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From: Oliver Upton <oliver.upton@linux.dev>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <maz@kernel.org>,
	Zenghui Yu <yuzenghui@huawei.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	kvmarm@lists.linux.dev,
	Jing Zhang <jingzhangos@google.com>,
	Oliver Upton <oliver.upton@linux.dev>
Subject: [PATCH 2/3] irqchip/gic-v3-its: Spin off GICv4 init into a separate function
Date: Mon, 19 Feb 2024 18:58:07 +0000
Message-ID: <20240219185809.286724-3-oliver.upton@linux.dev>
In-Reply-To: <20240219185809.286724-1-oliver.upton@linux.dev>
References: <20240219185809.286724-1-oliver.upton@linux.dev>
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Burying the GICv4 redistributor initialization into the routine for LPIs
is a bit confusing, and can lead to sillies where unexpected codepaths
may not fully initialize the RD.

Hoist it out of its_cpu_init_lpis() into a dedicated function.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
 drivers/irqchip/irq-gic-v3-its.c | 32 +++++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 11 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 0022852ce494..63d1743f08cc 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -3173,8 +3173,25 @@ static void its_cpu_init_lpis(void)
 	writel_relaxed(val, rbase + GICR_CTLR);
 
 out:
-	if (gic_rdists->has_vlpis && !gic_rdists->has_rvpeid) {
+	/* Make sure the GIC has seen the above */
+	dsb(sy);
+	gic_data_rdist()->flags |= RD_LOCAL_LPI_ENABLED;
+	pr_info("GICv3: CPU%d: using %s LPI pending table @%pa\n",
+		smp_processor_id(),
+		gic_data_rdist()->flags & RD_LOCAL_PENDTABLE_PREALLOCATED ?
+		"reserved" : "allocated",
+		&paddr);
+}
+
+static void its_cpu_init_vlpis(void)
+{
+	/* No vLPIs? No problem. */
+	if (!gic_rdists->has_vlpis)
+		return;
+
+	if (!gic_rdists->has_rvpeid) {
 		void __iomem *vlpi_base = gic_data_rdist_vlpi_base();
+		u64 val;
 
 		/*
 		 * It's possible for CPU to receive VLPIs before it is
@@ -3193,7 +3210,8 @@ static void its_cpu_init_lpis(void)
 		 * ancient programming gets left in and has possibility of
 		 * corrupting memory.
 		 */
-		val = its_clear_vpend_valid(vlpi_base, 0, 0);
+		its_clear_vpend_valid(vlpi_base, 0, 0);
+		return;
 	}
 
 	if (allocate_vpe_l1_table()) {
@@ -3205,15 +3223,6 @@ static void its_cpu_init_lpis(void)
 		gic_rdists->has_rvpeid = false;
 		gic_rdists->has_vlpis = false;
 	}
-
-	/* Make sure the GIC has seen the above */
-	dsb(sy);
-	gic_data_rdist()->flags |= RD_LOCAL_LPI_ENABLED;
-	pr_info("GICv3: CPU%d: using %s LPI pending table @%pa\n",
-		smp_processor_id(),
-		gic_data_rdist()->flags & RD_LOCAL_PENDTABLE_PREALLOCATED ?
-		"reserved" : "allocated",
-		&paddr);
 }
 
 static void its_cpu_init_collection(struct its_node *its)
@@ -5265,6 +5274,7 @@ int its_cpu_init(void)
 			return ret;
 
 		its_cpu_init_lpis();
+		its_cpu_init_vlpis();
 		its_cpu_init_collections();
 	}
 
-- 
2.44.0.rc0.258.g7320e95886-goog