[PATCH 035/208] x86/fpu: Factor out fpu__copy()

Ingo Molnar
2015-05-05T16:58:44Z

Introduce fpu__copy() and use it in arch_dup_task_struct(),
thus moving another chunk of FPU logic to fpu/core.c.

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 | 1 +
arch/x86/kernel/fpu/core.c | 18 ++++++++++++++++++
arch/x86/kernel/process.c | 12 +-----------
3 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
index f41170c6d376..6c1ceb7c3f9a 100644
--- a/arch/x86/include/asm/fpu-internal.h
+++ b/arch/x86/include/asm/fpu-internal.h
@@ -567,6 +567,7 @@ static inline unsigned short get_fpu_mxcsr(struct task_struct *tsk)
extern void fpstate_cache_init(void);

extern int fpstate_alloc(struct fpu *fpu);
+extern int fpu__copy(struct task_struct *dst, struct task_struct *src);

static inline void fpstate_free(struct fpu *fpu)
{
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 9dc4bb3f6f5a..e02c42965f53 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -178,6 +178,24 @@ int fpstate_alloc(struct fpu *fpu)
}
EXPORT_SYMBOL_GPL(fpstate_alloc);

+int fpu__copy(struct task_struct *dst, struct task_struct *src)
+{
+ dst->thread.fpu.counter = 0;
+ dst->thread.fpu.has_fpu = 0;
+ dst->thread.fpu.state = NULL;
+
+ task_disable_lazy_fpu_restore(dst);
+
+ if (tsk_used_math(src)) {
+ int err = fpstate_alloc(&dst->thread.fpu);
+
+ if (err)
+ return err;
+ fpu_copy(dst, src);
+ }
+ return 0;
+}
+
/*
* Allocate the backing store for the current task's FPU registers
* and initialize the registers themselves as well.
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index fda613eeeebd..1b4ea12e412d 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -83,17 +83,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
{
*dst = *src;

- dst->thread.fpu.counter = 0;
- dst->thread.fpu.has_fpu = 0;
- dst->thread.fpu.state = NULL;
- task_disable_lazy_fpu_restore(dst);
- if (tsk_used_math(src)) {
- int err = fpstate_alloc(&dst->thread.fpu);
- if (err)
- return err;
- fpu_copy(dst, src);
- }
- return 0;
+ return fpu__copy(dst, src);
}

void arch_release_task_struct(struct task_struct *tsk)
--
2.1.0