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, 960 insertions, 0 deletions

diff --git a/tools/tracing/rtla/src/osnoise.c b/tools/tracing/rtla/src/osnoise.c
new file mode 100644
index 000000000..4dee34390
--- /dev/null
+++ b/tools/tracing/rtla/src/osnoise.c
@@ -0,0 +1,960 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+
+#include "osnoise.h"
+#include "utils.h"
+
+/*
+ * osnoise_get_cpus - return the original "osnoise/cpus" content
+ *
+ * It also saves the value to be restored.
+ */
+char *osnoise_get_cpus(struct osnoise_context *context)
+{
+	if (context->curr_cpus)
+		return context->curr_cpus;
+
+	if (context->orig_cpus)
+		return context->orig_cpus;
+
+	context->orig_cpus = tracefs_instance_file_read(NULL, "osnoise/cpus", NULL);
+
+	/*
+	 * The error value (NULL) is the same for tracefs_instance_file_read()
+	 * and this functions, so:
+	 */
+	return context->orig_cpus;
+}
+
+/*
+ * osnoise_set_cpus - configure osnoise to run on *cpus
+ *
+ * "osnoise/cpus" file is used to set the cpus in which osnoise/timerlat
+ * will run. This function opens this file, saves the current value,
+ * and set the cpus passed as argument.
+ */
+int osnoise_set_cpus(struct osnoise_context *context, char *cpus)
+{
+	char *orig_cpus = osnoise_get_cpus(context);
+	char buffer[1024];
+	int retval;
+
+	if (!orig_cpus)
+		return -1;
+
+	context->curr_cpus = strdup(cpus);
+	if (!context->curr_cpus)
+		return -1;
+
+	snprintf(buffer, 1024, "%s\n", cpus);
+
+	debug_msg("setting cpus to %s from %s", cpus, context->orig_cpus);
+
+	retval = tracefs_instance_file_write(NULL, "osnoise/cpus", buffer);
+	if (retval < 0) {
+		free(context->curr_cpus);
+		context->curr_cpus = NULL;
+		return -1;
+	}
+
+	return 0;
+}
+
+/*
+ * osnoise_restore_cpus - restore the original "osnoise/cpus"
+ *
+ * osnoise_set_cpus() saves the original data for the "osnoise/cpus"
+ * file. This function restore the original config it was previously
+ * modified.
+ */
+void osnoise_restore_cpus(struct osnoise_context *context)
+{
+	int retval;
+
+	if (!context->orig_cpus)
+		return;
+
+	if (!context->curr_cpus)
+		return;
+
+	/* nothing to do? */
+	if (!strcmp(context->orig_cpus, context->curr_cpus))
+		goto out_done;
+
+	debug_msg("restoring cpus to %s", context->orig_cpus);
+
+	retval = tracefs_instance_file_write(NULL, "osnoise/cpus", context->orig_cpus);
+	if (retval < 0)
+		err_msg("could not restore original osnoise cpus\n");
+
+out_done:
+	free(context->curr_cpus);
+	context->curr_cpus = NULL;
+}
+
+/*
+ * osnoise_put_cpus - restore cpus config and cleanup data
+ */
+void osnoise_put_cpus(struct osnoise_context *context)
+{
+	osnoise_restore_cpus(context);
+
+	if (!context->orig_cpus)
+		return;
+
+	free(context->orig_cpus);
+	context->orig_cpus = NULL;
+}
+
+/*
+ * osnoise_read_ll_config - read a long long value from a config
+ *
+ * returns -1 on error.
+ */
+static long long osnoise_read_ll_config(char *rel_path)
+{
+	long long retval;
+	char *buffer;
+
+	buffer = tracefs_instance_file_read(NULL, rel_path, NULL);
+	if (!buffer)
+		return -1;
+
+	/* get_llong_from_str returns -1 on error */
+	retval = get_llong_from_str(buffer);
+
+	debug_msg("reading %s returned %lld\n", rel_path, retval);
+
+	free(buffer);
+
+	return retval;
+}
+
+/*
+ * osnoise_write_ll_config - write a long long value to a config in rel_path
+ *
+ * returns -1 on error.
