From: Tony Luck Date: Wed, 17 Dec 2025 17:20:54 +0000 (-0800) Subject: x86,fs/resctrl: Use struct rdt_domain_hdr when reading counters X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6b10cf7b6ea857cdf9570e21c077a05803f60575;p=thirdparty%2Fkernel%2Flinux.git x86,fs/resctrl: Use struct rdt_domain_hdr when reading counters Convert the whole call sequence from mon_event_read() to resctrl_arch_rmid_read() to pass resource independent struct rdt_domain_hdr instead of an L3 specific domain structure to prepare for monitoring events in other resources. This additional layer of indirection obscures which aspects of event counting depend on a valid domain. Event initialization, support for assignable counters, and normal event counting implicitly depend on a valid domain while summing of domains does not. Split summing domains from the core event counting handling to make their respective dependencies obvious. Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com --- diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index dffcc8307500a..3da970ea1903b 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -238,19 +238,25 @@ static u64 get_corrected_val(struct rdt_resource *r, struct rdt_mon_domain *d, return chunks * hw_res->mon_scale; } -int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_mon_domain *d, +int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain_hdr *hdr, u32 unused, u32 rmid, enum resctrl_event_id eventid, u64 *val, void *ignored) { - struct rdt_hw_mon_domain *hw_dom = resctrl_to_arch_mon_dom(d); - int cpu = cpumask_any(&d->hdr.cpu_mask); + struct rdt_hw_mon_domain *hw_dom; struct arch_mbm_state *am; + struct rdt_mon_domain *d; u64 msr_val; u32 prmid; + int cpu; int ret; resctrl_arch_rmid_read_context_check(); + if (!domain_header_is_valid(hdr, RESCTRL_MON_DOMAIN, RDT_RESOURCE_L3)) + return -EINVAL; + d = container_of(hdr, struct rdt_mon_domain, hdr); + hw_dom = resctrl_to_arch_mon_dom(d); + cpu = cpumask_any(&hdr->cpu_mask); prmid = logical_rmid_to_physical_rmid(cpu, rmid); ret = __rmid_read_phys(prmid, eventid, &msr_val); diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c index 3154cdc98a318..9242a2982e77b 100644 --- a/fs/resctrl/ctrlmondata.c +++ b/fs/resctrl/ctrlmondata.c @@ -554,25 +554,18 @@ void mon_event_read(struct rmid_read *rr, struct rdt_resource *r, struct rdt_domain_hdr *hdr, struct rdtgroup *rdtgrp, cpumask_t *cpumask, int evtid, int first) { - struct rdt_mon_domain *d = NULL; int cpu; /* When picking a CPU from cpu_mask, ensure it can't race with cpuhp */ lockdep_assert_cpus_held(); - if (hdr) { - if (!domain_header_is_valid(hdr, RESCTRL_MON_DOMAIN, RDT_RESOURCE_L3)) - return; - d = container_of(hdr, struct rdt_mon_domain, hdr); - } - /* * Setup the parameters to pass to mon_event_count() to read the data. */ rr->rgrp = rdtgrp; rr->evtid = evtid; rr->r = r; - rr->d = d; + rr->hdr = hdr; rr->first = first; if (resctrl_arch_mbm_cntr_assign_enabled(r) && resctrl_is_mbm_event(evtid)) { diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h index 5e52269b391e7..9912b774a580b 100644 --- a/fs/resctrl/internal.h +++ b/fs/resctrl/internal.h @@ -106,24 +106,26 @@ struct mon_data { * resource group then its event count is summed with the count from all * its child resource groups. * @r: Resource describing the properties of the event being read. - * @d: Domain that the counter should be read from. If NULL then sum all - * domains in @r sharing L3 @ci.id + * @hdr: Header of domain that the counter should be