arch: Remove Itanium (IA-64) architecture

The Itanium architecture is obsolete, and an informal survey [0] reveals
that any residual use of Itanium hardware in production is mostly HP-UX
or OpenVMS based. The use of Linux on Itanium appears to be limited to
enthusiasts that occasionally boot a fresh Linux kernel to see whether
things are still working as intended, and perhaps to churn out some
distro packages that are rarely used in practice.

None of the original companies behind Itanium still produce or support
any hardware or software for the architecture, and it is listed as
'Orphaned' in the MAINTAINERS file, as apparently, none of the engineers
that contributed on behalf of those companies (nor anyone else, for that
matter) have been willing to support or maintain the architecture
upstream or even be responsible for applying the odd fix. The Intel
firmware team removed all IA-64 support from the Tianocore/EDK2
reference implementation of EFI in 2018. (Itanium is the original
architecture for which EFI was developed, and the way Linux supports it
deviates significantly from other architectures.) Some distros, such as
Debian and Gentoo, still maintain [unofficial] ia64 ports, but many have
dropped support years ago.

While the argument is being made [1] that there is a 'for the common
good' angle to being able to build and run existing projects such as the
Grid Community Toolkit [2] on Itanium for interoperability testing, the
fact remains that none of those projects are known to be deployed on
Linux/ia64, and very few people actually have access to such a system in
the first place. Even if there were ways imaginable in which Linux/ia64
could be put to good use today, what matters is whether anyone is
actually doing that, and this does not appear to be the case.

There are no emulators widely available, and so boot testing Itanium is
generally infeasible for ordinary contributors. GCC still supports IA-64
but its compile farm [3] no longer has any IA-64 machines. GLIBC would
like to get rid of IA-64 [4] too because it would permit some overdue
code cleanups. In summary, the benefits to the ecosystem of having IA-64
be part of it are mostly theoretical, whereas the maintenance overhead
of keeping it supported is real.

So let's rip off the band aid, and remove the IA-64 arch code entirely.
This follows the timeline proposed by the Debian/ia64 maintainer [5],
which removes support in a controlled manner, leaving IA-64 in a known
good state in the most recent LTS release. Other projects will follow
once the kernel support is removed.

[0] https://lore.kernel.org/all/CAMj1kXFCMh_578jniKpUtx_j8ByHnt=s7S+yQ+vGbKt9ud7+kQ@mail.gmail.com/
[1] https://lore.kernel.org/all/0075883c-7c51-00f5-2c2d-5119c1820410@web.de/
[2] https://gridcf.org/gct-docs/latest/index.html
[3] https://cfarm.tetaneutral.net/machines/list/
[4] https://lore.kernel.org/all/87bkiilpc4.fsf@mid.deneb.enyo.de/
[5] https://lore.kernel.org/all/ff58a3e76e5102c94bb5946d99187b358def688a.camel@physik.fu-berlin.de/

Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

1 files changed, 0 insertions, 613 deletions

diff --git a/arch/ia64/lib/copy_user.S b/arch/ia64/lib/copy_user.S
deleted file mode 100644
index 8daab72cfe77..000000000000
--- a/arch/ia64/lib/copy_user.S
+++ /dev/null
@@ -1,613 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- *
- * Optimized version of the copy_user() routine.
- * It is used to copy date across the kernel/user boundary.
- *
- * The source and destination are always on opposite side of
- * the boundary. When reading from user space we must catch
- * faults on loads. When writing to user space we must catch
- * errors on stores. Note that because of the nature of the copy
- * we don't need to worry about overlapping regions.
- *
- *
- * Inputs:
- *	in0	address of source buffer
- *	in1	address of destination buffer
- *	in2	number of bytes to copy
- *
- * Outputs:
- *	ret0	0 in case of success. The number of bytes NOT copied in
- *		case of error.