+ */
+static long long osnoise_write_ll_config(char *rel_path, long long value)
+{
+	char buffer[BUFF_U64_STR_SIZE];
+	long long retval;
+
+	snprintf(buffer, sizeof(buffer), "%lld\n", value);
+
+	debug_msg("setting %s to %lld\n", rel_path, value);
+
+	retval = tracefs_instance_file_write(NULL, rel_path, buffer);
+	return retval;
+}
+
+/*
+ * osnoise_get_runtime - return the original "osnoise/runtime_us" value
+ *
+ * It also saves the value to be restored.
+ */
+unsigned long long osnoise_get_runtime(struct osnoise_context *context)
+{
+	long long runtime_us;
+
+	if (context->runtime_us != OSNOISE_TIME_INIT_VAL)
+		return context->runtime_us;
+
+	if (context->orig_runtime_us != OSNOISE_TIME_INIT_VAL)
+		return context->orig_runtime_us;
+
+	runtime_us = osnoise_read_ll_config("osnoise/runtime_us");
+	if (runtime_us < 0)
+		goto out_err;
+
+	context->orig_runtime_us = runtime_us;
+	return runtime_us;
+
+out_err:
+	return OSNOISE_TIME_INIT_VAL;
+}
+
+/*
+ * osnoise_get_period - return the original "osnoise/period_us" value
+ *
+ * It also saves the value to be restored.
+ */
+unsigned long long osnoise_get_period(struct osnoise_context *context)
+{
+	long long period_us;
+
+	if (context->period_us != OSNOISE_TIME_INIT_VAL)
+		return context->period_us;
+
+	if (context->orig_period_us != OSNOISE_TIME_INIT_VAL)
+		return context->orig_period_us;
+
+	period_us = osnoise_read_ll_config("osnoise/period_us");
+	if (period_us < 0)
+		goto out_err;
+
+	context->orig_period_us = period_us;
+	return period_us;
+
+out_err:
+	return OSNOISE_TIME_INIT_VAL;
+}
+
+static int __osnoise_write_runtime(struct osnoise_context *context,
+				   unsigned long long runtime)
+{
+	int retval;
+
+	if (context->orig_runtime_us == OSNOISE_TIME_INIT_VAL)
+		return -1;
+
+	retval = osnoise_write_ll_config("osnoise/runtime_us", runtime);
+	if (retval < 0)
+		return -1;
+
+	context->runtime_us = runtime;
+	return 0;
+}
+
+static int __osnoise_write_period(struct osnoise_context *context,
+				  unsigned long long period)
+{
+	int retval;
+
+	if (context->orig_period_us == OSNOISE_TIME_INIT_VAL)
+		return -1;
+
+	retval = osnoise_write_ll_config("osnoise/period_us", period);
+	if (retval < 0)
+		return -1;
+
+	context->period_us = period;
+	return 0;
+}
+
+/*
+ * osnoise_set_runtime_period - set osnoise runtime and period
+ *
+ * Osnoise's runtime and period are related as runtime <= period.
+ * Thus, this function saves the original values, and then tries
+ * to set the runtime and period if they are != 0.
