Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 55cc4678 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

x86/fpu: Make the system/cpu init distinction clear in the xstate code as well 



Rename existing xstate init functions along the system/cpu init principles:

	fpu__init_system_xstate(): called once per system bootup
	fpu__init_cpu_xstate():    called per CPU onlining

Also make the fpu__init_cpu_xstate() early code invariant:
if xfeatures_mask is not set yet then don't crash but return.

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 e35f6f14

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

+3 −0
Original line number Diff line number Diff line
@@ -39,6 +39,9 @@ extern unsigned int mxcsr_feature_mask; 
extern void fpu__cpu_init(void);

extern void eager_fpu_init(void);



extern void fpu__init_system_xstate(void);

extern void fpu__init_cpu_xstate(void);



DECLARE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx);



extern void convert_from_fxsr(struct user_i387_ia32_struct *env,

arch/x86/kernel/fpu/xsave.c

+14 −8
Original line number Diff line number Diff line
@@ -460,10 +460,14 @@ static void prepare_fx_sw_frame(void) 
}



/*

 * Enable the extended processor state save/restore feature

 * Enable the extended processor state save/restore feature.

 * Called once per CPU onlining.

 */

static inline void xstate_enable(void)

void fpu__init_cpu_xstate(void)

{

	if (!xfeatures_mask)

		return;



	cr4_set_bits(X86_CR4_OSXSAVE);

	xsetbv(XCR_XFEATURE_ENABLED_MASK, xfeatures_mask);

}
@@ -640,11 +644,12 @@ static void __init init_xstate_size(void) 


/*

 * Enable and initialize the xsave feature.

 * Called once per system bootup.

 *

 * ( Not marked __init because of false positive section warnings

 *   generated by xsave_init(). )

 */

static void /* __init */ xstate_enable_boot_cpu(void)

void fpu__init_system_xstate(void)

{

	unsigned int eax, ebx, ecx, edx;
@@ -666,7 +671,8 @@ static void /* __init */ xstate_enable_boot_cpu(void) 
	 */

	xfeatures_mask = xfeatures_mask & XCNTXT_MASK;



	xstate_enable();

	/* Enable xstate instructions to be able to continue with initialization: */

	fpu__init_cpu_xstate();



	/*

	 * Recompute the context size for enabled features
@@ -698,8 +704,8 @@ static void /* __init */ xstate_enable_boot_cpu(void) 
}



/*

 * For the very first instance, this calls xstate_enable_boot_cpu();

 * for all subsequent instances, this calls xstate_enable().

 * For the very first instance, this calls fpu__init_system_xstate();

 * for all subsequent instances, this calls fpu__init_cpu_xstate().

 */

void xsave_init(void)

{
@@ -715,9 +721,9 @@ void xsave_init(void) 


	if (on_boot_cpu) {

		on_boot_cpu = 0;

		xstate_enable_boot_cpu();

		fpu__init_system_xstate();

	} else {

		xstate_enable();

		fpu__init_cpu_xstate();

	}

}