[PATCH v7 06/11] arm_mpam: propagate MSC access errors for state saving function

Andre Przywara <[email protected]> Fri, 31 Jul 2026 19:03:19 +0200
Newsgroups org.kernel.vger.linux-acpi,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
Allow the mpam_save_mbwu_state() function to return an error, and
propagate read and write errors from the lower level up.

Signed-off-by: Andre Przywara <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>
Reviewed-by: Ben Horgan <[email protected]>
---
 drivers/resctrl/mpam_devices.c | 29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index fa8ed20a6740..38450c55e45e 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -1838,22 +1838,37 @@ static int mpam_save_mbwu_state(void *arg)
 
 		mon_sel = FIELD_PREP(MSMON_CFG_MON_SEL_MON_SEL, i) |
 			  FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx);
-		mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel);
-		mpam_read_monsel_reg(msc, CFG_MBWU_FLT, &cur_flt);
-		mpam_read_monsel_reg(msc, CFG_MBWU_CTL, &cur_ctl);
-		mpam_write_monsel_reg(msc, CFG_MBWU_CTL, 0);
+		ret = mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel);
+		if (ret)
+			return ret;
+		ret = mpam_read_monsel_reg(msc, CFG_MBWU_FLT, &cur_flt);
+		if (ret)
+			return ret;
+		ret = mpam_read_monsel_reg(msc, CFG_MBWU_CTL, &cur_ctl);
+		if (ret)
+			return ret;
+		ret = mpam_write_monsel_reg(msc, CFG_MBWU_CTL, 0);
+		if (ret)
+			return ret;
 
 		if (mpam_ris_has_mbwu_long_counter(ris)) {
 			ret = mpam_msc_read_mbwu_l(msc, &val);
 			if (ret)
 				return ret;
-			mpam_msc_zero_mbwu_l(msc);
+			ret = mpam_msc_zero_mbwu_l(msc);
+			if (ret)
+				return ret;
 		} else {
 			u32 val32;
 
-			mpam_read_monsel_reg(msc, MBWU, &val32);
+			ret = mpam_read_monsel_reg(msc, MBWU, &val32);
+			if (ret)
+				return ret;
+
 			val = val32;
-			mpam_write_monsel_reg(msc, MBWU, 0);
+			ret = mpam_write_monsel_reg(msc, MBWU, 0);
+			if (ret)
+				return ret;
 		}
 
 		cfg->mon = i;
-- 
2.43.0