+ */
+int osnoise_set_runtime_period(struct osnoise_context *context,
+			       unsigned long long runtime,
+			       unsigned long long period)
+{
+	unsigned long long curr_runtime_us;
+	unsigned long long curr_period_us;
+	int retval;
+
+	if (!period && !runtime)
+		return 0;
+
+	curr_runtime_us = osnoise_get_runtime(context);
+	curr_period_us = osnoise_get_period(context);
+
+	/* error getting any value? */
+	if (curr_period_us == OSNOISE_TIME_INIT_VAL || curr_runtime_us == OSNOISE_TIME_INIT_VAL)
+		return -1;
+
+	if (!period) {
+		if (runtime > curr_period_us)
+			return -1;
+		return __osnoise_write_runtime(context, runtime);
+	} else if (!runtime) {
+		if (period < curr_runtime_us)
+			return -1;
+		return __osnoise_write_period(context, period);
+	}
+
+	if (runtime > curr_period_us) {
+		retval = __osnoise_write_period(context, period);
+		if (retval)
+			return -1;
+		retval = __osnoise_write_runtime(context, runtime);
+		if (retval)
+			return -1;
+	} else {
+		retval = __osnoise_write_runtime(context, runtime);
+		if (retval)
+			return -1;
+		retval = __osnoise_write_period(context, period);
+		if (retval)
+			return -1;
+	}
+
+	return 0;
+}
+
+/*
+ * osnoise_restore_runtime_period - restore the original runtime and period
+ */
+void osnoise_restore_runtime_period(struct osnoise_context *context)
+{
+	unsigned long long orig_runtime = context->orig_runtime_us;
+	unsigned long long orig_period = context->orig_period_us;
+	unsigned long long curr_runtime = context->runtime_us;
+	unsigned long long curr_period = context->period_us;
+	int retval;
+
+	if ((orig_runtime == OSNOISE_TIME_INIT_VAL) && (orig_period == OSNOISE_TIME_INIT_VAL))
+		return;
+
+	if ((orig_period == curr_period) && (orig_runtime == curr_runtime))
+		goto out_done;
+
+	retval = osnoise_set_runtime_period(context, orig_runtime, orig_period);
+	if (retval)
+		err_msg("Could not restore original osnoise runtime/period\n");
+
+out_done:
+	context->runtime_us = OSNOISE_TIME_INIT_VAL;
+	context->period_us = OSNOISE_TIME_INIT_VAL;
+}
+
+/*
+ * osnoise_put_runtime_period - restore original values and cleanup data
+ */
+void osnoise_put_runtime_period(struct osnoise_context *context)
+{
+	osnoise_restore_runtime_period(context);
+
+	if (context->orig_runtime_us != OSNOISE_TIME_INIT_VAL)
+		context->orig_runtime_us = OSNOISE_TIME_INIT_VAL;
+
+	if (context->orig_period_us != OSNOISE_TIME_INIT_VAL)
+		context->orig_period_us = OSNOISE_TIME_INIT_VAL;
+}
+
+/*
+ * osnoise_get_timerlat_period_us - read and save the original "timerlat_period_us"
+ */
+static long long
+osnoise_get_timerlat_period_us(struct osnoise_context *context)
+{
+	long long timerlat_period_us;
+
+	if (context->timerlat_period_us != OSNOISE_TIME_INIT_VAL)
+		return context->timerlat_period_us;
+
+	if (context->orig_timerlat_period_us != OSNOISE_TIME_INIT_VAL)
+		return context->orig_timerlat_period_us;
+
+	timerlat_period_us = osnoise_read_ll_config("osnoise/timerlat_period_us");
+	if (timerlat_period_us < 0)
+		goto out_err;
+
+	context->orig_timerlat_period_us = timerlat_period_us;
+	return timerlat_period_us;
+
+out_err:
+	return OSNOISE_TIME_INIT_VAL;
+}
+
+/*
+ * osnoise_set_timerlat_period_us - set "timerlat_period_us"
+ */
+int osnoise_set_timerlat_period_us(struct osnoise_context *context, long long timerlat_period_us)
+{
+	long long curr_timerlat_period_us = osnoise_get_timerlat_period_us(context);
+	int retval;
+
+	if (curr_timerlat_period_us == OSNOISE_TIME_INIT_VAL)
+		return -1;
+
+	retval = osnoise_write_ll_config("osnoise/timerlat_period_us", timerlat_period_us);
