From: James Morse <james.morse@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Ben Horgan <ben.horgan@arm.com>,
Andre Przywara <andre.przywara@arm.com>,
Fuad Tabba <fuad.tabba@linux.dev>,
Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>,
Gavin Shan <gshan@redhat.com>, James Morse <james.morse@arm.com>
Subject: [PATCH 16/27] arm_mpam: propagate MSC access errors for hw_probe functions
Date: Fri, 2 Oct 2026 18:39:29 +0100 [thread overview]
Message-ID: <20261002173941.292319-17-james.morse@arm.com> (raw)
In-Reply-To: <20261002173941.292319-1-james.morse@arm.com>
From: Andre Przywara <andre.przywara@arm.com>
Allow the functions probing for MSC hardware and features to return an
error, and propagate read and write errors from the lower level up.
This uses some "scoped cleanup" functions like scoped_guard() and
ACQUIRE() to avoid the complexity of error handling when a lock has been
taken. Since the mon_sel_lock is a bit special (even more so in an
upcoming patch), we define a new GUARD type for it.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>
Reviewed-by: Ben Horgan <ben.horgan@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Tested-by: Gavin Shan <gshan@redhat.com> # on NVIDIA Grace Hopper
Signed-off-by: James Morse <james.morse@arm.com>
---
drivers/resctrl/mpam_devices.c | 145 ++++++++++++++++++++++----------
drivers/resctrl/mpam_internal.h | 4 +
2 files changed, 103 insertions(+), 46 deletions(-)
diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index 77502a87f0f4..a5365b56b1e7 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -792,44 +792,62 @@ static void mpam_enable_quirks(struct mpam_msc *msc)
* Try and see what values stick in this bit. If we can write either value,
* its probably not implemented by hardware.
*/
-static bool mpam_ris_hw_probe_csu_nrdy(struct mpam_msc_ris *ris)
+static int mpam_ris_hw_probe_csu_nrdy(struct mpam_msc_ris *ris)
{
u32 now, mon_sel, ctl_val;
bool can_set, can_clear;
struct mpam_msc *msc = ris->vmsc->msc;
+ int ret;
- if (WARN_ON_ONCE(!mpam_mon_sel_lock(msc)))
- return false;
+ ACQUIRE(mon_sel_lock, guard)(msc);
+ ret = ACQUIRE_ERR(mon_sel_lock, &guard);
+ if (ret)
+ return ret;
mon_sel = FIELD_PREP(MSMON_CFG_MON_SEL_MON_SEL, 0) |
FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx);
- mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel);
+ ret = mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel);
+ if (ret)
+ return ret;
/* Hardware might ignore nrdy if it's not enabled */
ctl_val = MSMON_CFG_CSU_CTL_TYPE_CSU;
ctl_val |= MSMON_CFG_x_CTL_MATCH_PARTID;
ctl_val |= MSMON_CFG_x_CTL_MATCH_PMG;
ctl_val |= MSMON_CFG_x_CTL_EN;
- mpam_write_monsel_reg(msc, CFG_CSU_FLT, 0);
- mpam_write_monsel_reg(msc, CFG_CSU_CTL, ctl_val);
+ ret = mpam_write_monsel_reg(msc, CFG_CSU_FLT, 0);
+ if (ret)
+ return ret;
+ ret = mpam_write_monsel_reg(msc, CFG_CSU_CTL, ctl_val);
+ if (ret)
+ return ret;
- _mpam_write_monsel_reg(msc, MSMON_CSU, MSMON___NRDY);
- _mpam_read_monsel_reg(msc, MSMON_CSU, &now);
+ ret = _mpam_write_monsel_reg(msc, MSMON_CSU, MSMON___NRDY);
+ if (ret)
+ return ret;
+ ret = _mpam_read_monsel_reg(msc, MSMON_CSU, &now);
+ if (ret)
+ return ret;
can_set = now & MSMON___NRDY;
- _mpam_write_monsel_reg(msc, MSMON_CSU, 0);
+ ret = _mpam_write_monsel_reg(msc, MSMON_CSU, 0);
+ if (ret)
+ return ret;
/* 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);
+ ret = mpam_write_monsel_reg(msc, CFG_CSU_FLT, 0x1);
+ if (ret)
+ return ret;
+ ret = _mpam_read_monsel_reg(msc, MSMON_CSU, &now);
+ if (ret)
+ return ret;
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;
+ int fw_has_nrdy_err, err;
struct mpam_msc *msc = ris->vmsc->msc;
struct device *dev = &msc->pdev->dev;
struct mpam_props *props = &ris->props;
@@ -842,7 +860,9 @@ 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 &&
@@ -867,7 +887,9 @@ 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)
@@ -877,8 +899,9 @@ 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);
@@ -907,8 +930,9 @@ 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)) {
@@ -929,20 +953,24 @@ 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
* CSU counters can't be used. Should we wait forever?
