blob: c34a35ec0f031a188fc29424bdef31cd54fa597d [file] [log] [blame]
// 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/cpu.h>
#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 - dirty tracking for all RMID.
* @closid: The CLOSID for this entry.
* @rmid: The RMID for this entry.
* @busy: The number of domains with cached data using this RMID.
* @list: Member of the rmid_free_lru list when busy == 0.
*
* Depending on the architecture the correct monitor is accessed using
* both @closid and @rmid, or @rmid only.
*
* Take the rdtgroup_mutex when accessing.
*/
struct rmid_entry {
u32 closid;
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);
/*
* @closid_num_dirty_rmid The number of dirty RMID each CLOSID has.
* Only allocated when CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID is defined.
* Indexed by CLOSID. Protected by rdtgroup_mutex.
*/
static u32 *closid_num_dirty_rmid;
/*
* @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;
}
/*
* x86 and arm64 differ in their handling of monitoring.
* x86's RMID are independent numbers, there is only one source of traffic
* with an RMID value of '1'.
* arm64's PMG extends the PARTID/CLOSID space, there are multiple sources of
* traffic with a PMG value of '1', one for each CLOSID, meaning the RMID
* value is no longer unique.
* To account for this, resctrl uses an index. On x86 this is just the RMID,
* on arm64 it encodes the CLOSID and RMID. This gives a unique number.
*
* The domain's rmid_busy_llc and rmid_ptrs[] are sized by index. The arch code
* must accept an attempt to read every index.
*/
static inline struct rmid_entry *__rmid_entry(u32 idx)
{
struct rmid_entry *entry;
u32 closid, rmid;
entry = &rmid_ptrs[idx];
resctrl_arch_rmid_idx_decode(idx, &closid, &rmid);
WARN_ON_ONCE(entry->closid != closid);
WARN_ON_ONCE(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 unused, 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 unused, u32 rmid, enum resctrl_event_id eventid,
u64 *val, void *ignored)
{
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;
resctrl_arch_rmid_read_context_check();
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;
}
static void limbo_release_entry(struct rmid_entry *entry)
{
lockdep_assert_held(&rdtgroup_mutex);
rmid_limbo_count--;
list_add_tail(&entry->list, &rmid_free_lru);
if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID))
closid_num_dirty_rmid[entry->closid]--;
}
/*
* 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;
u32 idx_limit = resctrl_arch_system_num_rmid_idx();
struct rmid_entry *entry;
u32 idx, cur_idx = 1;
void *arch_mon_ctx;
bool rmid_dirty;
u64 val = 0;
arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, QOS_L3_OCCUP_EVENT_ID);
if (IS_ERR(arch_mon_ctx)) {
pr_warn_ratelimited("Failed to allocate monitor context: %ld",
PTR_ERR(arch_mon_ctx));
return;
}
/*
* 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 (;;) {
idx = find_next_bit(d->rmid_busy_llc, idx_limit, cur_idx);
if (idx >= idx_limit)
break;
entry = __rmid_entry(idx);
if (resctrl_arch_rmid_read(r, d, entry->closid, entry->rmid,
QOS_L3_OCCUP_EVENT_ID, &val,
arch_mon_ctx)) {
rmid_dirty = true;
} else {
rmid_dirty = (val >= resctrl_rmid_realloc_threshold);
}
if (force_free || !rmid_dirty) {
clear_bit(idx, d->rmid_busy_llc);
if (!--entry->busy)
limbo_release_entry(entry);
}
cur_idx = idx + 1;
}
resctrl_arch_mon_ctx_free(r, QOS_L3_OCCUP_EVENT_ID, arch_mon_ctx);
}
bool has_busy_rmid(struct rdt_domain *d)
{
u32 idx_limit = resctrl_arch_system_num_rmid_idx();
return find_first_bit(d->rmid_busy_llc, idx_limit) != idx_limit;
}
static struct rmid_entry *resctrl_find_free_rmid(u32 closid)
{
struct rmid_entry *itr;
u32 itr_idx, cmp_idx;
if (list_empty(&rmid_free_lru))
return rmid_limbo_count ? ERR_PTR(-EBUSY) : ERR_PTR(-ENOSPC);
list_for_each_entry(itr, &rmid_free_lru, list) {
/*
* Get the index of this free RMID, and the index it would need
* to be if it were used with this CLOSID.
