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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2024-10-02 17:16:33 +0100 |
|---|---|---|
| committer | Russell King (Oracle) <rmk+kernel@armlinux.org.uk> | 2024-11-12 16:41:47 +0000 |
| commit | b54cdbad4a39bb3abc85ac151f4882b3d92c5d79 (patch) | |
| tree | 694982cbbb63ba97da68b090dbc86f72a6399404 /arch/arm | |
| parent | f26bdbe1fa9f79fa8cb0d0bf39303c3573c60552 (diff) | |
| download | lwn-b54cdbad4a39bb3abc85ac151f4882b3d92c5d79.tar.gz lwn-b54cdbad4a39bb3abc85ac151f4882b3d92c5d79.zip | |
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 <ardb@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/vfp/vfpmodule.c | 9 |
1 files 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(); - - local_bh_disable(); + vfp_state_hold(); - 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. */ |