[AMD Official Use Only - General]
Hi Fenghua,
> -----Original Message-----
> From: Yu, Fenghua <fenghua.yu@xxxxxxxxx>
> Sent: Tuesday, September 27, 2022 5:32 PM
> To: Moger, Babu <Babu.Moger@xxxxxxx>; corbet@xxxxxxx; Chatre, Reinette
> <reinette.chatre@xxxxxxxxx>; tglx@xxxxxxxxxxxxx; mingo@xxxxxxxxxx;
> bp@xxxxxxxxx
> Cc: dave.hansen@xxxxxxxxxxxxxxx; x86@xxxxxxxxxx; hpa@xxxxxxxxx;
> paulmck@xxxxxxxxxx; akpm@xxxxxxxxxxxxxxxxxxxx; quic_neeraju@xxxxxxxxxxx;
> rdunlap@xxxxxxxxxxxxx; damien.lemoal@xxxxxxxxxxxxxxxxxx;
> songmuchun@xxxxxxxxxxxxx; peterz@xxxxxxxxxxxxx; jpoimboe@xxxxxxxxxx;
> pbonzini@xxxxxxxxxx; Bae, Chang Seok <chang.seok.bae@xxxxxxxxx>;
> pawan.kumar.gupta@xxxxxxxxxxxxxxx; jmattson@xxxxxxxxxx;
> daniel.sneddon@xxxxxxxxxxxxxxx; Das1, Sandipan <Sandipan.Das@xxxxxxx>;
> Luck, Tony <tony.luck@xxxxxxxxx>; james.morse@xxxxxxx; linux-
> doc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; bagasdotme@xxxxxxxxx;
> Eranian, Stephane <eranian@xxxxxxxxxx>
> Subject: RE: [PATCH v5 09/12] x86/resctrl: Add sysfs interface to write
> mbm_total_bytes event configuration
>
> Hi, Babu,
>
> > diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> > b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> > index 27bf6ade0dbf..c1d43d03846a 100644
> > --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> > +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> > @@ -1491,6 +1491,144 @@ static int mbm_local_config_show(struct
> > kernfs_open_file *of,
> > return 0;
> > }
> >
> > +void mon_event_config_write(void *info) {
>
> Should this function be static?
Sure.
>
> > + struct mon_config_info *mon_info = info;
> > + u32 msr_index;
> > +
> > + switch (mon_info->evtid) {
> > + case QOS_L3_MBM_TOTAL_EVENT_ID:
> > + msr_index = 0;
> > + break;
> > + case QOS_L3_MBM_LOCAL_EVENT_ID:
> > + msr_index = 1;
> > + break;
> > + default:
> > + /* Not expected to come here */
> > + return;
> > + }
> > +
> > + wrmsr(MSR_IA32_EVT_CFG_BASE + msr_index, mon_info-
> >mon_config,
> > 0); }
> > +
> > +int mbm_config_write(struct rdt_resource *r, struct rdt_domain *d,
> > + u32 evtid, u32 val)
> > +{
> > + struct mon_config_info mon_info = {0};
> > + cpumask_var_t cpu_mask;
> > + int ret = 0, cpu;
> > +
> > + rdt_last_cmd_clear();
> > +
> > + /* mon_config cannot be more than the supported set of events */
> > + if (val > MAX_EVT_CONFIG_BITS) {
> > + rdt_last_cmd_puts("Invalid event configuration\n");
> > + return -EINVAL;
> > + }
> > +
> > + cpus_read_lock();
> > +
> > + if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) {
> > + rdt_last_cmd_puts("cpu_mask allocation failed\n");
> > + ret = -ENOMEM;
> > + goto e_unlock;
> > + }
> > +
> > + /*
> > + * Read the current config value first. If both are same then
> > + * we dont need to write it again.
