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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /drivers/cpufreq/cpufreq_governor.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
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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(). ...
Diffstat (limited to 'drivers/cpufreq/cpufreq_governor.c')
-rw-r--r--drivers/cpufreq/cpufreq_governor.c579
1 files changed, 579 insertions, 0 deletions
diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c
new file mode 100644
index 000000000..85da677c4
--- /dev/null
+++ b/drivers/cpufreq/cpufreq_governor.c
@@ -0,0 +1,579 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * drivers/cpufreq/cpufreq_governor.c
+ *
+ * CPUFREQ governors common code
+ *
+ * Copyright (C) 2001 Russell King
+ * (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
+ * (C) 2003 Jun Nakajima <jun.nakajima@intel.com>
+ * (C) 2009 Alexander Clouter <alex@digriz.org.uk>
+ * (c) 2012 Viresh Kumar <viresh.kumar@linaro.org>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/export.h>
+#include <linux/kernel_stat.h>
+#include <linux/slab.h>
+
+#include "cpufreq_governor.h"
+
+#define CPUFREQ_DBS_MIN_SAMPLING_INTERVAL (2 * TICK_NSEC / NSEC_PER_USEC)
+
+static DEFINE_PER_CPU(struct cpu_dbs_info, cpu_dbs);
+
+static DEFINE_MUTEX(gov_dbs_data_mutex);
+
+/* Common sysfs tunables */
+/*
+ * sampling_rate_store - update sampling rate effective immediately if needed.
+ *
+ * If new rate is smaller than the old, simply updating
+ * dbs.sampling_rate might not be appropriate. For example, if the
+ * original sampling_rate was 1 second and the requested new sampling rate is 10
+ * ms because the user needs immediate reaction from ondemand governor, but not
+ * sure if higher frequency will be required or not, then, the governor may
+ * change the sampling rate too late; up to 1 second later. Thus, if we are
+ * reducing the sampling rate, we need to make the new value effective
+ * immediately.
+ *
+ * This must be called with dbs_data->mutex held, otherwise traversing
+ * policy_dbs_list isn't safe.
+ */
+ssize_t sampling_rate_store(struct gov_attr_set *attr_set, const char *buf,
+ size_t count)
+{
+ struct dbs_data *dbs_data = to_dbs_data(attr_set);
+ struct policy_dbs_info *policy_dbs;
+ unsigned int sampling_interval;
+ int ret;
+
+ ret = sscanf(buf, "%u", &sampling_interval);
+ if (ret != 1 || sampling_interval < CPUFREQ_DBS_MIN_SAMPLING_INTERVAL)
+ return -EINVAL;
+
+ dbs_data->sampling_rate = sampling_interval;
+
+ /*
+ * We are operating under dbs_data->mutex and so the list and its
+ * entries can't be freed concurrently.
+ */
+ list_for_each_entry(policy_dbs, &attr_set->policy_list, list) {
+ mutex_lock(&policy_dbs->update_mutex);
+ /*
+ * On 32-bit architectures this may race with the
+ * sample_delay_ns read in dbs_update_util_handler(), but that
+ * really doesn't matter. If the read returns a value that's
+ * too big, the sample will be skipped, but the next invocation
+ * of dbs_update_util_handler() (when the update has been
+ * completed) will take a sample.
+ *
+ * If this runs in parallel with dbs_work_handler(), we may end
+ * up overwriting the sample_delay_ns value that it has just
+ * written, but it will be corrected next time a sample is
+ * taken, so it shouldn't be significant.
+ */
+ gov_update_sample_delay(policy_dbs, 0);
+ mutex_unlock(&policy_dbs->update_mutex);
+ }
+
+ return count;
+}
+EXPORT_SYMBOL_GPL(sampling_rate_store);
+
+/**
+ * gov_update_cpu_data - Update CPU load data.
+ * @dbs_data: Top-level governor data pointer.
+ *
+ * Update CPU load data for all CPUs in the domain governed by @dbs_data
+ * (that may be a single policy or a bunch of them if governor tunables are
+ * system-wide).
+ *
+ * Call under the @dbs_data mutex.
