diff options
Diffstat (limited to 'arch/x86/kernel/cpu/resctrl/monitor.c')
-rw-r--r-- | arch/x86/kernel/cpu/resctrl/monitor.c | 845 |
1 files changed, 845 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c new file mode 100644 index 0000000000..f136ac0468 --- /dev/null +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -0,0 +1,845 @@ +// 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/arch/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); + } +} + +/* + * Assumes that hardware counters are also reset and thus that there is + * no need to record initial non-zero counts. + */ +void resctrl_arch_reset_rmid_all(struct rdt_resource *r, struct rdt_domain *d) +{ + struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d); + + if (is_mbm_total_enabled()) + memset(hw_dom->arch_mbm_total, 0, + sizeof(*hw_dom->arch_mbm_total) * r->num_rmid); + + if (is_mbm_local_enabled()) + memset(hw_dom->arch_mbm_local, 0, + sizeof(*hw_dom->arch_mbm_local) * r->num_rmid); +} + +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 struct mbm_state *get_mbm_state(struct rdt_domain *d, u32 rmid, + enum resctrl_event_id evtid) +{ + switch (evtid) { + case QOS_L3_MBM_TOTAL_EVENT_ID: + return &d->mbm_total[rmid]; + case QOS_L3_MBM_LOCAL_EVENT_ID: + return &d->mbm_local[rmid]; + default: + return NULL; + } +} + +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); + m = get_mbm_state(rr->d, rmid, rr->evtid); + if (m) + memset(m, 0, sizeof(struct mbm_state)); + return 0; + } + + rr->err = resctrl_arch_rmid_read(rr->r, rr->d, rmid, rr->evtid, &tval); + if (rr->err) + return rr->err; + + 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 __init 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; + + if (rdt_cpu_has(X86_FEATURE_BMEC)) { + if (rdt_cpu_has(X86_FEATURE_CQM_MBM_TOTAL)) { + mbm_total_event.configurable = true; + mbm_config_rftype_init("mbm_total_bytes_config"); + } + if (rdt_cpu_has(X86_FEATURE_CQM_MBM_LOCAL)) { + mbm_local_event.configurable = true; + mbm_config_rftype_init("mbm_local_bytes_config"); + } + } + + 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; +} |