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arm_mpam: Track bandwidth counter state for power management

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Bandwidth counters need to run continuously to correctly reflect the
bandwidth.

Save the counter state when the hardware is reset due to CPU hotplug.
Add struct mbwu_state to track the bandwidth counter. Support for
tracking overflow with the same structure will be added in a
subsequent commit.

Cc: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Fenghua Yu <fenghuay@nvidia.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com>
Tested-by: Gavin Shan <gshan@redhat.com>
Tested-by: Zeng Heng <zengheng4@huawei.com>
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
James Morse
2025-11-19 12:22:57 +00:00
committed by Catalin Marinas
parent 823e7c3712
commit 41e8a14950
2 changed files with 145 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

126
drivers/resctrl/mpam_devices.c
View File

@@ -993,6 +993,7 @@ static void __ris_msmon_read(void *arg)
struct mon_read *m = arg;
struct mon_cfg *ctx = m->ctx;
struct mpam_msc_ris *ris = m->ris;
struct msmon_mbwu_state *mbwu_state;
struct mpam_props *rprops = &ris->props;
struct mpam_msc *msc = m->ris->vmsc->msc;
u32 mon_sel, ctl_val, flt_val, cur_ctl, cur_flt;
@@ -1023,11 +1024,21 @@ static void __ris_msmon_read(void *arg)
now = mpam_read_monsel_reg(msc, CSU);
if (mpam_has_feature(mpam_feat_msmon_csu_hw_nrdy, rprops))
nrdy = now & MSMON___NRDY;
now = FIELD_GET(MSMON___VALUE, now);
break;
case mpam_feat_msmon_mbwu:
now = mpam_read_monsel_reg(msc, MBWU);
if (mpam_has_feature(mpam_feat_msmon_mbwu_hw_nrdy, rprops))
nrdy = now & MSMON___NRDY;
now = FIELD_GET(MSMON___VALUE, now);
if (nrdy)
break;
mbwu_state = &ris->mbwu_state[ctx->mon];
/* Include bandwidth consumed before the last hardware reset */
now += mbwu_state->correction;
break;
default:
m->err = -EINVAL;
@@ -1039,7 +1050,6 @@ static void __ris_msmon_read(void *arg)
return;
}
now = FIELD_GET(MSMON___VALUE, now);
*m->val += now;
}
@@ -1235,6 +1245,67 @@ static void mpam_reprogram_ris_partid(struct mpam_msc_ris *ris, u16 partid,
mutex_unlock(&msc->part_sel_lock);
}
/* Call with msc cfg_lock held */
static int mpam_restore_mbwu_state(void *_ris)
{
int i;
struct mon_read mwbu_arg;
struct mpam_msc_ris *ris = _ris;
for (i = 0; i < ris->props.num_mbwu_mon; i++) {
if (ris->mbwu_state[i].enabled) {
mwbu_arg.ris = ris;
mwbu_arg.ctx = &ris->mbwu_state[i].cfg;
mwbu_arg.type = mpam_feat_msmon_mbwu;
__ris_msmon_read(&mwbu_arg);
}
}
return 0;
}
/* Call with MSC cfg_lock held */
static int mpam_save_mbwu_state(void *arg)
{
int i;
u64 val;
struct mon_cfg *cfg;
u32 cur_flt, cur_ctl, mon_sel;
struct mpam_msc_ris *ris = arg;
struct msmon_mbwu_state *mbwu_state;
struct mpam_msc *msc = ris->vmsc->msc;
for (i = 0; i < ris->props.num_mbwu_mon; i++) {
mbwu_state = &ris->mbwu_state[i];
cfg = &mbwu_state->cfg;
if (WARN_ON_ONCE(!mpam_mon_sel_lock(msc)))
return -EIO;
mon_sel = FIELD_PREP(MSMON_CFG_MON_SEL_MON_SEL, i) |
FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx);
mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel);
cur_flt = mpam_read_monsel_reg(msc, CFG_MBWU_FLT);
cur_ctl = mpam_read_monsel_reg(msc, CFG_MBWU_CTL);
mpam_write_monsel_reg(msc, CFG_MBWU_CTL, 0);
val = mpam_read_monsel_reg(msc, MBWU);
mpam_write_monsel_reg(msc, MBWU, 0);