+ */
+void gov_update_cpu_data(struct dbs_data *dbs_data)
+{
+ struct policy_dbs_info *policy_dbs;
+
+ list_for_each_entry(policy_dbs, &dbs_data->attr_set.policy_list, list) {
+ unsigned int j;
+
+ for_each_cpu(j, policy_dbs->policy->cpus) {
+ struct cpu_dbs_info *j_cdbs = &per_cpu(cpu_dbs, j);
+
+ j_cdbs->prev_cpu_idle = get_cpu_idle_time(j, &j_cdbs->prev_update_time,
+ dbs_data->io_is_busy);
+ if (dbs_data->ignore_nice_load)
+ j_cdbs->prev_cpu_nice = kcpustat_field(&kcpustat_cpu(j), CPUTIME_NICE, j);
+ }
+ }
+}
+EXPORT_SYMBOL_GPL(gov_update_cpu_data);
+
+unsigned int dbs_update(struct cpufreq_policy *policy)
+{
+ struct policy_dbs_info *policy_dbs = policy->governor_data;
+ struct dbs_data *dbs_data = policy_dbs->dbs_data;
+ unsigned int ignore_nice = dbs_data->ignore_nice_load;
+ unsigned int max_load = 0, idle_periods = UINT_MAX;
+ unsigned int sampling_rate, io_busy, j;
+
+ /*
+ * Sometimes governors may use an additional multiplier to increase
+ * sample delays temporarily. Apply that multiplier to sampling_rate
+ * so as to keep the wake-up-from-idle detection logic a bit
+ * conservative.
+ */
+ sampling_rate = dbs_data->sampling_rate * policy_dbs->rate_mult;
+ /*
+ * For the purpose of ondemand, waiting for disk IO is an indication
+ * that you're performance critical, and not that the system is actually
+ * idle, so do not add the iowait time to the CPU idle time then.
+ */
+ io_busy = dbs_data->io_is_busy;
+
+ /* Get Absolute Load */
+ for_each_cpu(j, policy->cpus) {
+ struct cpu_dbs_info *j_cdbs = &per_cpu(cpu_dbs, j);
+ u64 update_time, cur_idle_time;
+ unsigned int idle_time, time_elapsed;
+ unsigned int load;
+
+ cur_idle_time = get_cpu_idle_time(j, &update_time, io_busy);
+
+ time_elapsed = update_time - j_cdbs->prev_update_time;
+ j_cdbs->prev_update_time = update_time;
+
+ idle_time = cur_idle_time - j_cdbs->prev_cpu_idle;
+ j_cdbs->prev_cpu_idle = cur_idle_time;
+
+ if (ignore_nice) {
+ u64 cur_nice = kcpustat_field(&kcpustat_cpu(j), CPUTIME_NICE, j);
+
+ idle_time += div_u64(cur_nice - j_cdbs->prev_cpu_nice, NSEC_PER_USEC);
+ j_cdbs->prev_cpu_nice = cur_nice;
+ }
+
+ if (unlikely(!time_elapsed)) {
+ /*
+ * That can only happen when this function is called
+ * twice in a row with a very short interval between the
+ * calls, so the previous load value can be used then.
+ */
+ load = j_cdbs->prev_load;
+ } else if (unlikely((int)idle_time > 2 * sampling_rate &&
+ j_cdbs->prev_load)) {
+ /*
+ * If the CPU had gone completely idle and a task has
+ * just woken up on this CPU now, it would be unfair to
+ * calculate 'load' the usual way for this elapsed
+ * time-window, because it would show near-zero load,
+ * irrespective of how CPU intensive that task actually
+ * was. This is undesirable for latency-sensitive bursty
+ * workloads.
+ *
+ * To avoid this, reuse the 'load' from the previous
+ * time-window and give this task a chance to start with
+ * a reasonably high CPU frequency. However, that
+ * shouldn't be over-done, lest we get stuck at a high
+ * load (high frequency) for too long, even when the
+ * current system load has actually dropped down, so
+ * clear prev_load to guarantee that the load will be
+ * computed again next time.
+ *
+ * Detecting this situation is easy: an unusually large
+ * 'idle_time' (as compared to the sampling rate)
+ * indicates this scenario.
+ */
+ load = j_cdbs->prev_load;
+ j_cdbs->prev_load = 0;
+ } else {
+ if (time_elapsed >= idle_time) {
+ load = 100 * (time_elapsed - idle_time) / time_elapsed;
+ } else {
+ /*
+ * That can happen if idle_time is returned by
+ * get_cpu_idle_time_jiffy(). In that case
+ * idle_time is roughly equal to the difference
+ * between time_elapsed and "busy time" obtained
+ * from CPU statistics. Then, the "busy time"
+ * can end up being greater than time_elapsed
+ * (for example, if jiffies_64 and the CPU
+ * statistics are updated by different CPUs),
+ * so idle_time may in fact be negative. That
+ * means, though, that the CPU was busy all
+ * the time (on the rough average) during the
+ * last sampling interval and 100 can be
+ * returned as the load.
