Hi Babu, On 4/3/25 5:18 PM, Babu Moger wrote: > The ABMC feature provides an option to the user to assign a hardware > counter to an RMID, event pair and monitor the bandwidth as long as it > is assigned. The assigned RMID will be tracked by the hardware until the > user unassigns it manually. > > Implement an architecture-specific handler to assign and unassign the > counter. Configure counters by writing to the L3_QOS_ABMC_CFG MSR, > specifying the counter ID, bandwidth source (RMID), and event > configuration. > > The feature details are documented in the APM listed below [1]. > [1] AMD64 Architecture Programmer's Manual Volume 2: System Programming > Publication # 24593 Revision 3.41 section 19.3.3.3 Assignable Bandwidth > Monitoring (ABMC). > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 > Signed-off-by: Babu Moger <babu.moger@xxxxxxx> > --- ... > --- > arch/x86/kernel/cpu/resctrl/monitor.c | 39 +++++++++++++++++++++++++++ > include/linux/resctrl.h | 15 +++++++++++ > 2 files changed, 54 insertions(+) > > diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c > index 8a88ac29d57d..77f8662dc50b 100644 > --- a/arch/x86/kernel/cpu/resctrl/monitor.c > +++ b/arch/x86/kernel/cpu/resctrl/monitor.c > @@ -1430,3 +1430,42 @@ int resctrl_arch_mbm_cntr_assign_set(struct rdt_resource *r, bool enable) > > return 0; > } > + > +static void resctrl_abmc_config_one_amd(void *info) > +{ > + union l3_qos_abmc_cfg *abmc_cfg = info; > + > + wrmsrl(MSR_IA32_L3_QOS_ABMC_CFG, abmc_cfg->full); > +} > + > +/* > + * Send an IPI to the domain to assign the counter to RMID, event pair. > + */ > +int resctrl_arch_config_cntr(struct rdt_resource *r, struct rdt_mon_domain *d, > + enum resctrl_event_id evtid, u32 rmid, u32 closid, > + u32 cntr_id, u32 evt_cfg, bool assign) > +{ > + struct rdt_hw_mon_domain *hw_dom = resctrl_to_arch_mon_dom(d); > + union l3_qos_abmc_cfg abmc_cfg = { 0 }; > + struct arch_mbm_state *am; > + > + abmc_cfg.split.cfg_en = 1; > + abmc_cfg.split.cntr_en = assign ? 1 : 0; > + abmc_cfg.split.cntr_id = cntr_id; > + abmc_cfg.split.bw_src = rmid; > + abmc_cfg.split.bw_type = evt_cfg; > + > + smp_call_function_any(&d->hdr.cpu_mask, resctrl_abmc_config_one_amd, &abmc_cfg, 1); > + > + /* > + * Reset the architectural state so that reading of hardware > + * counter is not considered as an overflow in next update. Please add something like: "The hardware counter is reset (because cfg_en == 1) so there is no need to record initial non-zero counts." > + */ > + if (assign) { > + am = get_arch_mbm_state(hw_dom, rmid, evtid); > + if (am) > + memset(am, 0, sizeof(*am)); > + } > + > + return 0; > +} > diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h > index 294b15de664e..60270606f1b8 100644 > --- a/include/linux/resctrl.h > +++ b/include/linux/resctrl.h Please keep the declaration internal to the arch code. It can be moved when other architecture needs it. > @@ -394,6 +394,21 @@ void resctrl_arch_mon_event_config_set(void *config_info); > u32 resctrl_arch_mon_event_config_get(struct rdt_mon_domain *d, > enum resctrl_event_id eventid); > > +/** > + * resctrl_arch_config_cntr() - Configure the counter on the domain > + * @r: resource that the counter should be read from. > + * @d: domain that the counter should be read from. > + * @evtid: event type to assign > + * @rmid: rmid of the counter to read. > + * @closid: closid that matches the rmid. > + * @cntr_id: Counter ID to configure > + * @evt_cfg: event configuration "event configuration" is simply an expansion of member name and does not help to understand what the value represents. > + * @assign: assign or unassign Please rework the kernel doc: consistent sentence structure (starts with upper case, ends with period), use proper capitalization for acronyms (rmid -> RMID, etc.), make descriptions informative. > + */ > +int resctrl_arch_config_cntr(struct rdt_resource *r, struct rdt_mon_domain *d, > + enum resctrl_event_id evtid, u32 rmid, u32 closid, > + u32 cntr_id, u32 evt_cfg, bool assign); > + > /* For use by arch code to remap resctrl's smaller CDP CLOSID range */ > static inline u32 resctrl_get_config_index(u32 closid, > enum resctrl_conf_type type) This patch does not pass checkpatch.pl. Reinette
