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-rw-r--r--arch/x86/kernel/cpu/resctrl/monitor.c822
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diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
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+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
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+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Resource Director Technology(RDT)
+ * - Monitoring code
+ *
+ * Copyright (C) 2017 Intel Corporation
+ *
+ * Author:
+ * Vikas Shivappa <vikas.shivappa@intel.com>
+ *
+ * This replaces the cqm.c based on perf but we reuse a lot of
+ * code and datastructures originally from Peter Zijlstra and Matt Fleming.
+ *
+ * More information about RDT be found in the Intel (R) x86 Architecture
+ * Software Developer Manual June 2016, volume 3, section 17.17.
+ */
+
+#include <linux/module.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+
+#include <asm/cpu_device_id.h>
+#include <asm/resctrl.h>
+
+#include "internal.h"
+
+struct rmid_entry {
+ u32 rmid;
+ int busy;
+ struct list_head list;
+};
+
+/**
+ * @rmid_free_lru A least recently used list of free RMIDs
+ * These RMIDs are guaranteed to have an occupancy less than the
+ * threshold occupancy
+ */
+static LIST_HEAD(rmid_free_lru);
+
+/**
+ * @rmid_limbo_count count of currently unused but (potentially)
+ * dirty RMIDs.
+ * This counts RMIDs that no one is currently using but that
+ * may have a occupancy value > resctrl_rmid_realloc_threshold. User can
+ * change the threshold occupancy value.
+ */
+static unsigned int rmid_limbo_count;
+
+/**
+ * @rmid_entry - The entry in the limbo and free lists.
+ */
+static struct rmid_entry *rmid_ptrs;
+
+/*
+ * Global boolean for rdt_monitor which is true if any
+ * resource monitoring is enabled.
+ */
+bool rdt_mon_capable;
+
+/*
+ * Global to indicate which monitoring events are enabled.
+ */
+unsigned int rdt_mon_features;
+
+/*
+ * This is the threshold cache occupancy in bytes at which we will consider an
+ * RMID available for re-allocation.
+ */
+unsigned int resctrl_rmid_realloc_threshold;
+
+/*
+ * This is the maximum value for the reallocation threshold, in bytes.
+ */
+unsigned int resctrl_rmid_realloc_limit;
+
+#define CF(cf) ((unsigned long)(1048576 * (cf) + 0.5))
+
+/*
+ * The correction factor table is documented in Documentation/x86/resctrl.rst.
+ * If rmid > rmid threshold, MBM total and local values should be multiplied
+ * by the correction factor.
+ *
+ * The original table is modified for better code:
+ *
+ * 1. The threshold 0 is changed to rmid count - 1 so don't do correction
+ * for the case.
+ * 2. MBM total and local correction table indexed by core counter which is
+ * equal to (x86_cache_max_rmid + 1) / 8 - 1 and is from 0 up to 27.
+ * 3. The correction factor is normalized to 2^20 (1048576) so it's faster
+ * to calculate corrected value by shifting:
+ * corrected_value = (original_value * correction_factor) >> 20
+ */
+static const struct mbm_correction_factor_table {
+ u32 rmidthreshold;
+ u64 cf;
+} mbm_cf_table[] __initconst = {
+ {7, CF(1.000000)},
+ {15, CF(1.000000)},
+ {15, CF(0.969650)},
+ {31, CF(1.000000)},
+ {31, CF(1.066667)},
+ {31, CF(0.969650)},
+ {47, CF(1.142857)},
+ {63, CF(1.000000)},
+ {63, CF(1.185115)},
+ {63, CF(1.066553)},
+ {79, CF(1.454545)},
+ {95, CF(1.000000)},
+ {95, CF(1.230769)},
+ {95, CF(1.142857)},
+ {95, CF(1.066667)},
+ {127, CF(1.000000)},
+ {127, CF(1.254863)},
+ {127, CF(1.185255)},
+ {151, CF(1.000000)},
+ {127, CF(1.066667)},
+ {167, CF(1.000000)},
+ {159, CF(1.454334)},
+ {183, CF(1.000000)},
+ {127, CF(0.969744)},
+ {191, CF(1.280246)},
+ {191, CF(1.230921)},
+ {215, CF(1.000000)},
+ {191, CF(1.143118)},
+};
+
+static u32 mbm_cf_rmidthreshold __read_mostly = UINT_MAX;
+static u64 mbm_cf __read_mostly;
+
+static inline u64 get_corrected_mbm_count(u32 rmid, unsigned long val)
+{
+ /* Correct MBM value. */
+ if (rmid > mbm_cf_rmidthreshold)
+ val = (val * mbm_cf) >> 20;
+
+ return val;
+}
+
+static inline struct rmid_entry *__rmid_entry(u32 rmid)
+{
+ struct rmid_entry *entry;
+
+ entry = &rmid_ptrs[rmid];
+ WARN_ON(entry->rmid != rmid);
+
+ return entry;
+}
+
+static int __rmid_read(u32 rmid, enum resctrl_event_id eventid, u64 *val)
+{
+ u64 msr_val;
+
+ /*
+ * As per the SDM, when IA32_QM_EVTSEL.EvtID (bits 7:0) is configured
+ * with a valid event code for supported resource type and the bits
+ * IA32_QM_EVTSEL.RMID (bits 41:32) are configured with valid RMID,
+ * IA32_QM_CTR.data (bits 61:0) reports the monitored data.