+	if (retval < 0)
+		return -1;
+
+	context->timerlat_period_us = timerlat_period_us;
+
+	return 0;
+}
+
+/*
+ * osnoise_restore_timerlat_period_us - restore "timerlat_period_us"
+ */
+void osnoise_restore_timerlat_period_us(struct osnoise_context *context)
+{
+	int retval;
+
+	if (context->orig_timerlat_period_us == OSNOISE_TIME_INIT_VAL)
+		return;
+
+	if (context->orig_timerlat_period_us == context->timerlat_period_us)
+		goto out_done;
+
+	retval = osnoise_write_ll_config("osnoise/timerlat_period_us", context->orig_timerlat_period_us);
+	if (retval < 0)
+		err_msg("Could not restore original osnoise timerlat_period_us\n");
+
+out_done:
+	context->timerlat_period_us = OSNOISE_TIME_INIT_VAL;
+}
+
+/*
+ * osnoise_put_timerlat_period_us - restore original values and cleanup data
+ */
+void osnoise_put_timerlat_period_us(struct osnoise_context *context)
+{
+	osnoise_restore_timerlat_period_us(context);
+
+	if (context->orig_timerlat_period_us == OSNOISE_TIME_INIT_VAL)
+		return;
+
+	context->orig_timerlat_period_us = OSNOISE_TIME_INIT_VAL;
+}
+
+/*
+ * osnoise_get_stop_us - read and save the original "stop_tracing_us"
+ */
+static long long
+osnoise_get_stop_us(struct osnoise_context *context)
+{
+	long long stop_us;
+
+	if (context->stop_us != OSNOISE_OPTION_INIT_VAL)
+		return context->stop_us;
+
+	if (context->orig_stop_us != OSNOISE_OPTION_INIT_VAL)
+		return context->orig_stop_us;
+
+	stop_us = osnoise_read_ll_config("osnoise/stop_tracing_us");
+	if (stop_us < 0)
+		goto out_err;
+
+	context->orig_stop_us = stop_us;
+	return stop_us;
+
+out_err:
+	return OSNOISE_OPTION_INIT_VAL;
+}
+
+/*
+ * osnoise_set_stop_us - set "stop_tracing_us"
+ */
+int osnoise_set_stop_us(struct osnoise_context *context, long long stop_us)
+{
+	long long curr_stop_us = osnoise_get_stop_us(context);
+	int retval;
+
+	if (curr_stop_us == OSNOISE_OPTION_INIT_VAL)
+		return -1;
+
+	retval = osnoise_write_ll_config("osnoise/stop_tracing_us", stop_us);
+	if (retval < 0)
+		return -1;
+
+	context->stop_us = stop_us;
+
+	return 0;
+}
+
+/*
+ * osnoise_restore_stop_us - restore the original "stop_tracing_us"
+ */
+void osnoise_restore_stop_us(struct osnoise_context *context)
+{
+	int retval;
+
+	if (context->orig_stop_us == OSNOISE_OPTION_INIT_VAL)
+		return;
+
+	if (context->orig_stop_us == context->stop_us)
+		goto out_done;
+
+	retval = osnoise_write_ll_config("osnoise/stop_tracing_us", context->orig_stop_us);
+	if (retval < 0)
+		err_msg("Could not restore original osnoise stop_us\n");
+
+out_done:
+	context->stop_us = OSNOISE_OPTION_INIT_VAL;
+}
+
+/*
+ * osnoise_put_stop_us - restore original values and cleanup data
+ */
+void osnoise_put_stop_us(struct osnoise_context *context)
+{
+	osnoise_restore_stop_us(context);
+
+	if (context->orig_stop_us == OSNOISE_OPTION_INIT_VAL)
+		return;
+
+	context->orig_stop_us = OSNOISE_OPTION_INIT_VAL;
+}
+
+/*
+ * osnoise_get_stop_total_us - read and save the original "stop_tracing_total_us"
+ */
+static long long
+osnoise_get_stop_total_us(struct osnoise_context *context)
+{
+	long long stop_total_us;
+
+	if (context->stop_total_us != OSNOISE_OPTION_INIT_VAL)
+		return context->stop_total_us;
+
+	if (context->orig_stop_total_us != OSNOISE_OPTION_INIT_VAL)
+		return context->orig_stop_total_us;
+
+	stop_total_us = osnoise_read_ll_config("osnoise/stop_tracing_total_us");
+	if (stop_total_us < 0)
+		goto out_err;
+
+	context->orig_stop_total_us = stop_total_us;
+	return stop_total_us;
+
+out_err:
+	return OSNOISE_OPTION_INIT_VAL;
+}
+
+/*