*/
- err = device_property_read_u32(&msc->pdev->dev,
- "arm,not-ready-us",
- &msc->nrdy_usec);
+ fw_has_nrdy_err = device_property_read_u32(&msc->pdev->dev,
+ "arm,not-ready-us",
+ &msc->nrdy_usec);
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) {
@@ -954,13 +982,16 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris)
mpam_set_feature(mpam_feat_msmon_csu_xcl, props);
/* Is NRDY hardware managed? */
- hw_managed = mpam_ris_hw_probe_csu_nrdy(ris);
+ err = mpam_ris_hw_probe_csu_nrdy(ris);
+ if (err < 0)
+ return err;
+ hw_managed = err;
/*
* Accept the missing firmware property if NRDY appears
* un-implemented.
*/
- if (err && hw_managed)
+ if (fw_has_nrdy_err && hw_managed)
dev_err_once(dev, "Counters are not usable because not-ready timeout was not provided by firmware.");
}
}
@@ -968,7 +999,9 @@ 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) {
@@ -1001,16 +1034,22 @@ 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;
@@ -1025,11 +1064,15 @@ 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);
+ scoped_guard(mutex, &msc->part_sel_lock) {
+ ret = mpam_msc_read_idr(msc, &idr);
+ if (ret)
+ return ret;
- mutex_unlock(&msc->part_sel_lock);
+ ret = mpam_read_partsel_reg(msc, IIDR, &msc->iidr);
+ if (ret)
+ return ret;
+ }
mpam_enable_quirks(msc);
@@ -1040,10 +1083,15 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc)
msc->pmg_max = FIELD_GET(MPAMF_IDR_PMG_MAX, idr);
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);
- mutex_unlock(&msc->part_sel_lock);
+ scoped_guard(mutex, &msc->part_sel_lock) {
+ ret = __mpam_part_sel(ris_idx, 0, msc);
+ if (ret)
+ return ret;
+
+ ret = mpam_msc_read_idr(msc, &idr);
+ if (ret)
+ return ret;
+ }
partid_max = FIELD_GET(MPAMF_IDR_PARTID_MAX, idr);
pmg_max = FIELD_GET(MPAMF_IDR_PMG_MAX, idr);
@@ -1051,17 +1099,22 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc)
msc->pmg_max = min(msc->pmg_max, pmg_max);
msc->has_extd_esr = FIELD_GET(MPAMF_IDR_HAS_EXTD_ESR, idr);
- mutex_lock(&mpam_list_lock);
- ris = mpam_get_or_create_ris(msc, ris_idx);
- mutex_unlock(&mpam_list_lock);
- if (IS_ERR(ris))
- return PTR_ERR(ris);
+ scoped_guard(mutex, &mpam_list_lock) {
+ ris = mpam_get_or_create_ris(msc, ris_idx);
+ if (IS_ERR(ris))
+ return PTR_ERR(ris);
+ }
ris->idr = idr;
- mutex_lock(&msc->part_sel_lock);
- __mpam_part_sel(ris_idx, 0, msc);
- mpam_ris_hw_probe(ris);
- mutex_unlock(&msc->part_sel_lock);
+ scoped_guard(mutex, &msc->part_sel_lock) {
+ ret = __mpam_part_sel(ris_idx, 0, msc);
+ if (ret)
+ return ret;
+
+ ret = mpam_ris_hw_probe(ris);
+ if (ret)
+ return ret;
+ }
}
/* Clear any stale errors */
diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h
index def0e3a65c23..68a6cf2b9cc7 100644
--- a/drivers/resctrl/mpam_internal.h
+++ b/drivers/resctrl/mpam_internal.h
@@ -162,6 +162,10 @@ static inline void mpam_mon_sel_lock_init(struct mpam_msc *msc)
raw_spin_lock_init(&msc->_mon_sel_lock);
}
+DEFINE_GUARD(mon_sel, struct mpam_msc *,
+ mpam_mon_sel_lock(_T), mpam_mon_sel_unlock(_T));
+DEFINE_GUARD_COND(mon_sel, _lock, mpam_mon_sel_lock(_T), _RET);
+
/* Bits for mpam features bitmaps */
enum mpam_device_features {
