kill strlen_user()

no callers, no consistent semantics, no sane way to use it...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 1 insertions, 201 deletions

diff --git a/arch/ia64/lib/Makefile b/arch/ia64/lib/Makefile
index 0a40b14407b1..1a36a3a39624 100644
--- a/arch/ia64/lib/Makefile
+++ b/arch/ia64/lib/Makefile
@@ -5,7 +5,7 @@
 lib-y := io.o __divsi3.o __udivsi3.o __modsi3.o __umodsi3.o		\
 	__divdi3.o __udivdi3.o __moddi3.o __umoddi3.o			\
 	checksum.o clear_page.o csum_partial_copy.o			\
-	clear_user.o strncpy_from_user.o strlen_user.o strnlen_user.o	\
+	clear_user.o strncpy_from_user.o strnlen_user.o			\
 	flush.o ip_fast_csum.o do_csum.o				\
 	memset.o strlen.o xor.o
 
diff --git a/arch/ia64/lib/strlen_user.S b/arch/ia64/lib/strlen_user.S
deleted file mode 100644
index 9d257684e733..000000000000
--- a/arch/ia64/lib/strlen_user.S
+++ /dev/null
@@ -1,200 +0,0 @@
-/*
- * Optimized version of the strlen_user() function
- *
- * Inputs:
- *	in0	address of buffer
- *
- * Outputs:
- *	ret0	0 in case of fault, strlen(buffer)+1 otherwise
- *
- * Copyright (C) 1998, 1999, 2001 Hewlett-Packard Co
- *	David Mosberger-Tang <davidm@hpl.hp.com>
- *	Stephane Eranian <eranian@hpl.hp.com>
- *
- * 01/19/99 S.Eranian heavily enhanced version (see details below)
- * 09/24/99 S.Eranian added speculation recovery code
- */
-
-#include <asm/asmmacro.h>
-#include <asm/export.h>
-
-//
-// int strlen_user(char *)
-// ------------------------
-// Returns:
-//	- length of string + 1
-//	- 0 in case an exception is raised
-//
-// This is an enhanced version of the basic strlen_user. it includes a
-// combination of compute zero index (czx), parallel comparisons, speculative
-// loads and loop unroll using rotating registers.
-//
-// General Ideas about the algorithm:
-//	  The goal is to look at the string in chunks of 8 bytes.
-//	  so we need to do a few extra checks at the beginning because the
-//	  string may not be 8-byte aligned. In this case we load the 8byte
-//	  quantity which includes the start of the string and mask the unused
-//	  bytes with 0xff to avoid confusing czx.
-//	  We use speculative loads and software pipelining to hide memory
-//	  latency and do read ahead safely. This way we defer any exception.
-//
-//	  Because we don't want the kernel to be relying on particular
-//	  settings of the DCR register, we provide recovery code in case
-//	  speculation fails. The recovery code is going to "redo" the work using
-//	  only normal loads. If we still get a fault then we return an
-//	  error (ret0=0). Otherwise we return the strlen+1 as usual.
-//	  The fact that speculation may fail can be caused, for instance, by
-//	  the DCR.dm bit being set. In this case TLB misses are deferred, i.e.,
-//	  a NaT bit will be set if the translation is not present. The normal
-//	  load, on the other hand, will cause the translation to be inserted
-//	  if the mapping exists.
-//
-//	  It should be noted that we execute recovery code only when we need
-//	  to use the data that has been speculatively loaded: we don't execute
-//	  recovery code on pure read ahead data.
-//
-// Remarks:
-//	- the cmp r0,r0 is used as a fast way to initialize a predicate
-//	  register to 1. This is required to make sure that we get the parallel
-//	  compare correct.
-//
-//	- we don't use the epilogue counter to exit the loop but we need to set
-//	  it to zero beforehand.
-//
-//	- after the loop we must test for Nat values because neither the
-//	  czx nor cmp instruction raise a NaT consumption fault. We must be
-//	  careful not to look too far for a Nat for which we don't care.
-//	  For instance we don't need to look at a NaT in val2 if the zero byte
-//	  was in val1.
-//
-//	- Clearly performance tuning is required.
-//
-
-#define saved_pfs	r11
-#define	tmp		r10
-#define base		r16
-#define orig		r17
-#define saved_pr	r18
-#define src		r19
-#define mask		r20
