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, 501 insertions, 0 deletions

diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c
new file mode 100644
index 000000000..02f1a1b11
--- /dev/null
+++ b/drivers/acpi/acpi_pad.c
@@ -0,0 +1,501 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * acpi_pad.c ACPI Processor Aggregator Driver
+ *
+ * Copyright (c) 2009, Intel Corporation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/cpumask.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/kthread.h>
+#include <uapi/linux/sched/types.h>
+#include <linux/freezer.h>
+#include <linux/cpu.h>
+#include <linux/tick.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+#include <linux/perf_event.h>
+#include <asm/mwait.h>
+#include <xen/xen.h>
+
+#define ACPI_PROCESSOR_AGGREGATOR_CLASS	"acpi_pad"
+#define ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME "Processor Aggregator"
+#define ACPI_PROCESSOR_AGGREGATOR_NOTIFY 0x80
+static DEFINE_MUTEX(isolated_cpus_lock);
+static DEFINE_MUTEX(round_robin_lock);
+
+static unsigned long power_saving_mwait_eax;
+
+static unsigned char tsc_detected_unstable;
+static unsigned char tsc_marked_unstable;
+
+static void power_saving_mwait_init(void)
+{
+	unsigned int eax, ebx, ecx, edx;
+	unsigned int highest_cstate = 0;
+	unsigned int highest_subcstate = 0;
+	int i;
+
+	if (!boot_cpu_has(X86_FEATURE_MWAIT))
+		return;
+	if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
+		return;
+
+	cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &edx);
+
+	if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
+	    !(ecx & CPUID5_ECX_INTERRUPT_BREAK))
+		return;
+
+	edx >>= MWAIT_SUBSTATE_SIZE;
+	for (i = 0; i < 7 && edx; i++, edx >>= MWAIT_SUBSTATE_SIZE) {
+		if (edx & MWAIT_SUBSTATE_MASK) {
+			highest_cstate = i;
+			highest_subcstate = edx & MWAIT_SUBSTATE_MASK;
+		}
+	}
+	power_saving_mwait_eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) |
+		(highest_subcstate - 1);
+
+#if defined(CONFIG_X86)
+	switch (boot_cpu_data.x86_vendor) {
+	case X86_VENDOR_HYGON:
+	case X86_VENDOR_AMD:
+	case X86_VENDOR_INTEL:
+	case X86_VENDOR_ZHAOXIN:
+		/*
+		 * AMD Fam10h TSC will tick in all
+		 * C/P/S0/S1 states when this bit is set.
+		 */
+		if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
+			tsc_detected_unstable = 1;
+		break;
+	default:
+		/* TSC could halt in idle */
+		tsc_detected_unstable = 1;
+	}
+#endif
+}
+
+static unsigned long cpu_weight[NR_CPUS];
+static int tsk_in_cpu[NR_CPUS] = {[0 ... NR_CPUS-1] = -1};
+static DECLARE_BITMAP(pad_busy_cpus_bits, NR_CPUS);
+static void round_robin_cpu(unsigned int tsk_index)
+{
+	struct cpumask *pad_busy_cpus = to_cpumask(pad_busy_cpus_bits);
+	cpumask_var_t tmp;
+	int cpu;
+	unsigned long min_weight = -1;
+	unsigned long preferred_cpu;
+
+	if (!alloc_cpumask_var(&tmp, GFP_KERNEL))
+		return;
+
+	mutex_lock(&round_robin_lock);
+	cpumask_clear(tmp);
+	for_each_cpu(cpu, pad_busy_cpus)
