[PATCH v9 08/12] arm_mpam: propagate MSC access errors for interrupt control

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

Allow the functions dealing with interrupt registration and enablement
to check for and return errors, and propagate MSC read and write errors
from the lower level up.
This does not cover the IRQ handler yet, as this needs some more
attention.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 drivers/resctrl/mpam_devices.c | 31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index 49239b15a27f..1b07f7765f96 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -1105,7 +1105,9 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc)
 	}
 
 	/* Clear any stale errors */
-	mpam_msc_clear_esr(msc);
+	ret = mpam_msc_clear_esr(msc);
+	if (ret)
+		return ret;
 
 	spin_lock(&partid_max_lock);
 	mpam_partid_max = min(mpam_partid_max, msc->partid_max);
@@ -2660,9 +2662,7 @@ static int mpam_enable_msc_ecr(void *_msc)
 {
 	struct mpam_msc *msc = _msc;
 
-	__mpam_write_reg(msc, MPAMF_ECR, MPAMF_ECR_INTEN);
-
-	return 0;
+	return __mpam_write_reg(msc, MPAMF_ECR, MPAMF_ECR_INTEN);
 }
 
 /* This can run in mpam_disable(), and the interrupt handler on the same CPU */
@@ -2670,9 +2670,7 @@ static int mpam_disable_msc_ecr(void *_msc)
 {
 	struct mpam_msc *msc = _msc;
 
-	__mpam_write_reg(msc, MPAMF_ECR, 0);
-
-	return 0;
+	return __mpam_write_reg(msc, MPAMF_ECR, 0);
 }
 
 static irqreturn_t __mpam_irq_handler(int irq, struct mpam_msc *msc)
@@ -2769,11 +2767,13 @@ static int mpam_register_irqs(void)
 				return err;
 		}
 
-		mutex_lock(&msc->error_irq_lock);
-		msc->error_irq_req = true;
-		mpam_touch_msc(msc, mpam_enable_msc_ecr, msc);
-		msc->error_irq_hw_enabled = true;
-		mutex_unlock(&msc->error_irq_lock);
+		scoped_guard(mutex, &msc->error_irq_lock) {
+			msc->error_irq_req = true;
+			err = mpam_touch_msc(msc, mpam_enable_msc_ecr, msc);
+			if (err)
+				return err;
+			msc->error_irq_hw_enabled = true;
+		}
 	}
 
 	return 0;
@@ -2792,10 +2792,10 @@ static void mpam_unregister_irqs(void)
 		if (irq <= 0)
 			continue;
 
-		mutex_lock(&msc->error_irq_lock);
+		guard(mutex)(&msc->error_irq_lock);
 		if (msc->error_irq_hw_enabled) {
-			mpam_touch_msc(msc, mpam_disable_msc_ecr, msc);
-			msc->error_irq_hw_enabled = false;
+			if (!mpam_touch_msc(msc, mpam_disable_msc_ecr, msc))
+				msc->error_irq_hw_enabled = false;
 		}
 
 		if (msc->error_irq_req) {
@@ -2807,7 +2807,6 @@ static void mpam_unregister_irqs(void)
 			}
 			msc->error_irq_req = false;
 		}
-		mutex_unlock(&msc->error_irq_lock);
 	}
 }
 
-- 
2.43.0