pci: apple: Add preinitialized APIF hosts and native AIC MSI

Documentation/devicetree/bindings/pci/apple,apif-pcie.yaml

@@ -0,0 +1,119 @@
+# SPDX-License-Identifier: GPL-2.0-only
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pci/apple,apif-pcie.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Preinitialized Apple PCIe host in an Aura guest
+maintainers:
+  - Dj <hey@djdev.me>
+
+description: |
+  The boot producer configures the controller, PHY, link, apertures and
+  RID-to-SID routing before guest entry. It disables endpoint bus mastering
+  and MSI before transferring ownership. Linux uses ECAM and allocates MSI
+  from the native AIC range; it does not run raw cold-init register sequences.
+
+allOf:
+  - $ref: /schemas/pci/pci-host-bridge.yaml#
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: apple,t6050-pcie-apif
+    then:
+      required:
+        - apple,rid-to-sid
+        - max-link-speed
+        - num-lanes
+      properties:
+        reg:
+          minItems: 5
+        reg-names:
+          minItems: 5
+    else:
+      properties:
+        reg:
+          maxItems: 1
+        reg-names:
+          maxItems: 1
+        apple,rid-to-sid: false
+
+properties:
+  compatible:
+    oneOf:
+      - const: apple,apif-pcie
+      - items:
+          - const: apple,t6050-pcie-apif
+          - const: apple,apif-pcie
+  reg:
+    minItems: 1
+    items:
+      - description: ECAM configuration window
+      - description: T6050 port-0 control registers, at least 32 KiB
+      - description: T6050 port-0 PHY registers, at least 16 KiB
+      - description: Active-low PERST pad register, at least four bytes
+      - description: T6050 interrupt-to-AXI registers, at least 16 KiB
+  reg-names:
+    minItems: 1
+    items:
+      - const: ecam
+      - const: port
+      - const: phy
+      - const: perst
+      - const: intr2axi
+  apple,preinitialized:
+    type: boolean
+    description: Controller is initialized and endpoint DMA/MSI is stopped
+  apple,msi-address:
+    $ref: /schemas/types.yaml#/definitions/uint64
+    description: Native MSI doorbell; 4 KiB aligned for the T6050 layout
+  msi-ranges:
+    maxItems: 1
+    description: One four-cell native AIC edge interrupt range and vector count
+  apple,rid-to-sid:
+    $ref: /schemas/types.yaml#/definitions/uint32-matrix
+    minItems: 1
+    maxItems: 15
+    items:
+      items:
+        - description: Hardware routing slot
+          minimum: 1
+          maximum: 15
+        - description: Requester ID
+          maximum: 65535
+        - description: Firmware-assigned DART stream ID
+          maximum: 255
+    description: Restore existing routing after the optional preboot port cycle
+  iommu-map: true
+  iommu-map-mask: true
+  max-link-speed:
+    const: 3
+  num-lanes:
+    const: 1
+  dma-coherent: true
+
+patternProperties:
+  '^apple,(apcie-config|pcie-rc|pcie-rc-gen[345]-shadow)-tunables$':
+    $ref: /schemas/types.yaml#/definitions/uint32-matrix
+    maxItems: 16
+    items:
+      items:
+        - description: Register offset
+        - const: 4
+        - description: Clear mask
+        - description: Set mask
+    description: Boot-producer register tuples for the matched layout
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - ranges
+  - bus-range
+  - apple,preinitialized
+  - apple,msi-address
+  - msi-ranges
+  - iommu-map
+
+unevaluatedProperties: false

Documentation/driver-api/firmware/aurora-apif-pcie.rst

@@ -0,0 +1,30 @@
+.. SPDX-License-Identifier: GPL-2.0-only
+
+Preinitialized PCIe guests
+=========================
+
+``apple,apif-pcie`` admits an ECAM host whose producer has already configured
+its clocks, PHY, link, address windows and RID-to-SID routes. The producer
+must stop endpoint DMA and MSI before transferring ownership. Linux allocates
+MSI vectors from the single native four-cell AIC edge range in ``msi-ranges``;
+the doorbell is supplied by ``apple,msi-address``. Vector counts and addresses
+are checked before the routing tables are touched. No polling interrupt path
+or fixed IRQ assignment per function is introduced.
+
+A second compatible, ``apple,t6050-pcie-apif``, selects the known port-0
+register layout and supplies port, PHY, PERST and interrupt-to-AXI resources.
+It restores explicit ``apple,rid-to-sid`` tuples and the same declared MSI
+range after a controlled preboot cycle. Tunables come from the boot producer.
+Unknown layouts use only ECAM/MSI; they cannot enter the T6050 reset sequence.
+
+``apple_apif_pcie_cycle()`` is for the isolated N1 ROM/preboot function before
+radio functions are enumerated or have live DMA. The caller must quiesce all
+activity on that unit. PCI topology locking excludes sibling functions, and
+DART transitions refuse other Linux groups or retained firmware streams.
+Timeouts are bounded. A partial transition leaves bus mastering and bridge
+decoding stopped; it does not attempt a speculative DMA restart. This is not
+a general PCI bus reset API and does not add N1 Wi-Fi/Bluetooth drivers.
+
+The generic host and its matched port sequence require hardware qualification
+with the matching Aura monitor and boot description. Host sequence tests and
+native builds do not establish link recovery or radio firmware behavior.

