[PATCH 5.16 248/285] irqchip/gic-v3: Fix GICR_CTLR.RWP polling

Greg Kroah-Hartman
2022-04-12T08:25:33Z

From: Marc Zyngier <maz@kernel.org>

commit 0df6664531a12cdd8fc873f0cac0dcb40243d3e9 upstream.

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
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Link: https://lore.kernel.org/r/20220315165034.794482-2-maz@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/irqchip/irq-gic-v3.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -206,11 +206,11 @@ static inline void __iomem *gic_dist_bas
}
}

-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 __i
/* 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