Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 509 insertions, 0 deletions

diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
new file mode 100644
index 000000000..ea2eb2ec9
--- /dev/null
+++ b/arch/x86/pci/acpi.c
@@ -0,0 +1,509 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define pr_fmt(fmt) "PCI: " fmt
+
+#include <linux/pci.h>
+#include <linux/acpi.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/dmi.h>
+#include <linux/slab.h>
+#include <linux/pci-acpi.h>
+#include <asm/numa.h>
+#include <asm/pci_x86.h>
+
+struct pci_root_info {
+	struct acpi_pci_root_info common;
+	struct pci_sysdata sd;
+#ifdef	CONFIG_PCI_MMCONFIG
+	bool mcfg_added;
+	u8 start_bus;
+	u8 end_bus;
+#endif
+};
+
+bool pci_use_e820 = true;
+static bool pci_use_crs = true;
+static bool pci_ignore_seg;
+
+static int __init set_use_crs(const struct dmi_system_id *id)
+{
+	pci_use_crs = true;
+	return 0;
+}
+
+static int __init set_nouse_crs(const struct dmi_system_id *id)
+{
+	pci_use_crs = false;
+	return 0;
+}
+
+static int __init set_ignore_seg(const struct dmi_system_id *id)
+{
+	pr_info("%s detected: ignoring ACPI _SEG\n", id->ident);
+	pci_ignore_seg = true;
+	return 0;
+}
+
+static int __init set_no_e820(const struct dmi_system_id *id)
+{
+	pr_info("%s detected: not clipping E820 regions from _CRS\n",
+	        id->ident);
+	pci_use_e820 = false;
+	return 0;
+}
+
+static const struct dmi_system_id pci_crs_quirks[] __initconst = {
+	/* http://bugzilla.kernel.org/show_bug.cgi?id=14183 */
+	{
+		.callback = set_use_crs,
+		.ident = "IBM System x3800",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "x3800"),
+		},
+	},
+	/* https://bugzilla.kernel.org/show_bug.cgi?id=16007 */
+	/* 2006 AMD HT/VIA system with two host bridges */
+        {
+		.callback = set_use_crs,
+		.ident = "ASRock ALiveSATA2-GLAN",
+		.matches = {
+			DMI_MATCH(DMI_PRODUCT_NAME, "ALiveSATA2-GLAN"),
+                },
+        },
+	/* https://bugzilla.kernel.org/show_bug.cgi?id=30552 */
+	/* 2006 AMD HT/VIA system with two host bridges */
+	{
+		.callback = set_use_crs,
+		.ident = "ASUS M2V-MX SE",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
+			DMI_MATCH(DMI_BOARD_NAME, "M2V-MX SE"),
+			DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
+		},
+	},
+	/* https://bugzilla.kernel.org/show_bug.cgi?id=42619 */
+	{
+		.callback = set_use_crs,
+		.ident = "MSI MS-7253",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "MICRO-STAR INTERNATIONAL CO., LTD"),
+			DMI_MATCH(DMI_BOARD_NAME, "MS-7253"),
+			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies, LTD"),
+		},
+	},
+	/* https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/931368 */
+	/* https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1033299 */
+	{
+		.callback = set_use_crs,
+		.ident = "Foxconn K8M890-8237A",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "Foxconn"),
+			DMI_MATCH(DMI_BOARD_NAME, "K8M890-8237A"),
+			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies, LTD"),
+		},
+	},
+
+	/* Now for the blacklist.. */
+
+	/* https://bugzilla.redhat.com/show_bug.cgi?id=769657 */
+	{
+		.callback = set_nouse_crs,
+		.ident = "Dell Studio 1557",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "Dell Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Studio 1557"),
+			DMI_MATCH(DMI_BIOS_VERSION, "A09"),
+		},
+	},
+	/* https://bugzilla.redhat.com/show_bug.cgi?id=769657 */
+	{
+		.callback = set_nouse_crs,
+		.ident = "Thinkpad SL510",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "LENOVO"),
+			DMI_MATCH(DMI_BOARD_NAME, "2847DFG"),
+			DMI_MATCH(DMI_BIOS_VERSION, "6JET85WW (1.43 )"),
+		},
+	},
+	/* https://bugzilla.kernel.org/show_bug.cgi?id=42606 */
+	{
+		.callback = set_nouse_crs,
+		.ident = "Supermicro X8DTH",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "X8DTH-i/6/iF/6F"),
+			DMI_MATCH(DMI_BIOS_VERSION, "2.0a"),
+		},
+	},
+
+	/* https://bugzilla.kernel.org/show_bug.cgi?id=15362 */
+	{
+		.callback = set_ignore_seg,
+		.ident = "HP xw9300",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "HP xw9300 Workstation"),
+		},
+	},
+
+	/*
+	 * Many Lenovo models with "IIL" in their DMI_PRODUCT_VERSION have
+	 * an E820 reserved region that covers the entire 32-bit host
+	 * bridge memory window from _CRS.  Using the E820 region to clip
+	 * _CRS means no space is available for hot-added or uninitialized
+	 * PCI devices.  This typically breaks I2C controllers for touchpads
+	 * and hot-added Thunderbolt devices.  See the commit log for
+	 * models known to require this quirk and related bug reports.
