From: Ingo Molnar <mingo@kernel.org>
Date: Wed, 9 Apr 2025 21:11:20 +0000 (+0200)
Subject: x86/fpu: Introduce the x86_task_fpu() helper method
X-Git-Tag: v6.16-rc1~195^2~28^2~29
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=77fbccede633a5565cae084348b5459f6849086d;p=thirdparty%2Flinux.git

x86/fpu: Introduce the x86_task_fpu() helper method

The per-task FPU context/save area is allocated right
next to task_struct, currently in a variable-size
array via task_struct::thread.fpu[], but we plan to
fully hide it from the C type scope.

Introduce the x86_task_fpu() accessor that gets to the
FPU context pointer explicitly from the task pointer.

Right now this is a simple (task)->thread.fpu wrapper.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chang S. Bae <chang.seok.bae@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>
Link: https://lore.kernel.org/r/20250409211127.3544993-2-mingo@kernel.org
---

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 5d2f7e5aff261..2f631e0adea34 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -523,6 +523,8 @@ struct thread_struct {
 	 */
 };
 
+#define x86_task_fpu(task) (&(task)->thread.fpu)
+
 extern void fpu_thread_struct_whitelist(unsigned long *offset, unsigned long *size);
 
 static inline void arch_thread_struct_whitelist(unsigned long *offset,