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| author | Ben Horgan <ben.horgan@arm.com> | 2026-05-07 16:28:14 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2026-05-14 09:51:55 +0100 |
| commit | ccad6001be5c38426ccf45790c411467ad3c03c6 (patch) | |
| tree | 322c4a3f37f3ab82a088cfe00e3da7dd21bcdd89 /drivers/resctrl/mpam_devices.c | |
| parent | 4387970bbd84fd14e0c49c3089c5061ccd86b98a (diff) | |
| download | linux-next-ccad6001be5c38426ccf45790c411467ad3c03c6.tar.gz linux-next-ccad6001be5c38426ccf45790c411467ad3c03c6.zip | |
arm_mpam: Improve check for whether or not NRDY is hardware managed
mpam_ris_hw_probe_csu_nrdy() sets and clears MSMON_CSU.NRDY and checks
whether it's configuration sticks. However, hardware isn't given a chance
to disagree. Based on rule LRTGP, in MPAM specification IHI0099 version
B.b, the hardware will set NRDY if it needs time to establish a count after
a configuration change.
Enable the monitor so that NRDY becomes relevant and change the
configuration after clearing NRDY to try and coax the hardware into setting
it.
Fixes: 8c90dc68a5de ("arm_mpam: Probe the hardware features resctrl supports")
Cc: <stable@vger.kernel.org>
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'drivers/resctrl/mpam_devices.c')
| -rw-r--r-- | drivers/resctrl/mpam_devices.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 58e0c8970e8c..e145828f3f73 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -730,8 +730,7 @@ static void mpam_enable_quirks(struct mpam_msc *msc) */ static bool mpam_ris_hw_probe_csu_nrdy(struct mpam_msc_ris *ris) { - u32 now; - u32 mon_sel; + u32 now, mon_sel, ctl_val; bool can_set, can_clear; struct mpam_msc *msc = ris->vmsc->msc; @@ -742,11 +741,21 @@ static bool mpam_ris_hw_probe_csu_nrdy(struct mpam_msc_ris *ris) FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx); mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel); + /* 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); + _mpam_write_monsel_reg(msc, MSMON_CSU, MSMON___NRDY); now = _mpam_read_monsel_reg(msc, MSMON_CSU); 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); now = _mpam_read_monsel_reg(msc, MSMON_CSU); can_clear = !(now & MSMON___NRDY); mpam_mon_sel_unlock(msc); |