+		cpumask_or(tmp, tmp, topology_sibling_cpumask(cpu));
+	cpumask_andnot(tmp, cpu_online_mask, tmp);
+	/* avoid HT sibilings if possible */
+	if (cpumask_empty(tmp))
+		cpumask_andnot(tmp, cpu_online_mask, pad_busy_cpus);
+	if (cpumask_empty(tmp)) {
+		mutex_unlock(&round_robin_lock);
+		free_cpumask_var(tmp);
+		return;
+	}
+	for_each_cpu(cpu, tmp) {
+		if (cpu_weight[cpu] < min_weight) {
+			min_weight = cpu_weight[cpu];
+			preferred_cpu = cpu;
+		}
+	}
+
+	if (tsk_in_cpu[tsk_index] != -1)
+		cpumask_clear_cpu(tsk_in_cpu[tsk_index], pad_busy_cpus);
+	tsk_in_cpu[tsk_index] = preferred_cpu;
+	cpumask_set_cpu(preferred_cpu, pad_busy_cpus);
+	cpu_weight[preferred_cpu]++;
+	mutex_unlock(&round_robin_lock);
+
+	set_cpus_allowed_ptr(current, cpumask_of(preferred_cpu));
+
+	free_cpumask_var(tmp);
+}
+
+static void exit_round_robin(unsigned int tsk_index)
+{
+	struct cpumask *pad_busy_cpus = to_cpumask(pad_busy_cpus_bits);
+
+	cpumask_clear_cpu(tsk_in_cpu[tsk_index], pad_busy_cpus);
+	tsk_in_cpu[tsk_index] = -1;
+}
+
+static unsigned int idle_pct = 5; /* percentage */
+static unsigned int round_robin_time = 1; /* second */
+static int power_saving_thread(void *data)
+{
+	int do_sleep;
+	unsigned int tsk_index = (unsigned long)data;
+	u64 last_jiffies = 0;
+
+	sched_set_fifo_low(current);
+
+	while (!kthread_should_stop()) {
+		unsigned long expire_time;
+
+		/* round robin to cpus */
+		expire_time = last_jiffies + round_robin_time * HZ;
+		if (time_before(expire_time, jiffies)) {
+			last_jiffies = jiffies;
+			round_robin_cpu(tsk_index);
+		}
+
+		do_sleep = 0;
+
+		expire_time = jiffies + HZ * (100 - idle_pct) / 100;
+
+		while (!need_resched()) {
+			if (tsc_detected_unstable && !tsc_marked_unstable) {
+				/* TSC could halt in idle, so notify users */
+				mark_tsc_unstable("TSC halts in idle");
+				tsc_marked_unstable = 1;
+			}
+			local_irq_disable();
+
+			perf_lopwr_cb(true);
+
+			tick_broadcast_enable();
+			tick_broadcast_enter();
+			stop_critical_timings();
+
+			mwait_idle_with_hints(power_saving_mwait_eax, 1);
+
+			start_critical_timings();
+			tick_broadcast_exit();
+
+			perf_lopwr_cb(false);
+
+			local_irq_enable();
+
+			if (time_before(expire_time, jiffies)) {
+				do_sleep = 1;
+				break;
+			}
+		}
+
+		/*
+		 * current sched_rt has threshold for rt task running time.
+		 * When a rt task uses 95% CPU time, the rt thread will be
+		 * scheduled out for 5% CPU time to not starve other tasks. But
+		 * the mechanism only works when all CPUs have RT task running,
+		 * as if one CPU hasn't RT task, RT task from other CPUs will
+		 * borrow CPU time from this CPU and cause RT task use > 95%
+		 * CPU time. To make 'avoid starvation' work, takes a nap here.
+		 */
+		if (unlikely(do_sleep))
+			schedule_timeout_killable(HZ * idle_pct / 100);
+
+		/* If an external event has set the need_resched flag, then
+		 * we need to deal with it, or this loop will continue to
+		 * spin without calling __mwait().