+ */
+ load = (int)idle_time < 0 ? 100 : 0;
+ }
+ j_cdbs->prev_load = load;
+ }
+
+ if (unlikely((int)idle_time > 2 * sampling_rate)) {
+ unsigned int periods = idle_time / sampling_rate;
+
+ if (periods < idle_periods)
+ idle_periods = periods;
+ }
+
+ if (load > max_load)
+ max_load = load;
+ }
+
+ policy_dbs->idle_periods = idle_periods;
+
+ return max_load;
+}
+EXPORT_SYMBOL_GPL(dbs_update);
+
+static void dbs_work_handler(struct work_struct *work)
+{
+ struct policy_dbs_info *policy_dbs;
+ struct cpufreq_policy *policy;
+ struct dbs_governor *gov;
+
+ policy_dbs = container_of(work, struct policy_dbs_info, work);
+ policy = policy_dbs->policy;
+ gov = dbs_governor_of(policy);
+
+ /*
+ * Make sure cpufreq_governor_limits() isn't evaluating load or the
+ * ondemand governor isn't updating the sampling rate in parallel.
+ */
+ mutex_lock(&policy_dbs->update_mutex);
+ gov_update_sample_delay(policy_dbs, gov->gov_dbs_update(policy));
+ mutex_unlock(&policy_dbs->update_mutex);
+
+ /* Allow the utilization update handler to queue up more work. */
+ atomic_set(&policy_dbs->work_count, 0);
+ /*
+ * If the update below is reordered with respect to the sample delay
+ * modification, the utilization update handler may end up using a stale
+ * sample delay value.
+ */
+ smp_wmb();
+ policy_dbs->work_in_progress = false;
+}
+
+static void dbs_irq_work(struct irq_work *irq_work)
+{
+ struct policy_dbs_info *policy_dbs;
+
+ policy_dbs = container_of(irq_work, struct policy_dbs_info, irq_work);
+ schedule_work_on(smp_processor_id(), &policy_dbs->work);
+}
+
+static void dbs_update_util_handler(struct update_util_data *data, u64 time,
+ unsigned int flags)
+{
+ struct cpu_dbs_info *cdbs = container_of(data, struct cpu_dbs_info, update_util);
+ struct policy_dbs_info *policy_dbs = cdbs->policy_dbs;
+ u64 delta_ns, lst;
+
+ if (!cpufreq_this_cpu_can_update(policy_dbs->policy))
+ return;
+
+ /*
+ * The work may not be allowed to be queued up right now.
+ * Possible reasons:
+ * - Work has already been queued up or is in progress.
+ * - It is too early (too little time from the previous sample).
+ */
+ if (policy_dbs->work_in_progress)
+ return;
+
+ /*
+ * If the reads below are reordered before the check above, the value
+ * of sample_delay_ns used in the computation may be stale.
+ */
+ smp_rmb();
+ lst = READ_ONCE(policy_dbs->last_sample_time);
+ delta_ns = time - lst;
+ if ((s64)delta_ns < policy_dbs->sample_delay_ns)
+ return;
+
+ /*
+ * If the policy is not shared, the irq_work may be queued up right away
+ * at this point. Otherwise, we need to ensure that only one of the
+ * CPUs sharing the policy will do that.
+ */
+ if (policy_dbs->is_shared) {
+ if (!atomic_add_unless(&policy_dbs->work_count, 1, 1))
+ return;
+
+ /*
+ * If another CPU updated last_sample_time in the meantime, we
+ * shouldn't be here, so clear the work counter and bail out.