* If the CLOSID is irrelevant on this architecture, the two
* index values are always the same on every entry and thus the
* very first entry will be returned.
*/
itr_idx = resctrl_arch_rmid_idx_encode(itr->closid, itr->rmid);
cmp_idx = resctrl_arch_rmid_idx_encode(closid, itr->rmid);
if (itr_idx == cmp_idx)
return itr;
}
return ERR_PTR(-ENOSPC);
}
/**
* resctrl_find_cleanest_closid() - Find a CLOSID where all the associated
* RMID are clean, or the CLOSID that has
* the most clean RMID.
*
* MPAM's equivalent of RMID are per-CLOSID, meaning a freshly allocated CLOSID
* may not be able to allocate clean RMID. To avoid this the allocator will
* choose the CLOSID with the most clean RMID.
*
* When the CLOSID and RMID are independent numbers, the first free CLOSID will
* be returned.
*/
int resctrl_find_cleanest_closid(void)
{
u32 cleanest_closid = ~0;
int i = 0;
lockdep_assert_held(&rdtgroup_mutex);
if (!IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID))
return -EIO;
for (i = 0; i < closids_supported(); i++) {
int num_dirty;
if (closid_allocated(i))
continue;
num_dirty = closid_num_dirty_rmid[i];
if (num_dirty == 0)
return i;
if (cleanest_closid == ~0)
cleanest_closid = i;
if (num_dirty < closid_num_dirty_rmid[cleanest_closid])
cleanest_closid = i;
}
if (cleanest_closid == ~0)
return -ENOSPC;
return cleanest_closid;
}
/*
* For MPAM the RMID value is not unique, and has to be considered with
* the CLOSID. The (CLOSID, RMID) pair is allocated on all domains, which
* allows all domains to be managed by a single free list.
* Each domain also has a rmid_busy_llc to reduce the work of the limbo handler.
*/
int alloc_rmid(u32 closid)
{
struct rmid_entry *entry;
lockdep_assert_held(&rdtgroup_mutex);
entry = resctrl_find_free_rmid(closid);
if (IS_ERR(entry))
return PTR_ERR(entry);
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;
u32 idx;
lockdep_assert_held(&rdtgroup_mutex);
/* Walking r->domains, ensure it can't race with cpuhp */
lockdep_assert_cpus_held();
idx = resctrl_arch_rmid_idx_encode(entry->closid, entry->rmid);
entry->busy = 0;
list_for_each_entry(d, &r->domains, list) {
/*
* For the first limbo RMID in the domain,
* setup up the limbo worker.
*/
if (!has_busy_rmid(d))
cqm_setup_limbo_handler(d, CQM_LIMBOCHECK_INTERVAL,
RESCTRL_PICK_ANY_CPU);
set_bit(idx, d->rmid_busy_llc);
entry->busy++;
}
rmid_limbo_count++;
if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID))
closid_num_dirty_rmid[entry->closid]++;
}
void free_rmid(u32 closid, u32 rmid)
{
u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid);
struct rmid_entry *entry;
lockdep_assert_held(&rdtgroup_mutex);
/*
* Do not allow the default rmid to be free'd. Comparing by index
* allows architectures that ignore the closid parameter to avoid an
* unnecessary check.
*/
if (idx == resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID,
RESCTRL_RESERVED_RMID))
return;
entry = __rmid_entry(idx);
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 closid,
u32 rmid, enum resctrl_event_id evtid)
{
u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid);
switch (evtid) {
case QOS_L3_MBM_TOTAL_EVENT_ID:
return &d->mbm_total[idx];
case QOS_L3_MBM_LOCAL_EVENT_ID:
return &d->mbm_local[idx];
default:
return NULL;
}
}
static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr)
{
struct mbm_state *m;
u64 tval = 0;
if (rr->first) {
resctrl_arch_reset_rmid(rr->r, rr->d, closid, rmid, rr->evtid);
m = get_mbm_state(rr->d, closid, rmid, rr->evtid);
if (m)
memset(m, 0, sizeof(struct mbm_state));
return 0;
}
rr->err = resctrl_arch_rmid_read(rr->r, rr->d, closid, rmid, rr->evtid,
&tval, rr->arch_mon_ctx);
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().