> > + */
> > + mon_info.evtid = evtid;
> > + mondata_config_read(d, &mon_info);
> > + if (mon_info.mon_config == val)
> > + goto e_cpumask;
> > +
> > + mon_info.mon_config = val;
> > +
> > + /* Pick all the CPUs in the domain instance */
> > + for_each_cpu(cpu, &d->cpu_mask)
> > + cpumask_set_cpu(cpu, cpu_mask);
> > +
> > + /* Update MSR_IA32_EVT_CFG_BASE MSR on all the CPUs in cpu_mask
> > */
> > + on_each_cpu_mask(cpu_mask, mon_event_config_write, &mon_info,
> > 1);
> > +
> > + /*
> > + * When an Event Configuration is changed, the bandwidth counters
> > + * for all RMIDs and Events will be cleared by the hardware. The
> > + * hardware also sets MSR_IA32_QM_CTR.Unavailable (bit 62) for
> > + * every RMID on the next read to any event for every RMID.
> > + * Subsequent reads will have MSR_IA32_QM_CTR.Unavailable (bit 62)
> > + * cleared while it is tracked by the hardware. Clear the
> > + * mbm_local and mbm_total counts for all the RMIDs.
> > + */
> > + memset(d->mbm_local, 0, sizeof(struct mbm_state) * r->num_rmid);
> > + memset(d->mbm_total, 0, sizeof(struct mbm_state) * r->num_rmid);
> > +
> > +e_cpumask:
> > + free_cpumask_var(cpu_mask);
> > +
> > +e_unlock:
> > + cpus_read_unlock();
> > +
> > + return ret;
> > +}
> > +
> > +unsigned int mon_config_parse(struct rdt_resource *r, char *tok, u32
> > +evtid) {
>
> Should this function be static?
Sure. Thanks
Babu
>
> > + char *dom_str = NULL, *id_str;
> > + struct rdt_domain *d;
> > + unsigned long dom_id, val;
> > + int ret = 0;
> > +
> > +next:
> > + if (!tok || tok[0] == '\0')
> > + return 0;
> > +
> > + /* Start processing the strings for each domain */
> > + dom_str = strim(strsep(&tok, ";"));
> > + id_str = strsep(&dom_str, "=");
> > +
> > + if (!dom_str || kstrtoul(id_str, 10, &dom_id)) {
> > + rdt_last_cmd_puts("Missing '=' or non-numeric domain id\n");
> > + return -EINVAL;
> > + }
> > +
> > + if (!dom_str || kstrtoul(dom_str, 16, &val)) {
> > + rdt_last_cmd_puts("Missing '=' or non-numeric event
> > configuration value\n");
> > + return -EINVAL;
> > + }
> > +
> > + list_for_each_entry(d, &r->domains, list) {
> > + if (d->id == dom_id) {
> > + ret = mbm_config_write(r, d, evtid, val);
> > + if (ret)
> > + return -EINVAL;
> > + goto next;
> > + }
> > + }
> > +
> > + return -EINVAL;
> > +}
> > +
> > +static ssize_t mbm_total_config_write(struct kernfs_open_file *of,
> > + char *buf, size_t nbytes, loff_t off) {
> > + struct rdt_resource *r = of->kn->parent->priv;
> > + int ret;
> > +
> > + /* Valid input requires a trailing newline */
> > + if (nbytes == 0 || buf[nbytes - 1] != '\n')
> > + return -EINVAL;
> > +
> > + rdt_last_cmd_clear();
> > +
> > + buf[nbytes - 1] = '\0';
> > +
> > + ret = mon_config_parse(r, buf, QOS_L3_MBM_TOTAL_EVENT_ID);
> > +
> > + return ret ?: nbytes;
> > +}
> > +
> > /* rdtgroup information files for one cache resource. */ static
> > struct rftype res_common_files[] = {
> > {
> > @@ -1594,6 +1732,7 @@ static struct rftype res_common_files[] = {
> > .mode = 0644,
> > .kf_ops = &rdtgroup_kf_single_ops,
> > .seq_show = mbm_total_config_show,
> > + .write = mbm_total_config_write,
> > },
> > {
> > .name = "mbm_local_config",
> >
>
> Thanks.
>
> -Fenghua
