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Commit 9254aaa0 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

x86/fpu: Move XCR0 manipulation to the FPU code proper 



The suspend code accesses FPU state internals, add a helper for
it and isolate it.

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 84246fe4

arch/x86/include/asm/fpu/api.h

+1 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ extern void fpu__clear(struct task_struct *tsk); 
extern int dump_fpu(struct pt_regs *, struct user_i387_struct *);

extern void fpu__restore(void);

extern void fpu__init_check_bugs(void);

extern void fpu__resume_cpu(void);



extern bool irq_fpu_usable(void);

arch/x86/kernel/fpu/xsave.c

+12 −0
Original line number Diff line number Diff line
@@ -734,6 +734,18 @@ void __init_refok eager_fpu_init(void) 
		setup_init_fpu_buf();

}



/*

 * Restore minimal FPU state after suspend:

 */

void fpu__resume_cpu(void)

{

	/*

	 * Restore XCR0 on xsave capable CPUs:

	 */

	if (cpu_has_xsave)

		xsetbv(XCR_XFEATURE_ENABLED_MASK, xfeatures_mask);

}



/*

 * Given the xsave area and a state inside, this function returns the

 * address of the state.

arch/x86/power/cpu.c

+2 −8
Original line number Diff line number Diff line
@@ -18,10 +18,8 @@ 
#include <asm/mtrr.h>

#include <asm/page.h>

#include <asm/mce.h>

#include <asm/xcr.h>

#include <asm/suspend.h>

#include <asm/debugreg.h>

#include <asm/fpu/internal.h> /* xfeatures_mask */

#include <asm/cpu.h>



#ifdef CONFIG_X86_32
@@ -155,6 +153,8 @@ static void fix_processor_context(void) 
#endif

	load_TR_desc();				/* This does ltr */

	load_LDT(&current->active_mm->context);	/* This does lldt */



	fpu__resume_cpu();

}



/**
@@ -221,12 +221,6 @@ static void notrace __restore_processor_state(struct saved_context *ctxt) 
	wrmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base);

#endif



	/*

	 * restore XCR0 for xsave capable cpu's.

	 */

	if (cpu_has_xsave)

		xsetbv(XCR_XFEATURE_ENABLED_MASK, xfeatures_mask);



	fix_processor_context();



	do_fpu_end();