Commit 146ed598 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

x86/fpu: Move the no_387 handling and FPU detection code into init.c 



Both no_387() and fpu__detect() run at boot time, so they belong
into init.c.

Reviewed-by: default avatarBorislav 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: default avatarIngo Molnar <mingo@kernel.org>
parent 4445e6e9

arch/x86/kernel/fpu/core.c

+0 −34
Original line number Diff line number Diff line
@@ -581,37 +581,3 @@ int dump_fpu(struct pt_regs *regs, struct user_i387_struct *fpu) 
EXPORT_SYMBOL(dump_fpu);



#endif	/* CONFIG_X86_32 || CONFIG_IA32_EMULATION */
 


static int __init no_387(char *s)

{

	setup_clear_cpu_cap(X86_FEATURE_FPU);

	return 1;

}



__setup("no387", no_387);



/*

 * Set the X86_FEATURE_FPU CPU-capability bit based on

 * trying to execute an actual sequence of FPU instructions:

 */

void fpu__detect(struct cpuinfo_x86 *c)

{

	unsigned long cr0;

	u16 fsw, fcw;



	fsw = fcw = 0xffff;



	cr0 = read_cr0();

	cr0 &= ~(X86_CR0_TS | X86_CR0_EM);

	write_cr0(cr0);



	asm volatile("fninit ; fnstsw %0 ; fnstcw %1"

		     : "+m" (fsw), "+m" (fcw));



	if (fsw == 0 && (fcw & 0x103f) == 0x003f)

		set_cpu_cap(c, X86_FEATURE_FPU);

	else

		clear_cpu_cap(c, X86_FEATURE_FPU);



	/* The final cr0 value is set in fpu_init() */

}

arch/x86/kernel/fpu/init.c

+34 −0
Original line number Diff line number Diff line
@@ -91,3 +91,37 @@ void fpu__cpu_init(void) 
	xsave_init();

	eager_fpu_init();

}



static int __init no_387(char *s)

{

	setup_clear_cpu_cap(X86_FEATURE_FPU);

	return 1;

}



__setup("no387", no_387);



/*

 * Set the X86_FEATURE_FPU CPU-capability bit based on

 * trying to execute an actual sequence of FPU instructions:

 */

void fpu__detect(struct cpuinfo_x86 *c)

{

	unsigned long cr0;

	u16 fsw, fcw;



	fsw = fcw = 0xffff;



	cr0 = read_cr0();

	cr0 &= ~(X86_CR0_TS | X86_CR0_EM);

	write_cr0(cr0);



	asm volatile("fninit ; fnstsw %0 ; fnstcw %1"

		     : "+m" (fsw), "+m" (fcw));



	if (fsw == 0 && (fcw & 0x103f) == 0x003f)

		set_cpu_cap(c, X86_FEATURE_FPU);

	else

		clear_cpu_cap(c, X86_FEATURE_FPU);



	/* The final cr0 value is set in fpu_init() */

}

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