[PATCH v3 00/13] arm64: Optimise and update memcpy, user copy and string routines

[PATCH v3 00/13] arm64: Optimise and update memcpy, user copy and string routines

[Oliver Swede]

Hi, I have been working on a fix for this branch. The initial
version of this patchset imported new optimizations from Linaro's
cortex-strings project, and converted the instructions to the
macro equivalents in the usercopy template, in order to allow
each of the helper usercopy functions to use expansions that
insert exception table entries for exclusively the instructions
that could potentially fault during a copy. 

The 'cortex-strings' repository has since been renamed to
'optimized-routines' (this is public on GitHub at
https://github.com/ARM-software/optimized-routines),
and has been updated with further optimizations of various
library functions, and this includes a newer memcpy
implementation.

The address of page faults is exposed to the faulting instructions'
corresponding fixup code, and in v2 a fixup routine to correspond
to the previous copy algorithm was also implemented in a way that
utilized the fault address to try and efficiently calculate the
number of bytes that failed to copy. It returned the distance
between the fault and the end of the buffer, however this fixup
in [PATCH v2 2/14] had some issues due to the out-of-order nature
of the copy algorithm, and was flagged by the LTP testcase of the
preadv2() syscall (which makes multiple calls to copy_to_user).
This was due to preadv2() reporting SUCCESS for an invalid
destination address, NULL, where it expected EFAULT, because a
nonzero return value was calculated (indicating that some bytes
were copied) due to the fault not occurring at the start of the
buffer.

In this version I have imported the very latest optimized memcpy
routine, and re-written the fixup to use multiple routines that
encapsulate various properties of the algorithm (this is
explained in more detail in patches 11/13, 12/13, 13/13).
The aim is to return the exact number of bytes that haven't copied
when a fault occurs in copy_{to, in, from}_user, and to enable the
fixups to be modular so that they could be re-written without too
much trouble in the future if the copy algorithm was to be updated
again.

Initial testing indicates that the backtracking performed in the
fixup routines is accurate, and I am working on a separate
patchset containing more concise selftests that indirectly
call the usercopy functions via read()/write() - this will help
to ease the verification of expected behaviour.

I am going to post updated benchmark results, as the ~27% increase
in speed measured by Sam with the previous 'cortex-strings' memcpy
is no longer applicable due to the more recent replacement from
'optimized-routines', which should hopefully be even more efficient
and improve this further.

v1: https://lore.kernel.org/linux-arm-kernel/cover.1571073960.git.robin.murphy@arm.com/
v2: https://lore.kernel.org/linux-arm-kernel/cover.1571421836.git.robin.murphy@arm.com/

Changes since v2:

* Adds Robin's separate patch that fixes a compilation issue with KProbes fixup [1]
* Imports the most recent memcpy implementation by updating Sam's patch
  (and moves this patch to occur after the cortex-strings importing so
  that it's closer to the patches containing its corresponding fixups)
* Uses the stack to preserve the initial parameters
* Replaces the usercopy fixup routine in v2 with multiple longer
  fixups that each make use of the fault address to return the exact
  number of bytes that haven't yet copied.

[1] https://lore.kernel.org/linux-arm-kernel/e70f7b9de7e601b9e4a6fedad8eaf64d304b1637.1571326276.git.robin.murphy@arm.com/

Many thanks,
Oliver

Oliver Swede (4):
  arm64: Store the arguments to copy_*_user on the stack
  arm64: Use additional memcpy macros and fixups
  arm64: Add fixup routines for usercopy load exceptions
  arm64: Add fixup routines for usercopy store exceptions

Robin Murphy (2):
  arm64: Tidy up _asm_extable_faultaddr usage
  arm64: kprobes: Drop open-coded exception fixup

Sam Tebbs (7):
  arm64: Allow passing fault address to fixup handlers
  arm64: Import latest optimization of memcpy
  arm64: Import latest version of Cortex Strings' memcmp
  arm64: Import latest version of Cortex Strings' memmove
  arm64: Import latest version of Cortex Strings' strcmp
  arm64: Import latest version of Cortex Strings' strlen
  arm64: Import latest version of Cortex Strings' strncmp

 arch/arm64/include/asm/alternative.h |  36 ---
 arch/arm64/include/asm/assembler.h   |  13 +
 arch/arm64/include/asm/extable.h     |  10 +-
 arch/arm64/kernel/probes/kprobes.c   |   7 -
 arch/arm64/lib/copy_from_user.S      | 272 +++++++++++++++++--
 arch/arm64/lib/copy_in_user.S        | 287 ++++++++++++++++++--
 arch/arm64/lib/copy_template.S       | 377 +++++++++++++++------------
 arch/arm64/lib/copy_template_user.S  |  50 ++++
 arch/arm64/lib/copy_to_user.S        | 273 +++++++++++++++++--
 arch/arm64/lib/copy_user_fixup.S     | 277 ++++++++++++++++++++
 arch/arm64/lib/memcmp.S              | 333 +++++++++--------------
 arch/arm64/lib/memcpy.S              | 128 +++++++--
 arch/arm64/lib/memmove.S             | 232 ++++++-----------
 arch/arm64/lib/strcmp.S              | 272 ++++++++-----------
 arch/arm64/lib/strlen.S              | 247 ++++++++++++------
 arch/arm64/lib/strncmp.S             | 363 ++++++++++++--------------
 arch/arm64/mm/extable.c              |  13 +-
 arch/arm64/mm/fault.c                |   2 +-
 18 files changed, 2073 insertions(+), 1119 deletions(-)
 create mode 100644 arch/arm64/lib/copy_template_user.S
 create mode 100644 arch/arm64/lib/copy_user_fixup.S

-- 
2.17.1


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[PATCH v3 01/13] arm64: Allow passing fault address to fixup handlers

[Oliver Swede]

From: Sam Tebbs <sam.tebbs@arm.com>

Extend fixup_exception() to optionally place the faulting address in a
register when returning to a fixup handler. Since A64 instructions must
be 4-byte-aligned, we can mimic the IA-64 implementation and encode a
flag in the lower bits of the offset field to indicate handlers which
expect an address. This will allow us to use more efficient offset
addressing modes in usercopy routines, rather than updating the base
register on every access just for the sake of inferring where a fault
occurred in order to compute the return value upon failure.

The choice of x15 is somewhat arbitrary, but with the consideration that
as the highest-numbered temporary register with no possible 'special'
role in the ABI, it is most likely not used by hand-written assembly
code, and thus a minimally-invasive option for imported routines.

Signed-off-by: Sam Tebbs <sam.tebbs@arm.com>
[ rm: split into separate patch, use UL(), expand commit message ]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Oliver Swede <oli.swede@arm.com>
---
 arch/arm64/include/asm/assembler.h |  9 +++++++++
 arch/arm64/include/asm/extable.h   | 10 +++++++++-
 arch/arm64/mm/extable.c            | 13 +++++++++----
 arch/arm64/mm/fault.c              |  2 +-
 4 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 0bff325117b4..7017aeb4b29a 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -18,6 +18,7 @@
 #include <asm/cpufeature.h>
 #include <asm/cputype.h>
 #include <asm/debug-monitors.h>
+#include <asm/extable.h>
 #include <asm/page.h>
 #include <asm/pgtable-hwdef.h>
 #include <asm/ptrace.h>
@@ -129,6 +130,14 @@ alternative_endif
 	.popsection
 	.endm
 
+/*
+ * Emit an entry into the exception table.
+ * The fixup handler will receive the faulting address in x15
+ */
+	.macro		_asm_extable_faultaddr, from, to
+	_asm_extable	\from, \to + FIXUP_WITH_ADDR
+	.endm
+
 #define USER(l, x...)				\
 9999:	x;					\
 	_asm_extable	9999b, l
diff --git a/arch/arm64/include/asm/extable.h b/arch/arm64/include/asm/extable.h
index 56a4f68b262e..4c4955f2bb44 100644
--- a/arch/arm64/include/asm/extable.h
+++ b/arch/arm64/include/asm/extable.h
@@ -2,6 +2,12 @@
 #ifndef __ASM_EXTABLE_H
 #define __ASM_EXTABLE_H
 
+#include <linux/const.h>
+
+#define FIXUP_WITH_ADDR UL(1)
+
+#ifndef __ASSEMBLY__
+
 /*
  * The exception table consists of pairs of relative offsets: the first
  * is the relative offset to an instruction that is allowed to fault,
@@ -22,5 +28,7 @@ struct exception_table_entry
 
 #define ARCH_HAS_RELATIVE_EXTABLE
 
-extern int fixup_exception(struct pt_regs *regs);
+extern int fixup_exception(struct pt_regs *regs, unsigned long addr);
+
+#endif
 #endif
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 81e694af5f8c..e6578c2814b5 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -6,13 +6,18 @@
 #include <linux/extable.h>
 #include <linux/uaccess.h>
 
-int fixup_exception(struct pt_regs *regs)
+int fixup_exception(struct pt_regs *regs, unsigned long addr)
 {
 	const struct exception_table_entry *fixup;
 
 	fixup = search_exception_tables(instruction_pointer(regs));
-	if (fixup)
-		regs->pc = (unsigned long)&fixup->fixup + fixup->fixup;
-
+	if (fixup) {
+		unsigned long offset = fixup->fixup;
+		if (offset & FIXUP_WITH_ADDR) {
+			regs->regs[15] = addr;
+			offset &= ~FIXUP_WITH_ADDR;
+		}
+		regs->pc = (unsigned long)&fixup->fixup + offset;
+	}
 	return fixup != NULL;
 }
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index c9cedc0432d2..2c648343ab40 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -297,7 +297,7 @@ static void __do_kernel_fault(unsigned long addr, unsigned int esr,
 	 * Are we prepared to handle this kernel fault?
 	 * We are almost certainly not prepared to handle instruction faults.
 	 */
-	if (!is_el1_instruction_abort(esr) && fixup_exception(regs))
+	if (!is_el1_instruction_abort(esr) && fixup_exception(regs, addr))
 		return;
 
 	if (WARN_RATELIMIT(is_spurious_el1_translation_fault(addr, esr, regs),
-- 
2.17.1


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[PATCH v3 02/13] arm64: kprobes: Drop open-coded exception fixup

[Oliver Swede]

From: Robin Murphy <robin.murphy@arm.com>

The short-circuit call to fixup_exception() from kprobe_fault_handler()
poses a problem now that the former wants to consume the fault address
too, since the common kprobes API offers us no way to pass it through.
Fortunately, however, it works out to be unnecessary:

- uaccess instructions themselves are not probeable, so at most we
  should only ever expect to take a fixable fault from the pre or post
  handlers.
- the pre and post handler run with preemption disabled, thus for any
  fault they may cause, an unhandled return from kprobe_page_fault()
  will proceed directly to __do_kernel_fault() thanks to the
  faulthandler_disabled() check.
- __do_kernel_fault() will immediately call fixup_exception() unless
  we're in an EL1 instruction abort, and if we've somehow taken one of
  those on what we think is the middle of a uaccess routine, then the
  world is already very on fire.

Thus we can reasonably drop the call from kprobe_fault_handler() and
leave uaccess fixups to the regular flow.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Oliver Swede <oli.swede@arm.com>
---
 arch/arm64/kernel/probes/kprobes.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c
index d1c95dcf1d78..771635360110 100644
--- a/arch/arm64/kernel/probes/kprobes.c
+++ b/arch/arm64/kernel/probes/kprobes.c
@@ -334,13 +334,6 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, unsigned int fsr)
 		 */
 		if (cur->fault_handler && cur->fault_handler(cur, regs, fsr))
 			return 1;
-
-		/*
-		 * In case the user-specified fault handler returned
-		 * zero, try to fix up.
-		 */
-		if (fixup_exception(regs))
-			return 1;
 	}
 	return 0;
 }
-- 
2.17.1


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[PATCH v3 03/13] arm64: Import latest version of Cortex Strings' memcmp

[Oliver Swede]

From: Sam Tebbs <sam.tebbs@arm.com>

Import the latest version of Cortex Strings' memcmp function.

The upstream source is src/aarch64/memcmp.S as of commit f77e4c932b4f
in https://git.linaro.org/toolchain/cortex-strings.git.

