linux-kernel - [tip:x86/fpu] x86/fpu: Remove fpu__current_fpstate_write

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Message-ID: <tip-685c930d6e58e31e251ec354f9dca3958a4c5040@git.kernel.org>
Date:   Tue, 26 Sep 2017 01:32:06 -0700
From:   tip-bot for Ingo Molnar <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     hpa@...or.com, bobbypowers@...il.com, tglx@...utronix.de,
        yu-cheng.yu@...el.com, luto@...capital.net, ebiggers3@...il.com,
        bp@...en8.de, peterz@...radead.org, mingo@...nel.org,
        dave.hansen@...ux.intel.com, torvalds@...ux-foundation.org,
        oleg@...hat.com, linux-kernel@...r.kernel.org, riel@...hat.com,
        fenghua.yu@...el.com, akpm@...ux-foundation.org
Subject: [tip:x86/fpu] x86/fpu: Remove
 fpu__current_fpstate_write_begin/end()

Commit-ID:  685c930d6e58e31e251ec354f9dca3958a4c5040
Gitweb:     http://git.kernel.org/tip/685c930d6e58e31e251ec354f9dca3958a4c5040
Author:     Ingo Molnar <mingo@...nel.org>
AuthorDate: Sat, 23 Sep 2017 15:00:11 +0200
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Tue, 26 Sep 2017 09:42:20 +0200

x86/fpu: Remove fpu__current_fpstate_write_begin/end()

These functions are not used anymore, so remove them.

Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Andy Lutomirski <luto@...capital.net>
Cc: Bobby Powers <bobbypowers@...il.com>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: Eric Biggers <ebiggers3@...il.com>
Cc: Fenghua Yu <fenghua.yu@...el.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Oleg Nesterov <oleg@...hat.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Rik van Riel <riel@...hat.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Yu-cheng Yu <yu-cheng.yu@...el.com>
Link: http://lkml.kernel.org/r/20170923130016.21448-29-mingo@kernel.org
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/include/asm/fpu/internal.h |  2 --
 arch/x86/kernel/fpu/core.c          | 63 -------------------------------------
 2 files changed, 65 deletions(-)

diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index cf290d4..508e418 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -26,8 +26,6 @@
 extern void fpu__activate_curr(struct fpu *fpu);
 extern void fpu__activate_fpstate_read(struct fpu *fpu);
 extern void fpu__activate_fpstate_write(struct fpu *fpu);
-extern void fpu__current_fpstate_write_begin(void);
-extern void fpu__current_fpstate_write_end(void);
 extern void fpu__save(struct fpu *fpu);
 extern void fpu__restore(struct fpu *fpu);
 extern int  fpu__restore_sig(void __user *buf, int ia32_frame);
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index afd3f2a..b2cdeb3 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -317,69 +317,6 @@ void fpu__activate_fpstate_write(struct fpu *fpu)
 }
 
 /*
- * This function must be called before we write the current
- * task's fpstate.
- *
- * This call gets the current FPU register state and moves
- * it in to the 'fpstate'.  Preemption is disabled so that
- * no writes to the 'fpstate' can occur from context
- * swiches.
- *
- * Must be followed by a fpu__current_fpstate_write_end().
- */
-void fpu__current_fpstate_write_begin(void)
-{
-	struct fpu *fpu = &current->thread.fpu;
-
-	/*
-	 * Ensure that the context-switching code does not write
-	 * over the fpstate while we are doing our update.
-	 */
-	preempt_disable();
-
-	/*
-	 * Move the fpregs in to the fpu's 'fpstate'.
-	 */
-	fpu__activate_fpstate_read(fpu);
-
-	/*
-	 * The caller is about to write to 'fpu'.  Ensure that no
-	 * CPU thinks that its fpregs match the fpstate.  This
-	 * ensures we will not be lazy and skip a XRSTOR in the
-	 * future.
-	 */
-	__fpu_invalidate_fpregs_state(fpu);
-}
-
-/*
- * This function must be paired with fpu__current_fpstate_write_begin()
- *
- * This will ensure that the modified fpstate gets placed back in
- * the fpregs if necessary.
- *
- * Note: This function may be called whether or not an _actual_
- * write to the fpstate occurred.
- */
-void fpu__current_fpstate_write_end(void)
-{
-	struct fpu *fpu = &current->thread.fpu;
-
-	/*
-	 * 'fpu' now has an updated copy of the state, but the
-	 * registers may still be out of date.  Update them with
-	 * an XRSTOR if they are active.
-	 */
-	if (fpu->fpstate_active)
-		copy_kernel_to_fpregs(&fpu->state);
-
-	/*
-	 * Our update is done and the fpregs/fpstate are in sync
-	 * if necessary.  Context switches can happen again.
-	 */
-	preempt_enable();
-}
-
-/*
  * 'fpu__restore()' is called to copy FPU registers from
  * the FPU fpstate to the live hw registers and to activate
  * access to the hardware registers, so that FPU instructions