+ * osnoise_set_stop_total_us - set "stop_tracing_total_us"
+ */
+int osnoise_set_stop_total_us(struct osnoise_context *context, long long stop_total_us)
+{
+	long long curr_stop_total_us = osnoise_get_stop_total_us(context);
+	int retval;
+
+	if (curr_stop_total_us == OSNOISE_OPTION_INIT_VAL)
+		return -1;
+
+	retval = osnoise_write_ll_config("osnoise/stop_tracing_total_us", stop_total_us);
+	if (retval < 0)
+		return -1;
+
+	context->stop_total_us = stop_total_us;
+
+	return 0;
+}
+
+/*
+ * osnoise_restore_stop_total_us - restore the original "stop_tracing_total_us"
+ */
+void osnoise_restore_stop_total_us(struct osnoise_context *context)
+{
+	int retval;
+
+	if (context->orig_stop_total_us == OSNOISE_OPTION_INIT_VAL)
+		return;
+
+	if (context->orig_stop_total_us == context->stop_total_us)
+		goto out_done;
+
+	retval = osnoise_write_ll_config("osnoise/stop_tracing_total_us",
+			context->orig_stop_total_us);
+	if (retval < 0)
+		err_msg("Could not restore original osnoise stop_total_us\n");
+
+out_done:
+	context->stop_total_us = OSNOISE_OPTION_INIT_VAL;
+}
+
+/*
+ * osnoise_put_stop_total_us - restore original values and cleanup data
+ */
+void osnoise_put_stop_total_us(struct osnoise_context *context)
+{
+	osnoise_restore_stop_total_us(context);
+
+	if (context->orig_stop_total_us == OSNOISE_OPTION_INIT_VAL)
+		return;
+
+	context->orig_stop_total_us = OSNOISE_OPTION_INIT_VAL;
+}
+
+/*
+ * osnoise_get_print_stack - read and save the original "print_stack"
+ */
+static long long
+osnoise_get_print_stack(struct osnoise_context *context)
+{
+	long long print_stack;
+
+	if (context->print_stack != OSNOISE_OPTION_INIT_VAL)
+		return context->print_stack;
+
+	if (context->orig_print_stack != OSNOISE_OPTION_INIT_VAL)
+		return context->orig_print_stack;
+
+	print_stack = osnoise_read_ll_config("osnoise/print_stack");
+	if (print_stack < 0)
+		goto out_err;
+
+	context->orig_print_stack = print_stack;
+	return print_stack;
+
+out_err:
+	return OSNOISE_OPTION_INIT_VAL;
+}
+
+/*
+ * osnoise_set_print_stack - set "print_stack"
+ */
+int osnoise_set_print_stack(struct osnoise_context *context, long long print_stack)
+{
+	long long curr_print_stack = osnoise_get_print_stack(context);
+	int retval;
+
+	if (curr_print_stack == OSNOISE_OPTION_INIT_VAL)
+		return -1;
+
+	retval = osnoise_write_ll_config("osnoise/print_stack", print_stack);
+	if (retval < 0)
+		return -1;
+
+	context->print_stack = print_stack;
+
+	return 0;
+}
+
+/*
+ * osnoise_restore_print_stack - restore the original "print_stack"
+ */
+void osnoise_restore_print_stack(struct osnoise_context *context)
+{
+	int retval;
+
+	if (context->orig_print_stack == OSNOISE_OPTION_INIT_VAL)
+		return;
+
+	if (context->orig_print_stack == context->print_stack)
+		goto out_done;
+
+	retval = osnoise_write_ll_config("osnoise/print_stack", context->orig_print_stack);
+	if (retval < 0)
+		err_msg("Could not restore original osnoise print_stack\n");
+
+out_done:
+	context->print_stack = OSNOISE_OPTION_INIT_VAL;
+}
+
+/*
+ * osnoise_put_print_stack - restore original values and cleanup data
+ */
+void osnoise_put_print_stack(struct osnoise_context *context)
+{
+	osnoise_restore_print_stack(context);
+
+	if (context->orig_print_stack == OSNOISE_OPTION_INIT_VAL)
+		return;
+
+	context->orig_print_stack = OSNOISE_OPTION_INIT_VAL;
+}
+
+/*
+ * osnoise_get_tracing_thresh - read and save the original "tracing_thresh"
+ */
+static long long
+osnoise_get_tracing_thresh(struct osnoise_context *context)
+{
+	long long tracing_thresh;
+