+ */
+ if (unlikely(lst != READ_ONCE(policy_dbs->last_sample_time))) {
+ atomic_set(&policy_dbs->work_count, 0);
+ return;
+ }
+ }
+
+ policy_dbs->last_sample_time = time;
+ policy_dbs->work_in_progress = true;
+ irq_work_queue(&policy_dbs->irq_work);
+}
+
+static void gov_set_update_util(struct policy_dbs_info *policy_dbs,
+ unsigned int delay_us)
+{
+ struct cpufreq_policy *policy = policy_dbs->policy;
+ int cpu;
+
+ gov_update_sample_delay(policy_dbs, delay_us);
+ policy_dbs->last_sample_time = 0;
+
+ for_each_cpu(cpu, policy->cpus) {
+ struct cpu_dbs_info *cdbs = &per_cpu(cpu_dbs, cpu);
+
+ cpufreq_add_update_util_hook(cpu, &cdbs->update_util,
+ dbs_update_util_handler);
+ }
+}
+
+static inline void gov_clear_update_util(struct cpufreq_policy *policy)
+{
+ int i;
+
+ for_each_cpu(i, policy->cpus)
+ cpufreq_remove_update_util_hook(i);
+
+ synchronize_rcu();
+}
+
+static struct policy_dbs_info *alloc_policy_dbs_info(struct cpufreq_policy *policy,
+ struct dbs_governor *gov)
+{
+ struct policy_dbs_info *policy_dbs;
+ int j;
+
+ /* Allocate memory for per-policy governor data. */
+ policy_dbs = gov->alloc();
+ if (!policy_dbs)
+ return NULL;
+
+ policy_dbs->policy = policy;
+ mutex_init(&policy_dbs->update_mutex);
+ atomic_set(&policy_dbs->work_count, 0);
+ init_irq_work(&policy_dbs->irq_work, dbs_irq_work);
+ INIT_WORK(&policy_dbs->work, dbs_work_handler);
+
+ /* Set policy_dbs for all CPUs, online+offline */
+ for_each_cpu(j, policy->related_cpus) {
+ struct cpu_dbs_info *j_cdbs = &per_cpu(cpu_dbs, j);
+
+ j_cdbs->policy_dbs = policy_dbs;
+ }
+ return policy_dbs;
+}
+
+static void free_policy_dbs_info(struct policy_dbs_info *policy_dbs,
+ struct dbs_governor *gov)
+{
+ int j;
+
+ mutex_destroy(&policy_dbs->update_mutex);
+
+ for_each_cpu(j, policy_dbs->policy->related_cpus) {
+ struct cpu_dbs_info *j_cdbs = &per_cpu(cpu_dbs, j);
+
+ j_cdbs->policy_dbs = NULL;
+ j_cdbs->update_util.func = NULL;
+ }
+ gov->free(policy_dbs);
+}
+
+static void cpufreq_dbs_data_release(struct kobject *kobj)
+{
+ struct dbs_data *dbs_data = to_dbs_data(to_gov_attr_set(kobj));
+ struct dbs_governor *gov = dbs_data->gov;
+
+ gov->exit(dbs_data);
+ kfree(dbs_data);
+}
+
+int cpufreq_dbs_governor_init(struct cpufreq_policy *policy)
+{
+ struct dbs_governor *gov = dbs_governor_of(policy);
+ struct dbs_data *dbs_data;
+ struct policy_dbs_info *policy_dbs;
+ int ret = 0;
+
+ /* State should be equivalent to EXIT */
+ if (policy->governor_data)
+ return -EBUSY;
+
+ policy_dbs = alloc_policy_dbs_info(policy, gov);
+ if (!policy_dbs)
+ return -ENOMEM;
+
+ /* Protect gov->gdbs_data against concurrent updates. */
+ mutex_lock(&gov_dbs_data_mutex);
+
+ dbs_data = gov->gdbs_data;
+ if (dbs_data) {
+ if (WARN_ON(have_governor_per_policy())) {
+ ret = -EINVAL;
+ goto free_policy_dbs_info;
+ }
+ policy_dbs->dbs_data = dbs_data;
+ policy->governor_data = policy_dbs;
+
+ gov_attr_set_get(&dbs_data->attr_set, &policy_dbs->list);
+ goto out;
+ }
+
+ dbs_data = kzalloc(sizeof(*dbs_data), GFP_KERNEL);
+ if (!dbs_data) {
+ ret = -ENOMEM;
+ goto free_policy_dbs_info;
+ }
+
+ dbs_data->gov = gov;
+ gov_attr_set_init(&dbs_data->attr_set, &policy_dbs->list);
+
+ ret = gov->init(dbs_data);
+ if (ret)
+ goto free_policy_dbs_info;
+
+ /*
+ * The sampling interval should not be less than the transition latency
+ * of the CPU and it also cannot be too small for dbs_update() to work
+ * correctly.