Signed-off-by: Sam Tebbs <sam.tebbs@arm.com>
[ rm: update attribution, expand commit message ]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Oliver Swede <oli.swede@arm.com>
---
 arch/arm64/lib/memcmp.S | 333 ++++++++++++++--------------------------
 1 file changed, 117 insertions(+), 216 deletions(-)

diff --git a/arch/arm64/lib/memcmp.S b/arch/arm64/lib/memcmp.S
index c0671e793ea9..580dd0b12ccb 100644
--- a/arch/arm64/lib/memcmp.S
+++ b/arch/arm64/lib/memcmp.S
@@ -1,13 +1,12 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * Copyright (C) 2013 ARM Ltd.
- * Copyright (C) 2013 Linaro.
+ * Copyright (c) 2013, 2018 Linaro Limited. All rights reserved.
+ * Copyright (c) 2017 ARM Ltd. All rights reserved.
  *
- * This code is based on glibc cortex strings work originally authored by Linaro
- * be found @
+ * This code is based on glibc Cortex Strings work originally authored by
+ * Linaro, found at:
  *
- * http://bazaar.launchpad.net/~linaro-toolchain-dev/cortex-strings/trunk/
- * files/head:/src/aarch64/
+ * https://git.linaro.org/toolchain/cortex-strings.git
  */
 
 #include <linux/linkage.h>
@@ -25,223 +24,125 @@
 *  x0 - a compare result, maybe less than, equal to, or greater than ZERO
 */
 
+#define L(l) .L ## l
+
 /* Parameters and result.  */
-src1		.req	x0
-src2		.req	x1
-limit		.req	x2
-result		.req	x0
+#define src1		x0
+#define src2		x1
+#define limit		x2
+#define result		w0
 
 /* Internal variables.  */
-data1		.req	x3
-data1w		.req	w3
-data2		.req	x4
-data2w		.req	w4
-has_nul		.req	x5
-diff		.req	x6
-endloop		.req	x7
-tmp1		.req	x8
-tmp2		.req	x9
-tmp3		.req	x10
-pos		.req	x11
-limit_wd	.req	x12
-mask		.req	x13
+#define data1		x3
+#define data1w		w3
+#define data1h		x4
+#define data2		x5
+#define data2w		w5
+#define data2h		x6
+#define tmp1		x7
+#define tmp2		x8
 
 SYM_FUNC_START_WEAK_PI(memcmp)
-	cbz	limit, .Lret0
-	eor	tmp1, src1, src2
-	tst	tmp1, #7
-	b.ne	.Lmisaligned8
-	ands	tmp1, src1, #7
-	b.ne	.Lmutual_align
-	sub	limit_wd, limit, #1 /* limit != 0, so no underflow.  */
-	lsr	limit_wd, limit_wd, #3 /* Convert to Dwords.  */
-	/*
-	* The input source addresses are at alignment boundary.
-	* Directly compare eight bytes each time.
-	*/
-.Lloop_aligned:
-	ldr	data1, [src1], #8
-	ldr	data2, [src2], #8
-.Lstart_realigned:
-	subs	limit_wd, limit_wd, #1
-	eor	diff, data1, data2	/* Non-zero if differences found.  */
-	csinv	endloop, diff, xzr, cs	/* Last Dword or differences.  */
-	cbz	endloop, .Lloop_aligned
-
-	/* Not reached the limit, must have found a diff.  */
-	tbz	limit_wd, #63, .Lnot_limit
-
-	/* Limit % 8 == 0 => the diff is in the last 8 bytes. */
-	ands	limit, limit, #7
-	b.eq	.Lnot_limit
-	/*
-	* The remained bytes less than 8. It is needed to extract valid data
-	* from last eight bytes of the intended memory range.
-	*/
-	lsl	limit, limit, #3	/* bytes-> bits.  */
-	mov	mask, #~0
-CPU_BE( lsr	mask, mask, limit )
-CPU_LE( lsl	mask, mask, limit )
-	bic	data1, data1, mask
-	bic	data2, data2, mask
-
-	orr	diff, diff, mask
-	b	.Lnot_limit
-
-.Lmutual_align:
-	/*
-	* Sources are mutually aligned, but are not currently at an
-	* alignment boundary. Round down the addresses and then mask off
-	* the bytes that precede the start point.
-	*/
-	bic	src1, src1, #7
-	bic	src2, src2, #7
-	ldr	data1, [src1], #8
-	ldr	data2, [src2], #8
-	/*
-	* We can not add limit with alignment offset(tmp1) here. Since the
-	* addition probably make the limit overflown.
-	*/
-	sub	limit_wd, limit, #1/*limit != 0, so no underflow.*/
-	and	tmp3, limit_wd, #7
-	lsr	limit_wd, limit_wd, #3
-	add	tmp3, tmp3, tmp1
-	add	limit_wd, limit_wd, tmp3, lsr #3
-	add	limit, limit, tmp1/* Adjust the limit for the extra.  */
-
-	lsl	tmp1, tmp1, #3/* Bytes beyond alignment -> bits.*/
-	neg	tmp1, tmp1/* Bits to alignment -64.  */
-	mov	tmp2, #~0
-	/*mask off the non-intended bytes before the start address.*/
-CPU_BE( lsl	tmp2, tmp2, tmp1 )/*Big-endian.Early bytes are at MSB*/
-	/* Little-endian.  Early bytes are at LSB.  */
-CPU_LE( lsr	tmp2, tmp2, tmp1 )
-
-	orr	data1, data1, tmp2
-	orr	data2, data2, tmp2
-	b	.Lstart_realigned
-
-	/*src1 and src2 have different alignment offset.*/
-.Lmisaligned8:
-	cmp	limit, #8
-	b.lo	.Ltiny8proc /*limit < 8: compare byte by byte*/
-
-	and	tmp1, src1, #7
-	neg	tmp1, tmp1
-	add	tmp1, tmp1, #8/*valid length in the first 8 bytes of src1*/
-	and	tmp2, src2, #7
-	neg	tmp2, tmp2
-	add	tmp2, tmp2, #8/*valid length in the first 8 bytes of src2*/
-	subs	tmp3, tmp1, tmp2
-	csel	pos, tmp1, tmp2, hi /*Choose the maximum.*/
-
-	sub	limit, limit, pos
-	/*compare the proceeding bytes in the first 8 byte segment.*/
-.Ltinycmp:
-	ldrb	data1w, [src1], #1
-	ldrb	data2w, [src2], #1
-	subs	pos, pos, #1
-	ccmp	data1w, data2w, #0, ne  /* NZCV = 0b0000.  */
-	b.eq	.Ltinycmp
-	cbnz	pos, 1f /*diff occurred before the last byte.*/
-	cmp	data1w, data2w
-	b.eq	.Lstart_align
-1:
-	sub	result, data1, data2
-	ret
-
-.Lstart_align:
-	lsr	limit_wd, limit, #3
-	cbz	limit_wd, .Lremain8
-
-	ands	xzr, src1, #7
-	b.eq	.Lrecal_offset
-	/*process more leading bytes to make src1 aligned...*/
-	add	src1, src1, tmp3 /*backwards src1 to alignment boundary*/
-	add	src2, src2, tmp3
-	sub	limit, limit, tmp3
-	lsr	limit_wd, limit, #3
-	cbz	limit_wd, .Lremain8
-	/*load 8 bytes from aligned SRC1..*/
-	ldr	data1, [src1], #8
-	ldr	data2, [src2], #8
-
-	subs	limit_wd, limit_wd, #1
-	eor	diff, data1, data2  /*Non-zero if differences found.*/
-	csinv	endloop, diff, xzr, ne
-	cbnz	endloop, .Lunequal_proc
-	/*How far is the current SRC2 from the alignment boundary...*/
-	and	tmp3, tmp3, #7
-
-.Lrecal_offset:/*src1 is aligned now..*/
-	neg	pos, tmp3
-.Lloopcmp_proc:
-	/*
-	* Divide the eight bytes into two parts. First,backwards the src2
-	* to an alignment boundary,load eight bytes and compare from
-	* the SRC2 alignment boundary. If all 8 bytes are equal,then start
-	* the second part's comparison. Otherwise finish the comparison.
-	* This special handle can garantee all the accesses are in the
-	* thread/task space in avoid to overrange access.
-	*/
-	ldr	data1, [src1,pos]
-	ldr	data2, [src2,pos]
-	eor	diff, data1, data2  /* Non-zero if differences found.  */
-	cbnz	diff, .Lnot_limit
-
-	/*The second part process*/
-	ldr	data1, [src1], #8
-	ldr	data2, [src2], #8
-	eor	diff, data1, data2  /* Non-zero if differences found.  */
-	subs	limit_wd, limit_wd, #1
-	csinv	endloop, diff, xzr, ne/*if limit_wd is 0,will finish the cmp*/
-	cbz	endloop, .Lloopcmp_proc
-.Lunequal_proc:
-	cbz	diff, .Lremain8
-
-/* There is difference occurred in the latest comparison. */
-.Lnot_limit:
-/*
-* For little endian,reverse the low significant equal bits into MSB,then
-* following CLZ can find how many equal bits exist.
-*/
-CPU_LE( rev	diff, diff )
-CPU_LE( rev	data1, data1 )
-CPU_LE( rev	data2, data2 )
-
-	/*
-	* The MS-non-zero bit of DIFF marks either the first bit
-	* that is different, or the end of the significant data.
-	* Shifting left now will bring the critical information into the
-	* top bits.
-	*/
-	clz	pos, diff
-	lsl	data1, data1, pos
-	lsl	data2, data2, pos
-	/*
-	* We need to zero-extend (char is unsigned) the value and then
-	* perform a signed subtraction.
-	*/
-	lsr	data1, data1, #56
-	sub	result, data1, data2, lsr #56
+	subs	limit, limit, 8
+	b.lo	L(less8)
+
+	ldr	data1, [src1], 8
+	ldr	data2, [src2], 8
+	cmp	data1, data2
+	b.ne	L(return)
+
+	subs	limit, limit, 8
+	b.gt	L(more16)
+
+	ldr	data1, [src1, limit]
+	ldr	data2, [src2, limit]
+	b	L(return)
+
+L(more16):
+	ldr	data1, [src1], 8
+	ldr	data2, [src2], 8
+	cmp	data1, data2
+	bne	L(return)
+
+	/* Jump directly to comparing the last 16 bytes for 32 byte (or less)
+	   strings.  */
+	subs	limit, limit, 16
+	b.ls	L(last_bytes)
+
+	/* We overlap loads between 0-32 bytes at either side of SRC1 when we
+	   try to align, so limit it only to strings larger than 128 bytes.  */
+	cmp	limit, 96
+	b.ls	L(loop16)
+
+	/* Align src1 and adjust src2 with bytes not yet done.  */
+	and	tmp1, src1, 15
+	add	limit, limit, tmp1
+	sub	src1, src1, tmp1
+	sub	src2, src2, tmp1
+
+	/* Loop performing 16 bytes per iteration using aligned src1.
+	   Limit is pre-decremented by 16 and must be larger than zero.
+	   Exit if <= 16 bytes left to do or if the data is not equal.  */
+	.p2align 4
+L(loop16):
+	ldp	data1, data1h, [src1], 16
+	ldp	data2, data2h, [src2], 16
+	subs	limit, limit, 16
+	ccmp	data1, data2, 0, hi
+	ccmp	data1h, data2h, 0, eq
+	b.eq	L(loop16)
+
+	cmp	data1, data2
+	bne	L(return)
+	mov	data1, data1h
+	mov	data2, data2h
+	cmp	data1, data2
+	bne	L(return)
+
+	/* Compare last 1-16 bytes using unaligned access.  */
+L(last_bytes):
+	add	src1, src1, limit
+	add	src2, src2, limit
+	ldp	data1, data1h, [src1]
+	ldp	data2, data2h, [src2]
+	cmp	data1, data2
+	bne	L(return)
+	mov	data1, data1h
+	mov	data2, data2h
+	cmp	data1, data2
+
+	/* Compare data bytes and set return value to 0, -1 or 1.  */
+L(return):
+#ifndef __AARCH64EB__
+	rev	data1, data1
+	rev	data2, data2
+#endif
+	cmp	data1, data2
+L(ret_eq):
+	cset	result, ne
+	cneg	result, result, lo
 	ret
 
-.Lremain8:
-	/* Limit % 8 == 0 =>. all data are equal.*/
-	ands	limit, limit, #7
-	b.eq	.Lret0
-
-.Ltiny8proc:
-	ldrb	data1w, [src1], #1
-	ldrb	data2w, [src2], #1
-	subs	limit, limit, #1
-
-	ccmp	data1w, data2w, #0, ne  /* NZCV = 0b0000. */
-	b.eq	.Ltiny8proc
-	sub	result, data1, data2
-	ret
-.Lret0:
-	mov	result, #0
+	.p2align 4
+	/* Compare up to 8 bytes.  Limit is [-8..-1].  */
+L(less8):
+	adds	limit, limit, 4
+	b.lo	L(less4)
+	ldr	data1w, [src1], 4
+	ldr	data2w, [src2], 4
+	cmp	data1w, data2w
+	b.ne	L(return)
+	sub	limit, limit, 4
+L(less4):
+	adds	limit, limit, 4
+	beq	L(ret_eq)
+L(byte_loop):
+	ldrb	data1w, [src1], 1
+	ldrb	data2w, [src2], 1
+	subs	limit, limit, 1
+	ccmp	data1w, data2w, 0, ne	/* NZCV = 0b0000.  */
+	b.eq	L(byte_loop)
+	sub	result, data1w, data2w
 	ret
 SYM_FUNC_END_PI(memcmp)
 EXPORT_SYMBOL_NOKASAN(memcmp)
-- 
2.17.1


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[PATCH v3 04/13] arm64: Import latest version of Cortex Strings' memmove

[Oliver Swede]

From: Sam Tebbs <sam.tebbs@arm.com>

Import the latest version of Cortex Strings' memmove function.

