[PATCH v2 03/15] arm_mpam: propagate MSC read errors for hw_probe functions
Andre Przywara
andre.przywara at arm.com
Thu Jul 2 09:22:17 PDT 2026
Allow the functions probing for MSC hardware and features to return an
error, and propagate read errors from the lower level up.
Signed-off-by: Andre Przywara <andre.przywara at arm.com>
---
drivers/resctrl/mpam_devices.c | 62 ++++++++++++++++++++++++----------
1 file changed, 44 insertions(+), 18 deletions(-)
diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index ce8738adb6ff..011d1e3544d7 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -800,20 +800,22 @@ static bool mpam_ris_hw_probe_csu_nrdy(struct mpam_msc_ris *ris)
mpam_write_monsel_reg(msc, CFG_CSU_CTL, ctl_val);
_mpam_write_monsel_reg(msc, MSMON_CSU, MSMON___NRDY);
- _mpam_read_monsel_reg(msc, MSMON_CSU, &now);
+ if (_mpam_read_monsel_reg(msc, MSMON_CSU, &now))
+ return false;
can_set = now & MSMON___NRDY;
_mpam_write_monsel_reg(msc, MSMON_CSU, 0);
/* Configuration change to try and coax hardware into setting nrdy */
mpam_write_monsel_reg(msc, CFG_CSU_FLT, 0x1);
- _mpam_read_monsel_reg(msc, MSMON_CSU, &now);
+ if (_mpam_read_monsel_reg(msc, MSMON_CSU, &now))
+ return false;
can_clear = !(now & MSMON___NRDY);
mpam_mon_sel_unlock(msc);
return (!can_set || !can_clear);
}
-static void mpam_ris_hw_probe(struct mpam_msc_ris *ris)
+static int mpam_ris_hw_probe(struct mpam_msc_ris *ris)
{
int err;
struct mpam_msc *msc = ris->vmsc->msc;
@@ -828,7 +830,9 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris)
if (FIELD_GET(MPAMF_IDR_HAS_CCAP_PART, ris->idr)) {
u32 ccap_features;
- mpam_read_partsel_reg(msc, CCAP_IDR, &ccap_features);
+ err = mpam_read_partsel_reg(msc, CCAP_IDR, &ccap_features);
+ if (err)
+ return err;
props->cmax_wd = FIELD_GET(MPAMF_CCAP_IDR_CMAX_WD, ccap_features);
if (props->cmax_wd &&
@@ -853,7 +857,9 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris)
if (FIELD_GET(MPAMF_IDR_HAS_CPOR_PART, ris->idr)) {
u32 cpor_features;
- mpam_read_partsel_reg(msc, CPOR_IDR, &cpor_features);
+ err = mpam_read_partsel_reg(msc, CPOR_IDR, &cpor_features);
+ if (err)
+ return err;
props->cpbm_wd = FIELD_GET(MPAMF_CPOR_IDR_CPBM_WD, cpor_features);
if (props->cpbm_wd)
@@ -863,8 +869,9 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris)
/* Memory bandwidth partitioning */
if (FIELD_GET(MPAMF_IDR_HAS_MBW_PART, ris->idr)) {
u32 mbw_features;
-
- mpam_read_partsel_reg(msc, MBW_IDR, &mbw_features);
+ err = mpam_read_partsel_reg(msc, MBW_IDR, &mbw_features);
+ if (err)
+ return err;
/* portion bitmap resolution */
props->mbw_pbm_bits = FIELD_GET(MPAMF_MBW_IDR_BWPBM_WD, mbw_features);
@@ -893,8 +900,9 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris)
/* Priority partitioning */
if (FIELD_GET(MPAMF_IDR_HAS_PRI_PART, ris->idr)) {
u32 pri_features;
-
- mpam_read_partsel_reg(msc, PRI_IDR, &pri_features);
+ err = mpam_read_partsel_reg(msc, PRI_IDR, &pri_features);
+ if (err)
+ return err;