- *
- * Copyright (C) 2000-2001 Hewlett-Packard Co
- *	Stephane Eranian <eranian@hpl.hp.com>
- *
- * Fixme:
- *	- handle the case where we have more than 16 bytes and the alignment
- *	  are different.
- *	- more benchmarking
- *	- fix extraneous stop bit introduced by the EX() macro.
- */
-
-#include <linux/export.h>
-#include <asm/asmmacro.h>
-
-//
-// Tuneable parameters
-//
-#define COPY_BREAK	16	// we do byte copy below (must be >=16)
-#define PIPE_DEPTH	21	// pipe depth
-
-#define EPI		p[PIPE_DEPTH-1]
-
-//
-// arguments
-//
-#define dst		in0
-#define src		in1
-#define len		in2
-
-//
-// local registers
-//
-#define t1		r2	// rshift in bytes
-#define t2		r3	// lshift in bytes
-#define rshift		r14	// right shift in bits
-#define lshift		r15	// left shift in bits
-#define word1		r16
-#define word2		r17
-#define cnt		r18
-#define len2		r19
-#define saved_lc	r20
-#define saved_pr	r21
-#define tmp		r22
-#define val		r23
-#define src1		r24
-#define dst1		r25
-#define src2		r26
-#define dst2		r27
-#define len1		r28
-#define enddst		r29
-#define endsrc		r30
-#define saved_pfs	r31
-
-GLOBAL_ENTRY(__copy_user)
-	.prologue
-	.save ar.pfs, saved_pfs
-	alloc saved_pfs=ar.pfs,3,((2*PIPE_DEPTH+7)&~7),0,((2*PIPE_DEPTH+7)&~7)
-
-	.rotr val1[PIPE_DEPTH],val2[PIPE_DEPTH]
-	.rotp p[PIPE_DEPTH]
-
-	adds len2=-1,len	// br.ctop is repeat/until
-	mov ret0=r0
-
-	;;			// RAW of cfm when len=0
-	cmp.eq p8,p0=r0,len	// check for zero length
-	.save ar.lc, saved_lc
-	mov saved_lc=ar.lc	// preserve ar.lc (slow)
-(p8)	br.ret.spnt.many rp	// empty mempcy()
-	;;
-	add enddst=dst,len	// first byte after end of source
-	add endsrc=src,len	// first byte after end of destination
-	.save pr, saved_pr
-	mov saved_pr=pr		// preserve predicates
-
-	.body
-
-	mov dst1=dst		// copy because of rotation
-	mov ar.ec=PIPE_DEPTH
-	mov pr.rot=1<<16	// p16=true all others are false
-
-	mov src1=src		// copy because of rotation
-	mov ar.lc=len2		// initialize lc for small count
-	cmp.lt p10,p7=COPY_BREAK,len	// if len > COPY_BREAK then long copy
-
-	xor tmp=src,dst		// same alignment test prepare
-(p10)	br.cond.dptk .long_copy_user
-	;;			// RAW pr.rot/p16 ?
-	//
-	// Now we do the byte by byte loop with software pipeline
-	//
-	// p7 is necessarily false by now
-1:
-	EX(.failure_in_pipe1,(p16) ld1 val1[0]=[src1],1)
-	EX(.failure_out,(EPI) st1 [dst1]=val1[PIPE_DEPTH-1],1)
-	br.ctop.dptk.few 1b
-	;;
-	mov ar.lc=saved_lc
-	mov pr=saved_pr,0xffffffffffff0000
-	mov ar.pfs=saved_pfs		// restore ar.ec
-	br.ret.sptk.many rp		// end of short memcpy
-
-	//
-	// Not 8-byte aligned
-	//
-.diff_align_copy_user:
-	// At this point we know we have more than 16 bytes to copy
-	// and also that src and dest do _not_ have the same alignment.
-	and src2=0x7,src1				// src offset
-	and dst2=0x7,dst1				// dst offset
-	;;
-	// The basic idea is that we copy byte-by-byte at the head so
-	// that we can reach 8-byte alignment for both src1 and dst1.