+	if (context->tracing_thresh != OSNOISE_OPTION_INIT_VAL)
+		return context->tracing_thresh;
+
+	if (context->orig_tracing_thresh != OSNOISE_OPTION_INIT_VAL)
+		return context->orig_tracing_thresh;
+
+	tracing_thresh = osnoise_read_ll_config("tracing_thresh");
+	if (tracing_thresh < 0)
+		goto out_err;
+
+	context->orig_tracing_thresh = tracing_thresh;
+	return tracing_thresh;
+
+out_err:
+	return OSNOISE_OPTION_INIT_VAL;
+}
+
+/*
+ * osnoise_set_tracing_thresh - set "tracing_thresh"
+ */
+int osnoise_set_tracing_thresh(struct osnoise_context *context, long long tracing_thresh)
+{
+	long long curr_tracing_thresh = osnoise_get_tracing_thresh(context);
+	int retval;
+
+	if (curr_tracing_thresh == OSNOISE_OPTION_INIT_VAL)
+		return -1;
+
+	retval = osnoise_write_ll_config("tracing_thresh", tracing_thresh);
+	if (retval < 0)
+		return -1;
+
+	context->tracing_thresh = tracing_thresh;
+
+	return 0;
+}
+
+/*
+ * osnoise_restore_tracing_thresh - restore the original "tracing_thresh"
+ */
+void osnoise_restore_tracing_thresh(struct osnoise_context *context)
+{
+	int retval;
+
+	if (context->orig_tracing_thresh == OSNOISE_OPTION_INIT_VAL)
+		return;
+
+	if (context->orig_tracing_thresh == context->tracing_thresh)
+		goto out_done;
+
+	retval = osnoise_write_ll_config("tracing_thresh", context->orig_tracing_thresh);
+	if (retval < 0)
+		err_msg("Could not restore original tracing_thresh\n");
+
+out_done:
+	context->tracing_thresh = OSNOISE_OPTION_INIT_VAL;
+}
+
+/*
+ * osnoise_put_tracing_thresh - restore original values and cleanup data
+ */
+void osnoise_put_tracing_thresh(struct osnoise_context *context)
+{
+	osnoise_restore_tracing_thresh(context);
+
+	if (context->orig_tracing_thresh == OSNOISE_OPTION_INIT_VAL)
+		return;
+
+	context->orig_tracing_thresh = OSNOISE_OPTION_INIT_VAL;
+}
+
+/*
+ * enable_osnoise - enable osnoise tracer in the trace_instance
+ */
+int enable_osnoise(struct trace_instance *trace)
+{
+	return enable_tracer_by_name(trace->inst, "osnoise");
+}
+
+/*
+ * enable_timerlat - enable timerlat tracer in the trace_instance
+ */
+int enable_timerlat(struct trace_instance *trace)
+{
+	return enable_tracer_by_name(trace->inst, "timerlat");
+}
+
+enum {
+	FLAG_CONTEXT_NEWLY_CREATED	= (1 << 0),
+	FLAG_CONTEXT_DELETED		= (1 << 1),
+};
+
+/*
+ * osnoise_get_context - increase the usage of a context and return it
+ */
+int osnoise_get_context(struct osnoise_context *context)
+{
+	int ret;
+
+	if (context->flags & FLAG_CONTEXT_DELETED) {
+		ret = -1;
+	} else {
+		context->ref++;
+		ret = 0;
+	}
+
+	return ret;
+}
+
+/*
+ * osnoise_context_alloc - alloc an osnoise_context
+ *
+ * The osnoise context contains the information of the "osnoise/" configs.
+ * It is used to set and restore the config.
+ */
+struct osnoise_context *osnoise_context_alloc(void)
+{
+	struct osnoise_context *context;
+
+	context = calloc(1, sizeof(*context));
+	if (!context)
+		return NULL;
+
+	context->orig_stop_us		= OSNOISE_OPTION_INIT_VAL;
+	context->stop_us		= OSNOISE_OPTION_INIT_VAL;
+
+	context->orig_stop_total_us	= OSNOISE_OPTION_INIT_VAL;
+	context->stop_total_us		= OSNOISE_OPTION_INIT_VAL;
+
+	context->orig_print_stack	= OSNOISE_OPTION_INIT_VAL;
+	context->print_stack		= OSNOISE_OPTION_INIT_VAL;
+
+	context->orig_tracing_thresh	= OSNOISE_OPTION_INIT_VAL;
+	context->tracing_thresh		= OSNOISE_OPTION_INIT_VAL;
+
+	osnoise_get_context(context);
+
+	return context;
+}
+
+/*
+ * osnoise_put_context - put the osnoise_put_context
+ *
+ * If there is no other user for the context, the original data
+ * is restored.