The upstream source is src/aarch64/memmove.S as of commit 99b01ddb8e41
in https://git.linaro.org/toolchain/cortex-strings.git.

Signed-off-by: Sam Tebbs <sam.tebbs@arm.com>
[ rm: update attribution, expand commit message ]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Oliver Swede <oli.swede@arm.com>
---
 arch/arm64/lib/memmove.S | 232 +++++++++++++--------------------------
 1 file changed, 78 insertions(+), 154 deletions(-)

diff --git a/arch/arm64/lib/memmove.S b/arch/arm64/lib/memmove.S
index 02cda2e33bde..d0977d0ad745 100644
--- a/arch/arm64/lib/memmove.S
+++ b/arch/arm64/lib/memmove.S
@@ -1,13 +1,12 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * Copyright (C) 2013 ARM Ltd.
- * Copyright (C) 2013 Linaro.
+ * Copyright (c) 2013 Linaro Limited. All rights reserved.
+ * Copyright (c) 2015 ARM Ltd. All rights reserved.
  *
- * This code is based on glibc cortex strings work originally authored by Linaro
- * be found @
+ * This code is based on glibc Cortex Strings work originally authored by
+ * Linaro, found at:
  *
- * http://bazaar.launchpad.net/~linaro-toolchain-dev/cortex-strings/trunk/
- * files/head:/src/aarch64/
+ * https://git.linaro.org/toolchain/cortex-strings.git
  */
 
 #include <linux/linkage.h>
@@ -25,165 +24,90 @@
  * Returns:
  *	x0 - dest
  */
-dstin	.req	x0
-src	.req	x1
-count	.req	x2
-tmp1	.req	x3
-tmp1w	.req	w3
-tmp2	.req	x4
-tmp2w	.req	w4
-tmp3	.req	x5
-tmp3w	.req	w5
-dst	.req	x6
+/* Parameters and result.  */
+#define dstin	x0
+#define src	x1
+#define count	x2
+#define srcend	x3
+#define dstend	x4
+#define tmp1	x5
+#define A_l	x6
+#define A_h	x7
+#define B_l	x8
+#define B_h	x9
+#define C_l	x10
+#define C_h	x11
+#define D_l	x12
+#define D_h	x13
+#define E_l	count
+#define E_h	tmp1
 
-A_l	.req	x7
-A_h	.req	x8
-B_l	.req	x9
-B_h	.req	x10
-C_l	.req	x11
-C_h	.req	x12
-D_l	.req	x13
-D_h	.req	x14
+/* All memmoves up to 96 bytes are done by memcpy as it supports overlaps.
+   Larger backwards copies are also handled by memcpy. The only remaining
+   case is forward large copies.  The destination is aligned, and an
+   unrolled loop processes 64 bytes per iteration.
+*/
 
-	.weak memmove
+    .weak memmove
 SYM_FUNC_START_ALIAS(__memmove)
 SYM_FUNC_START_PI(memmove)
-	cmp	dstin, src
-	b.lo	__memcpy
-	add	tmp1, src, count
-	cmp	dstin, tmp1
-	b.hs	__memcpy		/* No overlap.  */
+	sub	tmp1, dstin, src
+	cmp	count, 96
+	ccmp	tmp1, count, 2, hi
+	b.hs	__memcpy
 
-	add	dst, dstin, count
-	add	src, src, count
-	cmp	count, #16
-	b.lo	.Ltail15  /*probably non-alignment accesses.*/
+	cbz	tmp1, 3f
+	add	dstend, dstin, count
+	add	srcend, src, count
 
-	ands	tmp2, src, #15     /* Bytes to reach alignment.  */
-	b.eq	.LSrcAligned
-	sub	count, count, tmp2
-	/*
-	* process the aligned offset length to make the src aligned firstly.
-	* those extra instructions' cost is acceptable. It also make the
-	* coming accesses are based on aligned address.
-	*/
-	tbz	tmp2, #0, 1f
-	ldrb	tmp1w, [src, #-1]!
-	strb	tmp1w, [dst, #-1]!
-1:
-	tbz	tmp2, #1, 2f
-	ldrh	tmp1w, [src, #-2]!
-	strh	tmp1w, [dst, #-2]!
-2:
-	tbz	tmp2, #2, 3f
-	ldr	tmp1w, [src, #-4]!
-	str	tmp1w, [dst, #-4]!
-3:
-	tbz	tmp2, #3, .LSrcAligned
-	ldr	tmp1, [src, #-8]!
-	str	tmp1, [dst, #-8]!
-
-.LSrcAligned:
-	cmp	count, #64
-	b.ge	.Lcpy_over64
+	/* Align dstend to 16 byte alignment so that we don't cross cache line
+	   boundaries on both loads and stores.	 There are at least 96 bytes
+	   to copy, so copy 16 bytes unaligned and then align.	The loop
+	   copies 64 bytes per iteration and prefetches one iteration ahead.  */
 
-	/*
-	* Deal with small copies quickly by dropping straight into the
-	* exit block.
-	*/
-.Ltail63:
-	/*
-	* Copy up to 48 bytes of data. At this point we only need the
-	* bottom 6 bits of count to be accurate.
-	*/
-	ands	tmp1, count, #0x30
-	b.eq	.Ltail15
-	cmp	tmp1w, #0x20
-	b.eq	1f
-	b.lt	2f
-	ldp	A_l, A_h, [src, #-16]!
-	stp	A_l, A_h, [dst, #-16]!
+	and	tmp1, dstend, 15
+	ldp	D_l, D_h, [srcend, -16]
+	sub	srcend, srcend, tmp1
+	sub	count, count, tmp1
+	ldp	A_l, A_h, [srcend, -16]
+	stp	D_l, D_h, [dstend, -16]
+	ldp	B_l, B_h, [srcend, -32]
+	ldp	C_l, C_h, [srcend, -48]
+	ldp	D_l, D_h, [srcend, -64]!
+	sub	dstend, dstend, tmp1
+	subs	count, count, 128
+	b.ls	2f
+	nop
 1:
-	ldp	A_l, A_h, [src, #-16]!
-	stp	A_l, A_h, [dst, #-16]!
-2:
-	ldp	A_l, A_h, [src, #-16]!
-	stp	A_l, A_h, [dst, #-16]!
+	stp	A_l, A_h, [dstend, -16]
+	ldp	A_l, A_h, [srcend, -16]
+	stp	B_l, B_h, [dstend, -32]
+	ldp	B_l, B_h, [srcend, -32]
+	stp	C_l, C_h, [dstend, -48]
+	ldp	C_l, C_h, [srcend, -48]
+	stp	D_l, D_h, [dstend, -64]!
+	ldp	D_l, D_h, [srcend, -64]!
+	subs	count, count, 64
+	b.hi	1b
 
-.Ltail15:
-	tbz	count, #3, 1f
-	ldr	tmp1, [src, #-8]!
-	str	tmp1, [dst, #-8]!
-1:
-	tbz	count, #2, 2f
-	ldr	tmp1w, [src, #-4]!
-	str	tmp1w, [dst, #-4]!
+	/* Write the last full set of 64 bytes.	 The remainder is at most 64
+	   bytes, so it is safe to always copy 64 bytes from the start even if
+	   there is just 1 byte left.  */
 2:
-	tbz	count, #1, 3f
-	ldrh	tmp1w, [src, #-2]!
-	strh	tmp1w, [dst, #-2]!
-3:
-	tbz	count, #0, .Lexitfunc
-	ldrb	tmp1w, [src, #-1]
-	strb	tmp1w, [dst, #-1]
-
-.Lexitfunc:
-	ret
-
-.Lcpy_over64:
-	subs	count, count, #128
-	b.ge	.Lcpy_body_large
-	/*
-	* Less than 128 bytes to copy, so handle 64 bytes here and then jump
-	* to the tail.
-	*/
-	ldp	A_l, A_h, [src, #-16]
-	stp	A_l, A_h, [dst, #-16]
-	ldp	B_l, B_h, [src, #-32]
-	ldp	C_l, C_h, [src, #-48]
-	stp	B_l, B_h, [dst, #-32]
-	stp	C_l, C_h, [dst, #-48]
-	ldp	D_l, D_h, [src, #-64]!
-	stp	D_l, D_h, [dst, #-64]!
-
-	tst	count, #0x3f
-	b.ne	.Ltail63
-	ret
-
-	/*
-	* Critical loop. Start at a new cache line boundary. Assuming
-	* 64 bytes per line this ensures the entire loop is in one line.
-	*/
-	.p2align	L1_CACHE_SHIFT
-.Lcpy_body_large:
-	/* pre-load 64 bytes data. */
-	ldp	A_l, A_h, [src, #-16]
-	ldp	B_l, B_h, [src, #-32]
-	ldp	C_l, C_h, [src, #-48]
-	ldp	D_l, D_h, [src, #-64]!
-1:
-	/*
-	* interlace the load of next 64 bytes data block with store of the last
-	* loaded 64 bytes data.
-	*/
-	stp	A_l, A_h, [dst, #-16]
-	ldp	A_l, A_h, [src, #-16]
-	stp	B_l, B_h, [dst, #-32]
-	ldp	B_l, B_h, [src, #-32]
-	stp	C_l, C_h, [dst, #-48]
-	ldp	C_l, C_h, [src, #-48]
-	stp	D_l, D_h, [dst, #-64]!
-	ldp	D_l, D_h, [src, #-64]!
-	subs	count, count, #64
-	b.ge	1b
-	stp	A_l, A_h, [dst, #-16]
-	stp	B_l, B_h, [dst, #-32]
-	stp	C_l, C_h, [dst, #-48]
-	stp	D_l, D_h, [dst, #-64]!
+	ldp	E_l, E_h, [src, 48]
+	stp	A_l, A_h, [dstend, -16]
+	ldp	A_l, A_h, [src, 32]
+	stp	B_l, B_h, [dstend, -32]
+	ldp	B_l, B_h, [src, 16]
+	stp	C_l, C_h, [dstend, -48]
+	ldp	C_l, C_h, [src]
+	stp	D_l, D_h, [dstend, -64]
+	stp	E_l, E_h, [dstin, 48]
+	stp	A_l, A_h, [dstin, 32]
+	stp	B_l, B_h, [dstin, 16]
+	stp	C_l, C_h, [dstin]
+3:	ret
 
-	tst	count, #0x3f
-	b.ne	.Ltail63
-	ret
 SYM_FUNC_END_PI(memmove)
 EXPORT_SYMBOL(memmove)
 SYM_FUNC_END_ALIAS(__memmove)
-- 
2.17.1


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[PATCH v3 05/13] arm64: Import latest version of Cortex Strings' strcmp

[Oliver Swede]

From: Sam Tebbs <sam.tebbs@arm.com>

Import the latest version of Cortex Strings' strcmp function.

The upstream source is src/aarch64/strcmp.S as of commit 90b61261ceb4
in https://git.linaro.org/toolchain/cortex-strings.git.