+	 */
+	{
+		.callback = set_no_e820,
+		.ident = "Lenovo *IIL* product version",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+			DMI_MATCH(DMI_PRODUCT_VERSION, "IIL"),
+		},
+	},
+
+	/*
+	 * The Acer Spin 5 (SP513-54N) has the same E820 reservation covering
+	 * the entire _CRS 32-bit window issue as the Lenovo *IIL* models.
+	 * See https://bugs.launchpad.net/bugs/1884232
+	 */
+	{
+		.callback = set_no_e820,
+		.ident = "Acer Spin 5 (SP513-54N)",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Spin SP513-54N"),
+		},
+	},
+
+	/*
+	 * Clevo X170KM-G barebones have the same E820 reservation covering
+	 * the entire _CRS 32-bit window issue as the Lenovo *IIL* models.
+	 * See https://bugzilla.kernel.org/show_bug.cgi?id=214259
+	 */
+	{
+		.callback = set_no_e820,
+		.ident = "Clevo X170KM-G Barebone",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_NAME, "X170KM-G"),
+		},
+	},
+	{}
+};
+
+void __init pci_acpi_crs_quirks(void)
+{
+	int year = dmi_get_bios_year();
+
+	if (year >= 0 && year < 2008 && iomem_resource.end <= 0xffffffff)
+		pci_use_crs = false;
+
+	/*
+	 * Some firmware includes unusable space (host bridge registers,
+	 * hidden PCI device BARs, etc) in PCI host bridge _CRS.  This is a
+	 * firmware defect, and 4dc2287c1805 ("x86: avoid E820 regions when
+	 * allocating address space") has clipped out the unusable space in
+	 * the past.
+	 *
+	 * But other firmware supplies E820 reserved regions that cover
+	 * entire _CRS windows, so clipping throws away the entire window,
+	 * leaving none for hot-added or uninitialized devices.  These E820
+	 * entries are probably *not* a firmware defect, so disable the
+	 * clipping by default for post-2022 machines.
+	 *
+	 * We already have quirks to disable clipping for pre-2023
+	 * machines, and we'll likely need quirks to *enable* clipping for
+	 * post-2022 machines that incorrectly include unusable space in
+	 * _CRS.
+	 */
+	if (year >= 2023)
+		pci_use_e820 = false;
+
+	dmi_check_system(pci_crs_quirks);
+
+	/*
+	 * If the user specifies "pci=use_crs" or "pci=nocrs" explicitly, that
+	 * takes precedence over anything we figured out above.
+	 */
+	if (pci_probe & PCI_ROOT_NO_CRS)
+		pci_use_crs = false;
+	else if (pci_probe & PCI_USE__CRS)
+		pci_use_crs = true;
+
+	pr_info("%s host bridge windows from ACPI; if necessary, use \"pci=%s\" and report a bug\n",
+	        pci_use_crs ? "Using" : "Ignoring",
+	        pci_use_crs ? "nocrs" : "use_crs");
+
+	/* "pci=use_e820"/"pci=no_e820" on the kernel cmdline takes precedence */
+	if (pci_probe & PCI_NO_E820)
+		pci_use_e820 = false;
+	else if (pci_probe & PCI_USE_E820)
+		pci_use_e820 = true;
+
+	pr_info("%s E820 reservations for host bridge windows\n",
+	        pci_use_e820 ? "Using" : "Ignoring");
+	if (pci_probe & (PCI_NO_E820 | PCI_USE_E820))
+		pr_info("Please notify linux-pci@vger.kernel.org so future kernels can do this automatically\n");
+}
+
+#ifdef	CONFIG_PCI_MMCONFIG
+static int check_segment(u16 seg, struct device *dev, char *estr)
+{
+	if (seg) {
+		dev_err(dev, "%s can't access configuration space under this host bridge\n",
+			estr);
+		return -EIO;
+	}
+
+	/*
+	 * Failure in adding MMCFG information is not fatal,
+	 * just can't access extended configuration space of
+	 * devices under this host bridge.
