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x86/fpu: Fold fpu_copy() into fpu__copy()

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Splitting it into two functions needlessly obfuscated the code.
While we're at it, improve the comment slightly.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: yu-cheng yu <yu-cheng.yu@intel.com>
Link: http://lkml.kernel.org/r/3eb5a63a9c5c84077b2677a7dfe684eef96fe59e.1453675014.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Andy Lutomirski 2016-01-24 14:38:08 -08:00 committed by Ingo Molnar
parent 5ed73f4073
commit a20d729704
1 changed files with 11 additions and 21 deletions
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32
arch/x86/kernel/fpu/core.c
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@ -231,14 +231,15 @@ void fpstate_init(union fpregs_state *state)
}
EXPORT_SYMBOL_GPL(fpstate_init);
/*
* Copy the current task's FPU state to a new task's FPU context.
*
* In both the 'eager' and the 'lazy' case we save hardware registers
* directly to the destination buffer.
*/
static void fpu_copy(struct fpu *dst_fpu, struct fpu *src_fpu)
int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu)
{
dst_fpu->counter = 0;
dst_fpu->fpregs_active = 0;
dst_fpu->last_cpu = -1;
if (!src_fpu->fpstate_active || !cpu_has_fpu)
return 0;
WARN_ON_FPU(src_fpu != &current->thread.fpu);
/*
@ -251,10 +252,9 @@ static void fpu_copy(struct fpu *dst_fpu, struct fpu *src_fpu)
/*
* Save current FPU registers directly into the child
* FPU context, without any memory-to-memory copying.
*
* If the FPU context got destroyed in the process (FNSAVE
* done on old CPUs) then copy it back into the source
* context and mark the current task for lazy restore.
* In lazy mode, if the FPU context isn't loaded into
* fpregs, CR0.TS will be set and do_device_not_available
* will load the FPU context.
*
* We have to do all this with preemption disabled,
* mostly because of the FNSAVE case, because in that
@ -274,16 +274,6 @@ static void fpu_copy(struct fpu *dst_fpu, struct fpu *src_fpu)
fpregs_deactivate(src_fpu);
}
preempt_enable();
}
int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu)
{
dst_fpu->counter = 0;
dst_fpu->fpregs_active = 0;
dst_fpu->last_cpu = -1;
if (src_fpu->fpstate_active && cpu_has_fpu)
fpu_copy(dst_fpu, src_fpu);
return 0;
}