Hardware provides a set of counters when mbm_assign_mode is supported. These counters are assigned to the MBM monitoring events of a CTRL_MON or MON group that needs to be tracked. The kernel must manage and track the available counters. Introduce mbm_cntr_free_map bitmap to track available counters and set of routines to allocate and free the counters. dom_data_init() requires mbm_cntr_assign state to initialize mbm_cntr_free_map bitmap. Move dom_data_init() after mbm_cntr_assign detection. Signed-off-by: Babu Moger <babu.moger@xxxxxxx> --- v9: Commit message update and kernel doc update. v8: Moved the init and exit functionality inside dom_data_init() and dom_data_exit() respectively. v7: Removed the static allocation and now allocating bitmap mbm_cntr_free_map dynamically. Passed the struct rdt_resource mbm_cntr_alloc and mbm_cntr_free. Removed the reference of ABMC and changed it mbm_cntr_assign. Few other text changes. v6: Removed the variable mbm_cntrs_free_map_len. This is not required. Removed the call mbm_cntrs_init() in arch code. This needs to be done at higher level. Used DECLARE_BITMAP to initialize mbm_cntrs_free_map. Moved all the counter interfaces mbm_cntr_alloc() and mbm_cntr_free() in here as part of separating arch and fs bits. v5: Updated the comments and commit log. Few renames num_cntrs_free_map -> mbm_cntrs_free_map num_cntrs_init -> mbm_cntrs_init Added initialization in rdt_get_tree because the default ABMC enablement happens during the init. v4: Changed the name to num_cntrs where applicable. Used bitmap apis. Added more comments for the globals. v3: Changed the bitmap name to assign_cntrs_free_map. Removed abmc from the name. v2: Changed the bitmap name to assignable_counter_free_map from abmc_counter_free_map. --- arch/x86/kernel/cpu/resctrl/core.c | 2 +- arch/x86/kernel/cpu/resctrl/internal.h | 4 ++- arch/x86/kernel/cpu/resctrl/monitor.c | 49 ++++++++++++++++++++++---- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 19 ++++++++++ include/linux/resctrl.h | 2 ++ 5 files changed, 67 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index 9603f5cb483c..02ccb4d2955d 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -1140,7 +1140,7 @@ static void __exit resctrl_exit(void) rdtgroup_exit(); if (r->mon_capable) - rdt_put_mon_l3_config(); + rdt_put_mon_l3_config(r); } __exitcall(resctrl_exit); diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index c07a93da31cc..8ab59d59c15a 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -633,7 +633,7 @@ void closid_free(int closid); int alloc_rmid(u32 closid); void free_rmid(u32 closid, u32 rmid); int __init rdt_get_mon_l3_config(struct rdt_resource *r); -void __exit rdt_put_mon_l3_config(void); +void __exit rdt_put_mon_l3_config(struct rdt_resource *r); bool __init rdt_cpu_has(int flag); void mon_event_count(void *info); int rdtgroup_mondata_show(struct seq_file *m, void *arg); @@ -654,6 +654,8 @@ void __check_limbo(struct rdt_mon_domain *d, bool force_free); void rdt_domain_reconfigure_cdp(struct rdt_resource *r); void __init resctrl_file_fflags_init(const char *config, unsigned long fflags); +int mbm_cntr_alloc(struct rdt_resource *r); +void mbm_cntr_free(struct rdt_resource *r, u32 cntr_id); void rdt_staged_configs_clear(void); bool closid_allocated(unsigned int closid); int resctrl_find_cleanest_closid(void); diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index e0d8080dcdcf..185ac210d46e 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -983,6 +983,27 @@ void mbm_setup_overflow_handler(struct rdt_mon_domain *dom, unsigned long delay_ schedule_delayed_work_on(cpu, &dom->mbm_over, delay); } +/* + * Bitmap to track the available hardware counters when operating in + * "mbm_cntr_assign" mode. A hardware counter can be assigned to a RMID, + * event pair. + */ +static __init unsigned long *mbm_cntrs_init(struct rdt_resource *r) +{ + r->mon.mbm_cntr_free_map = bitmap_zalloc(r->mon.num_mbm_cntrs, + GFP_KERNEL); + if (r->mon.mbm_cntr_free_map) + bitmap_fill(r->mon.mbm_cntr_free_map, r->mon.num_mbm_cntrs); + + return r->mon.mbm_cntr_free_map; +} + +static __exit void mbm_cntrs_exit(struct rdt_resource *r) +{ + bitmap_free(r->mon.mbm_cntr_free_map); + r->mon.mbm_cntr_free_map = NULL; +} + static __init int dom_data_init(struct rdt_resource *r) { u32 idx_limit = resctrl_arch_system_num_rmid_idx(); @@ -1020,6 +1041,17 @@ static __init int dom_data_init(struct rdt_resource *r) goto out_unlock; } + if (r->mon.mbm_cntr_assignable && !mbm_cntrs_init(r)) { + 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; + err = -ENOMEM; + goto out_unlock; + } + for (i = 0; i < idx_limit; i++) { entry = &rmid_ptrs[i]; INIT_LIST_HEAD(&entry->list); @@ -1044,7 +1076,7 @@ static __init int dom_data_init(struct rdt_resource *r) return err; } -static void __exit dom_data_exit(void) +static void __exit dom_data_exit(struct rdt_resource *r) { mutex_lock(&rdtgroup_mutex); @@ -1056,6 +1088,9 @@ static void __exit dom_data_exit(void) kfree(rmid_ptrs); rmid_ptrs = NULL; + if (r->mon.mbm_cntr_assignable) + mbm_cntrs_exit(r); + mutex_unlock(&rdtgroup_mutex); } @@ -1210,10 +1245,6 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r) */ 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; @@ -1240,6 +1271,10 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r) } } + ret = dom_data_init(r); + if (ret) + return ret; + l3_mon_evt_init(r); r->mon_capable = true; @@ -1247,9 +1282,9 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r) return 0; } -void __exit rdt_put_mon_l3_config(void) +void __exit rdt_put_mon_l3_config(struct rdt_resource *r) { - dom_data_exit(); + dom_data_exit(r); } void __init intel_rdt_mbm_apply_quirk(void) diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 339bb0b09a82..a4b92476f501 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -185,6 +185,25 @@ bool closid_allocated(unsigned int closid) return !test_bit(closid, &closid_free_map); } +int mbm_cntr_alloc(struct rdt_resource *r) +{ + int cntr_id; + + cntr_id = find_first_bit(r->mon.mbm_cntr_free_map, + r->mon.num_mbm_cntrs); + if (cntr_id >= r->mon.num_mbm_cntrs) + return -ENOSPC; + + __clear_bit(cntr_id, r->mon.mbm_cntr_free_map); + + return cntr_id; +} + +void mbm_cntr_free(struct rdt_resource *r, u32 cntr_id) +{ + __set_bit(cntr_id, r->mon.mbm_cntr_free_map); +} + /** * rdtgroup_mode_by_closid - Return mode of resource group with closid * @closid: closid if the resource group diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index f11d6fdfd977..afe3b22d3e60 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -187,12 +187,14 @@ enum resctrl_scope { * @num_rmid: Number of RMIDs available * @num_mbm_cntrs: Number of assignable monitoring counters * @mbm_cntr_assignable:Is system capable of supporting monitor assignment? + * @mbm_cntr_free_map: Bitmap of free MBM counters * @evt_list: List of monitoring events */ struct resctrl_mon { int num_rmid; int num_mbm_cntrs; bool mbm_cntr_assignable; + unsigned long *mbm_cntr_free_map; struct list_head evt_list; }; -- 2.34.1