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From: Marc Zyngier <maz@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Andre Przywara <andre.przywara@arm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Eric Auger <eric.auger@redhat.com>,
	stable@vger.kernel.org
Subject: [PATCH 1/3] irqchip/gic-v3: Fix GICR_CTLR.RWP polling
Date: Tue, 15 Mar 2022 16:50:32 +0000	[thread overview]
Message-ID: <20220315165034.794482-2-maz@kernel.org> (raw)
In-Reply-To: <20220315165034.794482-1-maz@kernel.org>

It turns out that our polling of RWP is totally wrong when checking
for it in the redistributors, as we test the *distributor* bit index,
whereas it is a different bit number in the RDs... Oopsie boo.

This is embarassing. Not only because it is wrong, but also because
it took *8 years* to notice the blunder...

Just fix the damn thing.

Fixes: 021f653791ad ("irqchip: gic-v3: Initial support for GICv3")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
---
 drivers/irqchip/irq-gic-v3.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 5e935d97207d..736163d36b13 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -206,11 +206,11 @@ static inline void __iomem *gic_dist_base(struct irq_data *d)
 	}
 }
 
-static void gic_do_wait_for_rwp(void __iomem *base)
+static void gic_do_wait_for_rwp(void __iomem *base, u32 bit)
 {
 	u32 count = 1000000;	/* 1s! */
 
-	while (readl_relaxed(base + GICD_CTLR) & GICD_CTLR_RWP) {
+	while (readl_relaxed(base + GICD_CTLR) & bit) {
 		count--;
 		if (!count) {
 			pr_err_ratelimited("RWP timeout, gone fishing\n");
@@ -224,13 +224,13 @@ static void gic_do_wait_for_rwp(void __iomem *base)
 /* Wait for completion of a distributor change */
 static void gic_dist_wait_for_rwp(void)
 {
-	gic_do_wait_for_rwp(gic_data.dist_base);
+	gic_do_wait_for_rwp(gic_data.dist_base, GICD_CTLR_RWP);
 }
 
 /* Wait for completion of a redistributor change */
 static void gic_redist_wait_for_rwp(void)
 {
-	gic_do_wait_for_rwp(gic_data_rdist_rd_base());
+	gic_do_wait_for_rwp(gic_data_rdist_rd_base(), GICR_CTLR_RWP);
 }
 
 #ifdef CONFIG_ARM64
-- 
2.34.1


  reply	other threads:[~2022-03-15 16:50 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-15 16:50 [PATCH 0/3] irqchip/gic-v3: Assorted fixes and improvements Marc Zyngier
2022-03-15 16:50 ` Marc Zyngier [this message]
2022-03-16 14:51   ` [PATCH 1/3] irqchip/gic-v3: Fix GICR_CTLR.RWP polling Andre Przywara
2022-03-16 15:19     ` Marc Zyngier
2022-03-17 17:03   ` Lorenzo Pieralisi
2022-03-21  9:19   ` [irqchip: irq/irqchip-next] " irqchip-bot for Marc Zyngier
2022-03-21 14:07   ` irqchip-bot for Marc Zyngier
2022-04-05 15:39   ` [irqchip: irq/irqchip-fixes] " irqchip-bot for Marc Zyngier
2022-03-15 16:50 ` [PATCH 2/3] irqchip/gic-v3: Detect LPI invalidation MMIO registers Marc Zyngier
2022-03-16 11:21   ` Marc Zyngier
2022-03-16 14:51   ` Andre Przywara
2022-03-16 15:36     ` Marc Zyngier
2022-03-16 15:52       ` Andre Przywara
2022-03-17 17:35   ` Lorenzo Pieralisi
2022-03-21  9:31     ` Marc Zyngier
2022-03-15 16:50 ` [PATCH 3/3] irqchip/gic-v3: Relax polling of GIC{R,D}_CTLR.RWP Marc Zyngier
2022-03-16 14:54   ` Andre Przywara
2022-03-16 15:42     ` Marc Zyngier

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