[PATCH 20/27] arm_mpam: propagate MSC access errors for state saving function

[James Morse <james.morse@arm.com>]

From: Andre Przywara <andre.przywara@arm.com>

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 <andre.przywara@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>
Reviewed-by: Ben Horgan <ben.horgan@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Tested-by: Gavin Shan <gshan@redhat.com> # on NVIDIA Grace Hopper
[morse: Fixed merge conflicts in mpam_save_mbwu_state() and __ris_msmon_read()]
Signed-off-by: James Morse <james.morse@arm.com>
---
 drivers/resctrl/mpam_devices.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index 853e5c5d7158..39437361ed7a 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -1859,6 +1859,7 @@ static int mpam_restore_mbwu_state(void *_ris)
 static int mpam_save_mbwu_state(void *arg)
 {
 	int i;
+	int ret;
 	u64 val;
 	struct mon_cfg *cfg;
 	struct mon_read mbwu_arg;
@@ -1877,10 +1878,18 @@ 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;
 
 		cfg->mon = i;
 		cfg->pmg = FIELD_GET(MSMON_CFG_x_FLT_PMG, cur_flt);
-- 
2.53.0