+ * IA32_QM_CTR.Error (bit 63) and IA32_QM_CTR.Unavailable (bit 62)
+ * are error bits.
+ */
+ wrmsr(MSR_IA32_QM_EVTSEL, eventid, rmid);
+ rdmsrl(MSR_IA32_QM_CTR, msr_val);
+
+ if (msr_val & RMID_VAL_ERROR)
+ return -EIO;
+ if (msr_val & RMID_VAL_UNAVAIL)
+ return -EINVAL;
+
+ *val = msr_val;
+ return 0;
+}
+
+static struct arch_mbm_state *get_arch_mbm_state(struct rdt_hw_domain *hw_dom,
+ u32 rmid,
+ enum resctrl_event_id eventid)
+{
+ switch (eventid) {
+ case QOS_L3_OCCUP_EVENT_ID:
+ return NULL;
+ case QOS_L3_MBM_TOTAL_EVENT_ID:
+ return &hw_dom->arch_mbm_total[rmid];
+ case QOS_L3_MBM_LOCAL_EVENT_ID:
+ return &hw_dom->arch_mbm_local[rmid];
+ }
+
+ /* Never expect to get here */
+ WARN_ON_ONCE(1);
+
+ return NULL;
+}
+
+void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_domain *d,
+ u32 rmid, enum resctrl_event_id eventid)
+{
+ struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d);
+ struct arch_mbm_state *am;
+
+ am = get_arch_mbm_state(hw_dom, rmid, eventid);
+ if (am) {
+ memset(am, 0, sizeof(*am));
+
+ /* Record any initial, non-zero count value. */
+ __rmid_read(rmid, eventid, &am->prev_msr);
+ }
+}
+
+static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int width)
+{
+ u64 shift = 64 - width, chunks;
+
+ chunks = (cur_msr << shift) - (prev_msr << shift);
+ return chunks >> shift;
+}
+
+int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d,
+ u32 rmid, enum resctrl_event_id eventid, u64 *val)
+{
+ struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
+ struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d);
+ struct arch_mbm_state *am;
+ u64 msr_val, chunks;
+ int ret;
+
+ if (!cpumask_test_cpu(smp_processor_id(), &d->cpu_mask))
+ return -EINVAL;
+
+ ret = __rmid_read(rmid, eventid, &msr_val);
+ if (ret)
+ return ret;
+
+ am = get_arch_mbm_state(hw_dom, rmid, eventid);
+ if (am) {
+ am->chunks += mbm_overflow_count(am->prev_msr, msr_val,
+ hw_res->mbm_width);
+ chunks = get_corrected_mbm_count(rmid, am->chunks);
+ am->prev_msr = msr_val;
+ } else {
+ chunks = msr_val;
+ }
+
+ *val = chunks * hw_res->mon_scale;
+
+ return 0;
+}
+
+/*
+ * Check the RMIDs that are marked as busy for this domain. If the
+ * reported LLC occupancy is below the threshold clear the busy bit and
+ * decrement the count. If the busy count gets to zero on an RMID, we
+ * free the RMID
+ */
+void __check_limbo(struct rdt_domain *d, bool force_free)
+{
+ struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
+ struct rmid_entry *entry;
+ u32 crmid = 1, nrmid;
+ bool rmid_dirty;
+ u64 val = 0;
+
+ /*
+ * Skip RMID 0 and start from RMID 1 and check all the RMIDs that
+ * are marked as busy for occupancy < threshold. If the occupancy
+ * is less than the threshold decrement the busy counter of the
+ * RMID and move it to the free list when the counter reaches 0.
