[PATCH v3 05/16] arm_mpam: propagate MSC read errors for msmon helpers

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

Allow the helper functions for msmon accesses 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 | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index 3b6f9e552a9f..041fca018e68 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -1201,25 +1201,31 @@ static void gen_msmon_ctl_flt_vals(struct mon_read *m, u32 *ctl_val,
 	}
 }
 
-static void read_msmon_ctl_flt_vals(struct mon_read *m, u32 *ctl_val,
-				    u32 *flt_val)
+static int read_msmon_ctl_flt_vals(struct mon_read *m, u32 *ctl_val,
+				   u32 *flt_val)
 {
 	struct mpam_msc *msc = m->ris->vmsc->msc;
+	int ret;
 
 	switch (m->type) {
 	case mpam_feat_msmon_csu:
-		mpam_read_monsel_reg(msc, CFG_CSU_CTL, ctl_val);
-		mpam_read_monsel_reg(msc, CFG_CSU_FLT, flt_val);
+		ret = mpam_read_monsel_reg(msc, CFG_CSU_CTL, ctl_val);
+		if (!ret)
+			ret = mpam_read_monsel_reg(msc, CFG_CSU_FLT, flt_val);
 		break;
 	case mpam_feat_msmon_mbwu_31counter:
 	case mpam_feat_msmon_mbwu_44counter:
 	case mpam_feat_msmon_mbwu_63counter:
-		mpam_read_monsel_reg(msc, CFG_MBWU_CTL, ctl_val);
-		mpam_read_monsel_reg(msc, CFG_MBWU_FLT, flt_val);
+		ret = mpam_read_monsel_reg(msc, CFG_MBWU_CTL, ctl_val);
+		if (!ret)
+			ret = mpam_read_monsel_reg(msc, CFG_MBWU_FLT, flt_val);
 		break;
 	default:
 		pr_warn("Unexpected monitor type %d\n", m->type);
+		return -EINVAL;
 	}
+
+	return ret;
 }
 
 /* Remove values set by the hardware to prevent apparent mismatches. */
-- 
2.43.0