props->intpri_wd = FIELD_GET(MPAMF_PRI_IDR_INTPRI_WD, pri_features);
if (props->intpri_wd && FIELD_GET(MPAMF_PRI_IDR_HAS_INTPRI, pri_features)) {
@@ -915,7 +923,9 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris)
if (FIELD_GET(MPAMF_IDR_HAS_MSMON, ris->idr)) {
u32 msmon_features;
- mpam_read_partsel_reg(msc, MSMON_IDR, &msmon_features);
+ err = mpam_read_partsel_reg(msc, MSMON_IDR, &msmon_features);
+ if (err)
+ return err;
/*
* If the firmware max-nrdy-us property is missing, the
@@ -928,7 +938,9 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris)
if (FIELD_GET(MPAMF_MSMON_IDR_MSMON_CSU, msmon_features)) {
u32 csumonidr;
- mpam_read_partsel_reg(msc, CSUMON_IDR, &csumonidr);
+ err = mpam_read_partsel_reg(msc, CSUMON_IDR, &csumonidr);
+ if (err)
+ return err;
props->num_csu_mon = FIELD_GET(MPAMF_CSUMON_IDR_NUM_MON, csumonidr);
if (props->num_csu_mon) {
@@ -954,7 +966,9 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris)
bool has_long;
u32 mbwumon_idr;
- mpam_read_partsel_reg(msc, MBWUMON_IDR, &mbwumon_idr);
+ err = mpam_read_partsel_reg(msc, MBWUMON_IDR, &mbwumon_idr);
+ if (err)
+ return err;
props->num_mbwu_mon = FIELD_GET(MPAMF_MBWUMON_IDR_NUM_MON, mbwumon_idr);
if (props->num_mbwu_mon) {
@@ -987,16 +1001,22 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris)
u16 partid_max;
u32 nrwidr;
- mpam_read_partsel_reg(msc, PARTID_NRW_IDR, &nrwidr);
+ err = mpam_read_partsel_reg(msc, PARTID_NRW_IDR, &nrwidr);
+ if (err)
+ return err;
+
partid_max = FIELD_GET(MPAMF_PARTID_NRW_IDR_INTPARTID_MAX, nrwidr);
mpam_set_feature(mpam_feat_partid_nrw, props);
msc->partid_max = min(msc->partid_max, partid_max);
}
+
+ return 0;
}
static int mpam_msc_hw_probe(struct mpam_msc *msc)
{
+ int ret;
u64 idr;
u16 partid_max;
u8 ris_idx, pmg_max;
@@ -1012,10 +1032,12 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc)
/* Grab an IDR value to find out how many RIS there are */
mutex_lock(&msc->part_sel_lock);
- mpam_msc_read_idr(msc, &idr);
- mpam_read_partsel_reg(msc, IIDR, &msc->iidr);
-
+ ret = mpam_msc_read_idr(msc, &idr);
+ if (!ret)
+ ret = mpam_read_partsel_reg(msc, IIDR, &msc->iidr);
mutex_unlock(&msc->part_sel_lock);
+ if (ret)
+ return ret;
mpam_enable_quirks(msc);
@@ -1028,8 +1050,10 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc)
for (ris_idx = 0; ris_idx <= msc->ris_max; ris_idx++) {
mutex_lock(&msc->part_sel_lock);
__mpam_part_sel(ris_idx, 0, msc);
- mpam_msc_read_idr(msc, &idr);
+ ret = mpam_msc_read_idr(msc, &idr);
mutex_unlock(&msc->part_sel_lock);
+ if (ret)
+ return ret;
partid_max = FIELD_GET(MPAMF_IDR_PARTID_MAX, idr);
pmg_max = FIELD_GET(MPAMF_IDR_PMG_MAX, idr);
@@ -1046,8 +1070,10 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc)
mutex_lock(&msc->part_sel_lock);
__mpam_part_sel(ris_idx, 0, msc);
- mpam_ris_hw_probe(ris);
+ ret = mpam_ris_hw_probe(ris);
mutex_unlock(&msc->part_sel_lock);
+ if (ret)
+ return ret;
}
/* Clear any stale errors */
--
2.43.0
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