+ */
+ for (;;) {
+ nrmid = find_next_bit(d->rmid_busy_llc, r->num_rmid, crmid);
+ if (nrmid >= r->num_rmid)
+ break;
+
+ entry = __rmid_entry(nrmid);
+
+ if (resctrl_arch_rmid_read(r, d, entry->rmid,
+ QOS_L3_OCCUP_EVENT_ID, &val)) {
+ rmid_dirty = true;
+ } else {
+ rmid_dirty = (val >= resctrl_rmid_realloc_threshold);
+ }
+
+ if (force_free || !rmid_dirty) {
+ clear_bit(entry->rmid, d->rmid_busy_llc);
+ if (!--entry->busy) {
+ rmid_limbo_count--;
+ list_add_tail(&entry->list, &rmid_free_lru);
+ }
+ }
+ crmid = nrmid + 1;
+ }
+}
+
+bool has_busy_rmid(struct rdt_resource *r, struct rdt_domain *d)
+{
+ return find_first_bit(d->rmid_busy_llc, r->num_rmid) != r->num_rmid;
+}
+
+/*
+ * As of now the RMIDs allocation is global.
+ * However we keep track of which packages the RMIDs
+ * are used to optimize the limbo list management.
+ */
+int alloc_rmid(void)
+{
+ struct rmid_entry *entry;
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ if (list_empty(&rmid_free_lru))
+ return rmid_limbo_count ? -EBUSY : -ENOSPC;
+
+ entry = list_first_entry(&rmid_free_lru,
+ struct rmid_entry, list);
+ list_del(&entry->list);
+
+ return entry->rmid;
+}
+
+static void add_rmid_to_limbo(struct rmid_entry *entry)
+{
+ struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
+ struct rdt_domain *d;
+ int cpu, err;
+ u64 val = 0;
+
+ entry->busy = 0;
+ cpu = get_cpu();
+ list_for_each_entry(d, &r->domains, list) {
+ if (cpumask_test_cpu(cpu, &d->cpu_mask)) {
+ err = resctrl_arch_rmid_read(r, d, entry->rmid,
+ QOS_L3_OCCUP_EVENT_ID,
+ &val);
+ if (err || val <= resctrl_rmid_realloc_threshold)
+ continue;
+ }
+
+ /*
+ * For the first limbo RMID in the domain,
+ * setup up the limbo worker.
+ */
+ if (!has_busy_rmid(r, d))
+ cqm_setup_limbo_handler(d, CQM_LIMBOCHECK_INTERVAL);
+ set_bit(entry->rmid, d->rmid_busy_llc);
+ entry->busy++;
+ }
+ put_cpu();
+
+ if (entry->busy)
+ rmid_limbo_count++;
+ else
+ list_add_tail(&entry->list, &rmid_free_lru);
+}
+
+void free_rmid(u32 rmid)
+{
+ struct rmid_entry *entry;
+
+ if (!rmid)
+ return;
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ entry = __rmid_entry(rmid);
+
+ if (is_llc_occupancy_enabled())
+ add_rmid_to_limbo(entry);
+ else
+ list_add_tail(&entry->list, &rmid_free_lru);
+}
+
+static int __mon_event_count(u32 rmid, struct rmid_read *rr)
+{
+ struct mbm_state *m;
+ u64 tval = 0;
+
+ if (rr->first)
+ resctrl_arch_reset_rmid(rr->r, rr->d, rmid, rr->evtid);
+
+ rr->err = resctrl_arch_rmid_read(rr->r, rr->d, rmid, rr->evtid, &tval);
+ if (rr->err)
+ return rr->err;
+
+ switch (rr->evtid) {
+ case QOS_L3_OCCUP_EVENT_ID:
+ rr->val += tval;
+ return 0;
+ case QOS_L3_MBM_TOTAL_EVENT_ID:
+ m = &rr->d->mbm_total[rmid];
+ break;
+ case QOS_L3_MBM_LOCAL_EVENT_ID:
+ m = &rr->d->mbm_local[rmid];
+ break;
+ default:
+ /*
+ * Code would never reach here because an invalid
+ * event id would fail in resctrl_arch_rmid_read().
