS_PCH_NOP(dev_priv)			(INTEL_PCH_TYPE(dev_priv) == PCH_NOP)
+#define HAS_PCH_SPLIT(dev_priv)			(INTEL_PCH_TYPE(dev_priv) != PCH_NONE)
+
+void intel_detect_pch(struct drm_i915_private *dev_priv);
+
+#endif /* __INTEL_PCH__ */