[PATCH v3 08/16] arm_mpam: propagate MSC read errors for state saving functions

[Andre Przywara <andre.przywara@arm.com>]

Allow the mpam_save_mbwu_state() function to return an error, and
propagate read errors from the lower level up.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 drivers/resctrl/mpam_devices.c | 30 +++++++++++++++++++-----------
 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index 530ac0fe97b5..b2ecaba29fcc 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -1782,7 +1782,7 @@ static int mpam_save_mbwu_state(void *arg)
 {
 	int i;
 	u64 val;
-	int ret = 0;
+	int ret;
 	struct mon_cfg *cfg;
 	u32 cur_flt, cur_ctl, mon_sel;
 	struct mpam_msc_ris *ris = arg;
@@ -1799,8 +1799,12 @@ 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);
+		ret = mpam_read_monsel_reg(msc, CFG_MBWU_FLT, &cur_flt);
+		if (ret)
+			goto out_unlock;
+		ret = mpam_read_monsel_reg(msc, CFG_MBWU_CTL, &cur_ctl);
+		if (ret)
+			goto out_unlock;
 		mpam_write_monsel_reg(msc, CFG_MBWU_CTL, 0);
 
 		if (mpam_ris_has_mbwu_long_counter(ris)) {
@@ -1811,20 +1815,24 @@ static int mpam_save_mbwu_state(void *arg)
 		} else {
 			u32 val32;
 
-			mpam_read_monsel_reg(msc, MBWU, &val32);
+			ret = mpam_read_monsel_reg(msc, MBWU, &val32);
+			if (ret)
+				goto out_unlock;
+
 			val = val32;
 			mpam_write_monsel_reg(msc, MBWU, 0);
 		}
 
-		cfg->mon = i;
-		cfg->pmg = FIELD_GET(MSMON_CFG_x_FLT_PMG, cur_flt);
-		cfg->match_pmg = FIELD_GET(MSMON_CFG_x_CTL_MATCH_PMG, cur_ctl);
-		cfg->partid = FIELD_GET(MSMON_CFG_x_FLT_PARTID, cur_flt);
-		mbwu_state->correction += val;
-		mbwu_state->enabled = FIELD_GET(MSMON_CFG_x_CTL_EN, cur_ctl);
+		if (val != MSMON___L_NRDY) {
+			cfg->mon = i;
+			cfg->pmg = FIELD_GET(MSMON_CFG_x_FLT_PMG, cur_flt);
+			cfg->match_pmg = FIELD_GET(MSMON_CFG_x_CTL_MATCH_PMG, cur_ctl);
+			cfg->partid = FIELD_GET(MSMON_CFG_x_FLT_PARTID, cur_flt);
+			mbwu_state->correction += val;
+			mbwu_state->enabled = FIELD_GET(MSMON_CFG_x_CTL_EN, cur_ctl);
+		}
 		mpam_mon_sel_unlock(msc);
 	}
-
 	return 0;
 
 out_unlock:
-- 
2.43.0