+ */
+ return -EINVAL;
+ }
+
+ if (rr->first) {
+ memset(m, 0, sizeof(struct mbm_state));
+ return 0;
+ }
+
+ rr->val += tval;
+
+ return 0;
+}
+
+/*
+ * mbm_bw_count() - Update bw count from values previously read by
+ * __mon_event_count().
+ * @rmid: The rmid used to identify the cached mbm_state.
+ * @rr: The struct rmid_read populated by __mon_event_count().
+ *
+ * Supporting function to calculate the memory bandwidth
+ * and delta bandwidth in MBps. The chunks value previously read by
+ * __mon_event_count() is compared with the chunks value from the previous
+ * invocation. This must be called once per second to maintain values in MBps.
+ */
+static void mbm_bw_count(u32 rmid, struct rmid_read *rr)
+{
+ struct mbm_state *m = &rr->d->mbm_local[rmid];
+ u64 cur_bw, bytes, cur_bytes;
+
+ cur_bytes = rr->val;
+ bytes = cur_bytes - m->prev_bw_bytes;
+ m->prev_bw_bytes = cur_bytes;
+
+ cur_bw = bytes / SZ_1M;
+
+ if (m->delta_comp)
+ m->delta_bw = abs(cur_bw - m->prev_bw);
+ m->delta_comp = false;
+ m->prev_bw = cur_bw;
+}
+
+/*
+ * This is called via IPI to read the CQM/MBM counters
+ * on a domain.
+ */
+void mon_event_count(void *info)
+{
+ struct rdtgroup *rdtgrp, *entry;
+ struct rmid_read *rr = info;
+ struct list_head *head;
+ int ret;
+
+ rdtgrp = rr->rgrp;
+
+ ret = __mon_event_count(rdtgrp->mon.rmid, rr);
+
+ /*
+ * For Ctrl groups read data from child monitor groups and
+ * add them together. Count events which are read successfully.
+ * Discard the rmid_read's reporting errors.
+ */
+ head = &rdtgrp->mon.crdtgrp_list;
+
+ if (rdtgrp->type == RDTCTRL_GROUP) {
+ list_for_each_entry(entry, head, mon.crdtgrp_list) {
+ if (__mon_event_count(entry->mon.rmid, rr) == 0)
+ ret = 0;
+ }
+ }
+
+ /*
+ * __mon_event_count() calls for newly created monitor groups may
+ * report -EINVAL/Unavailable if the monitor hasn't seen any traffic.
+ * Discard error if any of the monitor event reads succeeded.
+ */
+ if (ret == 0)
+ rr->err = 0;
+}
+
+/*
+ * Feedback loop for MBA software controller (mba_sc)
+ *
+ * mba_sc is a feedback loop where we periodically read MBM counters and
+ * adjust the bandwidth percentage values via the IA32_MBA_THRTL_MSRs so
+ * that:
+ *
+ * current bandwidth(cur_bw) < user specified bandwidth(user_bw)
+ *
+ * This uses the MBM counters to measure the bandwidth and MBA throttle
+ * MSRs to control the bandwidth for a particular rdtgrp. It builds on the
+ * fact that resctrl rdtgroups have both monitoring and control.
+ *
+ * The frequency of the checks is 1s and we just tag along the MBM overflow
+ * timer. Having 1s interval makes the calculation of bandwidth simpler.
+ *
+ * Although MBA's goal is to restrict the bandwidth to a maximum, there may
+ * be a need to increase the bandwidth to avoid unnecessarily restricting
+ * the L2 <-> L3 traffic.
