[tip: irq/core] irqchip/gic-v3: Spell out when pseudo-NMIs are enabled

From: tip-bot2 for Alexandru Elisei
Date: Sun Oct 11 2020 - 13:59:25 EST


The following commit has been merged into the irq/core branch of tip:

Commit-ID: 4e594ad1068ea1db359d6161f580f03edecf6cb0
Gitweb: https://git.kernel.org/tip/4e594ad1068ea1db359d6161f580f03edecf6cb0
Author: Alexandru Elisei <alexandru.elisei@xxxxxxx>
AuthorDate: Sat, 12 Sep 2020 16:37:06 +01:00
Committer: Marc Zyngier <maz@xxxxxxxxxx>
CommitterDate: Sun, 13 Sep 2020 17:51:35 +01:00

irqchip/gic-v3: Spell out when pseudo-NMIs are enabled

When NMIs cannot be enabled, the driver prints a message stating that
unambiguously. When they are enabled, the only feedback we get is a message
regarding the use of synchronization for ICC_PMR_EL1 writes, which is not
as useful for a user who is not intimately familiar with how NMIs are
implemented.

Let's make it obvious that pseudo-NMIs are enabled. Keep the message about
using a barrier for ICC_PMR_EL1 writes, because it has a non-negligible
impact on performance.

Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200912153707.667731-2-alexandru.elisei@xxxxxxx
---
drivers/irqchip/irq-gic-v3.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 850842f..aa9b43d 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -1564,8 +1564,8 @@ static void gic_enable_nmi_support(void)
if (gic_read_ctlr() & ICC_CTLR_EL1_PMHE_MASK)
static_branch_enable(&gic_pmr_sync);

- pr_info("%s ICC_PMR_EL1 synchronisation\n",
- static_branch_unlikely(&gic_pmr_sync) ? "Forcing" : "Relaxing");
+ pr_info("Pseudo-NMIs enabled using %s ICC_PMR_EL1 synchronisation\n",
+ static_branch_unlikely(&gic_pmr_sync) ? "forced" : "relaxed");

static_branch_enable(&supports_pseudo_nmis);