linux-kernel - [RFC PATCH] x86/paravirt: Kill some unused patching functions

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Date:	Tue,  3 Nov 2015 10:18:49 +0100
From:	Borislav Petkov <bp@...en8.de>
To:	LKML <linux-kernel@...r.kernel.org>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Andy Lutomirski <luto@...nel.org>,
	Chris Wright <chrisw@...s-sol.org>,
	"H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...hat.com>,
	Jeremy Fitzhardinge <jeremy@...p.org>,
	Juergen Gross <jgross@...e.com>,
	"Peter Zijlstra (Intel)" <peterz@...radead.org>,
	Rusty Russell <rusty@...tcorp.com.au>,
	Thomas Gleixner <tglx@...utronix.de>,
	virtualization@...ts.linux-foundation.org,
	xen-devel@...ts.xenproject.org
Subject: [RFC PATCH] x86/paravirt: Kill some unused patching functions

From: Borislav Petkov <bp@...e.de>

paravirt_patch_ignore() is completely unused and paravirt_patch_nop()
doesn't do a whole lot. Remove them both.

Signed-off-by: Borislav Petkov <bp@...e.de>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Andy Lutomirski <luto@...nel.org>
Cc: Chris Wright <chrisw@...s-sol.org>
Cc: "H. Peter Anvin" <hpa@...or.com>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: Jeremy Fitzhardinge <jeremy@...p.org>
Cc: Juergen Gross <jgross@...e.com>
Cc: "Peter Zijlstra (Intel)" <peterz@...radead.org>
Cc: Rusty Russell <rusty@...tcorp.com.au>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: virtualization@...ts.linux-foundation.org
Cc: xen-devel@...ts.xenproject.org
---
 arch/x86/include/asm/paravirt_types.h |  2 --
 arch/x86/kernel/paravirt.c            | 13 +------------
 2 files changed, 1 insertion(+), 14 deletions(-)

diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index 31247b5bff7c..e1f31dfc3b31 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -402,10 +402,8 @@ extern struct pv_lock_ops pv_lock_ops;
 	__visible extern const char start_##ops##_##name[], end_##ops##_##name[];	\
 	asm(NATIVE_LABEL("start_", ops, name) code NATIVE_LABEL("end_", ops, name))
 
-unsigned paravirt_patch_nop(void);
 unsigned paravirt_patch_ident_32(void *insnbuf, unsigned len);
 unsigned paravirt_patch_ident_64(void *insnbuf, unsigned len);
-unsigned paravirt_patch_ignore(unsigned len);
 unsigned paravirt_patch_call(void *insnbuf,
 			     const void *target, u16 tgt_clobbers,
 			     unsigned long addr, u16 site_clobbers,
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index c2130aef3f9d..4f32a10979db 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -74,16 +74,6 @@ void __init default_banner(void)
 /* Undefined instruction for dealing with missing ops pointers. */
 static const unsigned char ud2a[] = { 0x0f, 0x0b };
 
-unsigned paravirt_patch_nop(void)
-{
-	return 0;
-}
-
-unsigned paravirt_patch_ignore(unsigned len)
-{
-	return len;
-}
-
 struct branch {
 	unsigned char opcode;
 	u32 delta;
@@ -152,8 +142,7 @@ unsigned paravirt_patch_default(u8 type, u16 clobbers, void *insnbuf,
 		/* If there's no function, patch it with a ud2a (BUG) */
 		ret = paravirt_patch_insns(insnbuf, len, ud2a, ud2a+sizeof(ud2a));
 	else if (opfunc == _paravirt_nop)
-		/* If the operation is a nop, then nop the callsite */
-		ret = paravirt_patch_nop();
+		ret = 0;
 
 	/* identity functions just return their single argument */
 	else if (opfunc == _paravirt_ident_32)
-- 
2.3.5

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