Hardware provides a set of counters when mbm_assign_mode is supported.
These counters are assigned to the MBM monitoring events of a 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. Move dom_data_init() after
mbm_cntr_assign detection.
Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
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/internal.h | 2 ++
arch/x86/kernel/cpu/resctrl/monitor.c | 43 +++++++++++++++++++++++---
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 19 ++++++++++++
include/linux/resctrl.h | 2 ++
4 files changed, 62 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 92eae4672312..99f9103a35ba 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -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 66b06574f660..5c2a28565747 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);
}
+/*
+ * Counter bitmap for tracking the available counters.
+ * 'mbm_cntr_assign' mode provides set of hardware counters for assigning
+ * RMID, event pair. Each RMID and event pair takes one hardware counter.
+ */
+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);
@@ -1056,6 +1088,9 @@ static void __exit dom_data_exit(struct rdt_resource *r)
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;
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index c48b5450e6c2..8ffebd203c31 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..5a4d6adec974 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
