[PATCH v2 07/15] 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 | 47 +++++++++++++++++++++-------------
 1 file changed, 29 insertions(+), 18 deletions(-)

diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index d18c7be86aaa..c50ca0e4f426 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -1773,6 +1773,7 @@ static int mpam_save_mbwu_state(void *arg)
 {
 	int i;
 	u64 val;
+	int ret;
 	struct mon_cfg *cfg;
 	u32 cur_flt, cur_ctl, mon_sel;
 	struct mpam_msc_ris *ris = arg;
@@ -1789,31 +1790,41 @@ 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_read_monsel_reg(msc, CFG_MBWU_FLT, &cur_flt);
+		if (!ret)
+			ret = mpam_read_monsel_reg(msc, CFG_MBWU_CTL, &cur_ctl);
+		if (!ret)
+			mpam_write_monsel_reg(msc, CFG_MBWU_CTL, 0);
 
-		if (mpam_ris_has_mbwu_long_counter(ris)) {
-			val = mpam_msc_read_mbwu_l(msc);
-			mpam_msc_zero_mbwu_l(msc);
-		} else {
-			u32 val32;
+		if (!ret) {
+			if (mpam_ris_has_mbwu_long_counter(ris)) {
+				val = mpam_msc_read_mbwu_l(msc);
+				mpam_msc_zero_mbwu_l(msc);
+			} else {
+				u32 val32;
 
-			mpam_read_monsel_reg(msc, MBWU, &val32);
-			val = val32;
-			mpam_write_monsel_reg(msc, MBWU, 0);
+				ret = mpam_read_monsel_reg(msc, MBWU, &val32);
+				if (!ret) {
+					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 (!ret && 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);
+		if (ret)
+			break;
 	}
 
-	return 0;
+	return ret;
 }
 
 /*
-- 
2.43.0