+	 */
+	dev_warn(dev, "%s can't access extended configuration space under this bridge\n",
+		 estr);
+
+	return 0;
+}
+
+static int setup_mcfg_map(struct acpi_pci_root_info *ci)
+{
+	int result, seg;
+	struct pci_root_info *info;
+	struct acpi_pci_root *root = ci->root;
+	struct device *dev = &ci->bridge->dev;
+
+	info = container_of(ci, struct pci_root_info, common);
+	info->start_bus = (u8)root->secondary.start;
+	info->end_bus = (u8)root->secondary.end;
+	info->mcfg_added = false;
+	seg = info->sd.domain;
+
+	/* return success if MMCFG is not in use */
+	if (raw_pci_ext_ops && raw_pci_ext_ops != &pci_mmcfg)
+		return 0;
+
+	if (!(pci_probe & PCI_PROBE_MMCONF))
+		return check_segment(seg, dev, "MMCONFIG is disabled,");
+
+	result = pci_mmconfig_insert(dev, seg, info->start_bus, info->end_bus,
+				     root->mcfg_addr);
+	if (result == 0) {
+		/* enable MMCFG if it hasn't been enabled yet */
+		if (raw_pci_ext_ops == NULL)
+			raw_pci_ext_ops = &pci_mmcfg;
+		info->mcfg_added = true;
+	} else if (result != -EEXIST)
+		return check_segment(seg, dev,
+			 "fail to add MMCONFIG information,");
+
+	return 0;
+}
+
+static void teardown_mcfg_map(struct acpi_pci_root_info *ci)
+{
+	struct pci_root_info *info;
+
+	info = container_of(ci, struct pci_root_info, common);
+	if (info->mcfg_added) {
+		pci_mmconfig_delete(info->sd.domain,
+				    info->start_bus, info->end_bus);
+		info->mcfg_added = false;
+	}
+}
+#else
+static int setup_mcfg_map(struct acpi_pci_root_info *ci)
+{
+	return 0;
+}
+
+static void teardown_mcfg_map(struct acpi_pci_root_info *ci)
+{
+}
+#endif
+
+static int pci_acpi_root_get_node(struct acpi_pci_root *root)
+{
+	int busnum = root->secondary.start;
+	struct acpi_device *device = root->device;
+	int node = acpi_get_node(device->handle);
+
+	if (node == NUMA_NO_NODE) {
+		node = x86_pci_root_bus_node(busnum);
+		if (node != 0 && node != NUMA_NO_NODE)
+			dev_info(&device->dev, FW_BUG "no _PXM; falling back to node %d from hardware (may be inconsistent with ACPI node numbers)\n",
+				node);
+	}
+	if (node != NUMA_NO_NODE && !node_online(node))
+		node = NUMA_NO_NODE;
+
+	return node;
+}
+
+static int pci_acpi_root_init_info(struct acpi_pci_root_info *ci)
+{
+	return setup_mcfg_map(ci);
+}
+
+static void pci_acpi_root_release_info(struct acpi_pci_root_info *ci)
+{
+	teardown_mcfg_map(ci);
+	kfree(container_of(ci, struct pci_root_info, common));
+}
+
+/*
+ * An IO port or MMIO resource assigned to a PCI host bridge may be
+ * consumed by the host bridge itself or available to its child
+ * bus/devices. The ACPI specification defines a bit (Producer/Consumer)
+ * to tell whether the resource is consumed by the host bridge itself,
+ * but firmware hasn't used that bit consistently, so we can't rely on it.
+ *
+ * On x86 and IA64 platforms, all IO port and MMIO resources are assumed
+ * to be available to child bus/devices except one special case:
+ *     IO port [0xCF8-0xCFF] is consumed by the host bridge itself
+ *     to access PCI configuration space.
+ *
+ * So explicitly filter out PCI CFG IO ports[0xCF8-0xCFF].