-	// Then copy the body using software pipelined 8-byte copy,
-	// shifting the two back-to-back words right and left, then copy
-	// the tail by copying byte-by-byte.
-	//
-	// Fault handling. If the byte-by-byte at the head fails on the
-	// load, then restart and finish the pipleline by copying zeros
-	// to the dst1. Then copy zeros for the rest of dst1.
-	// If 8-byte software pipeline fails on the load, do the same as
-	// failure_in3 does. If the byte-by-byte at the tail fails, it is
-	// handled simply by failure_in_pipe1.
-	//
-	// The case p14 represents the source has more bytes in the
-	// the first word (by the shifted part), whereas the p15 needs to
-	// copy some bytes from the 2nd word of the source that has the
-	// tail of the 1st of the destination.
-	//
-
-	//
-	// Optimization. If dst1 is 8-byte aligned (quite common), we don't need
-	// to copy the head to dst1, to start 8-byte copy software pipeline.
-	// We know src1 is not 8-byte aligned in this case.
-	//
-	cmp.eq p14,p15=r0,dst2
-(p15)	br.cond.spnt 1f
-	;;
-	sub t1=8,src2
-	mov t2=src2
-	;;
-	shl rshift=t2,3
-	sub len1=len,t1					// set len1
-	;;
-	sub lshift=64,rshift
-	;;
-	br.cond.spnt .word_copy_user
-	;;
-1:
-	cmp.leu	p14,p15=src2,dst2
-	sub t1=dst2,src2
-	;;
-	.pred.rel "mutex", p14, p15
-(p14)	sub word1=8,src2				// (8 - src offset)
-(p15)	sub t1=r0,t1					// absolute value
-(p15)	sub word1=8,dst2				// (8 - dst offset)
-	;;
-	// For the case p14, we don't need to copy the shifted part to
-	// the 1st word of destination.
-	sub t2=8,t1
-(p14)	sub word1=word1,t1
-	;;
-	sub len1=len,word1				// resulting len
-(p15)	shl rshift=t1,3					// in bits
-(p14)	shl rshift=t2,3
-	;;
-(p14)	sub len1=len1,t1
-	adds cnt=-1,word1
-	;;
-	sub lshift=64,rshift
-	mov ar.ec=PIPE_DEPTH
-	mov pr.rot=1<<16	// p16=true all others are false
-	mov ar.lc=cnt
-	;;
-2:
-	EX(.failure_in_pipe2,(p16) ld1 val1[0]=[src1],1)
-	EX(.failure_out,(EPI) st1 [dst1]=val1[PIPE_DEPTH-1],1)
-	br.ctop.dptk.few 2b
-	;;
-	clrrrb
-	;;
-.word_copy_user:
-	cmp.gtu p9,p0=16,len1
-(p9)	br.cond.spnt 4f			// if (16 > len1) skip 8-byte copy
-	;;
-	shr.u cnt=len1,3		// number of 64-bit words
-	;;
-	adds cnt=-1,cnt
-	;;
-	.pred.rel "mutex", p14, p15
-(p14)	sub src1=src1,t2
-(p15)	sub src1=src1,t1
-	//
-	// Now both src1 and dst1 point to an 8-byte aligned address. And
-	// we have more than 8 bytes to copy.
-	//
-	mov ar.lc=cnt
-	mov ar.ec=PIPE_DEPTH
-	mov pr.rot=1<<16	// p16=true all others are false
-	;;
-3:
-	//
-	// The pipleline consists of 3 stages:
-	// 1 (p16):	Load a word from src1
-	// 2 (EPI_1):	Shift right pair, saving to tmp
-	// 3 (EPI):	Store tmp to dst1
-	//
-	// To make it simple, use at least 2 (p16) loops to set up val1[n]
-	// because we need 2 back-to-back val1[] to get tmp.
