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x86/fpu: Simplify fpstate_init_curr() usage 

Now that fpstate_init_curr() is not doing implicit allocations
anymore, almost all uses of it involve a very simple pattern:

	if (!fpu->fpstate_active)
		fpstate_init_curr(fpu);

which is basically activating the FPU fpstate if it was not active
before.

So propagate the check into the function itself, and rename the
function according to its new purpose:

	fpu__activate_curr(fpu);

Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
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: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar 2015-04-27 07:18:17 +02:00
parent 0ee6a51725
commit c4d72e2db3
5 changed files with 15 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/x86/include/asm/fpu/internal.h
View File

@ -44,7 +44,7 @@ extern void fpu__init_system_xstate(void);
extern void fpu__init_cpu_xstate(void);
extern void fpu__init_system(struct cpuinfo_x86 *c);
extern void fpstate_init_curr(struct fpu *fpu);
extern void fpu__activate_curr(struct fpu *fpu);
extern void fpstate_init(struct fpu *fpu);
extern void fpu__clear(struct task_struct *tsk);

21
arch/x86/kernel/fpu/core.c
View File

@ -259,19 +259,21 @@ int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu)
}
/*
* Initialize the current task's in-memory FPU context:
* Activate the current task's in-memory FPU context,
* if it has not been used before:
*/
void fpstate_init_curr(struct fpu *fpu)
void fpu__activate_curr(struct fpu *fpu)
{
WARN_ON_ONCE(fpu != &current->thread.fpu);
WARN_ON_ONCE(fpu->fpstate_active);
fpstate_init(fpu);
if (!fpu->fpstate_active) {
fpstate_init(fpu);
/* Safe to do for the current task: */
fpu->fpstate_active = 1;
/* Safe to do for the current task: */
fpu->fpstate_active = 1;
}
}
EXPORT_SYMBOL_GPL(fpstate_init_curr);
EXPORT_SYMBOL_GPL(fpu__activate_curr);
/*
* This function is called before we modify a stopped child's
@ -325,8 +327,7 @@ void fpu__restore(void)
struct task_struct *tsk = current;
struct fpu *fpu = &tsk->thread.fpu;
if (!fpu->fpstate_active)
fpstate_init_curr(fpu);
fpu__activate_curr(fpu);
/* Avoid __kernel_fpu_begin() right after fpregs_activate() */
kernel_fpu_disable();
@ -352,7 +353,7 @@ void fpu__clear(struct task_struct *tsk)
drop_fpu(fpu);
} else {
if (!fpu->fpstate_active) {
fpstate_init_curr(fpu);
fpu__activate_curr(fpu);
user_fpu_begin();
}
restore_init_xstate();

3
arch/x86/kernel/fpu/xsave.c
View File

@ -358,8 +358,7 @@ int __restore_xstate_sig(void __user *buf, void __user *buf_fx, int size)
if (!access_ok(VERIFY_READ, buf, size))
return -EACCES;
if (!fpu->fpstate_active)
fpstate_init_curr(fpu);
fpu__activate_curr(fpu);
if (!static_cpu_has(X86_FEATURE_FPU))
return fpregs_soft_set(current, NULL,

3
arch/x86/kvm/x86.c
View File

@ -6601,8 +6601,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
int r;
sigset_t sigsaved;
if (!fpu->fpstate_active)
fpstate_init_curr(fpu);
fpu__activate_curr(fpu);
if (vcpu->sigset_active)
sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);

3
arch/x86/math-emu/fpu_entry.c
View File

@ -149,8 +149,7 @@ void math_emulate(struct math_emu_info *info)
struct desc_struct code_descriptor;
struct fpu *fpu = &current->thread.fpu;
if (!fpu->fpstate_active)
fpstate_init_curr(fpu);
fpu__activate_curr(fpu);
#ifdef RE_ENTRANT_CHECKING
if (emulating) {