Commit-ID:  9ad93fe35aff616fca4e2b9581fdeed498605f9e
Gitweb:     http://git.kernel.org/tip/9ad93fe35aff616fca4e2b9581fdeed498605f9e
Author:     Rik van Riel <[email protected]>
AuthorDate: Tue, 4 Oct 2016 20:34:38 -0400
Committer:  Ingo Molnar <[email protected]>
CommitDate: Fri, 7 Oct 2016 11:14:43 +0200

x86/fpu: Split old & new FPU code paths

Now that CR0.TS is no longer being manipulated, we can simplify
switch_fpu_prepare() by no longer nesting the handling of new_fpu
inside the two branches for the old_fpu.

Signed-off-by: Rik van Riel <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Quentin Casasnovas <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: 
http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
 arch/x86/include/asm/fpu/internal.h | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/arch/x86/include/asm/fpu/internal.h 
b/arch/x86/include/asm/fpu/internal.h
index d0324bc..1dcb29e 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -581,23 +581,17 @@ switch_fpu_prepare(struct fpu *old_fpu, struct fpu 
*new_fpu, int cpu)
                /* But leave fpu_fpregs_owner_ctx! */
                old_fpu->fpregs_active = 0;
                trace_x86_fpu_regs_deactivated(old_fpu);
+       } else
+               old_fpu->last_cpu = -1;
 
-               /* Don't change CR0.TS if we just switch! */
-               if (fpu.preload) {
-                       fpregs_activate(new_fpu);
-                       trace_x86_fpu_regs_activated(new_fpu);
+       if (fpu.preload) {
+               if (fpregs_state_valid(new_fpu, cpu))
+                       fpu.preload = 0;
+               else
                        prefetch(&new_fpu->state);
-               }
-       } else {
-               old_fpu->last_cpu = -1;
-               if (fpu.preload) {
-                       if (fpregs_state_valid(new_fpu, cpu))
-                               fpu.preload = 0;
-                       else
-                               prefetch(&new_fpu->state);
-                       fpregs_activate(new_fpu);
-               }
+               fpregs_activate(new_fpu);
        }
+
        return fpu;
 }
 

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