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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: Borislav 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: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Borislav Petkov 2016-04-04 22:24:58 +02:00 committed by Ingo Molnar
parent dda9edf7c1
commit a402a8dffc
5 changed files with 8 additions and 9 deletions
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1
arch/x86/include/asm/cpufeature.h
View File

@ -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)

2
arch/x86/kernel/cpu/cyrix.c
View File

@ -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 */

2
arch/x86/kernel/fpu/bugs.c
View File

@ -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();
}

4
arch/x86/kernel/fpu/core.c
View File

@ -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);

8
arch/x86/kernel/fpu/init.c
View File

@ -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.