[PATCH 055/208] x86/fpu: Remove 'struct task_struct' usage from drop_fpu()

Ingo Molnar
2015-05-05T16:29:16Z

Migrate this function to pure 'struct fpu' usage.

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: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/include/asm/fpu-internal.h | 9 +++++----
arch/x86/kernel/fpu/core.c | 2 +-
arch/x86/kernel/fpu/xsave.c | 2 +-
arch/x86/kernel/process.c | 3 ++-
4 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
index 9311126571ab..e8f7134f0ffb 100644
--- a/arch/x86/include/asm/fpu-internal.h
+++ b/arch/x86/include/asm/fpu-internal.h
@@ -358,14 +358,13 @@ static inline void __thread_fpu_begin(struct fpu *fpu)
__thread_set_has_fpu(fpu);
}

-static inline void drop_fpu(struct task_struct *tsk)
+static inline void drop_fpu(struct fpu *fpu)
{
- struct fpu *fpu = &tsk->thread.fpu;
/*
* Forget coprocessor state..
*/
preempt_disable();
- tsk->thread.fpu.counter = 0;
+ fpu->counter = 0;

if (fpu->has_fpu) {
/* Ignore delayed exceptions from user space */
@@ -394,8 +393,10 @@ static inline void restore_init_xstate(void)
*/
static inline void fpu_reset_state(struct task_struct *tsk)
{
+ struct fpu *fpu = &tsk->thread.fpu;
+
if (!use_eager_fpu())
- drop_fpu(tsk);
+ drop_fpu(fpu);
else
restore_init_xstate();
}
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index cc15461b9bee..39b78f1cc93b 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -389,7 +389,7 @@ void fpu__flush_thread(struct task_struct *tsk)

if (!use_eager_fpu()) {
/* FPU state will be reallocated lazily at the first use. */
- drop_fpu(tsk);
+ drop_fpu(fpu);
fpstate_free(&tsk->thread.fpu);
} else if (!fpu->fpstate_active) {
/* kthread execs. TODO: cleanup this horror. */
diff --git a/arch/x86/kernel/fpu/xsave.c b/arch/x86/kernel/fpu/xsave.c
index dc346e19c0df..049dc619481d 100644
--- a/arch/x86/kernel/fpu/xsave.c
+++ b/arch/x86/kernel/fpu/xsave.c
@@ -392,7 +392,7 @@ int __restore_xstate_sig(void __user *buf, void __user *buf_fx, int size)
* We will be ready to restore/save the state only after
* fpu->fpstate_active is again set.
*/
- drop_fpu(tsk);
+ drop_fpu(fpu);

if (__copy_from_user(&fpu->state->xsave, buf_fx, state_size) ||
__copy_from_user(&env, buf, sizeof(env))) {
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 1b4ea12e412d..40bc28624628 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -104,6 +104,7 @@ void exit_thread(void)
struct task_struct *me = current;
struct thread_struct *t = &me->thread;
unsigned long *bp = t->io_bitmap_ptr;
+ struct fpu *fpu = &t->fpu;

if (bp) {
struct tss_struct *tss = &per_cpu(cpu_tss, get_cpu());
@@ -119,7 +120,7 @@ void exit_thread(void)
kfree(bp);
}

- drop_fpu(me);
+ drop_fpu(fpu);
}

void flush_thread(void)
--
2.1.0