-	// Note that this implies EPI_2 must be p18 or greater.
-	//
-
-#define EPI_1		p[PIPE_DEPTH-2]
-#define SWITCH(pred, shift)	cmp.eq pred,p0=shift,rshift
-#define CASE(pred, shift)	\
-	(pred)	br.cond.spnt .copy_user_bit##shift
-#define BODY(rshift)						\
-.copy_user_bit##rshift:						\
-1:								\
-	EX(.failure_out,(EPI) st8 [dst1]=tmp,8);		\
-(EPI_1) shrp tmp=val1[PIPE_DEPTH-2],val1[PIPE_DEPTH-1],rshift;	\
-	EX(3f,(p16) ld8 val1[1]=[src1],8);			\
-(p16)	mov val1[0]=r0;						\
-	br.ctop.dptk 1b;					\
-	;;							\
-	br.cond.sptk.many .diff_align_do_tail;			\
-2:								\
-(EPI)	st8 [dst1]=tmp,8;					\
-(EPI_1)	shrp tmp=val1[PIPE_DEPTH-2],val1[PIPE_DEPTH-1],rshift;	\
-3:								\
-(p16)	mov val1[1]=r0;						\
-(p16)	mov val1[0]=r0;						\
-	br.ctop.dptk 2b;					\
-	;;							\
-	br.cond.sptk.many .failure_in2
-
-	//
-	// Since the instruction 'shrp' requires a fixed 128-bit value
-	// specifying the bits to shift, we need to provide 7 cases
-	// below.
-	//
-	SWITCH(p6, 8)
-	SWITCH(p7, 16)
-	SWITCH(p8, 24)
-	SWITCH(p9, 32)
-	SWITCH(p10, 40)
-	SWITCH(p11, 48)
-	SWITCH(p12, 56)
-	;;
-	CASE(p6, 8)
-	CASE(p7, 16)
-	CASE(p8, 24)
-	CASE(p9, 32)
-	CASE(p10, 40)
-	CASE(p11, 48)
-	CASE(p12, 56)
-	;;
-	BODY(8)
-	BODY(16)
-	BODY(24)
-	BODY(32)
-	BODY(40)
-	BODY(48)
-	BODY(56)
-	;;
-.diff_align_do_tail:
-	.pred.rel "mutex", p14, p15
-(p14)	sub src1=src1,t1
-(p14)	adds dst1=-8,dst1
-(p15)	sub dst1=dst1,t1
-	;;
-4:
-	// Tail correction.
-	//
-	// The problem with this piplelined loop is that the last word is not
-	// loaded and thus parf of the last word written is not correct.
-	// To fix that, we simply copy the tail byte by byte.
-
-	sub len1=endsrc,src1,1
-	clrrrb
-	;;
-	mov ar.ec=PIPE_DEPTH
-	mov pr.rot=1<<16	// p16=true all others are false
-	mov ar.lc=len1
-	;;
-5:
-	EX(.failure_in_pipe1,(p16) ld1 val1[0]=[src1],1)
-	EX(.failure_out,(EPI) st1 [dst1]=val1[PIPE_DEPTH-1],1)
-	br.ctop.dptk.few 5b
-	;;
-	mov ar.lc=saved_lc
-	mov pr=saved_pr,0xffffffffffff0000
-	mov ar.pfs=saved_pfs
-	br.ret.sptk.many rp
-
-	//
-	// Beginning of long mempcy (i.e. > 16 bytes)
-	//
-.long_copy_user:
-	tbit.nz p6,p7=src1,0	// odd alignment
-	and tmp=7,tmp
-	;;
-	cmp.eq p10,p8=r0,tmp
-	mov len1=len		// copy because of rotation
-(p8)	br.cond.dpnt .diff_align_copy_user
-	;;
-	// At this point we know we have more than 16 bytes to copy
-	// and also that both src and dest have the same alignment
-	// which may not be the one we want. So for now we must move
-	// forward slowly until we reach 16byte alignment: no need to
-	// worry about reaching the end of buffer.
