devices: pcie: add pcie upstream and downstream port

To support pcie switch, we need to add both pcie upstream and
downstream port. This patch adds a new file pcie_switch.rs and add
basic implementation for pcie upstream and downstream port.

BUG=b:199986018
TEST=./tools/presubmit

Change-Id: I7cc40d4fd0f017e06c5a0e8b0e3b68a8df9ee185
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3508737
Commit-Queue: Daniel Verkamp <dverkamp@chromium.org>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>

devices/src/pci/pcie/pcie_switch.rs

@@ -0,0 +1,162 @@
+// Copyright 2022 The ChromiumOS Authors.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+use crate::pci::pci_configuration::PciCapabilityID;
+use crate::pci::{PciAddress, PciCapability, PciDeviceError};
+
+use crate::pci::pcie::pci_bridge::PciBridgeBusRange;
+use crate::pci::pcie::pcie_device::{PciPmcCap, PcieCap, PcieDevice};
+use crate::pci::pcie::pcie_port::PciePort;
+use crate::pci::pcie::*;
+
+use resources::SystemAllocator;
+
+const PCIE_UP_DID: u16 = 0x3500;
+const PCIE_DP_DID: u16 = 0x3510;
+
+pub struct PcieUpstreamPort {
+    pcie_port: PciePort,
+}
+
+impl PcieUpstreamPort {
+    /// Constructs a new PCIE upstream port
+    pub fn new(primary_bus_num: u8, secondary_bus_num: u8) -> Self {
+        PcieUpstreamPort {
+            pcie_port: PciePort::new(
+                PCIE_UP_DID,
+                "PcieUpstreamPort".to_string(),
+                primary_bus_num,
+                secondary_bus_num,
+                false,
+            ),
+        }
+    }
+
+    pub fn new_from_host(pcie_host: PcieHostPort) -> Self {
+        PcieUpstreamPort {
+            pcie_port: PciePort::new_from_host(pcie_host, false),
+        }
+    }
+}
+
+impl PcieDevice for PcieUpstreamPort {
+    fn get_device_id(&self) -> u16 {
+        self.pcie_port.get_device_id()
+    }
+
+    fn debug_label(&self) -> String {
+        self.pcie_port.debug_label()
+    }
+
+    fn allocate_address(
+        &mut self,
+        resources: &mut SystemAllocator,
+    ) -> std::result::Result<PciAddress, PciDeviceError> {
+        self.pcie_port.allocate_address(resources)
+    }
+
+    fn read_config(&self, reg_idx: usize, data: &mut u32) {
+        self.pcie_port.read_config(reg_idx, data);
+    }
+
+    fn write_config(&mut self, reg_idx: usize, offset: u64, data: &[u8]) {
+        self.pcie_port.write_config(reg_idx, offset, data);
+    }
+
+    fn get_caps(&self) -> Vec<Box<dyn PciCapability>> {
+        vec![
+            Box::new(PcieCap::new(PcieDevicePortType::UpstreamPort, false, 0)),
+            Box::new(PciPmcCap::new()),
+        ]
+    }
+
+    fn set_capability_reg_idx(&mut self, id: PciCapabilityID, reg_idx: usize) {
+        self.pcie_port.set_capability_reg_idx(id, reg_idx);
+    }
+
+    fn get_bus_range(&self) -> Option<PciBridgeBusRange> {
+        self.pcie_port.get_bus_range()
+    }
+
+    fn hotplug_implemented(&self) -> bool {
+        false
+    }
+
+    fn get_bridge_window_size(&self) -> (u64, u64) {
+        self.pcie_port.get_bridge_window_size()
+    }
+}
+
+pub struct PcieDownstreamPort {
+    pcie_port: PciePort,
+}
+
+impl PcieDownstreamPort {
+    /// Constructs a new PCIE downstream port
+    pub fn new(primary_bus_num: u8, secondary_bus_num: u8) -> Self {
+        PcieDownstreamPort {
+            pcie_port: PciePort::new(
+                PCIE_DP_DID,
+                "PcieDownstreamPort".to_string(),
+                primary_bus_num,
+                secondary_bus_num,
+                false,
+            ),
+        }
+    }
+
+    pub fn new_from_host(pcie_host: PcieHostPort) -> Self {
+        PcieDownstreamPort {
+            pcie_port: PciePort::new_from_host(pcie_host, false),
+        }
+    }
+}
+
+impl PcieDevice for PcieDownstreamPort {
+    fn get_device_id(&self) -> u16 {
+        self.pcie_port.get_device_id()
+    }
+
+    fn debug_label(&self) -> String {
+        self.pcie_port.debug_label()
+    }
+
+    fn allocate_address(
+        &mut self,
+        resources: &mut SystemAllocator,
+    ) -> std::result::Result<PciAddress, PciDeviceError> {
+        self.pcie_port.allocate_address(resources)
+    }
+
+    fn read_config(&self, reg_idx: usize, data: &mut u32) {
+        self.pcie_port.read_config(reg_idx, data);
+    }
+
+    fn write_config(&mut self, reg_idx: usize, offset: u64, data: &[u8]) {
+        self.pcie_port.write_config(reg_idx, offset, data);
+    }
+
+    fn get_caps(&self) -> Vec<Box<dyn PciCapability>> {
+        vec![
+            Box::new(PcieCap::new(PcieDevicePortType::DownstreamPort, false, 0)),
+            Box::new(PciPmcCap::new()),
+        ]
+    }
+
+    fn set_capability_reg_idx(&mut self, id: PciCapabilityID, reg_idx: usize) {
+        self.pcie_port.set_capability_reg_idx(id, reg_idx);
+    }
+
+    fn get_bus_range(&self) -> Option<PciBridgeBusRange> {
+        self.pcie_port.get_bus_range()
+    }
+
+    fn hotplug_implemented(&self) -> bool {
+        false
+    }
+
+    fn get_bridge_window_size(&self) -> (u64, u64) {
+        self.pcie_port.get_bridge_window_size()
+    }
+}