diff options
| author | Mark Rutland <mark.rutland@arm.com> | 2023-10-02 18:00:36 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2023-10-06 12:34:41 +0100 |
| commit | a07a594152173a3dd3bdd12fc7d73dbba54cdbca (patch) | |
| tree | 35ed5150f5d29e90385d2bf0cdf1c74925e5b6b8 /arch/arm64/kernel/smp.c | |
| parent | 62817d5ba25d2361488184f85d628b5b540e254b (diff) | |
arm64: smp: avoid NMI IPIs with broken MediaTek FW
Some MediaTek devices have broken firmware which corrupts some GICR
registers behind the back of the OS, and pseudo-NMIs cannot be used on
these devices. For more details see commit:
44bd78dd2b8897f5 ("irqchip/gic-v3: Disable pseudo NMIs on Mediatek devices w/ firmware issues")
We did not take this problem into account in commit:
331a1b3a836c0f38 ("arm64: smp: Add arch support for backtrace using pseudo-NMI")
Since that commit arm64's SMP code will try to setup some IPIs as
pseudo-NMIs, even on systems with broken FW. The GICv3 code will
(rightly) reject attempts to request interrupts as pseudo-NMIs,
resulting in boot-time failures.
Avoid the problem by taking the broken FW into account when deciding to
request IPIs as pseudo-NMIs. The GICv3 driver maintains a static_key
named "supports_pseudo_nmis" which is false on systems with broken FW,
and we can consult this within ipi_should_be_nmi().
Fixes: 331a1b3a836c ("arm64: smp: Add arch support for backtrace using pseudo-NMI")
Reported-by: Chen-Yu Tsai <wenst@chromium.org>
Closes: https://issuetracker.google.com/issues/197061987#comment68
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/smp.c')
| -rw-r--r-- | arch/arm64/kernel/smp.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 814d9aa93b21..061c69160f90 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -964,7 +964,10 @@ static void smp_cross_call(const struct cpumask *target, unsigned int ipinr) static bool ipi_should_be_nmi(enum ipi_msg_type ipi) { - if (!system_uses_irq_prio_masking()) + DECLARE_STATIC_KEY_FALSE(supports_pseudo_nmis); + + if (!system_uses_irq_prio_masking() || + !static_branch_likely(&supports_pseudo_nmis)) return false; switch (ipi) { |