-	//
-	EX(.failure_in1,(p6) ld1 val1[0]=[src1],1)	// 1-byte aligned
-(p6)	adds len1=-1,len1;;
-	tbit.nz p7,p0=src1,1
-	;;
-	EX(.failure_in1,(p7) ld2 val1[1]=[src1],2)	// 2-byte aligned
-(p7)	adds len1=-2,len1;;
-	tbit.nz p8,p0=src1,2
-	;;
-	//
-	// Stop bit not required after ld4 because if we fail on ld4
-	// we have never executed the ld1, therefore st1 is not executed.
-	//
-	EX(.failure_in1,(p8) ld4 val2[0]=[src1],4)	// 4-byte aligned
-	;;
-	EX(.failure_out,(p6) st1 [dst1]=val1[0],1)
-	tbit.nz p9,p0=src1,3
-	;;
-	//
-	// Stop bit not required after ld8 because if we fail on ld8
-	// we have never executed the ld2, therefore st2 is not executed.
-	//
-	EX(.failure_in1,(p9) ld8 val2[1]=[src1],8)	// 8-byte aligned
-	EX(.failure_out,(p7) st2 [dst1]=val1[1],2)
-(p8)	adds len1=-4,len1
-	;;
-	EX(.failure_out, (p8) st4 [dst1]=val2[0],4)
-(p9)	adds len1=-8,len1;;
-	shr.u cnt=len1,4		// number of 128-bit (2x64bit) words
-	;;
-	EX(.failure_out, (p9) st8 [dst1]=val2[1],8)
-	tbit.nz p6,p0=len1,3
-	cmp.eq p7,p0=r0,cnt
-	adds tmp=-1,cnt			// br.ctop is repeat/until
-(p7)	br.cond.dpnt .dotail		// we have less than 16 bytes left
-	;;
-	adds src2=8,src1
-	adds dst2=8,dst1
-	mov ar.lc=tmp
-	;;
-	//
-	// 16bytes/iteration
-	//
-2:
-	EX(.failure_in3,(p16) ld8 val1[0]=[src1],16)
-(p16)	ld8 val2[0]=[src2],16
-
-	EX(.failure_out, (EPI)	st8 [dst1]=val1[PIPE_DEPTH-1],16)
-(EPI)	st8 [dst2]=val2[PIPE_DEPTH-1],16
-	br.ctop.dptk 2b
-	;;			// RAW on src1 when fall through from loop
-	//
-	// Tail correction based on len only
-	//
-	// No matter where we come from (loop or test) the src1 pointer
-	// is 16 byte aligned AND we have less than 16 bytes to copy.
-	//
-.dotail:
-	EX(.failure_in1,(p6) ld8 val1[0]=[src1],8)	// at least 8 bytes
-	tbit.nz p7,p0=len1,2
-	;;
-	EX(.failure_in1,(p7) ld4 val1[1]=[src1],4)	// at least 4 bytes
-	tbit.nz p8,p0=len1,1
-	;;
-	EX(.failure_in1,(p8) ld2 val2[0]=[src1],2)	// at least 2 bytes
-	tbit.nz p9,p0=len1,0
-	;;
-	EX(.failure_out, (p6) st8 [dst1]=val1[0],8)
-	;;
-	EX(.failure_in1,(p9) ld1 val2[1]=[src1])	// only 1 byte left
-	mov ar.lc=saved_lc
-	;;
-	EX(.failure_out,(p7) st4 [dst1]=val1[1],4)
-	mov pr=saved_pr,0xffffffffffff0000
-	;;
-	EX(.failure_out, (p8)	st2 [dst1]=val2[0],2)
-	mov ar.pfs=saved_pfs
-	;;
-	EX(.failure_out, (p9)	st1 [dst1]=val2[1])
-	br.ret.sptk.many rp
-
-
-	//
-	// Here we handle the case where the byte by byte copy fails
-	// on the load.