+		 */
+		if (unlikely(need_resched()))
+			schedule();
+	}
+
+	exit_round_robin(tsk_index);
+	return 0;
+}
+
+static struct task_struct *ps_tsks[NR_CPUS];
+static unsigned int ps_tsk_num;
+static int create_power_saving_task(void)
+{
+	int rc;
+
+	ps_tsks[ps_tsk_num] = kthread_run(power_saving_thread,
+		(void *)(unsigned long)ps_tsk_num,
+		"acpi_pad/%d", ps_tsk_num);
+
+	if (IS_ERR(ps_tsks[ps_tsk_num])) {
+		rc = PTR_ERR(ps_tsks[ps_tsk_num]);
+		ps_tsks[ps_tsk_num] = NULL;
+	} else {
+		rc = 0;
+		ps_tsk_num++;
+	}
+
+	return rc;
+}
+
+static void destroy_power_saving_task(void)
+{
+	if (ps_tsk_num > 0) {
+		ps_tsk_num--;
+		kthread_stop(ps_tsks[ps_tsk_num]);
+		ps_tsks[ps_tsk_num] = NULL;
+	}
+}
+
+static void set_power_saving_task_num(unsigned int num)
+{
+	if (num > ps_tsk_num) {
+		while (ps_tsk_num < num) {
+			if (create_power_saving_task())
+				return;
+		}
+	} else if (num < ps_tsk_num) {
+		while (ps_tsk_num > num)
+			destroy_power_saving_task();
+	}
+}
+
+static void acpi_pad_idle_cpus(unsigned int num_cpus)
+{
+	cpus_read_lock();
+
+	num_cpus = min_t(unsigned int, num_cpus, num_online_cpus());
+	set_power_saving_task_num(num_cpus);
+
+	cpus_read_unlock();
+}
+
+static uint32_t acpi_pad_idle_cpus_num(void)
+{
+	return ps_tsk_num;
+}
+
+static ssize_t rrtime_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long num;
+
+	if (kstrtoul(buf, 0, &num))
+		return -EINVAL;
+	if (num < 1 || num >= 100)
+		return -EINVAL;
+	mutex_lock(&isolated_cpus_lock);
+	round_robin_time = num;
+	mutex_unlock(&isolated_cpus_lock);
+	return count;
+}
+
+static ssize_t rrtime_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%d\n", round_robin_time);
+}
+static DEVICE_ATTR_RW(rrtime);
+
+static ssize_t idlepct_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long num;
+
+	if (kstrtoul(buf, 0, &num))
+		return -EINVAL;
+	if (num < 1 || num >= 100)
+		return -EINVAL;
+	mutex_lock(&isolated_cpus_lock);
+	idle_pct = num;
+	mutex_unlock(&isolated_cpus_lock);
+	return count;
+}
+
+static ssize_t idlepct_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%d\n", idle_pct);
+}
+static DEVICE_ATTR_RW(idlepct);
+
+static ssize_t idlecpus_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long num;
+
+	if (kstrtoul(buf, 0, &num))
+		return -EINVAL;
+	mutex_lock(&isolated_cpus_lock);
+	acpi_pad_idle_cpus(num);
+	mutex_unlock(&isolated_cpus_lock);
+	return count;
+}
+
+static ssize_t idlecpus_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	return cpumap_print_to_pagebuf(false, buf,
+				       to_cpumask(pad_busy_cpus_bits));
+}
+
+static DEVICE_ATTR_RW(idlecpus);
+
+static int acpi_pad_add_sysfs(struct acpi_device *device)
+{
+	int result;
+
+	result = device_create_file(&device->dev, &dev_attr_idlecpus);
+	if (result)
+		return -ENODEV;
+	result = device_create_file(&device->dev, &dev_attr_idlepct);
+	if (result) {
+		device_remove_file(&device->dev, &dev_attr_idlecpus);
+		return -ENODEV;
+	}
+	result = device_create_file(&device->dev, &dev_attr_rrtime);
+	if (result) {
+		device_remove_file(&device->dev, &dev_attr_idlecpus);
+		device_remove_file(&device->dev, &dev_attr_idlepct);
+		return -ENODEV;
+	}
+	return 0;
+}
+
+static void acpi_pad_remove_sysfs(struct acpi_device *device)
+{
+	device_remove_file(&device->dev, &dev_attr_idlecpus);
+	device_remove_file(&device->dev, &dev_attr_idlepct);
