Commit-ID: fc560a80bac91e512fc37cdfe03a982ef4543c6b Gitweb: http://git.kernel.org/tip/fc560a80bac91e512fc37cdfe03a982ef4543c6b Author: Andy Lutomirski <l...@kernel.org> AuthorDate: Mon, 31 Oct 2016 15:18:43 -0700 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Tue, 1 Nov 2016 07:47:53 +0100
x86/fpu: Stop saving and restoring CR0.TS in fpu__init_check_bugs() fpu__init_check_bugs() runs long after the early FPU init, so CR0.TS will be clear by the time it runs. The save-and-restore dance would have been unnecessary anyway, though, as kernel_fpu_begin() would have been good enough. Signed-off-by: Andy Lutomirski <l...@kernel.org> Cc: Borislav Petkov <b...@alien8.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Dave Hansen <dave.han...@linux.intel.com> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: Fenghua Yu <fenghua...@intel.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Josh Poimboeuf <jpoim...@redhat.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Oleg Nesterov <o...@redhat.com> Cc: Paolo Bonzini <pbonz...@redhat.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Quentin Casasnovas <quentin.casasno...@oracle.com> Cc: Rik van Riel <r...@redhat.com> Cc: Rusty Russell <ru...@rustcorp.com.au> Cc: Thomas Gleixner <t...@linutronix.de> Cc: kvm list <k...@vger.kernel.org> Link: http://lkml.kernel.org/r/76d1f1eacb5caead98197d1eb50ac6110ab20c6a.1477951965.git.l...@kernel.org Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/kernel/fpu/bugs.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/arch/x86/kernel/fpu/bugs.c b/arch/x86/kernel/fpu/bugs.c index aad34aa..d913047 100644 --- a/arch/x86/kernel/fpu/bugs.c +++ b/arch/x86/kernel/fpu/bugs.c @@ -23,17 +23,12 @@ static double __initdata y = 3145727.0; */ void __init fpu__init_check_bugs(void) { - u32 cr0_saved; s32 fdiv_bug; /* kernel_fpu_begin/end() relies on patched alternative instructions. */ if (!boot_cpu_has(X86_FEATURE_FPU)) return; - /* We might have CR0::TS set already, clear it: */ - cr0_saved = read_cr0(); - write_cr0(cr0_saved & ~X86_CR0_TS); - kernel_fpu_begin(); /* @@ -56,8 +51,6 @@ void __init fpu__init_check_bugs(void) kernel_fpu_end(); - write_cr0(cr0_saved); - if (fdiv_bug) { set_cpu_bug(&boot_cpu_data, X86_BUG_FDIV); pr_warn("Hmm, FPU with FDIV bug\n");
