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Date: Tue, 5 May 2015 19:58:03 +0200
From: Ingo Molnar <mingo@...nel.org>
To: linux-kernel@...r.kernel.org
Cc: Andy Lutomirski <luto@...capital.net>,
Borislav Petkov <bp@...en8.de>,
Dave Hansen <dave.hansen@...ux.intel.com>,
Fenghua Yu <fenghua.yu@...el.com>,
"H. Peter Anvin" <hpa@...or.com>,
Linus Torvalds <torvalds@...ux-foundation.org>,
Oleg Nesterov <oleg@...hat.com>,
Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH 179/208] x86/fpu: Move all the fpu__*() high level methods closer to each other
The fpu__*() methods are closely related, but they are defined
in scattered places within the FPU code.
Concentrate them, and also uninline fpu__save(), fpu__drop()
and fpu__reset() to save about 5K of kernel text on 64-bit kernels:
text data bss dec filename
14113063 2575280 1634304 18322647 vmlinux.before
14108070 2575280 1634304 18317654 vmlinux.after
Cc: Andy Lutomirski <luto@...capital.net>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: Fenghua Yu <fenghua.yu@...el.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Oleg Nesterov <oleg@...hat.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
arch/x86/include/asm/fpu/internal.h | 53 ++++++++++-------------------------------------------
arch/x86/kernel/fpu/core.c | 38 ++++++++++++++++++++++++++++++++++++++
2 files changed, 48 insertions(+), 43 deletions(-)
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index c09aea145e09..f20a0030f6a1 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -46,10 +46,19 @@ extern void fpu__init_system(struct cpuinfo_x86 *c);
extern void fpu__activate_curr(struct fpu *fpu);
extern void fpstate_init(struct fpu *fpu);
-extern void fpu__clear(struct task_struct *tsk);
extern int dump_fpu(struct pt_regs *, struct user_i387_struct *);
+
+/*
+ * High level FPU state handling functions:
+ */
+extern void fpu__save(struct fpu *fpu);
extern void fpu__restore(void);
+extern void fpu__drop(struct fpu *fpu);
+extern int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu);
+extern void fpu__reset(struct fpu *fpu);
+extern void fpu__clear(struct task_struct *tsk);
+
extern void fpu__init_check_bugs(void);
extern void fpu__resume_cpu(void);
@@ -287,8 +296,6 @@ static inline int copy_fpregs_to_fpstate(struct fpu *fpu)
return 0;
}
-extern void fpu__save(struct fpu *fpu);
-
static inline int __copy_fpstate_to_fpregs(struct fpu *fpu)
{
if (use_xsave())
@@ -382,33 +389,6 @@ static inline void fpregs_deactivate(struct fpu *fpu)
__fpregs_deactivate_hw();
}
-/*
- * Drops current FPU state: deactivates the fpregs and
- * the fpstate. NOTE: it still leaves previous contents
- * in the fpregs in the eager-FPU case.
- *
- * This function can be used in cases where we know that
- * a state-restore is coming: either an explicit one,
- * or a reschedule.
- */
-static inline void fpu__drop(struct fpu *fpu)
-{
- preempt_disable();
- fpu->counter = 0;
-
- if (fpu->fpregs_active) {
- /* Ignore delayed exceptions from user space */
- asm volatile("1: fwait\n"
- "2:\n"
- _ASM_EXTABLE(1b, 2b));
- fpregs_deactivate(fpu);
- }
-
- fpu->fpstate_active = 0;
-
- preempt_enable();
-}
-
static inline void restore_init_xstate(void)
{
if (use_xsave())
@@ -418,17 +398,6 @@ static inline void restore_init_xstate(void)
}
/*
- * Reset the FPU state back to init state.
- */
-static inline void fpu__reset(struct fpu *fpu)
-{
- if (!use_eager_fpu())
- fpu__drop(fpu);
- else
- restore_init_xstate();
-}
-
-/*
* Definitions for the eXtended Control Register instructions
*/
@@ -597,8 +566,6 @@ static inline unsigned short get_fpu_mxcsr(struct task_struct *tsk)
}
}
-extern int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu);
-
static inline unsigned long
alloc_mathframe(unsigned long sp, int ia32_frame, unsigned long *buf_fx,
unsigned long *size)
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 72e3f02db40d..cba02f7e337b 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -349,6 +349,44 @@ void fpu__restore(void)
EXPORT_SYMBOL_GPL(fpu__restore);
/*
+ * Drops current FPU state: deactivates the fpregs and
+ * the fpstate. NOTE: it still leaves previous contents
+ * in the fpregs in the eager-FPU case.
+ *
+ * This function can be used in cases where we know that
+ * a state-restore is coming: either an explicit one,
+ * or a reschedule.
+ */
+void fpu__drop(struct fpu *fpu)
+{
+ preempt_disable();
+ fpu->counter = 0;
+
+ if (fpu->fpregs_active) {
+ /* Ignore delayed exceptions from user space */
+ asm volatile("1: fwait\n"
+ "2:\n"
+ _ASM_EXTABLE(1b, 2b));
+ fpregs_deactivate(fpu);
+ }
+
+ fpu->fpstate_active = 0;
+
+ preempt_enable();
+}
+
+/*
+ * Reset the FPU state back to init state:
+ */
+void fpu__reset(struct fpu *fpu)
+{
+ if (!use_eager_fpu())
+ fpu__drop(fpu);
+ else
+ restore_init_xstate();
+}
+
+/*
* Called by sys_execve() to clear the FPU fpregs, so that FPU state
* of the previous binary does not leak over into the exec()ed binary:
*/
--
2.1.0
--
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