+	device_remove_file(&device->dev, &dev_attr_rrtime);
+}
+
+/*
+ * Query firmware how many CPUs should be idle
+ * return -1 on failure
+ */
+static int acpi_pad_pur(acpi_handle handle)
+{
+	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
+	union acpi_object *package;
+	int num = -1;
+
+	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_PUR", NULL, &buffer)))
+		return num;
+
+	if (!buffer.length || !buffer.pointer)
+		return num;
+
+	package = buffer.pointer;
+
+	if (package->type == ACPI_TYPE_PACKAGE &&
+		package->package.count == 2 &&
+		package->package.elements[0].integer.value == 1) /* rev 1 */
+
+		num = package->package.elements[1].integer.value;
+
+	kfree(buffer.pointer);
+	return num;
+}
+
+static void acpi_pad_handle_notify(acpi_handle handle)
+{
+	int num_cpus;
+	uint32_t idle_cpus;
+	struct acpi_buffer param = {
+		.length = 4,
+		.pointer = (void *)&idle_cpus,
+	};
+
+	mutex_lock(&isolated_cpus_lock);
+	num_cpus = acpi_pad_pur(handle);
+	if (num_cpus < 0) {
+		mutex_unlock(&isolated_cpus_lock);
+		return;
+	}
+	acpi_pad_idle_cpus(num_cpus);
+	idle_cpus = acpi_pad_idle_cpus_num();
+	acpi_evaluate_ost(handle, ACPI_PROCESSOR_AGGREGATOR_NOTIFY, 0, &param);
+	mutex_unlock(&isolated_cpus_lock);
+}
+
+static void acpi_pad_notify(acpi_handle handle, u32 event,
+	void *data)
+{
+	struct acpi_device *device = data;
+
+	switch (event) {
+	case ACPI_PROCESSOR_AGGREGATOR_NOTIFY:
+		acpi_pad_handle_notify(handle);
+		acpi_bus_generate_netlink_event(device->pnp.device_class,
+			dev_name(&device->dev), event, 0);
+		break;
+	default:
+		pr_warn("Unsupported event [0x%x]\n", event);
+		break;
+	}
+}
+
+static int acpi_pad_add(struct acpi_device *device)
+{
+	acpi_status status;
+
+	strcpy(acpi_device_name(device), ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME);
+	strcpy(acpi_device_class(device), ACPI_PROCESSOR_AGGREGATOR_CLASS);
+
+	if (acpi_pad_add_sysfs(device))
+		return -ENODEV;
+
+	status = acpi_install_notify_handler(device->handle,
+		ACPI_DEVICE_NOTIFY, acpi_pad_notify, device);
+	if (ACPI_FAILURE(status)) {
+		acpi_pad_remove_sysfs(device);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static void acpi_pad_remove(struct acpi_device *device)
+{
+	mutex_lock(&isolated_cpus_lock);
+	acpi_pad_idle_cpus(0);
+	mutex_unlock(&isolated_cpus_lock);
+
+	acpi_remove_notify_handler(device->handle,
+		ACPI_DEVICE_NOTIFY, acpi_pad_notify);
+	acpi_pad_remove_sysfs(device);
+}
+
+static const struct acpi_device_id pad_device_ids[] = {
+	{"ACPI000C", 0},
+	{"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, pad_device_ids);
+
+static struct acpi_driver acpi_pad_driver = {
+	.name = "processor_aggregator",
+	.class = ACPI_PROCESSOR_AGGREGATOR_CLASS,
+	.ids = pad_device_ids,
+	.ops = {
+		.add = acpi_pad_add,
+		.remove = acpi_pad_remove,
+	},
+};
+
+static int __init acpi_pad_init(void)
+{
+	/* Xen ACPI PAD is used when running as Xen Dom0. */
+	if (xen_initial_domain())
+		return -ENODEV;
+
+	power_saving_mwait_init();
+	if (power_saving_mwait_eax == 0)
+		return -EINVAL;
+
+	return acpi_bus_register_driver(&acpi_pad_driver);
+}
+
+static void __exit acpi_pad_exit(void)
+{
+	acpi_bus_unregister_driver(&acpi_pad_driver);
+}
+
+module_init(acpi_pad_init);
+module_exit(acpi_pad_exit);
+MODULE_AUTHOR("Shaohua Li<shaohua.li@intel.com>");
+MODULE_DESCRIPTION("ACPI Processor Aggregator Driver");
+MODULE_LICENSE("GPL");