Signed-off-by: Sam Tebbs <sam.tebbs@arm.com>
[ rm: update attribution, expand commit message ]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Oliver Swede <oli.swede@arm.com>
---
 arch/arm64/lib/strcmp.S | 272 +++++++++++++++++-----------------------
 1 file changed, 113 insertions(+), 159 deletions(-)

diff --git a/arch/arm64/lib/strcmp.S b/arch/arm64/lib/strcmp.S
index 4e79566726c8..e00ff46c4ffc 100644
--- a/arch/arm64/lib/strcmp.S
+++ b/arch/arm64/lib/strcmp.S
@@ -1,13 +1,11 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * Copyright (C) 2013 ARM Ltd.
- * Copyright (C) 2013 Linaro.
+ * Copyright (c) 2012,2018 Linaro Limited. All rights reserved.
  *
- * This code is based on glibc cortex strings work originally authored by Linaro
- * be found @
+ * This code is based on glibc Cortex Strings work originally authored by
+ * Linaro, found at:
  *
- * http://bazaar.launchpad.net/~linaro-toolchain-dev/cortex-strings/trunk/
- * files/head:/src/aarch64/
+ * https://git.linaro.org/toolchain/cortex-strings.git
  */
 
 #include <linux/linkage.h>
@@ -25,60 +23,106 @@
  * or be greater than s2.
  */
 
+#define L(label) .L ## label
+
 #define REP8_01 0x0101010101010101
 #define REP8_7f 0x7f7f7f7f7f7f7f7f
 #define REP8_80 0x8080808080808080
 
 /* Parameters and result.  */
-src1		.req	x0
-src2		.req	x1
-result		.req	x0
+#define src1		x0
+#define src2		x1
+#define result		x0
 
 /* Internal variables.  */
-data1		.req	x2
-data1w		.req	w2
-data2		.req	x3
-data2w		.req	w3
-has_nul		.req	x4
-diff		.req	x5
-syndrome	.req	x6
-tmp1		.req	x7
-tmp2		.req	x8
-tmp3		.req	x9
-zeroones	.req	x10
-pos		.req	x11
-
+#define data1		x2
+#define data1w		w2
+#define data2		x3
+#define data2w		w3
+#define has_nul		x4
+#define diff		x5
+#define syndrome	x6
+#define tmp1		x7
+#define tmp2		x8
+#define tmp3		x9
+#define zeroones	x10
+#define pos		x11
+
+	/* Start of performance-critical section  -- one 64B cache line.  */
 SYM_FUNC_START_WEAK_PI(strcmp)
 	eor	tmp1, src1, src2
 	mov	zeroones, #REP8_01
 	tst	tmp1, #7
-	b.ne	.Lmisaligned8
+	b.ne	L(misaligned8)
 	ands	tmp1, src1, #7
-	b.ne	.Lmutual_align
-
-	/*
-	* NUL detection works on the principle that (X - 1) & (~X) & 0x80
-	* (=> (X - 1) & ~(X | 0x7f)) is non-zero iff a byte is zero, and
-	* can be done in parallel across the entire word.
-	*/
-.Lloop_aligned:
+	b.ne	L(mutual_align)
+	/* NUL detection works on the principle that (X - 1) & (~X) & 0x80
+	   (=> (X - 1) & ~(X | 0x7f)) is non-zero iff a byte is zero, and
+	   can be done in parallel across the entire word.  */
+L(loop_aligned):
 	ldr	data1, [src1], #8
 	ldr	data2, [src2], #8
-.Lstart_realigned:
+L(start_realigned):
 	sub	tmp1, data1, zeroones
 	orr	tmp2, data1, #REP8_7f
 	eor	diff, data1, data2	/* Non-zero if differences found.  */
 	bic	has_nul, tmp1, tmp2	/* Non-zero if NUL terminator.  */
 	orr	syndrome, diff, has_nul
-	cbz	syndrome, .Lloop_aligned
-	b	.Lcal_cmpresult
-
-.Lmutual_align:
-	/*
-	* Sources are mutually aligned, but are not currently at an
-	* alignment boundary.  Round down the addresses and then mask off
-	* the bytes that preceed the start point.
-	*/
+	cbz	syndrome, L(loop_aligned)
+	/* End of performance-critical section  -- one 64B cache line.  */
+
+L(end):
+CPU_LE(rev	syndrome, syndrome)
+CPU_LE(rev	data1, data1)
+	/* The MS-non-zero bit of the syndrome marks either the first bit
+	   that is different, or the top bit of the first zero byte.
+	   Shifting left now will bring the critical information into the
+	   top bits.  */
+CPU_LE(clz	pos, syndrome)
+CPU_LE(rev	data2, data2)
+CPU_LE(lsl	data1, data1, pos)
+CPU_LE(lsl	data2, data2, pos)
+	/* But we need to zero-extend (char is unsigned) the value and then
+	   perform a signed 32-bit subtraction.  */
+CPU_LE(lsr	data1, data1, #56)
+CPU_LE(sub	result, data1, data2, lsr #56)
+CPU_LE(ret)
+	/* For big-endian we cannot use the trick with the syndrome value
+	   as carry-propagation can corrupt the upper bits if the trailing
+	   bytes in the string contain 0x01.  */
+	/* However, if there is no NUL byte in the dword, we can generate
+	   the result directly.  We can't just subtract the bytes as the
+	   MSB might be significant.  */
+CPU_BE(cbnz	has_nul, 1f)
+CPU_BE(cmp	data1, data2)
+CPU_BE(cset	result, ne)
+CPU_BE(cneg	result, result, lo)
+CPU_BE(ret)
+1:
+	/* Re-compute the NUL-byte detection, using a byte-reversed value.  */
+CPU_BE(rev	tmp3, data1)
+CPU_BE(sub	tmp1, tmp3, zeroones)
+CPU_BE(orr	tmp2, tmp3, #REP8_7f)
+CPU_BE(bic	has_nul, tmp1, tmp2)
+CPU_BE(rev	has_nul, has_nul)
+CPU_BE(orr	syndrome, diff, has_nul)
+CPU_BE(clz	pos, syndrome)
+	/* The MS-non-zero bit of the syndrome marks either the first bit
+	   that is different, or the top bit of the first zero byte.
+	   Shifting left now will bring the critical information into the
+	   top bits.  */
+CPU_BE(lsl	data1, data1, pos)
+CPU_BE(lsl	data2, data2, pos)
+	/* But we need to zero-extend (char is unsigned) the value and then
+	   perform a signed 32-bit subtraction.  */
+CPU_BE(lsr	data1, data1, #56)
+CPU_BE(sub	result, data1, data2, lsr #56)
+CPU_BE(ret)
+
+L(mutual_align):
+	/* Sources are mutually aligned, but are not currently at an
+	   alignment boundary.  Round down the addresses and then mask off
+	   the bytes that preceed the start point.  */
 	bic	src1, src1, #7
 	bic	src2, src2, #7
 	lsl	tmp1, tmp1, #3		/* Bytes beyond alignment -> bits.  */
@@ -87,137 +131,47 @@ SYM_FUNC_START_WEAK_PI(strcmp)
 	ldr	data2, [src2], #8
 	mov	tmp2, #~0
 	/* Big-endian.  Early bytes are at MSB.  */
-CPU_BE( lsl	tmp2, tmp2, tmp1 )	/* Shift (tmp1 & 63).  */
+CPU_BE(lsl	tmp2, tmp2, tmp1)    /* Shift (tmp1 & 63).  */
 	/* Little-endian.  Early bytes are at LSB.  */
-CPU_LE( lsr	tmp2, tmp2, tmp1 )	/* Shift (tmp1 & 63).  */
-
+CPU_LE(lsr	tmp2, tmp2, tmp1)	/* Shift (tmp1 & 63).  */
 	orr	data1, data1, tmp2
 	orr	data2, data2, tmp2
-	b	.Lstart_realigned
-
-.Lmisaligned8:
-	/*
-	* Get the align offset length to compare per byte first.
-	* After this process, one string's address will be aligned.
-	*/
-	and	tmp1, src1, #7
-	neg	tmp1, tmp1
-	add	tmp1, tmp1, #8
-	and	tmp2, src2, #7
-	neg	tmp2, tmp2
-	add	tmp2, tmp2, #8
-	subs	tmp3, tmp1, tmp2
-	csel	pos, tmp1, tmp2, hi /*Choose the maximum. */
-.Ltinycmp:
+	b	L(start_realigned)
+
+L(misaligned8):
+	/* Align SRC1 to 8 bytes and then compare 8 bytes at a time, always
+	   checking to make sure that we don't access beyond page boundary in
+	   SRC2.  */
+	tst	src1, #7
+	b.eq	L(loop_misaligned)
+L(do_misaligned):
 	ldrb	data1w, [src1], #1
 	ldrb	data2w, [src2], #1
-	subs	pos, pos, #1
-	ccmp	data1w, #1, #0, ne  /* NZCV = 0b0000.  */
-	ccmp	data1w, data2w, #0, cs  /* NZCV = 0b0000.  */
-	b.eq	.Ltinycmp
-	cbnz	pos, 1f /*find the null or unequal...*/
 	cmp	data1w, #1
-	ccmp	data1w, data2w, #0, cs
-	b.eq	.Lstart_align /*the last bytes are equal....*/
-1:
-	sub	result, data1, data2
-	ret
-
-.Lstart_align:
-	ands	xzr, src1, #7
-	b.eq	.Lrecal_offset
-	/*process more leading bytes to make str1 aligned...*/
-	add	src1, src1, tmp3
-	add	src2, src2, tmp3
-	/*load 8 bytes from aligned str1 and non-aligned str2..*/
+	ccmp	data1w, data2w, #0, cs	/* NZCV = 0b0000.  */
+	b.ne	L(done)
+	tst	src1, #7
+	b.ne	L(do_misaligned)
+
+L(loop_misaligned):
+	/* Test if we are within the last dword of the end of a 4K page.  If
+	   yes then jump back to the misaligned loop to copy a byte at a time.  */
+	and	tmp1, src2, #0xff8
+	eor	tmp1, tmp1, #0xff8
+	cbz	tmp1, L(do_misaligned)
 	ldr	data1, [src1], #8
 	ldr	data2, [src2], #8
 
 	sub	tmp1, data1, zeroones
 	orr	tmp2, data1, #REP8_7f
-	bic	has_nul, tmp1, tmp2
-	eor	diff, data1, data2 /* Non-zero if differences found.  */
-	orr	syndrome, diff, has_nul
-	cbnz	syndrome, .Lcal_cmpresult
-	/*How far is the current str2 from the alignment boundary...*/
-	and	tmp3, tmp3, #7
-.Lrecal_offset:
-	neg	pos, tmp3
-.Lloopcmp_proc:
-	/*
-	* Divide the eight bytes into two parts. First,backwards the src2
-	* to an alignment boundary,load eight bytes from the SRC2 alignment
-	* boundary,then compare with the relative bytes from SRC1.
-	* If all 8 bytes are equal,then start the second part's comparison.
-	* Otherwise finish the comparison.
-	* This special handle can garantee all the accesses are in the
-	* thread/task space in avoid to overrange access.
-	*/
-	ldr	data1, [src1,pos]
-	ldr	data2, [src2,pos]
-	sub	tmp1, data1, zeroones
-	orr	tmp2, data1, #REP8_7f
-	bic	has_nul, tmp1, tmp2
-	eor	diff, data1, data2  /* Non-zero if differences found.  */
-	orr	syndrome, diff, has_nul
-	cbnz	syndrome, .Lcal_cmpresult
-
-	/*The second part process*/
-	ldr	data1, [src1], #8
-	ldr	data2, [src2], #8
-	sub	tmp1, data1, zeroones
-	orr	tmp2, data1, #REP8_7f
-	bic	has_nul, tmp1, tmp2
-	eor	diff, data1, data2  /* Non-zero if differences found.  */
+	eor	diff, data1, data2	/* Non-zero if differences found.  */
+	bic	has_nul, tmp1, tmp2	/* Non-zero if NUL terminator.  */
 	orr	syndrome, diff, has_nul
-	cbz	syndrome, .Lloopcmp_proc
+	cbz	syndrome, L(loop_misaligned)
+	b	L(end)
 
