x86/fpu: Change fpu_owner_task to fpu_fpregs_owner_ctx
Track the FPU owner context instead of the owner task: this change,
together with other changes, will allow in subsequent patches the
elimination of 'struct task_struct' usage in various FPU code:
we'll be able to use 'struct fpu' only.
There's no change in code size:
text data bss dec hex filename
13066467 2545248 1626112 17237827 1070743 vmlinux.before
13066467 2545248 1626112 17237827 1070743 vmlinux.after
Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@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>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
index 94c068b..d0fe7bb 100644
--- a/arch/x86/include/asm/fpu-internal.h
+++ b/arch/x86/include/asm/fpu-internal.h
@@ -37,7 +37,7 @@
extern void fpu__cpu_init(void);
extern void eager_fpu_init(void);
-DECLARE_PER_CPU(struct task_struct *, fpu_owner_task);
+DECLARE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx);
extern void convert_from_fxsr(struct user_i387_ia32_struct *env,
struct task_struct *tsk);
@@ -63,7 +63,7 @@
#endif
/*
- * Must be run with preemption disabled: this clears the fpu_owner_task,
+ * Must be run with preemption disabled: this clears the fpu_fpregs_owner_ctx,
* on this CPU.
*
* This will disable any lazy FPU state restore of the current FPU state,
@@ -71,7 +71,7 @@
*/
static inline void __cpu_disable_lazy_restore(unsigned int cpu)
{
- per_cpu(fpu_owner_task, cpu) = NULL;
+ per_cpu(fpu_fpregs_owner_ctx, cpu) = NULL;
}
/*
@@ -86,7 +86,7 @@
static inline int fpu_lazy_restore(struct task_struct *new, unsigned int cpu)
{
- return new == this_cpu_read_stable(fpu_owner_task) &&
+ return &new->thread.fpu == this_cpu_read_stable(fpu_fpregs_owner_ctx) &&
cpu == new->thread.fpu.last_cpu;
}
@@ -327,14 +327,14 @@
static inline void __thread_clear_has_fpu(struct fpu *fpu)
{
fpu->has_fpu = 0;
- this_cpu_write(fpu_owner_task, NULL);
+ this_cpu_write(fpu_fpregs_owner_ctx, NULL);
}
/* Must be paired with a 'clts' before! */
static inline void __thread_set_has_fpu(struct task_struct *tsk)
{
tsk->thread.fpu.has_fpu = 1;
- this_cpu_write(fpu_owner_task, tsk);
+ this_cpu_write(fpu_fpregs_owner_ctx, &tsk->thread.fpu);
}
/*
@@ -431,7 +431,7 @@
else
old->thread.fpu.last_cpu = cpu;
- /* But leave fpu_owner_task! */
+ /* But leave fpu_fpregs_owner_ctx! */
old->thread.fpu.has_fpu = 0;
/* Don't change CR0.TS if we just switch! */