+ *
+ * Since MBA controls the L2 external bandwidth where as MBM measures the
+ * L3 external bandwidth the following sequence could lead to such a
+ * situation.
+ *
+ * Consider an rdtgroup which had high L3 <-> memory traffic in initial
+ * phases -> mba_sc kicks in and reduced bandwidth percentage values -> but
+ * after some time rdtgroup has mostly L2 <-> L3 traffic.
+ *
+ * In this case we may restrict the rdtgroup's L2 <-> L3 traffic as its
+ * throttle MSRs already have low percentage values. To avoid
+ * unnecessarily restricting such rdtgroups, we also increase the bandwidth.
+ */
+static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_domain *dom_mbm)
+{
+ u32 closid, rmid, cur_msr_val, new_msr_val;
+ struct mbm_state *pmbm_data, *cmbm_data;
+ u32 cur_bw, delta_bw, user_bw;
+ struct rdt_resource *r_mba;
+ struct rdt_domain *dom_mba;
+ struct list_head *head;
+ struct rdtgroup *entry;
+
+ if (!is_mbm_local_enabled())
+ return;
+
+ r_mba = &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl;
+
+ closid = rgrp->closid;
+ rmid = rgrp->mon.rmid;
+ pmbm_data = &dom_mbm->mbm_local[rmid];
+
+ dom_mba = get_domain_from_cpu(smp_processor_id(), r_mba);
+ if (!dom_mba) {
+ pr_warn_once("Failure to get domain for MBA update\n");
+ return;
+ }
+
+ cur_bw = pmbm_data->prev_bw;
+ user_bw = dom_mba->mbps_val[closid];
+ delta_bw = pmbm_data->delta_bw;
+
+ /* MBA resource doesn't support CDP */
+ cur_msr_val = resctrl_arch_get_config(r_mba, dom_mba, closid, CDP_NONE);
+
+ /*
+ * For Ctrl groups read data from child monitor groups.
+ */
+ head = &rgrp->mon.crdtgrp_list;
+ list_for_each_entry(entry, head, mon.crdtgrp_list) {
+ cmbm_data = &dom_mbm->mbm_local[entry->mon.rmid];
+ cur_bw += cmbm_data->prev_bw;
+ delta_bw += cmbm_data->delta_bw;
+ }
+
+ /*
+ * Scale up/down the bandwidth linearly for the ctrl group. The
+ * bandwidth step is the bandwidth granularity specified by the
+ * hardware.
+ *
+ * The delta_bw is used when increasing the bandwidth so that we
+ * dont alternately increase and decrease the control values
+ * continuously.
+ *
+ * For ex: consider cur_bw = 90MBps, user_bw = 100MBps and if
+ * bandwidth step is 20MBps(> user_bw - cur_bw), we would keep
+ * switching between 90 and 110 continuously if we only check
+ * cur_bw < user_bw.
+ */
+ if (cur_msr_val > r_mba->membw.min_bw && user_bw < cur_bw) {
+ new_msr_val = cur_msr_val - r_mba->membw.bw_gran;
+ } else if (cur_msr_val < MAX_MBA_BW &&
+ (user_bw > (cur_bw + delta_bw))) {
+ new_msr_val = cur_msr_val + r_mba->membw.bw_gran;
+ } else {
+ return;
+ }
+
+ resctrl_arch_update_one(r_mba, dom_mba, closid, CDP_NONE, new_msr_val);
+
+ /*
+ * Delta values are updated dynamically package wise for each
+ * rdtgrp every time the throttle MSR changes value.
+ *
+ * This is because (1)the increase in bandwidth is not perfectly
+ * linear and only "approximately" linear even when the hardware
+ * says it is linear.(2)Also since MBA is a core specific
+ * mechanism, the delta values vary based on number of cores used
+ * by the rdtgrp.
+ */
+ pmbm_data->delta_comp = true;
+ list_for_each_entry(entry, head, mon.crdtgrp_list) {
+ cmbm_data = &dom_mbm->mbm_local[entry->mon.rmid];
+ cmbm_data->delta_comp = true;
+ }
+}
+
+static void mbm_update(struct rdt_resource *r, struct rdt_domain *d, int rmid)
+{
+ struct rmid_read rr;
+
+ rr.first = false;
+ rr.r = r;
+ rr.d = d;
+
+ /*
+ * This is protected from concurrent reads from user
+ * as both the user and we hold the global mutex.