-.Lcal_cmpresult:
-	/*
-	* reversed the byte-order as big-endian,then CLZ can find the most
-	* significant zero bits.
-	*/
-CPU_LE( rev	syndrome, syndrome )
-CPU_LE( rev	data1, data1 )
-CPU_LE( rev	data2, data2 )
-
-	/*
-	* For big-endian we cannot use the trick with the syndrome value
-	* as carry-propagation can corrupt the upper bits if the trailing
-	* bytes in the string contain 0x01.
-	* However, if there is no NUL byte in the dword, we can generate
-	* the result directly.  We cannot just subtract the bytes as the
-	* MSB might be significant.
-	*/
-CPU_BE( cbnz	has_nul, 1f )
-CPU_BE( cmp	data1, data2 )
-CPU_BE( cset	result, ne )
-CPU_BE( cneg	result, result, lo )
-CPU_BE( ret )
-CPU_BE( 1: )
-	/*Re-compute the NUL-byte detection, using a byte-reversed value. */
-CPU_BE(	rev	tmp3, data1 )
-CPU_BE(	sub	tmp1, tmp3, zeroones )
-CPU_BE(	orr	tmp2, tmp3, #REP8_7f )
-CPU_BE(	bic	has_nul, tmp1, tmp2 )
-CPU_BE(	rev	has_nul, has_nul )
-CPU_BE(	orr	syndrome, diff, has_nul )
-
-	clz	pos, syndrome
-	/*
-	* The MS-non-zero bit of the syndrome marks either the first bit
-	* that is different, or the top bit of the first zero byte.
-	* Shifting left now will bring the critical information into the
-	* top bits.
-	*/
-	lsl	data1, data1, pos
-	lsl	data2, data2, pos
-	/*
-	* But we need to zero-extend (char is unsigned) the value and then
-	* perform a signed 32-bit subtraction.
-	*/
-	lsr	data1, data1, #56
-	sub	result, data1, data2, lsr #56
+L(done):
+	sub	result, data1, data2
 	ret
 SYM_FUNC_END_PI(strcmp)
 EXPORT_SYMBOL_NOKASAN(strcmp)
-- 
2.17.1


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[PATCH v3 06/13] arm64: Import latest version of Cortex Strings' strlen

[Oliver Swede]

From: Sam Tebbs <sam.tebbs@arm.com>

Import latest version of Cortex Strings' strlen function.

The upstream source is src/aarch64/strlen.S as of commit eb80ac77a6cd
in https://git.linaro.org/toolchain/cortex-strings.git.

Signed-off-by: Sam Tebbs <sam.tebbs@arm.com>
[ rm: update attribution, expand commit message ]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Oliver Swede <oli.swede@arm.com>
---
 arch/arm64/lib/strlen.S | 247 +++++++++++++++++++++++++++-------------
 1 file changed, 168 insertions(+), 79 deletions(-)

diff --git a/arch/arm64/lib/strlen.S b/arch/arm64/lib/strlen.S
index ee3ed882dd79..974b67dcc186 100644
--- a/arch/arm64/lib/strlen.S
+++ b/arch/arm64/lib/strlen.S
@@ -1,13 +1,11 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * Copyright (C) 2013 ARM Ltd.
- * Copyright (C) 2013 Linaro.
+ * Copyright (c) 2013-2015 Linaro Limited. All rights reserved.
  *
- * This code is based on glibc cortex strings work originally authored by Linaro
- * be found @
+ * This code is based on glibc Cortex Strings work originally authored by
+ * Linaro, found at:
  *
- * http://bazaar.launchpad.net/~linaro-toolchain-dev/cortex-strings/trunk/
- * files/head:/src/aarch64/
+ * https://git.linaro.org/toolchain/cortex-strings.git
  */
 
 #include <linux/linkage.h>
@@ -23,93 +21,184 @@
  */
 
 /* Arguments and results.  */
-srcin		.req	x0
-len		.req	x0
+#define srcin		x0
+#define len		x0
 
 /* Locals and temporaries.  */
-src		.req	x1
-data1		.req	x2
-data2		.req	x3
-data2a		.req	x4
-has_nul1	.req	x5
-has_nul2	.req	x6
-tmp1		.req	x7
-tmp2		.req	x8
-tmp3		.req	x9
-tmp4		.req	x10
-zeroones	.req	x11
-pos		.req	x12
+#define src		x1
+#define data1		x2
+#define data2		x3
+#define has_nul1	x4
+#define has_nul2	x5
+#define tmp1		x4
+#define tmp2		x5
+#define tmp3		x6
+#define tmp4		x7
+#define zeroones	x8
+
+#define L(l) .L ## l
+
+	/* NUL detection works on the principle that (X - 1) & (~X) & 0x80
+	   (=> (X - 1) & ~(X | 0x7f)) is non-zero iff a byte is zero, and
+	   can be done in parallel across the entire word. A faster check
+	   (X - 1) & 0x80 is zero for non-NUL ASCII characters, but gives
+	   false hits for characters 129..255.	*/
 
 #define REP8_01 0x0101010101010101
 #define REP8_7f 0x7f7f7f7f7f7f7f7f
 #define REP8_80 0x8080808080808080
 
+#ifdef TEST_PAGE_CROSS
+# define MIN_PAGE_SIZE 15
+#else
+# define MIN_PAGE_SIZE 4096
+#endif
+
+	/* Since strings are short on average, we check the first 16 bytes
+	   of the string for a NUL character.  In order to do an unaligned ldp
+	   safely we have to do a page cross check first.  If there is a NUL
+	   byte we calculate the length from the 2 8-byte words using
+	   conditional select to reduce branch mispredictions (it is unlikely
+	   strlen will be repeatedly called on strings with the same length).
+
+	   If the string is longer than 16 bytes, we align src so don't need
+	   further page cross checks, and process 32 bytes per iteration
+	   using the fast NUL check.  If we encounter non-ASCII characters,
+	   fallback to a second loop using the full NUL check.
+
+	   If the page cross check fails, we read 16 bytes from an aligned
+	   address, remove any characters before the string, and continue
+	   in the main loop using aligned loads.  Since strings crossing a
+	   page in the first 16 bytes are rare (probability of
+	   16/MIN_PAGE_SIZE ~= 0.4%), this case does not need to be optimized.
+
+	   AArch64 systems have a minimum page size of 4k.  We don't bother
+	   checking for larger page sizes - the cost of setting up the correct
+	   page size is just not worth the extra gain from a small reduction in
+	   the cases taking the slow path.  Note that we only care about
+	   whether the first fetch, which may be misaligned, crosses a page
+	   boundary.  */
+
 SYM_FUNC_START_WEAK_PI(strlen)
-	mov	zeroones, #REP8_01
-	bic	src, srcin, #15
-	ands	tmp1, srcin, #15
-	b.ne	.Lmisaligned
-	/*
-	* NUL detection works on the principle that (X - 1) & (~X) & 0x80
-	* (=> (X - 1) & ~(X | 0x7f)) is non-zero iff a byte is zero, and
-	* can be done in parallel across the entire word.
-	*/
-	/*
-	* The inner loop deals with two Dwords at a time. This has a
-	* slightly higher start-up cost, but we should win quite quickly,
-	* especially on cores with a high number of issue slots per
-	* cycle, as we get much better parallelism out of the operations.
-	*/
-.Lloop:
-	ldp	data1, data2, [src], #16
-.Lrealigned:
+	and	tmp1, srcin, MIN_PAGE_SIZE - 1
+	mov	zeroones, REP8_01
+	cmp	tmp1, MIN_PAGE_SIZE - 16
+	b.gt	L(page_cross)
+	ldp	data1, data2, [srcin]
+	/* For big-endian, carry propagation (if the final byte in the
+	   string is 0x01) means we cannot use has_nul1/2 directly.
+	   Since we expect strings to be small and early-exit,
+	   byte-swap the data now so has_null1/2 will be correct.  */
+CPU_BE(rev	data1, data1)
+CPU_BE(rev	data2, data2)
+	sub	tmp1, data1, zeroones
+	orr	tmp2, data1, REP8_7f
+	sub	tmp3, data2, zeroones
+	orr	tmp4, data2, REP8_7f
+	bics	has_nul1, tmp1, tmp2
+	bic	has_nul2, tmp3, tmp4
+	ccmp	has_nul2, 0, 0, eq
+	beq	L(main_loop_entry)
+
+	/* Enter with C = has_nul1 == 0.  */
+	csel	has_nul1, has_nul1, has_nul2, cc
+	mov	len, 8
+	rev	has_nul1, has_nul1
+	clz	tmp1, has_nul1
+	csel	len, xzr, len, cc
+	add	len, len, tmp1, lsr 3
+	ret
+
+	/* The inner loop processes 32 bytes per iteration and uses the fast
+	   NUL check.  If we encounter non-ASCII characters, use a second
+	   loop with the accurate NUL check.  */
+	.p2align 4
+L(main_loop_entry):
+	bic	src, srcin, 15
+	sub	src, src, 16
+L(main_loop):
+	ldp	data1, data2, [src, 32]!
+.Lpage_cross_entry:
 	sub	tmp1, data1, zeroones
-	orr	tmp2, data1, #REP8_7f
 	sub	tmp3, data2, zeroones
-	orr	tmp4, data2, #REP8_7f
-	bic	has_nul1, tmp1, tmp2
-	bics	has_nul2, tmp3, tmp4
-	ccmp	has_nul1, #0, #0, eq	/* NZCV = 0000  */
-	b.eq	.Lloop
+	orr	tmp2, tmp1, tmp3
+	tst	tmp2, zeroones, lsl 7
+	bne	1f
+	ldp	data1, data2, [src, 16]
+	sub	tmp1, data1, zeroones
+	sub	tmp3, data2, zeroones
+	orr	tmp2, tmp1, tmp3
+	tst	tmp2, zeroones, lsl 7
+	beq	L(main_loop)
+	add	src, src, 16
+1:
+	/* The fast check failed, so do the slower, accurate NUL check.	 */
+	orr	tmp2, data1, REP8_7f
+	orr	tmp4, data2, REP8_7f
+	bics	has_nul1, tmp1, tmp2
+	bic	has_nul2, tmp3, tmp4
+	ccmp	has_nul2, 0, 0, eq
+	beq	L(nonascii_loop)
 
+	/* Enter with C = has_nul1 == 0.  */
+L(tail):
+	/* For big-endian, carry propagation (if the final byte in the
+	   string is 0x01) means we cannot use has_nul1/2 directly.  The
+	   easiest way to get the correct byte is to byte-swap the data
+	   and calculate the syndrome a second time.  */
+CPU_BE(csel	data1, data1, data2, cc)
+CPU_BE(rev	data1, data1)
+CPU_BE(sub	tmp1, data1, zeroones)
+CPU_BE(orr	tmp2, data1, REP8_7f)
+CPU_BE(bic	has_nul1, tmp1, tmp2)
+CPU_LE(csel	has_nul1, has_nul1, has_nul2, cc)
 	sub	len, src, srcin
-	cbz	has_nul1, .Lnul_in_data2
-CPU_BE(	mov	data2, data1 )	/*prepare data to re-calculate the syndrome*/
-	sub	len, len, #8
-	mov	has_nul2, has_nul1
-.Lnul_in_data2:
-	/*
-	* For big-endian, carry propagation (if the final byte in the
-	* string is 0x01) means we cannot use has_nul directly.  The
-	* easiest way to get the correct byte is to byte-swap the data
-	* and calculate the syndrome a second time.
-	*/
-CPU_BE( rev	data2, data2 )
-CPU_BE( sub	tmp1, data2, zeroones )
-CPU_BE( orr	tmp2, data2, #REP8_7f )
-CPU_BE( bic	has_nul2, tmp1, tmp2 )
-
-	sub	len, len, #8
-	rev	has_nul2, has_nul2
-	clz	pos, has_nul2
-	add	len, len, pos, lsr #3		/* Bits to bytes.  */
+	rev	has_nul1, has_nul1
+	add	tmp2, len, 8
+	clz	tmp1, has_nul1
+	csel	len, len, tmp2, cc
+	add	len, len, tmp1, lsr 3
 	ret
 
