Commit 6d79d86f authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Borislav Petkov
Browse files

x86/fpu: Simplify kernel_fpu_begin() 



Merge two helpers into the main function, remove a pointless local
variable and flatten a conditional.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Acked-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190604071524.12835-3-hch@lst.de
parent b78ea19a

arch/x86/kernel/fpu/core.c

+12 −24
Original line number Diff line number Diff line
@@ -43,12 +43,6 @@ static DEFINE_PER_CPU(bool, in_kernel_fpu); 
 */

DEFINE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx);



static void kernel_fpu_disable(void)

{

	WARN_ON_FPU(this_cpu_read(in_kernel_fpu));

	this_cpu_write(in_kernel_fpu, true);

}



static bool kernel_fpu_disabled(void)

{

	return this_cpu_read(in_kernel_fpu);
@@ -88,32 +82,26 @@ bool irq_fpu_usable(void) 
}

EXPORT_SYMBOL(irq_fpu_usable);



static void __kernel_fpu_begin(void)

void kernel_fpu_begin(void)

{

	struct fpu *fpu = &current->thread.fpu;

	preempt_disable();



	WARN_ON_FPU(!irq_fpu_usable());

	WARN_ON_FPU(this_cpu_read(in_kernel_fpu));



	kernel_fpu_disable();

	this_cpu_write(in_kernel_fpu, true);



	if (!(current->flags & PF_KTHREAD)) {

		if (!test_thread_flag(TIF_NEED_FPU_LOAD)) {

	if (!(current->flags & PF_KTHREAD) &&

	    !test_thread_flag(TIF_NEED_FPU_LOAD)) {

		set_thread_flag(TIF_NEED_FPU_LOAD);

		/*

		 * Ignore return value -- we don't care if reg state

		 * is clobbered.

		 */

			copy_fpregs_to_fpstate(fpu);

		}

		copy_fpregs_to_fpstate(&current->thread.fpu);

	}

	__cpu_invalidate_fpregs_state();

}



void kernel_fpu_begin(void)

{

	preempt_disable();

	__kernel_fpu_begin();

}

EXPORT_SYMBOL_GPL(kernel_fpu_begin);



void kernel_fpu_end(void)

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