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Commit a402a8df authored by Borislav Petkov's avatar Borislav Petkov Committed by Ingo Molnar
Browse files

x86/cpufeature: Replace cpu_has_fpu with boot_cpu_has() usage 



Use static_cpu_has() in the timing-sensitive paths in fpstate_init() and
fpu__copy().

While at it, simplify the use in init_cyrix() and get rid of the ternary
operator.

Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1459801503-15600-6-git-send-email-bp@alien8.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent dda9edf7

arch/x86/include/asm/cpufeature.h

+0 −1
Original line number Diff line number Diff line
@@ -118,7 +118,6 @@ extern const char * const x86_bug_flags[NBUGINTS*32]; 
	set_bit(bit, (unsigned long *)cpu_caps_set);	\

} while (0)



#define cpu_has_fpu		boot_cpu_has(X86_FEATURE_FPU)

#define cpu_has_tsc		boot_cpu_has(X86_FEATURE_TSC)

#define cpu_has_apic		boot_cpu_has(X86_FEATURE_APIC)

#define cpu_has_fxsr		boot_cpu_has(X86_FEATURE_FXSR)

arch/x86/kernel/cpu/cyrix.c

+1 −1
Original line number Diff line number Diff line
@@ -333,7 +333,7 @@ static void init_cyrix(struct cpuinfo_x86 *c) 
		switch (dir0_lsn) {

		case 0xd:  /* either a 486SLC or DLC w/o DEVID */

			dir0_msn = 0;

			p = Cx486_name[(cpu_has_fpu ? 1 : 0)];

			p = Cx486_name[!!boot_cpu_has(X86_FEATURE_FPU)];

			break;



		case 0xe:  /* a 486S A step */

arch/x86/kernel/fpu/bugs.c

+1 −1
Original line number Diff line number Diff line
@@ -66,6 +66,6 @@ void __init fpu__init_check_bugs(void) 
	 * kernel_fpu_begin/end() in check_fpu() relies on the patched

	 * alternative instructions.

	 */

	if (cpu_has_fpu)

	if (boot_cpu_has(X86_FEATURE_FPU))

		check_fpu();

}

arch/x86/kernel/fpu/core.c

+2 −2
Original line number Diff line number Diff line
@@ -217,7 +217,7 @@ static inline void fpstate_init_fstate(struct fregs_state *fp) 


void fpstate_init(union fpregs_state *state)

{

	if (!cpu_has_fpu) {

	if (!static_cpu_has(X86_FEATURE_FPU)) {

		fpstate_init_soft(&state->soft);

		return;

	}
@@ -237,7 +237,7 @@ int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu) 
	dst_fpu->fpregs_active = 0;

	dst_fpu->last_cpu = -1;



	if (!src_fpu->fpstate_active || !cpu_has_fpu)

	if (!src_fpu->fpstate_active || !static_cpu_has(X86_FEATURE_FPU))

		return 0;



	WARN_ON_FPU(src_fpu != &current->thread.fpu);

arch/x86/kernel/fpu/init.c

+4 −4
Original line number Diff line number Diff line
@@ -38,13 +38,13 @@ static void fpu__init_cpu_generic(void) 


	cr0 = read_cr0();

	cr0 &= ~(X86_CR0_TS|X86_CR0_EM); /* clear TS and EM */

	if (!cpu_has_fpu)

	if (!boot_cpu_has(X86_FEATURE_FPU))

		cr0 |= X86_CR0_EM;

	write_cr0(cr0);



	/* Flush out any pending x87 state: */

#ifdef CONFIG_MATH_EMULATION

	if (!cpu_has_fpu)

	if (!boot_cpu_has(X86_FEATURE_FPU))

		fpstate_init_soft(&current->thread.fpu.state.soft);

	else

#endif
@@ -89,7 +89,7 @@ static void fpu__init_system_early_generic(struct cpuinfo_x86 *c) 
	}



#ifndef CONFIG_MATH_EMULATION

	if (!cpu_has_fpu) {

	if (!boot_cpu_has(X86_FEATURE_FPU)) {

		pr_emerg("x86/fpu: Giving up, no FPU found and no math emulation present\n");

		for (;;)

			asm volatile("hlt");
@@ -212,7 +212,7 @@ static void __init fpu__init_system_xstate_size_legacy(void) 
	 * fpu__init_system_xstate().

	 */



	if (!cpu_has_fpu) {

	if (!boot_cpu_has(X86_FEATURE_FPU)) {

		/*

		 * Disable xsave as we do not support it if i387

		 * emulation is enabled.