-.Lmisaligned:
-	cmp	tmp1, #8
-	neg	tmp1, tmp1
-	ldp	data1, data2, [src], #16
-	lsl	tmp1, tmp1, #3		/* Bytes beyond alignment -> bits.  */
-	mov	tmp2, #~0
-	/* Big-endian.  Early bytes are at MSB.  */
-CPU_BE( lsl	tmp2, tmp2, tmp1 )	/* Shift (tmp1 & 63).  */
-	/* Little-endian.  Early bytes are at LSB.  */
-CPU_LE( lsr	tmp2, tmp2, tmp1 )	/* Shift (tmp1 & 63).  */
+L(nonascii_loop):
+	ldp	data1, data2, [src, 16]!
+	sub	tmp1, data1, zeroones
+	orr	tmp2, data1, REP8_7f
+	sub	tmp3, data2, zeroones
+	orr	tmp4, data2, REP8_7f
+	bics	has_nul1, tmp1, tmp2
+	bic	has_nul2, tmp3, tmp4
+	ccmp	has_nul2, 0, 0, eq
+	bne	L(tail)
+	ldp	data1, data2, [src, 16]!
+	sub	tmp1, data1, zeroones
+	orr	tmp2, data1, REP8_7f
+	sub	tmp3, data2, zeroones
+	orr	tmp4, data2, REP8_7f
+	bics	has_nul1, tmp1, tmp2
+	bic	has_nul2, tmp3, tmp4
+	ccmp	has_nul2, 0, 0, eq
+	beq	L(nonascii_loop)
+	b	L(tail)
 
-	orr	data1, data1, tmp2
-	orr	data2a, data2, tmp2
-	csinv	data1, data1, xzr, le
-	csel	data2, data2, data2a, le
-	b	.Lrealigned
+	/* Load 16 bytes from [srcin & ~15] and force the bytes that precede
+	   srcin to 0x7f, so we ignore any NUL bytes before the string.
+	   Then continue in the aligned loop.  */
+L(page_cross):
+	bic	src, srcin, 15
+	ldp	data1, data2, [src]
+	lsl	tmp1, srcin, 3
+	mov	tmp4, -1
+	/* Big-endian.	Early bytes are at MSB.	 */
+CPU_BE(lsr	tmp1, tmp4, tmp1)	/* Shift (tmp1 & 63).  */
+	/* Little-endian.  Early bytes are at LSB.  */
+CPU_LE(lsl	tmp1, tmp4, tmp1)	/* Shift (tmp1 & 63).  */
+	orr	tmp1, tmp1, REP8_80
+	orn	data1, data1, tmp1
+	orn	tmp2, data2, tmp1
+	tst	srcin, 8
+	csel	data1, data1, tmp4, eq
+	csel	data2, data2, tmp2, eq
+	b	L(page_cross_entry)
 SYM_FUNC_END_PI(strlen)
 EXPORT_SYMBOL_NOKASAN(strlen)
-- 
2.17.1


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[PATCH v3 07/13] arm64: Import latest version of Cortex Strings' strncmp

[Oliver Swede]

From: Sam Tebbs <sam.tebbs@arm.com>

Import latest version of Cortex Strings' strncmp function.

The upstream source is src/aarch64/strncmp.S as of commit 071fe283b28d
in https://git.linaro.org/toolchain/cortex-strings.git.

Signed-off-by: Sam Tebbs <sam.tebbs@arm.com>
[ rm: update attribution, expand commit message ]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Oliver Swede <oli.swede@arm.com>
---
 arch/arm64/lib/strncmp.S | 363 ++++++++++++++++++---------------------
 1 file changed, 163 insertions(+), 200 deletions(-)

diff --git a/arch/arm64/lib/strncmp.S b/arch/arm64/lib/strncmp.S
index 2a7ee949ed47..b954e0fd93be 100644
--- a/arch/arm64/lib/strncmp.S
+++ b/arch/arm64/lib/strncmp.S
@@ -1,13 +1,11 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * Copyright (C) 2013 ARM Ltd.
- * Copyright (C) 2013 Linaro.
+ * Copyright (c) 2013,2018 Linaro Limited. All rights reserved.
  *
- * This code is based on glibc cortex strings work originally authored by Linaro
- * be found @
+ * This code is based on glibc Cortex Strings work originally authored by
+ * Linaro, found at:
  *
- * http://bazaar.launchpad.net/~linaro-toolchain-dev/cortex-strings/trunk/
- * files/head:/src/aarch64/
+ * https://git.linaro.org/toolchain/cortex-strings.git
  */
 
 #include <linux/linkage.h>
@@ -30,49 +28,49 @@
 #define REP8_80 0x8080808080808080
 
 /* Parameters and result.  */
-src1		.req	x0
-src2		.req	x1
-limit		.req	x2
-result		.req	x0
+#define src1		x0
+#define src2		x1
+#define limit		x2
+#define result		x0
 
 /* Internal variables.  */
-data1		.req	x3
-data1w		.req	w3
-data2		.req	x4
-data2w		.req	w4
-has_nul		.req	x5
-diff		.req	x6
-syndrome	.req	x7
-tmp1		.req	x8
-tmp2		.req	x9
-tmp3		.req	x10
-zeroones	.req	x11
-pos		.req	x12
-limit_wd	.req	x13
-mask		.req	x14
-endloop		.req	x15
+#define data1		x3
+#define data1w		w3
+#define data2		x4
+#define data2w		w4
+#define has_nul		x5
+#define diff		x6
+#define syndrome	x7
+#define tmp1		x8
+#define tmp2		x9
+#define tmp3		x10
+#define zeroones	x11
+#define pos		x12
+#define limit_wd	x13
+#define mask		x14
+#define endloop		x15
+#define count		mask
 
+	.p2align 6
+	.rep 7
+	nop	/* Pad so that the loop below fits a cache line.  */
+	.endr
 SYM_FUNC_START_WEAK_PI(strncmp)
 	cbz	limit, .Lret0
 	eor	tmp1, src1, src2
 	mov	zeroones, #REP8_01
 	tst	tmp1, #7
+	and	count, src1, #7
 	b.ne	.Lmisaligned8
-	ands	tmp1, src1, #7
-	b.ne	.Lmutual_align
+	cbnz	count, .Lmutual_align
 	/* Calculate the number of full and partial words -1.  */
-	/*
-	* when limit is mulitply of 8, if not sub 1,
-	* the judgement of last dword will wrong.
-	*/
-	sub	limit_wd, limit, #1 /* limit != 0, so no underflow.  */
-	lsr	limit_wd, limit_wd, #3  /* Convert to Dwords.  */
+	sub	limit_wd, limit, #1	/* limit != 0, so no underflow.  */
+	lsr	limit_wd, limit_wd, #3	/* Convert to Dwords.  */
 
-	/*
-	* NUL detection works on the principle that (X - 1) & (~X) & 0x80
-	* (=> (X - 1) & ~(X | 0x7f)) is non-zero iff a byte is zero, and
-	* can be done in parallel across the entire word.
-	*/
+	/* NUL detection works on the principle that (X - 1) & (~X) & 0x80
+	   (=> (X - 1) & ~(X | 0x7f)) is non-zero iff a byte is zero, and
+	   can be done in parallel across the entire word.  */
+	/* Start of performance-critical section  -- one 64B cache line.  */
 .Lloop_aligned:
 	ldr	data1, [src1], #8
 	ldr	data2, [src2], #8
@@ -80,23 +78,24 @@ SYM_FUNC_START_WEAK_PI(strncmp)
 	subs	limit_wd, limit_wd, #1
 	sub	tmp1, data1, zeroones
 	orr	tmp2, data1, #REP8_7f
-	eor	diff, data1, data2  /* Non-zero if differences found.  */
-	csinv	endloop, diff, xzr, pl  /* Last Dword or differences.*/
-	bics	has_nul, tmp1, tmp2 /* Non-zero if NUL terminator.  */
+	eor	diff, data1, data2	/* Non-zero if differences found.  */
+	csinv	endloop, diff, xzr, pl	/* Last Dword or differences.  */
+	bics	has_nul, tmp1, tmp2	/* Non-zero if NUL terminator.  */
 	ccmp	endloop, #0, #0, eq
 	b.eq	.Lloop_aligned
+	/* End of performance-critical section  -- one 64B cache line.  */
 
-	/*Not reached the limit, must have found the end or a diff.  */
+	/* Not reached the limit, must have found the end or a diff.  */
 	tbz	limit_wd, #63, .Lnot_limit
 
 	/* Limit % 8 == 0 => all bytes significant.  */
 	ands	limit, limit, #7
 	b.eq	.Lnot_limit
 
-	lsl	limit, limit, #3    /* Bits -> bytes.  */
+	lsl	limit, limit, #3	/* Bits -> bytes.  */
 	mov	mask, #~0
-CPU_BE( lsr	mask, mask, limit )
-CPU_LE( lsl	mask, mask, limit )
+CPU_BE(lsr	mask, mask, limit)
+CPU_LE(lsl	mask, mask, limit)
 	bic	data1, data1, mask
 	bic	data2, data2, mask
 
@@ -105,192 +104,156 @@ CPU_LE( lsl	mask, mask, limit )
 
 .Lnot_limit:
 	orr	syndrome, diff, has_nul
-	b	.Lcal_cmpresult
+
+	CPU_LE(rev	syndrome, syndrome)
+	CPU_LE(rev	data1, data1)
+	/* The MS-non-zero bit of the syndrome marks either the first bit
+	   that is different, or the top bit of the first zero byte.
+	   Shifting left now will bring the critical information into the
+	   top bits.  */
+	CPU_LE(clz	pos, syndrome)
+	CPU_LE(rev	data2, data2)
+	CPU_LE(lsl	data1, data1, pos)
+	CPU_LE(lsl	data2, data2, pos)
+	/* But we need to zero-extend (char is unsigned) the value and then
+	   perform a signed 32-bit subtraction.  */
+	CPU_LE(lsr	data1, data1, #56)
+	CPU_LE(sub	result, data1, data2, lsr #56)
+	CPU_LE(ret)
+	/* For big-endian we cannot use the trick with the syndrome value
+	   as carry-propagation can corrupt the upper bits if the trailing
+	   bytes in the string contain 0x01.  */
+	/* However, if there is no NUL byte in the dword, we can generate
+	   the result directly.  We can't just subtract the bytes as the
+	   MSB might be significant.  */
+	CPU_BE(cbnz	has_nul, 1f)
+	CPU_BE(cmp	data1, data2)
+	CPU_BE(cset	result, ne)
+	CPU_BE(cneg	result, result, lo)
+	CPU_BE(ret)
+1:
+	/* Re-compute the NUL-byte detection, using a byte-reversed value.  */
+	CPU_BE(rev	tmp3, data1)
+	CPU_BE(sub	tmp1, tmp3, zeroones)
+	CPU_BE(orr	tmp2, tmp3, #REP8_7f)
+	CPU_BE(bic	has_nul, tmp1, tmp2)
+	CPU_BE(rev	has_nul, has_nul)
+	CPU_BE(orr	syndrome, diff, has_nul)
+	CPU_BE(clz	pos, syndrome)
+	/* The MS-non-zero bit of the syndrome marks either the first bit
+	   that is different, or the top bit of the first zero byte.
+	   Shifting left now will bring the critical information into the
+	   top bits.  */
+	CPU_BE(lsl	data1, data1, pos)
+	CPU_BE(lsl	data2, data2, pos)
+	/* But we need to zero-extend (char is unsigned) the value and then
+	   perform a signed 32-bit subtraction.  */
+	CPU_BE(lsr	data1, data1, #56)
+	CPU_BE(sub	result, data1, data2, lsr #56)
+	CPU_BE(ret)
 
