To indicate that the configuration, of the controls used by resctrl, in a
RIS need resetting to driver defaults the reset flags in mpam_config are
set. However, these flags are only ever set temporarily at RIS scope in
mpam_reset_ris() and hence mpam_cpu_online() will never reset these
controls to default. As the hardware reset is unknown this leads to unknown
configuration when the control values haven't been configured away from the
defaults.
Use the policy that an unset feature configuration bit means reset. In this
way the mpam_config in the component can encode that it should be in reset
state and mpam_reprogram_msc() will reset controls as needed.
Fixes: 09b89d2a72f3 ("arm_mpam: Allow configuration to be applied and restored during cpu online")
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
---
This goes back to the initial feature configuration policy that James
used in the MPAM base driver rfc but I unfortunately
suggested him to change it.
---
drivers/resctrl/mpam_devices.c | 40 ++++++++++------------------------
1 file changed, 12 insertions(+), 28 deletions(-)
diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index 0fd6590a9b5c..ff861291bd4e 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -1364,17 +1364,15 @@ static void mpam_reprogram_ris_partid(struct mpam_msc_ris *ris, u16 partid,
__mpam_intpart_sel(ris->ris_idx, partid, msc);
}
- if (mpam_has_feature(mpam_feat_cpor_part, rprops) &&
- mpam_has_feature(mpam_feat_cpor_part, cfg)) {
- if (cfg->reset_cpbm)
- mpam_reset_msc_bitmap(msc, MPAMCFG_CPBM, rprops->cpbm_wd);
- else
+ if (mpam_has_feature(mpam_feat_cpor_part, rprops)) {
+ if (mpam_has_feature(mpam_feat_cpor_part, cfg))
mpam_write_partsel_reg(msc, CPBM, cfg->cpbm);
+ else
+ mpam_reset_msc_bitmap(msc, MPAMCFG_CPBM, rprops->cpbm_wd);
}
- if (mpam_has_feature(mpam_feat_mbw_part, rprops) &&
- mpam_has_feature(mpam_feat_mbw_part, cfg)) {
- if (cfg->reset_mbw_pbm)
+ if (mpam_has_feature(mpam_feat_mbw_part, rprops)) {
+ if (mpam_has_feature(mpam_feat_mbw_part, cfg))
mpam_reset_msc_bitmap(msc, MPAMCFG_MBW_PBM, rprops->mbw_pbm_bits);
else
mpam_write_partsel_reg(msc, MBW_PBM, cfg->mbw_pbm);
@@ -1384,16 +1382,14 @@ static void mpam_reprogram_ris_partid(struct mpam_msc_ris *ris, u16 partid,
mpam_has_feature(mpam_feat_mbw_min, cfg))
mpam_write_partsel_reg(msc, MBW_MIN, 0);
- if (mpam_has_feature(mpam_feat_mbw_max, rprops) &&
- mpam_has_feature(mpam_feat_mbw_max, cfg)) {
- if (cfg->reset_mbw_max)
- mpam_write_partsel_reg(msc, MBW_MAX, MPAMCFG_MBW_MAX_MAX);
- else
+ if (mpam_has_feature(mpam_feat_mbw_max, rprops)) {
+ if (mpam_has_feature(mpam_feat_mbw_max, cfg))
mpam_write_partsel_reg(msc, MBW_MAX, cfg->mbw_max);
+ else
+ mpam_write_partsel_reg(msc, MBW_MAX, MPAMCFG_MBW_MAX_MAX);
}
- if (mpam_has_feature(mpam_feat_mbw_prop, rprops) &&
- mpam_has_feature(mpam_feat_mbw_prop, cfg))
+ if (mpam_has_feature(mpam_feat_mbw_prop, rprops))
mpam_write_partsel_reg(msc, MBW_PROP, 0);
if (mpam_has_feature(mpam_feat_cmax_cmax, rprops))
@@ -1491,16 +1487,6 @@ static int mpam_save_mbwu_state(void *arg)
return 0;
}
-static void mpam_init_reset_cfg(struct mpam_config *reset_cfg)
-{
- *reset_cfg = (struct mpam_config) {
- .reset_cpbm = true,
- .reset_mbw_pbm = true,
- .reset_mbw_max = true,
- };
- bitmap_fill(reset_cfg->features, MPAM_FEATURE_LAST);
-}
-
/*
* Called via smp_call_on_cpu() to prevent migration, while still being
* pre-emptible. Caller must hold mpam_srcu.
@@ -1508,14 +1494,12 @@ static void mpam_init_reset_cfg(struct mpam_config *reset_cfg)
static int mpam_reset_ris(void *arg)
{
u16 partid, partid_max;
- struct mpam_config reset_cfg;
+ struct mpam_config reset_cfg = {};
struct mpam_msc_ris *ris = arg;
if (ris->in_reset_state)
return 0;
- mpam_init_reset_cfg(&reset_cfg);
-
spin_lock(&partid_max_lock);
partid_max = mpam_partid_max;
spin_unlock(&partid_max_lock);
--
2.43.0