-	// Several factors make the zeroing of the rest of the buffer kind of
-	// tricky:
-	//	- the pipeline: loads/stores are not in sync (pipeline)
-	//
-	//	  In the same loop iteration, the dst1 pointer does not directly
-	//	  reflect where the faulty load was.
-	//
-	//	- pipeline effect
-	//	  When you get a fault on load, you may have valid data from
-	//	  previous loads not yet store in transit. Such data must be
-	//	  store normally before moving onto zeroing the rest.
-	//
-	//	- single/multi dispersal independence.
-	//
-	// solution:
-	//	- we don't disrupt the pipeline, i.e. data in transit in
-	//	  the software pipeline will be eventually move to memory.
-	//	  We simply replace the load with a simple mov and keep the
-	//	  pipeline going. We can't really do this inline because
-	//	  p16 is always reset to 1 when lc > 0.
-	//
-.failure_in_pipe1:
-	sub ret0=endsrc,src1	// number of bytes to zero, i.e. not copied
-1:
-(p16)	mov val1[0]=r0
-(EPI)	st1 [dst1]=val1[PIPE_DEPTH-1],1
-	br.ctop.dptk 1b
-	;;
-	mov pr=saved_pr,0xffffffffffff0000
-	mov ar.lc=saved_lc
-	mov ar.pfs=saved_pfs
-	br.ret.sptk.many rp
-
-	//
-	// This is the case where the byte by byte copy fails on the load
-	// when we copy the head. We need to finish the pipeline and copy
-	// zeros for the rest of the destination. Since this happens
-	// at the top we still need to fill the body and tail.
-.failure_in_pipe2:
-	sub ret0=endsrc,src1	// number of bytes to zero, i.e. not copied
-2:
-(p16)	mov val1[0]=r0
-(EPI)	st1 [dst1]=val1[PIPE_DEPTH-1],1
-	br.ctop.dptk 2b
-	;;
-	sub len=enddst,dst1,1		// precompute len
-	br.cond.dptk.many .failure_in1bis
-	;;
-
-	//
-	// Here we handle the head & tail part when we check for alignment.
-	// The following code handles only the load failures. The
-	// main diffculty comes from the fact that loads/stores are
-	// scheduled. So when you fail on a load, the stores corresponding
-	// to previous successful loads must be executed.
-	//
-	// However some simplifications are possible given the way
-	// things work.
-	//
-	// 1) HEAD
-	// Theory of operation:
-	//
-	//  Page A   | Page B
-	//  ---------|-----
-	//          1|8 x
-	//	  1 2|8 x
-	//	    4|8 x
-	//	  1 4|8 x
-	//        2 4|8 x
-	//      1 2 4|8 x
-	//	     |1
-	//	     |2 x
-	//	     |4 x
-	//
-	// page_size >= 4k (2^12).  (x means 4, 2, 1)
-	// Here we suppose Page A exists and Page B does not.
-	//
-	// As we move towards eight byte alignment we may encounter faults.
-	// The numbers on each page show the size of the load (current alignment).
-	//
-	// Key point:
-	//	- if you fail on 1, 2, 4 then you have never executed any smaller
-	//	  size loads, e.g. failing ld4 means no ld1 nor ld2 executed
-	//	  before.
-	//
-	// This allows us to simplify the cleanup code, because basically you
-	// only have to worry about "pending" stores in the case of a failing
-	// ld8(). Given the way the code is written today, this means only
-	// worry about st2, st4. There we can use the information encapsulated
-	// into the predicates.
-	//
-	// Other key point:
-	//	- if you fail on the ld8 in the head, it means you went straight
-	//	  to it, i.e. 8byte alignment within an unexisting page.
-	// Again this comes from the fact that if you crossed just for the ld8 then
-	// you are 8byte aligned but also 16byte align, therefore you would
-	// either go for the 16byte copy loop OR the ld8 in the tail part.
