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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: 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>
hifive-unleashed-5.1
Ingo Molnar 2015-04-24 10:02:32 +02:00
parent 84246fe4e3
commit 9254aaa0fe
3 changed files with 15 additions and 8 deletions
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1
arch/x86/include/asm/fpu/api.h
View File

@ -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);

12
arch/x86/kernel/fpu/xsave.c
View File

@ -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.

10
arch/x86/power/cpu.c
View File

@ -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();