Documentation/driver-api/firmware/index.rst

@@ -6,6 +6,7 @@ Linux Firmware API
 
    aurora-apif
    aurora-apif-nvme
+   aurora-apif-pcie
    introduction
    core
    efi/index

drivers/iommu/apple-dart-apif.c

@@ -1743,10 +1743,16 @@ static const struct iommu_ops apple_dart_apif_ops = {
 /* Used only after the PCI host has stopped every endpoint on this DART.
  * Native POWERDOWN/POWERUP retains the SPTM-owned tables and live mappings.
  */
+static int apif_other_group_device(struct device *member, void *data)
+{
+	return member == data ? 0 : -EBUSY;
+}
+
 int apple_dart_apif_set_power(struct device *dev, bool on)
 {
 	struct apple_dart_apif_master *master;
 	struct apple_dart_apif *dart;
+	struct iommu_group *group;
 	unsigned long flags;
 	int ret;
 
@@ -1757,8 +1763,25 @@ int apple_dart_apif_set_power(struct device *dev, bool on)
 	if (!master || master->num_darts != 1)
 		return -ENODEV;
 	dart = master->streams[0].dart;
+	group = iommu_group_get(dev);
+	if (!group)
+		return -ENODEV;
+	ret = iommu_group_for_each_dev(group, dev, apif_other_group_device);
+	if (ret)
+		goto put_group;
+	mutex_lock(&apple_dart_apif_groups_lock);
+	/* Native DISABLE affects the entire unit. Retained firmware streams or
+	 * another Linux group must never be stopped by one endpoint's reset.
+	 */
+	for (unsigned int sid = 0; sid < dart->num_streams; sid++) {
+		if (dart->retained[sid] ||
+		    (dart->sid2group[sid] && dart->sid2group[sid] != group)) {
+			ret = -EBUSY;
+			goto unlock_groups;
+		}
+	}
 	mutex_lock(&dart->init_lock);
-	if (!dart->inited) {
+	if (!dart->inited || dart->ownership_uncertain) {
 		ret = -EINVAL;
 		goto out;
 	}
@@ -1769,6 +1792,10 @@ int apple_dart_apif_set_power(struct device *dev, bool on)
 	spin_unlock_irqrestore(&dart->batch_lock, flags);
 out:
 	mutex_unlock(&dart->init_lock);
+unlock_groups:
+	mutex_unlock(&apple_dart_apif_groups_lock);
+put_group:
+	iommu_group_put(group);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(apple_dart_apif_set_power);

drivers/pci/controller/Kconfig

@@ -409,3 +409,14 @@ source "drivers/pci/controller/dwc/Kconfig"
 source "drivers/pci/controller/mobiveil/Kconfig"
 source "drivers/pci/controller/plda/Kconfig"
 endmenu
+
+config PCIE_APPLE_APIF
+	tristate "Preinitialized Apple PCIe host for Aura guests"
+	depends on ARM64 && OF && PCI_MSI
+	depends on APPLE_DART_APIF
+	select PCI_HOST_COMMON
+	help
+	  Admit an ECAM host initialized by the boot producer. Allocate MSI
+	  vectors from the native AIC range described in its guest device tree.
+	  A matching T6050 layout additionally supports a controlled preboot
+	  port transition; other layouts never enter that sequence.

drivers/pci/controller/Makefile

@@ -67,3 +67,4 @@ endif
 endif
 
 obj-$(CONFIG_PCIE_APPLE_PIODMA_DIAG) += pcie-apple-piodma-diag.o
+obj-$(CONFIG_PCIE_APPLE_APIF) += apple-apif/

drivers/pci/controller/apple-apif/Makefile

@@ -0,0 +1,2 @@
+obj-$(CONFIG_PCIE_APPLE_APIF) += pcie-apple-apif.o
+pcie-apple-apif-y := host.o t6050.o t6050_pcie_port.o t6050_pcie_disable.o t6050_pcie_gpio.o t6050_pcie_msi.o