From b54cdbad4a39bb3abc85ac151f4882b3d92c5d79 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Wed, 2 Oct 2024 17:16:33 +0100 Subject: [PATCH] ARM: 9424/1: vfp: Use vfp_state_hold() in vfp_sync_hwstate(). vfp_sync_hwstate() uses preempt_disable() followed by local_bh_disable() to ensure that it won't get interrupted while checking the VFP state. This harms PREEMPT_RT because softirq handling can get preempted and local_bh_disable() synchronizes the related section with a sleeping lock which does not work with disabled preemption. Use the vfp_state_hold() to synchronize the access. Reviewed-by: Ard Biesheuvel Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Russell King (Oracle) --- arch/arm/vfp/vfpmodule.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c index 63de164c7fc7..1726db050076 100644 --- a/arch/arm/vfp/vfpmodule.c +++ b/arch/arm/vfp/vfpmodule.c @@ -540,11 +540,9 @@ static inline void vfp_pm_init(void) { } */ void vfp_sync_hwstate(struct thread_info *thread) { - unsigned int cpu = get_cpu(); + vfp_state_hold(); - local_bh_disable(); - - if (vfp_state_in_hw(cpu, thread)) { + if (vfp_state_in_hw(raw_smp_processor_id(), thread)) { u32 fpexc = fmrx(FPEXC); /* @@ -555,8 +553,7 @@ void vfp_sync_hwstate(struct thread_info *thread) fmxr(FPEXC, fpexc); } - local_bh_enable(); - put_cpu(); + vfp_state_release(); } /* Ensure that the thread reloads the hardware VFP state on the next use. */