* @closid: The closid used to identify the cached mbm_state.
* @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 closid, u32 rmid, struct rmid_read *rr)
{
u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid);
struct mbm_state *m = &rr->d->mbm_local[idx];
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;
m->prev_bw = cur_bw;
}
/*
* This is scheduled by mon_event_read() 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->closid, 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->closid, 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;
struct rdt_resource *r_mba;
struct rdt_domain *dom_mba;
u32 cur_bw, user_bw, idx;
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;
idx = resctrl_arch_rmid_idx_encode(closid, rmid);
pmbm_data = &dom_mbm->mbm_local[idx];
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];
/* 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;
}
/*
* Scale up/down the bandwidth linearly for the ctrl group. The
* bandwidth step is the bandwidth granularity specified by the
* hardware.
* Always increase throttling if current bandwidth is above the
* target set by user.
* But avoid thrashing up and down on every poll by checking
* whether a decrease in throttling is likely to push the group
* back over target. E.g. if currently throttling to 30% of bandwidth
* on a system with 10% granularity steps, check whether moving to
* 40% would go past the limit by multiplying current bandwidth by
* "(30 + 10) / 30".
*/
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 * (cur_msr_val + r_mba->membw.min_bw) / cur_msr_val))) {
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);
}
static void mbm_update(struct rdt_resource *r, struct rdt_domain *d,
u32 closid, u32 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;
rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid);
if (IS_ERR(rr.arch_mon_ctx)) {
pr_warn_ratelimited("Failed to allocate monitor context: %ld",
PTR_ERR(rr.arch_mon_ctx));
return;
}
__mon_event_count(closid, rmid, &rr);
resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx);
}
if (is_mbm_local_enabled()) {
rr.evtid = QOS_L3_MBM_LOCAL_EVENT_ID;
rr.val = 0;
rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid);
if (IS_ERR(rr.arch_mon_ctx)) {
pr_warn_ratelimited("Failed to allocate monitor context: %ld",
PTR_ERR(rr.arch_mon_ctx));
return;
}
__mon_event_count(closid, 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(closid, rmid, &rr);
resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx);
}
}
/*
* 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);
struct rdt_domain *d;
cpus_read_lock();
mutex_lock(&rdtgroup_mutex);
d = container_of(work, struct rdt_domain, cqm_limbo.work);
__check_limbo(d, false);
if (has_busy_rmid(d)) {
d->cqm_work_cpu = cpumask_any_housekeeping(&d->cpu_mask,
RESCTRL_PICK_ANY_CPU);
schedule_delayed_work_on(d->cqm_work_cpu, &d->cqm_limbo,
delay);
}
mutex_unlock(&rdtgroup_mutex);
cpus_read_unlock();
}
/**
* cqm_setup_limbo_handler() - Schedule the limbo handler to run for this
* domain.
* @dom: The domain the limbo handler should run for.
* @delay_ms: How far in the future the handler should run.
* @exclude_cpu: Which CPU the handler should not run on,
* RESCTRL_PICK_ANY_CPU to pick any CPU.
*/
void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms,
int exclude_cpu)
{
unsigned long delay = msecs_to_jiffies(delay_ms);
int cpu;
cpu = cpumask_any_housekeeping(&dom->cpu_mask, exclude_cpu);
dom->cqm_work_cpu = cpu;
if (cpu < nr_cpu_ids)
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;
struct list_head *head;
struct rdt_resource *r;
struct rdt_domain *d;
cpus_read_lock();
mutex_lock(&rdtgroup_mutex);
/*
* If the filesystem has been unmounted this work no longer needs to
* run.
*/
if (!resctrl_mounted || !resctrl_arch_mon_capable())
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->closid, prgrp->mon.rmid);
head = &prgrp->mon.crdtgrp_list;
list_for_each_entry(crgrp, head, mon.crdtgrp_list)
mbm_update(r, d, crgrp->closid, crgrp->mon.rmid);
if (is_mba_sc(NULL))
update_mba_bw(prgrp, d);
}
/*
* Re-check for housekeeping CPUs. This allows the overflow handler to
* move off a nohz_full CPU quickly.
