Messages in this thread Patch in this message | | | From | James Morse <> | Subject | [PATCH v1 14/20] x86/resctrl: Abstract __rmid_read() | Date | Thu, 29 Jul 2021 22:36:04 +0000 |
| |
__rmid_read() selects the specified eventid and returns the counter value from the msr. The error handling is architecture specific, and handled by the callers, rdtgroup_mondata_show() and __mon_event_count().
Error handling should be handled by architecture specific code, as a different architecture may have different requirements. MPAM's counters can report that they are 'not ready', requiring a second read after a short delay. This should be hidden from resctrl.
Make __rmid_read() the architecture specific function for reading a counter. Rename it resctrl_arch_rmid_read() and move the error handling into it.
Signed-off-by: James Morse <james.morse@arm.com> --- arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 4 +-- arch/x86/kernel/cpu/resctrl/internal.h | 2 +- arch/x86/kernel/cpu/resctrl/monitor.c | 44 ++++++++++++++--------- include/linux/resctrl.h | 1 + 4 files changed, 31 insertions(+), 20 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c index 5104f39928fd..3269ee954941 100644 --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c @@ -579,9 +579,9 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg) mon_event_read(&rr, r, d, rdtgrp, evtid, false); - if (rr.val & RMID_VAL_ERROR) + if (rr.err == -EIO) seq_puts(m, "Error\n"); - else if (rr.val & RMID_VAL_UNAVAIL) + else if (rr.err == -EINVAL) seq_puts(m, "Unavailable\n"); else seq_printf(m, "%llu\n", rr.val * hw_res->mon_scale); diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index f3f31315a907..eca7793d3342 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -40,7 +40,6 @@ */ #define MBM_CNTR_WIDTH_OFFSET_MAX (62 - MBM_CNTR_WIDTH_BASE) - struct rdt_fs_context { struct kernfs_fs_context kfc; bool enable_cdpl2; @@ -94,6 +93,7 @@ struct rmid_read { struct rdt_domain *d; enum resctrl_event_id evtid; bool first; + int err; u64 val; }; diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index 3b8b29470a5c..e7c43c40ff28 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -164,9 +164,9 @@ void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_domain *d, memset(m, 0, sizeof(*m)); } -static u64 __rmid_read(u32 rmid, enum resctrl_event_id eventid) +int resctrl_arch_rmid_read(u32 rmid, enum resctrl_event_id eventid, u64 *val) { - u64 val; + u64 msr_val; /* * As per the SDM, when IA32_QM_EVTSEL.EvtID (bits 7:0) is configured @@ -177,14 +177,24 @@ static u64 __rmid_read(u32 rmid, enum resctrl_event_id eventid) * are error bits. */ wrmsr(MSR_IA32_QM_EVTSEL, eventid, rmid); - rdmsrl(MSR_IA32_QM_CTR, val); + rdmsrl(MSR_IA32_QM_CTR, msr_val); - return val; + if (msr_val & RMID_VAL_ERROR) + return -EIO; + if (msr_val & RMID_VAL_UNAVAIL) + return -EINVAL; + + *val = msr_val; + + return 0; } static bool rmid_dirty(struct rmid_entry *entry) { - u64 val = __rmid_read(entry->rmid, QOS_L3_OCCUP_EVENT_ID); + u64 val = 0; + + if (resctrl_arch_rmid_read(entry->rmid, QOS_L3_OCCUP_EVENT_ID, &val)) + return true; return val >= resctrl_cqm_threshold; } @@ -256,8 +266,8 @@ static void add_rmid_to_limbo(struct rmid_entry *entry) { struct rdt_resource *r; struct rdt_domain *d; - int cpu; - u64 val; + int cpu, err; + u64 val = 0; r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; @@ -265,8 +275,10 @@ static void add_rmid_to_limbo(struct rmid_entry *entry) cpu = get_cpu(); list_for_each_entry(d, &r->domains, list) { if (cpumask_test_cpu(cpu, &d->cpu_mask)) { - val = __rmid_read(entry->rmid, QOS_L3_OCCUP_EVENT_ID); - if (val <= resctrl_cqm_threshold) + err = resctrl_arch_rmid_read(entry->rmid, + QOS_L3_OCCUP_EVENT_ID, + &val); + if (err || val <= resctrl_cqm_threshold) continue; } @@ -316,16 +328,15 @@ static int __mon_event_count(u32 rmid, struct rmid_read *rr) { struct rdt_hw_resource *hw_res = resctrl_to_arch_res(rr->r); struct mbm_state *m; - u64 chunks, tval; + u64 chunks, tval = 0; if (rr->first) resctrl_arch_reset_rmid(rr->r, rr->d, rmid, rr->evtid); - tval = __rmid_read(rmid, rr->evtid); - if (tval & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL)) { - rr->val = tval; + rr->err = resctrl_arch_rmid_read(rmid, rr->evtid, &tval); + if (rr->err) return -EINVAL; - } + switch (rr->evtid) { case QOS_L3_OCCUP_EVENT_ID: rr->val += tval; @@ -361,10 +372,9 @@ static void mbm_bw_count(u32 rmid, struct rmid_read *rr) { struct rdt_hw_resource *hw_res = resctrl_to_arch_res(rr->r); struct mbm_state *m = &rr->d->mbm_local[rmid]; - u64 tval, cur_bw, chunks, bw_chunks; + u64 tval = 0, cur_bw, chunks, bw_chunks; - tval = __rmid_read(rmid, rr->evtid); - if (tval & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL)) + if (resctrl_arch_rmid_read(rmid, rr->evtid, &tval)) return; chunks = mbm_overflow_count(m->prev_msr, tval, hw_res->mbm_width); diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 79e83ce3dfbc..543f6d0599a9 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -228,6 +228,7 @@ void resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d, u32 *value); int resctrl_online_domain(struct rdt_resource *r, struct rdt_domain *d); void resctrl_offline_domain(struct rdt_resource *r, struct rdt_domain *d); +int resctrl_arch_rmid_read(u32 rmid, enum resctrl_event_id eventid, u64 *res); /** * resctrl_arch_reset_rmid() - Reset any private state associated with rmid -- 2.30.2
| |