cfg->mon = i;
cfg->pmg = FIELD_GET(MSMON_CFG_x_FLT_PMG, cur_flt);
cfg->match_pmg = FIELD_GET(MSMON_CFG_x_CTL_MATCH_PMG, cur_ctl);
cfg->partid = FIELD_GET(MSMON_CFG_x_FLT_PARTID, cur_flt);
mbwu_state->correction += val;
mbwu_state->enabled = FIELD_GET(MSMON_CFG_x_CTL_EN, cur_ctl);
mpam_mon_sel_unlock(msc);
}
return 0;
}
static void mpam_init_reset_cfg(struct mpam_config *reset_cfg)
{
*reset_cfg = (struct mpam_config) {
@@ -1343,6 +1414,9 @@ static void mpam_reprogram_msc(struct mpam_msc *msc)
mpam_touch_msc(msc, __write_config, &arg);
}
ris->in_reset_state = reset;
if (mpam_has_feature(mpam_feat_msmon_mbwu, &ris->props))
mpam_touch_msc(msc, &mpam_restore_mbwu_state, ris);
}
mutex_unlock(&msc->cfg_lock);
}
@@ -1436,6 +1510,9 @@ static int mpam_cpu_offline(unsigned int cpu)
* lost while the CPUs are offline.
*/
ris->in_reset_state = false;
if (mpam_is_enabled())
mpam_touch_msc(msc, &mpam_save_mbwu_state, ris);
}
mutex_unlock(&msc->cfg_lock);
}
@@ -2109,7 +2186,22 @@ static void mpam_unregister_irqs(void)
static void __destroy_component_cfg(struct mpam_component *comp)
{
struct mpam_msc *msc;
struct mpam_vmsc *vmsc;
struct mpam_msc_ris *ris;
lockdep_assert_held(&mpam_list_lock);
add_to_garbage(comp->cfg);
list_for_each_entry(vmsc, &comp->vmsc, comp_list) {
msc = vmsc->msc;
if (mpam_mon_sel_lock(msc)) {
list_for_each_entry(ris, &vmsc->ris, vmsc_list)
add_to_garbage(ris->mbwu_state);
mpam_mon_sel_unlock(msc);
}
}
}
static void mpam_reset_component_cfg(struct mpam_component *comp)
@@ -2135,6 +2227,8 @@ static void mpam_reset_component_cfg(struct mpam_component *comp)
static int __allocate_component_cfg(struct mpam_component *comp)
{
struct mpam_vmsc *vmsc;
mpam_assert_partid_sizes_fixed();
if (comp->cfg)
@@ -2152,6 +2246,36 @@ static int __allocate_component_cfg(struct mpam_component *comp)
mpam_reset_component_cfg(comp);
list_for_each_entry(vmsc, &comp->vmsc, comp_list) {
struct mpam_msc *msc;
struct mpam_msc_ris *ris;
struct msmon_mbwu_state *mbwu_state;
if (!vmsc->props.num_mbwu_mon)
continue;
msc = vmsc->msc;
list_for_each_entry(ris, &vmsc->ris, vmsc_list) {
if (!ris->props.num_mbwu_mon)
continue;
mbwu_state = kcalloc(ris->props.num_mbwu_mon,
sizeof(*ris->mbwu_state),
GFP_KERNEL);
if (!mbwu_state) {
__destroy_component_cfg(comp);
return -ENOMEM;
}
init_garbage(&mbwu_state[0].garbage);
if (mpam_mon_sel_lock(msc)) {
ris->mbwu_state = mbwu_state;
mpam_mon_sel_unlock(msc);
}
}
}
return 0;
}

21
drivers/resctrl/mpam_internal.h
View File

@@ -91,7 +91,10 @@ struct mpam_msc {
*/
struct mutex part_sel_lock;
/* cfg_lock protects the msc configuration. */
/*
* cfg_lock protects the msc configuration and guards against mbwu_state
* save and restore racing.
*/
struct mutex cfg_lock;
/*
@@ -202,6 +205,19 @@ struct mon_cfg {
enum mon_filter_options opts;
};
/* Changes to msmon_mbwu_state are protected by the msc's mon_sel_lock. */
struct msmon_mbwu_state {
bool enabled;
struct mon_cfg cfg;
/*
* The value to add to the new reading to account for power management.
*/
u64 correction;
struct mpam_garbage garbage;
};
struct mpam_class {
/* mpam_components in this class */
struct list_head components;
@@ -295,6 +311,9 @@ struct mpam_msc_ris {
/* parent: */
struct mpam_vmsc *vmsc;
/* msmon mbwu configuration is preserved over reset */
struct msmon_mbwu_state *mbwu_state;
struct mpam_garbage garbage;
};