*/
d->mbm_work_cpu = cpumask_any_housekeeping(&d->cpu_mask,
RESCTRL_PICK_ANY_CPU);
schedule_delayed_work_on(d->mbm_work_cpu, &d->mbm_over, delay);
out_unlock:
mutex_unlock(&rdtgroup_mutex);
cpus_read_unlock();
}
/**
* mbm_setup_overflow_handler() - Schedule the overflow handler to run for this
* domain.
* @dom: The domain the overflow handler should run for.
* @delay_ms: How far in the future the handler should run.
* @exclude_cpu: Which CPU the handler should not run on,
* RESCTRL_PICK_ANY_CPU to pick any CPU.
*/
void mbm_setup_overflow_handler(struct rdt_domain *dom, unsigned long delay_ms,
int exclude_cpu)
{
unsigned long delay = msecs_to_jiffies(delay_ms);
int cpu;
/*
* When a domain comes online there is no guarantee the filesystem is
* mounted. If not, there is no need to catch counter overflow.
*/
if (!resctrl_mounted || !resctrl_arch_mon_capable())
return;
cpu = cpumask_any_housekeeping(&dom->cpu_mask, exclude_cpu);
dom->mbm_work_cpu = cpu;
if (cpu < nr_cpu_ids)
schedule_delayed_work_on(cpu, &dom->mbm_over, delay);
}
static int dom_data_init(struct rdt_resource *r)
{
u32 idx_limit = resctrl_arch_system_num_rmid_idx();
u32 num_closid = resctrl_arch_get_num_closid(r);
struct rmid_entry *entry = NULL;
int err = 0, i;
u32 idx;
mutex_lock(&rdtgroup_mutex);
if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) {
u32 *tmp;
/*
* If the architecture hasn't provided a sanitised value here,
* this may result in larger arrays than necessary. Resctrl will
* use a smaller system wide value based on the resources in
* use.
*/
tmp = kcalloc(num_closid, sizeof(*tmp), GFP_KERNEL);
if (!tmp) {
err = -ENOMEM;
goto out_unlock;
}
closid_num_dirty_rmid = tmp;
}
rmid_ptrs = kcalloc(idx_limit, sizeof(struct rmid_entry), GFP_KERNEL);
if (!rmid_ptrs) {
if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) {
kfree(closid_num_dirty_rmid);
closid_num_dirty_rmid = NULL;
}
err = -ENOMEM;
goto out_unlock;
}
for (i = 0; i < idx_limit; i++) {
entry = &rmid_ptrs[i];
INIT_LIST_HEAD(&entry->list);
resctrl_arch_rmid_idx_decode(i, &entry->closid, &entry->rmid);
list_add_tail(&entry->list, &rmid_free_lru);
}
/*
* RESCTRL_RESERVED_CLOSID and RESCTRL_RESERVED_RMID are special and
* are always allocated. These are used for the rdtgroup_default
* control group, which will be setup later in rdtgroup_init().
*/
idx = resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID,
RESCTRL_RESERVED_RMID);
entry = __rmid_entry(idx);
list_del(&entry->list);
out_unlock:
mutex_unlock(&rdtgroup_mutex);
return err;
}
static void __exit dom_data_exit(void)
{
mutex_lock(&rdtgroup_mutex);
if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) {
kfree(closid_num_dirty_rmid);
closid_num_dirty_rmid = NULL;
}
kfree(rmid_ptrs);
rmid_ptrs = NULL;
mutex_unlock(&rdtgroup_mutex);
}
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)) {
u32 eax, ebx, ecx, edx;
/* Detect list of bandwidth sources that can be tracked */
cpuid_count(0x80000020, 3, &eax, &ebx, &ecx, &edx);
hw_res->mbm_cfg_mask = ecx & MAX_EVT_CONFIG_BITS;
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 __exit rdt_put_mon_l3_config(void)
{
dom_data_exit();
}
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;
}