 .Lmutual_align:
-	/*
-	* Sources are mutually aligned, but are not currently at an
-	* alignment boundary.  Round down the addresses and then mask off
-	* the bytes that precede the start point.
-	* We also need to adjust the limit calculations, but without
-	* overflowing if the limit is near ULONG_MAX.
-	*/
+	/* Sources are mutually aligned, but are not currently at an
+	   alignment boundary.  Round down the addresses and then mask off
+	   the bytes that precede the start point.
+	   We also need to adjust the limit calculations, but without
+	   overflowing if the limit is near ULONG_MAX.  */
 	bic	src1, src1, #7
 	bic	src2, src2, #7
 	ldr	data1, [src1], #8
-	neg	tmp3, tmp1, lsl #3  /* 64 - bits(bytes beyond align). */
+	neg	tmp3, count, lsl #3	/* 64 - bits(bytes beyond align). */
 	ldr	data2, [src2], #8
 	mov	tmp2, #~0
-	sub	limit_wd, limit, #1 /* limit != 0, so no underflow.  */
+	sub	limit_wd, limit, #1	/* limit != 0, so no underflow.  */
 	/* Big-endian.  Early bytes are at MSB.  */
-CPU_BE( lsl	tmp2, tmp2, tmp3 )	/* Shift (tmp1 & 63).  */
+	CPU_BE(lsl	tmp2, tmp2, tmp3)	/* Shift (count & 63).  */
 	/* Little-endian.  Early bytes are at LSB.  */
-CPU_LE( lsr	tmp2, tmp2, tmp3 )	/* Shift (tmp1 & 63).  */
-
+	CPU_LE(lsr	tmp2, tmp2, tmp3)	/* Shift (count & 63).  */
 	and	tmp3, limit_wd, #7
 	lsr	limit_wd, limit_wd, #3
-	/* Adjust the limit. Only low 3 bits used, so overflow irrelevant.*/
-	add	limit, limit, tmp1
-	add	tmp3, tmp3, tmp1
+	/* Adjust the limit. Only low 3 bits used, so overflow irrelevant.  */
+	add	limit, limit, count
+	add	tmp3, tmp3, count
 	orr	data1, data1, tmp2
 	orr	data2, data2, tmp2
 	add	limit_wd, limit_wd, tmp3, lsr #3
 	b	.Lstart_realigned
 
-/*when src1 offset is not equal to src2 offset...*/
+	.p2align 6
+	/* Don't bother with dwords for up to 16 bytes.  */
 .Lmisaligned8:
-	cmp	limit, #8
-	b.lo	.Ltiny8proc /*limit < 8... */
-	/*
-	* Get the align offset length to compare per byte first.
-	* After this process, one string's address will be aligned.*/
-	and	tmp1, src1, #7
-	neg	tmp1, tmp1
-	add	tmp1, tmp1, #8
-	and	tmp2, src2, #7
-	neg	tmp2, tmp2
-	add	tmp2, tmp2, #8
-	subs	tmp3, tmp1, tmp2
-	csel	pos, tmp1, tmp2, hi /*Choose the maximum. */
-	/*
-	* Here, limit is not less than 8, so directly run .Ltinycmp
-	* without checking the limit.*/
-	sub	limit, limit, pos
-.Ltinycmp:
+	cmp	limit, #16
+	b.hs	.Ltry_misaligned_words
+
+.Lbyte_loop:
+	/* Perhaps we can do better than this.  */
 	ldrb	data1w, [src1], #1
 	ldrb	data2w, [src2], #1
-	subs	pos, pos, #1
-	ccmp	data1w, #1, #0, ne  /* NZCV = 0b0000.  */
-	ccmp	data1w, data2w, #0, cs  /* NZCV = 0b0000.  */
-	b.eq	.Ltinycmp
-	cbnz	pos, 1f /*find the null or unequal...*/
-	cmp	data1w, #1
-	ccmp	data1w, data2w, #0, cs
-	b.eq	.Lstart_align /*the last bytes are equal....*/
-1:
+	subs	limit, limit, #1
+	ccmp	data1w, #1, #0, hi	/* NZCV = 0b0000.  */
+	ccmp	data1w, data2w, #0, cs	/* NZCV = 0b0000.  */
+	b.eq	.Lbyte_loop
+.Ldone:
 	sub	result, data1, data2
 	ret
-
-.Lstart_align:
+	/* Align the SRC1 to a dword by doing a bytewise compare and then do
+	   the dword loop.  */
+.Ltry_misaligned_words:
 	lsr	limit_wd, limit, #3
-	cbz	limit_wd, .Lremain8
-	/*process more leading bytes to make str1 aligned...*/
-	ands	xzr, src1, #7
-	b.eq	.Lrecal_offset
-	add	src1, src1, tmp3	/*tmp3 is positive in this branch.*/
-	add	src2, src2, tmp3
-	ldr	data1, [src1], #8
-	ldr	data2, [src2], #8
+	cbz	count, .Ldo_misaligned
 
-	sub	limit, limit, tmp3
+	neg	count, count
+	and	count, count, #7
+	sub	limit, limit, count
 	lsr	limit_wd, limit, #3
-	subs	limit_wd, limit_wd, #1
 
-	sub	tmp1, data1, zeroones
-	orr	tmp2, data1, #REP8_7f
-	eor	diff, data1, data2  /* Non-zero if differences found.  */
-	csinv	endloop, diff, xzr, ne/*if limit_wd is 0,will finish the cmp*/
-	bics	has_nul, tmp1, tmp2
-	ccmp	endloop, #0, #0, eq /*has_null is ZERO: no null byte*/
-	b.ne	.Lunequal_proc
-	/*How far is the current str2 from the alignment boundary...*/
-	and	tmp3, tmp3, #7
-.Lrecal_offset:
-	neg	pos, tmp3
-.Lloopcmp_proc:
-	/*
-	* Divide the eight bytes into two parts. First,backwards the src2
-	* to an alignment boundary,load eight bytes from the SRC2 alignment
-	* boundary,then compare with the relative bytes from SRC1.
-	* If all 8 bytes are equal,then start the second part's comparison.
-	* Otherwise finish the comparison.
-	* This special handle can garantee all the accesses are in the
-	* thread/task space in avoid to overrange access.
-	*/
-	ldr	data1, [src1,pos]
-	ldr	data2, [src2,pos]
-	sub	tmp1, data1, zeroones
-	orr	tmp2, data1, #REP8_7f
-	bics	has_nul, tmp1, tmp2 /* Non-zero if NUL terminator.  */
-	eor	diff, data1, data2  /* Non-zero if differences found.  */
-	csinv	endloop, diff, xzr, eq
-	cbnz	endloop, .Lunequal_proc
+.Lpage_end_loop:
+	ldrb	data1w, [src1], #1
+	ldrb	data2w, [src2], #1
+	cmp	data1w, #1
+	ccmp	data1w, data2w, #0, cs	/* NZCV = 0b0000.  */
+	b.ne	.Ldone
+	subs	count, count, #1
+	b.hi	.Lpage_end_loop
+
+.Ldo_misaligned:
+	/* Prepare ourselves for the next page crossing.  Unlike the aligned
+	   loop, we fetch 1 less dword because we risk crossing bounds on
+	   SRC2.  */
+	mov	count, #8
+	subs	limit_wd, limit_wd, #1
+	b.lo	.Ldone_loop
+.Lloop_misaligned:
+	and	tmp2, src2, #0xff8
+	eor	tmp2, tmp2, #0xff8
+	cbz	tmp2, .Lpage_end_loop
 
-	/*The second part process*/
 	ldr	data1, [src1], #8
 	ldr	data2, [src2], #8
-	subs	limit_wd, limit_wd, #1
 	sub	tmp1, data1, zeroones
 	orr	tmp2, data1, #REP8_7f
-	eor	diff, data1, data2  /* Non-zero if differences found.  */
-	csinv	endloop, diff, xzr, ne/*if limit_wd is 0,will finish the cmp*/
-	bics	has_nul, tmp1, tmp2
-	ccmp	endloop, #0, #0, eq /*has_null is ZERO: no null byte*/
-	b.eq	.Lloopcmp_proc
-
-.Lunequal_proc:
-	orr	syndrome, diff, has_nul
-	cbz	syndrome, .Lremain8
-.Lcal_cmpresult:
-	/*
-	* reversed the byte-order as big-endian,then CLZ can find the most
-	* significant zero bits.
-	*/
-CPU_LE( rev	syndrome, syndrome )
-CPU_LE( rev	data1, data1 )
-CPU_LE( rev	data2, data2 )
-	/*
-	* For big-endian we cannot use the trick with the syndrome value
-	* as carry-propagation can corrupt the upper bits if the trailing
-	* bytes in the string contain 0x01.
-	* However, if there is no NUL byte in the dword, we can generate
-	* the result directly.  We can't just subtract the bytes as the
-	* MSB might be significant.
-	*/
-CPU_BE( cbnz	has_nul, 1f )
-CPU_BE( cmp	data1, data2 )
-CPU_BE( cset	result, ne )
-CPU_BE( cneg	result, result, lo )
-CPU_BE( ret )
-CPU_BE( 1: )
-	/* Re-compute the NUL-byte detection, using a byte-reversed value.*/
-CPU_BE( rev	tmp3, data1 )
-CPU_BE( sub	tmp1, tmp3, zeroones )
-CPU_BE( orr	tmp2, tmp3, #REP8_7f )
-CPU_BE( bic	has_nul, tmp1, tmp2 )
-CPU_BE( rev	has_nul, has_nul )
-CPU_BE( orr	syndrome, diff, has_nul )
-	/*
-	* The MS-non-zero bit of the syndrome marks either the first bit
-	* that is different, or the top bit of the first zero byte.
-	* Shifting left now will bring the critical information into the
-	* top bits.
-	*/
-	clz	pos, syndrome
-	lsl	data1, data1, pos
-	lsl	data2, data2, pos
-	/*
-	* But we need to zero-extend (char is unsigned) the value and then
-	* perform a signed 32-bit subtraction.
-	*/
-	lsr	data1, data1, #56
-	sub	result, data1, data2, lsr #56
-	ret
-
-.Lremain8:
-	/* Limit % 8 == 0 => all bytes significant.  */
-	ands	limit, limit, #7
-	b.eq	.Lret0
-.Ltiny8proc:
-	ldrb	data1w, [src1], #1
-	ldrb	data2w, [src2], #1
-	subs	limit, limit, #1
+	eor	diff, data1, data2	/* Non-zero if differences found.  */
+	bics	has_nul, tmp1, tmp2	/* Non-zero if NUL terminator.  */
+	ccmp	diff, #0, #0, eq
+	b.ne	.Lnot_limit
+	subs	limit_wd, limit_wd, #1
+	b.pl	.Lloop_misaligned
 
-	ccmp	data1w, #1, #0, ne  /* NZCV = 0b0000.  */
-	ccmp	data1w, data2w, #0, cs  /* NZCV = 0b0000.  */
-	b.eq	.Ltiny8proc
-	sub	result, data1, data2
-	ret
+.Ldone_loop:
+	/* We found a difference or a NULL before the limit was reached.  */
+	and	limit, limit, #7
+	cbz	limit, .Lnot_limit
+	/* Read the last word.  */
+	sub	src1, src1, 8
+	sub	src2, src2, 8
+	ldr	data1, [src1, limit]
+	ldr	data2, [src2, limit]
+	sub	tmp1, data1, zeroones
+	orr	tmp2, data1, #REP8_7f
+	eor	diff, data1, data2	/* Non-zero if differences found.  */
+	bics	has_nul, tmp1, tmp2	/* Non-zero if NUL terminator.  */
+	ccmp	diff, #0, #0, eq
+	b.ne	.Lnot_limit
 
 .Lret0:
 	mov	result, #0
-- 
2.17.1


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[PATCH v3 08/13] arm64: Import latest optimization of memcpy

[Oliver Swede]

From: Sam Tebbs <sam.tebbs@arm.com>

Import the latest memcpy implementation into memcpy,
copy_{from, to and in}_user.
The implementation of the user routines is separated into two forms:
one for when UAO is enabled and one for when UAO is disabled, with
the two being chosen between with a runtime patch.
This avoids executing the many NOPs emitted when UAO is disabled.

The project containing optimized implementations for various library
functions has now been renamed from 'cortex-strings' to
'optimized-routines', and the new upstream source is
string/aarch64/memcpy.S as of commit 4c175c8be12 in
https://github.com/ARM-software/optimized-routines.