read from. If NULL then + * sum all domains in @r sharing L3 @ci.id * @evtid: Which monitor event to read. * @first: Initialize MBM counter when true. - * @ci: Cacheinfo for L3. Only set when @d is NULL. Used when summing domains. + * @ci: Cacheinfo for L3. Only set when @hdr is NULL. Used when summing + * domains. * @is_mbm_cntr: true if "mbm_event" counter assignment mode is enabled and it * is an MBM event. * @err: Error encountered when reading counter. - * @val: Returned value of event counter. If @rgrp is a parent resource group, - * @val includes the sum of event counts from its child resource groups. - * If @d is NULL, @val includes the sum of all domains in @r sharing @ci.id, - * (summed across child resource groups if @rgrp is a parent resource group). + * @val: Returned value of event counter. If @rgrp is a parent resource + * group, @val includes the sum of event counts from its child + * resource groups. If @hdr is NULL, @val includes the sum of all + * domains in @r sharing @ci.id, (summed across child resource groups + * if @rgrp is a parent resource group). * @arch_mon_ctx: Hardware monitor allocated for this read request (MPAM only). */ struct rmid_read { struct rdtgroup *rgrp; struct rdt_resource *r; - struct rdt_mon_domain *d; + struct rdt_domain_hdr *hdr; enum resctrl_event_id evtid; bool first; struct cacheinfo *ci; diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c index b5e0db38c8bfd..e1c12201388fb 100644 --- a/fs/resctrl/monitor.c +++ b/fs/resctrl/monitor.c @@ -159,7 +159,7 @@ void __check_limbo(struct rdt_mon_domain *d, bool force_free) break; entry = __rmid_entry(idx); - if (resctrl_arch_rmid_read(r, d, entry->closid, entry->rmid, + if (resctrl_arch_rmid_read(r, &d->hdr, entry->closid, entry->rmid, QOS_L3_OCCUP_EVENT_ID, &val, arch_mon_ctx)) { rmid_dirty = true; @@ -421,11 +421,16 @@ static int __l3_mon_event_count(struct rdtgroup *rdtgrp, struct rmid_read *rr) struct rdt_mon_domain *d; int cntr_id = -ENOENT; struct mbm_state *m; - int err, ret; u64 tval = 0; + if (!domain_header_is_valid(rr->hdr, RESCTRL_MON_DOMAIN, RDT_RESOURCE_L3)) { + rr->err = -EIO; + return -EINVAL; + } + d = container_of(rr->hdr, struct rdt_mon_domain, hdr); + if (rr->is_mbm_cntr) { - cntr_id = mbm_cntr_get(rr->r, rr->d, rdtgrp, rr->evtid); + cntr_id = mbm_cntr_get(rr->r, d, rdtgrp, rr->evtid); if (cntr_id < 0) { rr->err = -ENOENT; return -EINVAL; @@ -434,31 +439,50 @@ static int __l3_mon_event_count(struct rdtgroup *rdtgrp, struct rmid_read *rr) if (rr->first) { if (rr->is_mbm_cntr) - resctrl_arch_reset_cntr(rr->r, rr->d, closid, rmid, cntr_id, rr->evtid); + resctrl_arch_reset_cntr(rr->r, d, closid, rmid, cntr_id, rr->evtid); else - resctrl_arch_reset_rmid(rr->r, rr->d, closid, rmid, rr->evtid); - m = get_mbm_state(rr->d, closid, rmid, rr->evtid); + resctrl_arch_reset_rmid(rr->r, d, closid, rmid, rr->evtid); + m = get_mbm_state(d, closid, rmid, rr->evtid); if (m) memset(m, 0, sizeof(struct mbm_state)); return 0; } - if (rr->d) { - /* Reading a single domain, must be on a CPU in that domain. */ - if (!cpumask_test_cpu(cpu, &rr->d->hdr.cpu_mask)) - return -EINVAL; - if (rr->is_mbm_cntr) - rr->err = resctrl_arch_cntr_read(rr->r, rr->d, closid, rmid, cntr_id, - rr->evtid, &tval); - else - 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; + /* Reading a single domain, must be on a CPU in that domain. */ + if (!cpumask_test_cpu(cpu, &d->hdr.cpu_mask)) + return -EINVAL; + if (rr->is_mbm_cntr) + rr->err = resctrl_arch_cntr_read(rr->r, d, closid, rmid, cntr_id, + rr->evtid, &tval); + else + rr->err = resctrl_arch_rmid_read(rr->r, rr->hdr, closid, rmid, + rr->evtid, &tval, rr->arch_mon_ctx); + if (rr->err) + return rr->err; - rr->val += tval; + rr->val += tval; - return 0; + return 0; +} + +static int __l3_mon_event_count_sum(struct rdtgroup *rdtgrp, struct rmid_read *rr) +{ + int cpu = smp_processor_id(); + u32 closid = rdtgrp->closid; + u32 rmid = rdtgrp->mon.rmid; + struct rdt_mon_domain *d; + u64 tval = 0; + int err, ret; + + /* + * Summing across domains is only done for systems that implement + * Sub-NUMA Cluster. There is no overlap with systems that support + * assignable counters. + */ + if (rr->is_mbm_cntr) { + pr_warn_once("Summing domains using assignable counters is not supported\n"); + rr->err = -EINVAL; + return -EINVAL; } /* Summing domains that share a cache, must be on a CPU for that cache. */ @@ -476,12 +500,8 @@ static int __l3_mon_event_count(struct rdtgroup *rdtgrp, struct rmid_read *rr) list_for_each_entry(d, &rr->r->mon_domains, hdr.list) { if (d->ci_id != rr->ci->id) continue; - if (rr->is_mbm_cntr) - err = resctrl_arch_cntr_read(rr->r, d, closid, rmid, cntr_id, - rr->evtid, &tval); - else - err = resctrl_arch_rmid_read(rr->r, d, closid, rmid, - rr->evtid, &tval, rr->arch_mon_ctx); + err = resctrl_arch_rmid_read(rr->r, &d->hdr, closid, rmid, + rr->evtid, &tval, rr->arch_mon_ctx); if (!err) { rr->val += tval; ret = 0; @@ -498,7 +518,10 @@ static int __mon_event_count(struct rdtgroup *rdtgrp, struct rmid_read *rr) { switch (rr->r->rid) { case RDT_RESOURCE_L3: - return __l3_mon_event_count(rdtgrp, rr); + if (rr->hdr) + return __l3_mon_event_count(rdtgrp, rr); + else + return __l3_mon_event_count_sum(rdtgrp, rr); default: rr->err = -EINVAL; return -EINVAL; @@ -522,9 +545,13 @@ static void mbm_bw_count(struct rdtgroup *rdtgrp, struct rmid_read *rr) u64 cur_bw, bytes, cur_bytes; u32 closid = rdtgrp->closid; u32 rmid = rdtgrp->mon.rmid; + struct rdt_mon_domain *d; struct mbm_state *m; - m = get_mbm_state(rr->d, closid, rmid, rr->evtid); + if (!domain_header_is_valid(rr->hdr, RESCTRL_MON_DOMAIN, RDT_RESOURCE_L3)) + return; + d = container_of(rr->hdr, struct rdt_mon_domain, hdr); + m = get_mbm_state(d, closid, rmid, rr->evtid); if (WARN_ON_ONCE(!m)) return; @@ -697,7 +724,7 @@ static void mbm_update_one_event(struct rdt_resource *r, struct rdt_mon_domain * struct rmid_read rr = {0}; rr.r = r; - rr.d = d; + rr.hdr = &d->hdr; rr.evtid = evtid; if (resctrl_arch_mbm_cntr_assign_enabled(r)) { rr.is_mbm_cntr = true; diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 5db37c7e89c5c..9b9877fb3238a 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -517,7 +517,7 @@ void resctrl_offline_cpu(unsigned int cpu); * resctrl_arch_rmid_read() - Read the eventid counter corresponding to rmid * for this resource and domain. * @r: resource that the counter should be read from. - * @d: domain that the counter should be read from. + * @hdr: Header of domain that the counter should be read from. * @closid: closid that matches the rmid. Depending on the architecture, the * counter may match traffic of both @closid and @rmid, or @rmid * only. @@ -538,7 +538,7 @@ void resctrl_offline_cpu(unsigned int cpu); * Return: * 0 on success, or -EIO, -EINVAL etc on error. */ -int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_mon_domain *d, +int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain_hdr *hdr, u32 closid, u32 rmid, enum resctrl_event_id eventid, u64 *val, void *arch_mon_ctx);