[RFC PATCH 06/10] arm_mpam: Clamp cmax_wd to 16

[Jinjie Ruan]

The CMAX_WD field of MPAMF_CCAP_IDR describes the width of a 16-bit
register field, as BWA_WD does, but can report up to 63. The
fixed-point conversion of a CMAX/CMIN value shifts by 16 - wd, so a
width above 16 would shift the wrong way.

Clamp it the same way bwa_wd is clamped.

Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
---
 drivers/resctrl/mpam_devices.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index 22169436689a..0bed6c430af7 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -803,6 +803,8 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris)
 		u32 ccap_features = mpam_read_partsel_reg(msc, CCAP_IDR);
 
 		props->cmax_wd = FIELD_GET(MPAMF_CCAP_IDR_CMAX_WD, ccap_features);
+		/* As with bwa_wd, the field reports a 16-bit register field */
+		props->cmax_wd = min(props->cmax_wd, 16);
 		if (props->cmax_wd &&
 		    FIELD_GET(MPAMF_CCAP_IDR_HAS_CMAX_SOFTLIM, ccap_features))
 			mpam_set_feature(mpam_feat_cmax_softlim, props);
-- 
2.34.1