+ */
+void osnoise_put_context(struct osnoise_context *context)
+{
+	if (--context->ref < 1)
+		context->flags |= FLAG_CONTEXT_DELETED;
+
+	if (!(context->flags & FLAG_CONTEXT_DELETED))
+		return;
+
+	osnoise_put_cpus(context);
+	osnoise_put_runtime_period(context);
+	osnoise_put_stop_us(context);
+	osnoise_put_stop_total_us(context);
+	osnoise_put_timerlat_period_us(context);
+	osnoise_put_print_stack(context);
+	osnoise_put_tracing_thresh(context);
+
+	free(context);
+}
+
+/*
+ * osnoise_destroy_tool - disable trace, restore configs and free data
+ */
+void osnoise_destroy_tool(struct osnoise_tool *top)
+{
+	if (!top)
+		return;
+
+	trace_instance_destroy(&top->trace);
+
+	if (top->context)
+		osnoise_put_context(top->context);
+
+	free(top);
+}
+
+/*
+ * osnoise_init_tool - init an osnoise tool
+ *
+ * It allocs data, create a context to store data and
+ * creates a new trace instance for the tool.
+ */
+struct osnoise_tool *osnoise_init_tool(char *tool_name)
+{
+	struct osnoise_tool *top;
+	int retval;
+
+	top = calloc(1, sizeof(*top));
+	if (!top)
+		return NULL;
+
+	top->context = osnoise_context_alloc();
+	if (!top->context)
+		goto out_err;
+
+	retval = trace_instance_init(&top->trace, tool_name);
+	if (retval)
+		goto out_err;
+
+	return top;
+out_err:
+	osnoise_destroy_tool(top);
+	return NULL;
+}
+
+/*
+ * osnoise_init_trace_tool - init a tracer instance to trace osnoise events
+ */
+struct osnoise_tool *osnoise_init_trace_tool(char *tracer)
+{
+	struct osnoise_tool *trace;
+	int retval;
+
+	trace = osnoise_init_tool("osnoise_trace");
+	if (!trace)
+		return NULL;
+
+	retval = tracefs_event_enable(trace->trace.inst, "osnoise", NULL);
+	if (retval < 0 && !errno) {
+		err_msg("Could not find osnoise events\n");
+		goto out_err;
+	}
+
+	retval = enable_tracer_by_name(trace->trace.inst, tracer);
+	if (retval) {
+		err_msg("Could not enable %s tracer for tracing\n", tracer);
+		goto out_err;
+	}
+
+	return trace;
+out_err:
+	osnoise_destroy_tool(trace);
+	return NULL;
+}
+
+static void osnoise_usage(int err)
+{
+	int i;
+
+	static const char *msg[] = {
+		"",
+		"osnoise version " VERSION,
+		"",
+		"  usage: [rtla] osnoise [MODE] ...",
+		"",
+		"  modes:",
+		"     top   - prints the summary from osnoise tracer",
+		"     hist  - prints a histogram of osnoise samples",
+		"",
+		"if no MODE is given, the top mode is called, passing the arguments",
+		NULL,
+	};
+
+	for (i = 0; msg[i]; i++)
+		fprintf(stderr, "%s\n", msg[i]);
+	exit(err);
+}
+
+int osnoise_main(int argc, char *argv[])
+{
+	if (argc == 0)
+		goto usage;
+
+	/*
+	 * if osnoise was called without any argument, run the
+	 * default cmdline.
+	 */
+	if (argc == 1) {
+		osnoise_top_main(argc, argv);
+		exit(0);
+	}
+
+	if ((strcmp(argv[1], "-h") == 0) || (strcmp(argv[1], "--help") == 0)) {
+		osnoise_usage(0);
+	} else if (strncmp(argv[1], "-", 1) == 0) {
+		/* the user skipped the tool, call the default one */
+		osnoise_top_main(argc, argv);
+		exit(0);
+	} else if (strcmp(argv[1], "top") == 0) {
+		osnoise_top_main(argc-1, &argv[1]);
+		exit(0);
+	} else if (strcmp(argv[1], "hist") == 0) {
+		osnoise_hist_main(argc-1, &argv[1]);
+		exit(0);
+	}
+
+usage:
+	osnoise_usage(1);
+	exit(1);
+}