+ */
+ if (is_mbm_total_enabled()) {
+ rr.evtid = QOS_L3_MBM_TOTAL_EVENT_ID;
+ rr.val = 0;
+ __mon_event_count(rmid, &rr);
+ }
+ if (is_mbm_local_enabled()) {
+ rr.evtid = QOS_L3_MBM_LOCAL_EVENT_ID;
+ rr.val = 0;
+ __mon_event_count(rmid, &rr);
+
+ /*
+ * Call the MBA software controller only for the
+ * control groups and when user has enabled
+ * the software controller explicitly.
+ */
+ if (is_mba_sc(NULL))
+ mbm_bw_count(rmid, &rr);
+ }
+}
+
+/*
+ * Handler to scan the limbo list and move the RMIDs
+ * to free list whose occupancy < threshold_occupancy.
+ */
+void cqm_handle_limbo(struct work_struct *work)
+{
+ unsigned long delay = msecs_to_jiffies(CQM_LIMBOCHECK_INTERVAL);
+ int cpu = smp_processor_id();
+ struct rdt_resource *r;
+ struct rdt_domain *d;
+
+ mutex_lock(&rdtgroup_mutex);
+
+ r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
+ d = container_of(work, struct rdt_domain, cqm_limbo.work);
+
+ __check_limbo(d, false);
+
+ if (has_busy_rmid(r, d))
+ schedule_delayed_work_on(cpu, &d->cqm_limbo, delay);
+
+ mutex_unlock(&rdtgroup_mutex);
+}
+
+void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms)
+{
+ unsigned long delay = msecs_to_jiffies(delay_ms);
+ int cpu;
+
+ cpu = cpumask_any(&dom->cpu_mask);
+ dom->cqm_work_cpu = cpu;
+
+ schedule_delayed_work_on(cpu, &dom->cqm_limbo, delay);
+}
+
+void mbm_handle_overflow(struct work_struct *work)
+{
+ unsigned long delay = msecs_to_jiffies(MBM_OVERFLOW_INTERVAL);
+ struct rdtgroup *prgrp, *crgrp;
+ int cpu = smp_processor_id();
+ struct list_head *head;
+ struct rdt_resource *r;
+ struct rdt_domain *d;
+
+ mutex_lock(&rdtgroup_mutex);
+
+ if (!static_branch_likely(&rdt_mon_enable_key))
+ goto out_unlock;
+
+ r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
+ d = container_of(work, struct rdt_domain, mbm_over.work);
+
+ list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
+ mbm_update(r, d, prgrp->mon.rmid);
+
+ head = &prgrp->mon.crdtgrp_list;
+ list_for_each_entry(crgrp, head, mon.crdtgrp_list)
+ mbm_update(r, d, crgrp->mon.rmid);
+
+ if (is_mba_sc(NULL))
+ update_mba_bw(prgrp, d);
+ }
+
+ schedule_delayed_work_on(cpu, &d->mbm_over, delay);
+
+out_unlock:
+ mutex_unlock(&rdtgroup_mutex);
+}
+
+void mbm_setup_overflow_handler(struct rdt_domain *dom, unsigned long delay_ms)
+{
+ unsigned long delay = msecs_to_jiffies(delay_ms);
+ int cpu;
+
+ if (!static_branch_likely(&rdt_mon_enable_key))
+ return;
+ cpu = cpumask_any(&dom->cpu_mask);
+ dom->mbm_work_cpu = cpu;
+ schedule_delayed_work_on(cpu, &dom->mbm_over, delay);
+}
+
+static int dom_data_init(struct rdt_resource *r)
+{
+ struct rmid_entry *entry = NULL;
+ int i, nr_rmids;
+
+ nr_rmids = r->num_rmid;
+ rmid_ptrs = kcalloc(nr_rmids, sizeof(struct rmid_entry), GFP_KERNEL);
+ if (!rmid_ptrs)
+ return -ENOMEM;
+
+ for (i = 0; i < nr_rmids; i++) {
+ entry = &rmid_ptrs[i];
+ INIT_LIST_HEAD(&entry->list);
+
+ entry->rmid = i;
+ list_add_tail(&entry->list, &rmid_free_lru);
+ }
+
+ /*
+ * RMID 0 is special and is always allocated. It's used for all
+ * tasks that are not monitored.