+ */
+static bool resource_is_pcicfg_ioport(struct resource *res)
+{
+	return (res->flags & IORESOURCE_IO) &&
+		res->start == 0xCF8 && res->end == 0xCFF;
+}
+
+static int pci_acpi_root_prepare_resources(struct acpi_pci_root_info *ci)
+{
+	struct acpi_device *device = ci->bridge;
+	int busnum = ci->root->secondary.start;
+	struct resource_entry *entry, *tmp;
+	int status;
+
+	status = acpi_pci_probe_root_resources(ci);
+
+	if (pci_use_crs) {
+		resource_list_for_each_entry_safe(entry, tmp, &ci->resources)
+			if (resource_is_pcicfg_ioport(entry->res))
+				resource_list_destroy_entry(entry);
+		return status;
+	}
+
+	resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
+		dev_printk(KERN_DEBUG, &device->dev,
+			   "host bridge window %pR (ignored)\n", entry->res);
+		resource_list_destroy_entry(entry);
+	}
+	x86_pci_root_bus_resources(busnum, &ci->resources);
+
+	return 0;
+}
+
+static struct acpi_pci_root_ops acpi_pci_root_ops = {
+	.pci_ops = &pci_root_ops,
+	.init_info = pci_acpi_root_init_info,
+	.release_info = pci_acpi_root_release_info,
+	.prepare_resources = pci_acpi_root_prepare_resources,
+};
+
+struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
+{
+	int domain = root->segment;
+	int busnum = root->secondary.start;
+	int node = pci_acpi_root_get_node(root);
+	struct pci_bus *bus;
+
+	if (pci_ignore_seg)
+		root->segment = domain = 0;
+
+	if (domain && !pci_domains_supported) {
+		pr_warn("pci_bus %04x:%02x: ignored (multiple domains not supported)\n",
+		        domain, busnum);
+		return NULL;
+	}
+
+	bus = pci_find_bus(domain, busnum);
+	if (bus) {
+		/*
+		 * If the desired bus has been scanned already, replace
+		 * its bus->sysdata.
+		 */
+		struct pci_sysdata sd = {
+			.domain = domain,
+			.node = node,
+			.companion = root->device
+		};
+
+		memcpy(bus->sysdata, &sd, sizeof(sd));
+	} else {
+		struct pci_root_info *info;
+
+		info = kzalloc(sizeof(*info), GFP_KERNEL);
+		if (!info)
+			dev_err(&root->device->dev,
+				"pci_bus %04x:%02x: ignored (out of memory)\n",
+				domain, busnum);
+		else {
+			info->sd.domain = domain;
+			info->sd.node = node;
+			info->sd.companion = root->device;
+			bus = acpi_pci_root_create(root, &acpi_pci_root_ops,
+						   &info->common, &info->sd);
+		}
+	}
+
+	/* After the PCI-E bus has been walked and all devices discovered,
+	 * configure any settings of the fabric that might be necessary.
+	 */
+	if (bus) {
+		struct pci_bus *child;
+		list_for_each_entry(child, &bus->children, node)
+			pcie_bus_configure_settings(child);
+	}
+
+	return bus;
+}
+
+int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
+{
+	/*
+	 * We pass NULL as parent to pci_create_root_bus(), so if it is not NULL
+	 * here, pci_create_root_bus() has been called by someone else and
+	 * sysdata is likely to be different from what we expect.  Let it go in
+	 * that case.
+	 */
+	if (!bridge->dev.parent) {
+		struct pci_sysdata *sd = bridge->bus->sysdata;
+		ACPI_COMPANION_SET(&bridge->dev, sd->companion);
+	}
+	return 0;
+}
+
+int __init pci_acpi_init(void)
+{
+	struct pci_dev *dev = NULL;
+
+	if (acpi_noirq)
+		return -ENODEV;
+
+	pr_info("Using ACPI for IRQ routing\n");
+	acpi_irq_penalty_init();
+	pcibios_enable_irq = acpi_pci_irq_enable;
+	pcibios_disable_irq = acpi_pci_irq_disable;
+	x86_init.pci.init_irq = x86_init_noop;
+
+	if (pci_routeirq) {
+		/*
+		 * PCI IRQ routing is set up by pci_enable_device(), but we
+		 * also do it here in case there are still broken drivers that
+		 * don't use pci_enable_device().
+		 */
+		pr_info("Routing PCI interrupts for all devices because \"pci=routeirq\" specified\n");
+		for_each_pci_dev(dev)
+			acpi_pci_irq_enable(dev);
+	}
+
+	return 0;
+}