+ */
+ dbs_data->sampling_rate = max_t(unsigned int,
+ CPUFREQ_DBS_MIN_SAMPLING_INTERVAL,
+ cpufreq_policy_transition_delay_us(policy));
+
+ if (!have_governor_per_policy())
+ gov->gdbs_data = dbs_data;
+
+ policy_dbs->dbs_data = dbs_data;
+ policy->governor_data = policy_dbs;
+
+ gov->kobj_type.sysfs_ops = &governor_sysfs_ops;
+ gov->kobj_type.release = cpufreq_dbs_data_release;
+ ret = kobject_init_and_add(&dbs_data->attr_set.kobj, &gov->kobj_type,
+ get_governor_parent_kobj(policy),
+ "%s", gov->gov.name);
+ if (!ret)
+ goto out;
+
+ /* Failure, so roll back. */
+ pr_err("initialization failed (dbs_data kobject init error %d)\n", ret);
+
+ kobject_put(&dbs_data->attr_set.kobj);
+
+ policy->governor_data = NULL;
+
+ if (!have_governor_per_policy())
+ gov->gdbs_data = NULL;
+ gov->exit(dbs_data);
+ kfree(dbs_data);
+
+free_policy_dbs_info:
+ free_policy_dbs_info(policy_dbs, gov);
+
+out:
+ mutex_unlock(&gov_dbs_data_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cpufreq_dbs_governor_init);
+
+void cpufreq_dbs_governor_exit(struct cpufreq_policy *policy)
+{
+ struct dbs_governor *gov = dbs_governor_of(policy);
+ struct policy_dbs_info *policy_dbs = policy->governor_data;
+ struct dbs_data *dbs_data = policy_dbs->dbs_data;
+ unsigned int count;
+
+ /* Protect gov->gdbs_data against concurrent updates. */
+ mutex_lock(&gov_dbs_data_mutex);
+
+ count = gov_attr_set_put(&dbs_data->attr_set, &policy_dbs->list);
+
+ policy->governor_data = NULL;
+
+ if (!count && !have_governor_per_policy())
+ gov->gdbs_data = NULL;
+
+ free_policy_dbs_info(policy_dbs, gov);
+
+ mutex_unlock(&gov_dbs_data_mutex);
+}
+EXPORT_SYMBOL_GPL(cpufreq_dbs_governor_exit);
+
+int cpufreq_dbs_governor_start(struct cpufreq_policy *policy)
+{
+ struct dbs_governor *gov = dbs_governor_of(policy);
+ struct policy_dbs_info *policy_dbs = policy->governor_data;
+ struct dbs_data *dbs_data = policy_dbs->dbs_data;
+ unsigned int sampling_rate, ignore_nice, j;
+ unsigned int io_busy;
+
+ if (!policy->cur)
+ return -EINVAL;
+
+ policy_dbs->is_shared = policy_is_shared(policy);
+ policy_dbs->rate_mult = 1;
+
+ sampling_rate = dbs_data->sampling_rate;
+ ignore_nice = dbs_data->ignore_nice_load;
+ io_busy = dbs_data->io_is_busy;
+
+ for_each_cpu(j, policy->cpus) {
+ struct cpu_dbs_info *j_cdbs = &per_cpu(cpu_dbs, j);
+
+ j_cdbs->prev_cpu_idle = get_cpu_idle_time(j, &j_cdbs->prev_update_time, io_busy);
+ /*
+ * Make the first invocation of dbs_update() compute the load.
+ */
+ j_cdbs->prev_load = 0;
+
+ if (ignore_nice)
+ j_cdbs->prev_cpu_nice = kcpustat_field(&kcpustat_cpu(j), CPUTIME_NICE, j);
+ }
+
+ gov->start(policy);
+
+ gov_set_update_util(policy_dbs, sampling_rate);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cpufreq_dbs_governor_start);
+
+void cpufreq_dbs_governor_stop(struct cpufreq_policy *policy)
+{
+ struct policy_dbs_info *policy_dbs = policy->governor_data;
+
+ gov_clear_update_util(policy_dbs->policy);
+ irq_work_sync(&policy_dbs->irq_work);
+ cancel_work_sync(&policy_dbs->work);
+ atomic_set(&policy_dbs->work_count, 0);
+ policy_dbs->work_in_progress = false;
+}
+EXPORT_SYMBOL_GPL(cpufreq_dbs_governor_stop);
+
+void cpufreq_dbs_governor_limits(struct cpufreq_policy *policy)
+{
+ struct policy_dbs_info *policy_dbs;
+
+ /* Protect gov->gdbs_data against cpufreq_dbs_governor_exit() */
+ mutex_lock(&gov_dbs_data_mutex);
+ policy_dbs = policy->governor_data;
+ if (!policy_dbs)
+ goto out;
+
+ mutex_lock(&policy_dbs->update_mutex);
+ cpufreq_policy_apply_limits(policy);
+ gov_update_sample_delay(policy_dbs, 0);
+ mutex_unlock(&policy_dbs->update_mutex);
+
+out:
+ mutex_unlock(&gov_dbs_data_mutex);
+}
+EXPORT_SYMBOL_GPL(cpufreq_dbs_governor_limits);