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@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200912153707.667731-2-alexandru.elisei@arm.com

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 850842f27beeec8229c973ff2602618ba0ed74d8..aa9b43d412b252c4badb39a3d7984f3544ce84de 100644 (file)
--- 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);