[PATCH v2 20/36] irqchip/gic-v4.1: Suppress per-VLPI doorbell

From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Jason Cooper <jason@lakedaemon.net>,
	Robert Richter <rrichter@marvell.com>,
	Jayachandran C <jnair@marvell.com>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH v2 20/36] irqchip/gic-v4.1: Suppress per-VLPI doorbell
Date: Sun, 27 Oct 2019 14:42:18 +0000	[thread overview]
Message-ID: <20191027144234.8395-21-maz@kernel.org> (raw)
In-Reply-To: <20191027144234.8395-1-maz@kernel.org>

Since GICv4.1 gives us a per-VPE doorbell, avoid programming anything
else on VMOVI/VMAPI/VMAPTI and on any other action that would have
otherwise resulted in a per-VLPI doorbell to be programmed.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/irqchip/irq-gic-v3-its.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 10bd156aa042..75c4d1a6f20d 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -691,7 +691,7 @@ static struct its_vpe *its_build_vmapti_cmd(struct its_node *its,
 {
 	u32 db;
 
-	if (desc->its_vmapti_cmd.db_enabled)
+	if (!is_v4_1(its) && desc->its_vmapti_cmd.db_enabled)
 		db = desc->its_vmapti_cmd.vpe->vpe_db_lpi;
 	else
 		db = 1023;
@@ -714,7 +714,7 @@ static struct its_vpe *its_build_vmovi_cmd(struct its_node *its,
 {
 	u32 db;
 
-	if (desc->its_vmovi_cmd.db_enabled)
+	if (!is_v4_1(its) && desc->its_vmovi_cmd.db_enabled)
 		db = desc->its_vmovi_cmd.vpe->vpe_db_lpi;
 	else
 		db = 1023;
@@ -1227,6 +1227,13 @@ static void its_vlpi_set_doorbell(struct irq_data *d, bool enable)
 	struct its_device *its_dev = irq_data_get_irq_chip_data(d);
 	u32 event = its_get_event_id(d);
 
+	/*
+	 * GICv4.1 does away with the per-LPI nonsense, nothing to do
+	 * here.
+	 */
+	if (is_v4_1(its_dev->its))
+		return;
+
 	if (its_dev->event_map.vlpi_maps[event].db_enabled == enable)
 		return;
 
-- 
2.20.1

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