mpam_feat_cpor_part,
--
2.53.0
next prev parent reply other threads:[~2026-10-02 17:40 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-02 17:39 [GIT PULL/PATCH 00/27] MPAM driver changes for v7.4 James Morse
2026-10-02 17:39 ` [PATCH 01/27] arm_mpam: Move MPAMF_ECR write helpers to allow reuse James Morse
2026-10-02 17:39 ` [PATCH 02/27] arm_mpam: Restore the error interrupt enable from mpam_cpu_online() James Morse
2026-10-02 17:39 ` [PATCH 03/27] arm_mpam: Set mpam_feat_msmon_mbwu_31counter when there are bandwidth counters James Morse
2026-10-02 17:39 ` [PATCH 04/27] arm_mpam: Add missing mon_sel locking in MBWU save and restore James Morse
2026-10-02 17:39 ` [PATCH 05/27] arm_mpam: Ensure MBWU counters are reset on restore James Morse
2026-10-02 17:39 ` [PATCH 06/27] arm_mpam: Use __ris_msmon_read() for saving MBWU state James Morse
2026-10-02 18:52 ` Ben Horgan
2026-10-02 18:54 ` Catalin Marinas
2026-10-02 17:39 ` [PATCH 07/27] arm_mpam: Initialize all of struct mon_read in mpam_restore_mbwu_state() James Morse
2026-10-02 17:39 ` [PATCH 08/27] arm_mpam: resctrl: Correct check that existing class is L3 James Morse
2026-10-02 17:39 ` [PATCH 09/27] arm_mpam: resctrl: Make read_mon_cdp_safe() self consistent James Morse
2026-10-02 17:39 ` [PATCH 10/27] arm_mpam: Don't loop forever if there is the maximum possible amount of PARTIDs James Morse
2026-10-02 17:39 ` [PATCH 11/27] arm_mpam: Switch to kvzmalloc_objs() for allocation of component cfg James Morse
2026-10-02 17:39 ` [PATCH 12/27] arm_mpam: resctrl: Don't stop early when tearing down a class James Morse
2026-10-02 17:39 ` [PATCH 13/27] MAINTAINERS: Add mpam.rst to the MPAM DRIVER entry James Morse
2026-10-02 17:39 ` [PATCH 15/27] arm_mpam: let low level MSC accessors return an error James Morse
2026-10-02 17:39 ` James Morse [this message]
2026-10-02 17:39 ` [PATCH 17/27] arm_mpam: propagate MSC access errors for MBWU counters James Morse
2026-10-02 17:39 ` [PATCH 18/27] arm_mpam: propagate MSC access errors for msmon helpers James Morse
2026-10-02 17:39 ` [PATCH 19/27] arm_mpam: propagate MSC access errors for __ris_msmon_read() James Morse
2026-10-02 17:39 ` [PATCH 20/27] arm_mpam: propagate MSC access errors for state saving function James Morse
2026-10-02 17:39 ` [PATCH 21/27] arm_mpam: propagate MSC access errors for mpam_reprogram_ris_partid() James Morse
2026-10-02 17:39 ` [PATCH 22/27] arm_mpam: propagate MSC access errors for interrupt control James Morse
2026-10-02 17:39 ` [PATCH 23/27] arm_mpam: propagate MSC access errors in mpam_reset_class_locked() James Morse
2026-10-02 17:39 ` [PATCH 24/27] arm_mpam: prepare mon_sel locking for MPAM-Fb James Morse
2026-10-02 17:39 ` [PATCH 25/27] arm_mpam: add MPAM-Fb MSC firmware access support James Morse
2026-10-02 17:39 ` [PATCH 26/27] arm_mpam: change MPAM-Fb error IRQ to use a threaded IRQ handler James Morse
2026-10-02 17:39 ` [PATCH 27/27] arm_mpam: detect and enable MPAM-Fb PCC support James Morse
2026-10-02 19:02 ` [GIT PULL/PATCH 00/27] MPAM driver changes for v7.4 Catalin Marinas
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