+ */
+ entry = __rmid_entry(0);
+ list_del(&entry->list);
+
+ return 0;
+}
+
+static struct mon_evt llc_occupancy_event = {
+ .name = "llc_occupancy",
+ .evtid = QOS_L3_OCCUP_EVENT_ID,
+};
+
+static struct mon_evt mbm_total_event = {
+ .name = "mbm_total_bytes",
+ .evtid = QOS_L3_MBM_TOTAL_EVENT_ID,
+};
+
+static struct mon_evt mbm_local_event = {
+ .name = "mbm_local_bytes",
+ .evtid = QOS_L3_MBM_LOCAL_EVENT_ID,
+};
+
+/*
+ * Initialize the event list for the resource.
+ *
+ * Note that MBM events are also part of RDT_RESOURCE_L3 resource
+ * because as per the SDM the total and local memory bandwidth
+ * are enumerated as part of L3 monitoring.
+ */
+static void l3_mon_evt_init(struct rdt_resource *r)
+{
+ INIT_LIST_HEAD(&r->evt_list);
+
+ if (is_llc_occupancy_enabled())
+ list_add_tail(&llc_occupancy_event.list, &r->evt_list);
+ if (is_mbm_total_enabled())
+ list_add_tail(&mbm_total_event.list, &r->evt_list);
+ if (is_mbm_local_enabled())
+ list_add_tail(&mbm_local_event.list, &r->evt_list);
+}
+
+int rdt_get_mon_l3_config(struct rdt_resource *r)
+{
+ unsigned int mbm_offset = boot_cpu_data.x86_cache_mbm_width_offset;
+ struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
+ unsigned int threshold;
+ int ret;
+
+ resctrl_rmid_realloc_limit = boot_cpu_data.x86_cache_size * 1024;
+ hw_res->mon_scale = boot_cpu_data.x86_cache_occ_scale;
+ r->num_rmid = boot_cpu_data.x86_cache_max_rmid + 1;
+ hw_res->mbm_width = MBM_CNTR_WIDTH_BASE;
+
+ if (mbm_offset > 0 && mbm_offset <= MBM_CNTR_WIDTH_OFFSET_MAX)
+ hw_res->mbm_width += mbm_offset;
+ else if (mbm_offset > MBM_CNTR_WIDTH_OFFSET_MAX)
+ pr_warn("Ignoring impossible MBM counter offset\n");
+
+ /*
+ * A reasonable upper limit on the max threshold is the number
+ * of lines tagged per RMID if all RMIDs have the same number of
+ * lines tagged in the LLC.
+ *
+ * For a 35MB LLC and 56 RMIDs, this is ~1.8% of the LLC.
+ */
+ threshold = resctrl_rmid_realloc_limit / r->num_rmid;
+
+ /*
+ * Because num_rmid may not be a power of two, round the value
+ * to the nearest multiple of hw_res->mon_scale so it matches a
+ * value the hardware will measure. mon_scale may not be a power of 2.
+ */
+ resctrl_rmid_realloc_threshold = resctrl_arch_round_mon_val(threshold);
+
+ ret = dom_data_init(r);
+ if (ret)
+ return ret;
+
+ l3_mon_evt_init(r);
+
+ r->mon_capable = true;
+
+ return 0;
+}
+
+void __init intel_rdt_mbm_apply_quirk(void)
+{
+ int cf_index;
+
+ cf_index = (boot_cpu_data.x86_cache_max_rmid + 1) / 8 - 1;
+ if (cf_index >= ARRAY_SIZE(mbm_cf_table)) {
+ pr_info("No MBM correction factor available\n");
+ return;
+ }
+
+ mbm_cf_rmidthreshold = mbm_cf_table[cf_index].rmidthreshold;
+ mbm_cf = mbm_cf_table[cf_index].cf;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-21 23:04:10 +0000