-	// The combination ld1, ld2, ld4, ld8 where you fail on ld8 is impossible
-	// because it would mean you had 15bytes to copy in which case you
-	// would have defaulted to the byte by byte copy.
-	//
-	//
-	// 2) TAIL
-	// Here we now we have less than 16 bytes AND we are either 8 or 16 byte
-	// aligned.
-	//
-	// Key point:
-	// This means that we either:
-	//		- are right on a page boundary
-	//	OR
-	//		- are at more than 16 bytes from a page boundary with
-	//		  at most 15 bytes to copy: no chance of crossing.
-	//
-	// This allows us to assume that if we fail on a load we haven't possibly
-	// executed any of the previous (tail) ones, so we don't need to do
-	// any stores. For instance, if we fail on ld2, this means we had
-	// 2 or 3 bytes left to copy and we did not execute the ld8 nor ld4.
-	//
-	// This means that we are in a situation similar the a fault in the
-	// head part. That's nice!
-	//
-.failure_in1:
-	sub ret0=endsrc,src1	// number of bytes to zero, i.e. not copied
-	sub len=endsrc,src1,1
-	//
-	// we know that ret0 can never be zero at this point
-	// because we failed why trying to do a load, i.e. there is still
-	// some work to do.
-	// The failure_in1bis and length problem is taken care of at the
-	// calling side.
-	//
-	;;
-.failure_in1bis:		// from (.failure_in3)
-	mov ar.lc=len		// Continue with a stupid byte store.
-	;;
-5:
-	st1 [dst1]=r0,1
-	br.cloop.dptk 5b
-	;;
-	mov pr=saved_pr,0xffffffffffff0000
-	mov ar.lc=saved_lc
-	mov ar.pfs=saved_pfs
-	br.ret.sptk.many rp
-
-	//
-	// Here we simply restart the loop but instead
-	// of doing loads we fill the pipeline with zeroes
-	// We can't simply store r0 because we may have valid
-	// data in transit in the pipeline.
-	// ar.lc and ar.ec are setup correctly at this point
-	//
-	// we MUST use src1/endsrc here and not dst1/enddst because
-	// of the pipeline effect.
-	//
-.failure_in3:
-	sub ret0=endsrc,src1	// number of bytes to zero, i.e. not copied
-	;;
-2:
-(p16)	mov val1[0]=r0
-(p16)	mov val2[0]=r0
-(EPI)	st8 [dst1]=val1[PIPE_DEPTH-1],16
-(EPI)	st8 [dst2]=val2[PIPE_DEPTH-1],16
-	br.ctop.dptk 2b
-	;;
-	cmp.ne p6,p0=dst1,enddst	// Do we need to finish the tail ?
-	sub len=enddst,dst1,1		// precompute len
-(p6)	br.cond.dptk .failure_in1bis
-	;;
-	mov pr=saved_pr,0xffffffffffff0000
-	mov ar.lc=saved_lc
-	mov ar.pfs=saved_pfs
-	br.ret.sptk.many rp
-
-.failure_in2:
-	sub ret0=endsrc,src1
-	cmp.ne p6,p0=dst1,enddst	// Do we need to finish the tail ?
-	sub len=enddst,dst1,1		// precompute len
-(p6)	br.cond.dptk .failure_in1bis
-	;;
-	mov pr=saved_pr,0xffffffffffff0000
-	mov ar.lc=saved_lc
-	mov ar.pfs=saved_pfs
-	br.ret.sptk.many rp
-
-	//
-	// handling of failures on stores: that's the easy part
-	//
-.failure_out:
-	sub ret0=enddst,dst1
-	mov pr=saved_pr,0xffffffffffff0000
-	mov ar.lc=saved_lc
-
-	mov ar.pfs=saved_pfs
-	br.ret.sptk.many rp
-END(__copy_user)
-EXPORT_SYMBOL(__copy_user)