-#define val		r21
-#define val1		r22
-#define val2		r23
-
-GLOBAL_ENTRY(__strlen_user)
-	.prologue
-	.save ar.pfs, saved_pfs
-	alloc saved_pfs=ar.pfs,11,0,0,8
-
-	.rotr v[2], w[2]	// declares our 4 aliases
-
-	extr.u tmp=in0,0,3	// tmp=least significant 3 bits
-	mov orig=in0		// keep trackof initial byte address
-	dep src=0,in0,0,3	// src=8byte-aligned in0 address
-	.save pr, saved_pr
-	mov saved_pr=pr		// preserve predicates (rotation)
-	;;
-
-	.body
-
-	ld8.s v[1]=[src],8	// load the initial 8bytes (must speculate)
-	shl tmp=tmp,3		// multiply by 8bits/byte
-	mov mask=-1		// our mask
-	;;
-	ld8.s w[1]=[src],8	// load next 8 bytes in 2nd pipeline
-	cmp.eq p6,p0=r0,r0	// sets p6 (required because of // cmp.and)
-	sub tmp=64,tmp		// how many bits to shift our mask on the right
-	;;
-	shr.u	mask=mask,tmp	// zero enough bits to hold v[1] valuable part
-	mov ar.ec=r0		// clear epilogue counter (saved in ar.pfs)
-	;;
-	add base=-16,src	// keep track of aligned base
-	chk.s v[1], .recover	// if already NaT, then directly skip to recover
-	or v[1]=v[1],mask	// now we have a safe initial byte pattern
-	;;
-1:
-	ld8.s v[0]=[src],8	// speculatively load next
-	czx1.r val1=v[1]	// search 0 byte from right
-	czx1.r val2=w[1]	// search 0 byte from right following 8bytes
-	;;
-	ld8.s w[0]=[src],8	// speculatively load next to next
-	cmp.eq.and p6,p0=8,val1	// p6 = p6 and val1==8
-	cmp.eq.and p6,p0=8,val2	// p6 = p6 and mask==8
-(p6)	br.wtop.dptk.few 1b	// loop until p6 == 0
-	;;
-	//
-	// We must return try the recovery code iff
-	// val1_is_nat || (val1==8 && val2_is_nat)
-	//
-	// XXX Fixme
-	//	- there must be a better way of doing the test
-	//
-	cmp.eq  p8,p9=8,val1	// p6 = val1 had zero (disambiguate)
-	tnat.nz p6,p7=val1	// test NaT on val1
-(p6)	br.cond.spnt .recover	// jump to recovery if val1 is NaT
-	;;
-	//
-	// if we come here p7 is true, i.e., initialized for // cmp
-	//
-	cmp.eq.and  p7,p0=8,val1// val1==8?
-	tnat.nz.and p7,p0=val2	// test NaT if val2
-(p7)	br.cond.spnt .recover	// jump to recovery if val2 is NaT
-	;;
-(p8)	mov val1=val2		// val2 contains the value
-(p8)	adds src=-16,src	// correct position when 3 ahead
-(p9)	adds src=-24,src	// correct position when 4 ahead
-	;;
-	sub ret0=src,orig	// distance from origin
-	sub tmp=7,val1		// 7=8-1 because this strlen returns strlen+1
-	mov pr=saved_pr,0xffffffffffff0000
-	;;
-	sub ret0=ret0,tmp	// length=now - back -1
-	mov ar.pfs=saved_pfs	// because of ar.ec, restore no matter what
-	br.ret.sptk.many rp	// end of normal execution
-
-	//
-	// Outlined recovery code when speculation failed
-	//
-	// This time we don't use speculation and rely on the normal exception
-	// mechanism. that's why the loop is not as good as the previous one
-	// because read ahead is not possible
-	//
-	// XXX Fixme
-	//	- today we restart from the beginning of the string instead
-	//	  of trying to continue where we left off.
-	//
-.recover:
-	EX(.Lexit1, ld8 val=[base],8)	// load the initial bytes
-	;;
-	or val=val,mask			// remask first bytes
-	cmp.eq p0,p6=r0,r0		// nullify first ld8 in loop
-	;;
-	//
-	// ar.ec is still zero here
-	//
-2:
-	EX(.Lexit1, (p6) ld8 val=[base],8)
-	;;
-	czx1.r val1=val		// search 0 byte from right
-	;;
-	cmp.eq p6,p0=8,val1	// val1==8 ?
-(p6)	br.wtop.dptk.few 2b	// loop until p6 == 0
-	;;
-	sub ret0=base,orig	// distance from base
-	sub tmp=7,val1		// 7=8-1 because this strlen returns strlen+1
-	mov pr=saved_pr,0xffffffffffff0000
-	;;
-	sub ret0=ret0,tmp	// length=now - back -1
-	mov ar.pfs=saved_pfs	// because of ar.ec, restore no matter what
-	br.ret.sptk.many rp	// end of successful recovery code
-
-	//
-	// We failed even on the normal load (called from exception handler)
-	//
-.Lexit1:
-	mov ret0=0
-	mov pr=saved_pr,0xffffffffffff0000
-	mov ar.pfs=saved_pfs	// because of ar.ec, restore no matter what
-	br.ret.sptk.many rp
-END(__strlen_user)
-EXPORT_SYMBOL(__strlen_user)