Signed-off-by: Sam Tebbs <sam.tebbs@arm.com>
[ rm: add UAO fixups, streamline copy_exit paths, expand commit message ]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[ os: import newer memcpy algorithm, replace innaccurate fixup routine
  with placeholder, update commit message ]
Signed-off-by: Oliver Swede <oli.swede@arm.com>
---
 arch/arm64/include/asm/alternative.h |  36 ---
 arch/arm64/lib/copy_from_user.S      | 115 ++++++--
 arch/arm64/lib/copy_in_user.S        | 130 ++++++++--
 arch/arm64/lib/copy_template.S       | 375 +++++++++++++++------------
 arch/arm64/lib/copy_template_user.S  |  24 ++
 arch/arm64/lib/copy_to_user.S        | 113 ++++++--
 arch/arm64/lib/copy_user_fixup.S     |   9 +
 arch/arm64/lib/memcpy.S              |  48 ++--
 8 files changed, 557 insertions(+), 293 deletions(-)
 create mode 100644 arch/arm64/lib/copy_template_user.S
 create mode 100644 arch/arm64/lib/copy_user_fixup.S

diff --git a/arch/arm64/include/asm/alternative.h b/arch/arm64/include/asm/alternative.h
index 5e5dc05d63a0..7ab752104170 100644
--- a/arch/arm64/include/asm/alternative.h
+++ b/arch/arm64/include/asm/alternative.h
@@ -230,36 +230,6 @@ alternative_endif
  * unprivileged instructions, and USER() only works for single instructions.
  */
 #ifdef CONFIG_ARM64_UAO
-	.macro uao_ldp l, reg1, reg2, addr, post_inc
-		alternative_if_not ARM64_HAS_UAO
-8888:			ldp	\reg1, \reg2, [\addr], \post_inc;
-8889:			nop;
-			nop;
-		alternative_else
-			ldtr	\reg1, [\addr];
-			ldtr	\reg2, [\addr, #8];
-			add	\addr, \addr, \post_inc;
-		alternative_endif
-
-		_asm_extable	8888b,\l;
-		_asm_extable	8889b,\l;
-	.endm
-
-	.macro uao_stp l, reg1, reg2, addr, post_inc
-		alternative_if_not ARM64_HAS_UAO
-8888:			stp	\reg1, \reg2, [\addr], \post_inc;
-8889:			nop;
-			nop;
-		alternative_else
-			sttr	\reg1, [\addr];
-			sttr	\reg2, [\addr, #8];
-			add	\addr, \addr, \post_inc;
-		alternative_endif
-
-		_asm_extable	8888b,\l;
-		_asm_extable	8889b,\l;
-	.endm
-
 	.macro uao_user_alternative l, inst, alt_inst, reg, addr, post_inc
 		alternative_if_not ARM64_HAS_UAO
 8888:			\inst	\reg, [\addr], \post_inc;
@@ -272,12 +242,6 @@ alternative_endif
 		_asm_extable	8888b,\l;
 	.endm
 #else
-	.macro uao_ldp l, reg1, reg2, addr, post_inc
-		USER(\l, ldp \reg1, \reg2, [\addr], \post_inc)
-	.endm
-	.macro uao_stp l, reg1, reg2, addr, post_inc
-		USER(\l, stp \reg1, \reg2, [\addr], \post_inc)
-	.endm
 	.macro uao_user_alternative l, inst, alt_inst, reg, addr, post_inc
 		USER(\l, \inst \reg, [\addr], \post_inc)
 	.endm
diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S
index 8e25e89ad01f..dbf768cc7650 100644
--- a/arch/arm64/lib/copy_from_user.S
+++ b/arch/arm64/lib/copy_from_user.S
@@ -20,49 +20,112 @@
  *	x0 - bytes not copied
  */
 
-	.macro ldrb1 ptr, regB, val
-	uao_user_alternative 9998f, ldrb, ldtrb, \ptr, \regB, \val
+	.macro ldrb1 reg, ptr, offset=0
+	8888: ldtrb \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
 	.endm
 
-	.macro strb1 ptr, regB, val
-	strb \ptr, [\regB], \val
+	.macro strb1 reg, ptr, offset=0
+	strb \reg, [\ptr, \offset]
 	.endm
 
-	.macro ldrh1 ptr, regB, val
-	uao_user_alternative 9998f, ldrh, ldtrh, \ptr, \regB, \val
+	.macro ldrb1_reg reg, ptr, offset
+	add \ptr, \ptr, \offset
+	8888: ldtrb \reg, [\ptr]
+	sub \ptr, \ptr, \offset
+	_asm_extable_faultaddr	8888b,9998f;
 	.endm
 
-	.macro strh1 ptr, regB, val
-	strh \ptr, [\regB], \val
+	.macro strb1_reg reg, ptr, offset
+	strb \reg, [\ptr, \offset]
 	.endm
 
-	.macro ldr1 ptr, regB, val
-	uao_user_alternative 9998f, ldr, ldtr, \ptr, \regB, \val
+	.macro ldr1 reg, ptr, offset=0
+	8888: ldtr \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
 	.endm
 
-	.macro str1 ptr, regB, val
-	str \ptr, [\regB], \val
+	.macro str1 reg, ptr, offset=0
+	str \reg, [\ptr, \offset]
 	.endm
 
-	.macro ldp1 ptr, regB, regC, val
-	uao_ldp 9998f, \ptr, \regB, \regC, \val
+	.macro ldp1 regA, regB, ptr, offset=0
+	8888: ldtr \regA, [\ptr, \offset]
+	8889: ldtr \regB, [\ptr, \offset + 8]
+	_asm_extable_faultaddr	8888b,9998f;
+	_asm_extable_faultaddr	8889b,9998f;
 	.endm
 
-	.macro stp1 ptr, regB, regC, val
-	stp \ptr, \regB, [\regC], \val
+	.macro stp1 regA, regB, ptr, offset=0
+	stp \regA, \regB, [\ptr, \offset]
+	.endm
+
+	.macro ldp1_pre regA, regB, ptr, offset
+	8888: ldtr \regA, [\ptr, \offset]
+	8889: ldtr \regB, [\ptr, \offset + 8]
+	add \ptr, \ptr, \offset
+	_asm_extable_faultaddr	8888b,9998f;
+	_asm_extable_faultaddr	8889b,9998f;
+	.endm
+
+	.macro stp1_pre regA, regB, ptr, offset
+	stp \regA, \regB, [\ptr, \offset]!
+	.endm
+
+	.macro ldrb1_nuao reg, ptr, offset=0
+	8888: ldrb \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro strb1_nuao reg, ptr, offset=0
+	strb \reg, [\ptr, \offset]
+	.endm
+
+	.macro ldrb1_nuao_reg reg, ptr, offset=0
+	8888: ldrb \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro strb1_nuao_reg reg, ptr, offset=0
+	strb \reg, [\ptr, \offset]
+	.endm
+
+	.macro ldr1_nuao reg, ptr, offset=0
+	8888: ldr \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro str1_nuao reg, ptr, offset=0
+	str \reg, [\ptr, \offset]
+	.endm
+
+	.macro ldp1_nuao  regA, regB, ptr, offset=0
+	8888: ldp \regA, \regB, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro stp1_nuao regA, regB, ptr, offset=0
+	stp \regA, \regB, [\ptr, \offset]
+	.endm
+
+	.macro ldp1_pre_nuao regA, regB, ptr, offset
+	8888: ldp \regA, \regB, [\ptr, \offset]!
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro stp1_pre_nuao regA, regB, ptr, offset
+	stp \regA, \regB, [\ptr, \offset]!
+	.endm
+
+	.macro copy_exit
+	b	.Luaccess_finish
 	.endm
 
-end	.req	x5
 SYM_FUNC_START(__arch_copy_from_user)
-	add	end, x0, x2
-#include "copy_template.S"
-	mov	x0, #0				// Nothing to copy
+#include "copy_template_user.S"
+.Luaccess_finish:
+	mov	x0, #0
 	ret
 SYM_FUNC_END(__arch_copy_from_user)
 EXPORT_SYMBOL(__arch_copy_from_user)
-
-	.section .fixup,"ax"
-	.align	2
-9998:	sub	x0, end, dst			// bytes not copied
-	ret
-	.previous
+#include "copy_user_fixup.S"
diff --git a/arch/arm64/lib/copy_in_user.S b/arch/arm64/lib/copy_in_user.S
index 667139013ed1..f08d4b36a857 100644
--- a/arch/arm64/lib/copy_in_user.S
+++ b/arch/arm64/lib/copy_in_user.S
@@ -21,50 +21,130 @@
  * Returns:
  *	x0 - bytes not copied
  */
-	.macro ldrb1 ptr, regB, val
-	uao_user_alternative 9998f, ldrb, ldtrb, \ptr, \regB, \val
+
+	.macro ldrb1 reg, ptr, offset=0
+	8888: ldtrb \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro strb1 reg, ptr, offset=0
+	8888: sttrb \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro ldrb1_reg reg, ptr, offset
+	add \ptr, \ptr, \offset
+	8888: ldtrb \reg, [\ptr]
+	sub \ptr, \ptr, \offset
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro strb1_reg reg, ptr, offset
+	add \ptr, \ptr, \offset
+	8888: sttrb \reg, [\ptr]
+	sub \ptr, \ptr, \offset
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro ldr1 reg, ptr, offset=0
+	8888: ldtr \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro str1 reg, ptr, offset=0
+	8888: sttr \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro ldp1 regA, regB, ptr, offset=0
+	8888: ldtr \regA, [\ptr, \offset]
+	8889: ldtr \regB, [\ptr, \offset + 8]
+	_asm_extable_faultaddr	8888b,9998f;
+	_asm_extable_faultaddr	8889b,9998f;
+	.endm
+
+	.macro stp1 regA, regB, ptr, offset=0
+	8888: sttr \regA, [\ptr, \offset]
+	8889: sttr \regB, [\ptr, \offset + 8]
+	_asm_extable_faultaddr	8888b,9998f;
+	_asm_extable_faultaddr	8889b,9998f;
+	.endm
+
+	.macro ldp1_pre regA, regB, ptr, offset
+	8888: ldtr \regA, [\ptr, \offset]
+	8889: ldtr \regB, [\ptr, \offset + 8]
+	add \ptr, \ptr, \offset
+	_asm_extable_faultaddr	8888b,9998f;
+	_asm_extable_faultaddr	8889b,9998f;
+	.endm
+
+	.macro stp1_pre regA, regB, ptr, offset
+	8888: sttr \regA, [\ptr, \offset]
+	8889: sttr \regB, [\ptr, \offset + 8]
+	add \ptr, \ptr, \offset
+	_asm_extable_faultaddr	8888b,9998f;
+	_asm_extable_faultaddr	8889b,9998f;
+	.endm
+
+	.macro ldrb1_nuao reg, ptr, offset=0
+	8888: ldrb \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
 	.endm
 
-	.macro strb1 ptr, regB, val
-	uao_user_alternative 9998f, strb, sttrb, \ptr, \regB, \val
+	.macro strb1_nuao reg, ptr, offset=0
+	8888: strb \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
 	.endm
 
-	.macro ldrh1 ptr, regB, val
-	uao_user_alternative 9998f, ldrh, ldtrh, \ptr, \regB, \val
+	.macro ldrb1_nuao_reg reg, ptr, offset=0
+	8888: ldrb \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
 	.endm
 
-	.macro strh1 ptr, regB, val
-	uao_user_alternative 9998f, strh, sttrh, \ptr, \regB, \val
+	.macro strb1_nuao_reg reg, ptr, offset=0
+	8888: strb \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
 	.endm
 
-	.macro ldr1 ptr, regB, val
-	uao_user_alternative 9998f, ldr, ldtr, \ptr, \regB, \val
+	.macro ldr1_nuao reg, ptr, offset=0
+	8888: ldr \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
 	.endm
 
-	.macro str1 ptr, regB, val
-	uao_user_alternative 9998f, str, sttr, \ptr, \regB, \val
+	.macro str1_nuao reg, ptr, offset=0
+	8888: str \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
 	.endm
 
-	.macro ldp1 ptr, regB, regC, val
-	uao_ldp 9998f, \ptr, \regB, \regC, \val
+	.macro ldp1_nuao  regA, regB, ptr, offset=0
+	8888: ldp \regA, \regB, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
 	.endm
 
-	.macro stp1 ptr, regB, regC, val
-	uao_stp 9998f, \ptr, \regB, \regC, \val
+	.macro stp1_nuao regA, regB, ptr, offset=0
+	8888: stp \regA, \regB, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
 	.endm
 
-end	.req	x5
+	.macro ldp1_pre_nuao regA, regB, ptr, offset
+	8888: ldp \regA, \regB, [\ptr, \offset]!
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro stp1_pre_nuao regA, regB, ptr, offset
+	8888: stp \regA, \regB, [\ptr, \offset]!
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro copy_exit
+	b	.Luaccess_finish
+	.endm
 
 SYM_FUNC_START(__arch_copy_in_user)
-	add	end, x0, x2
-#include "copy_template.S"
+#include "copy_template_user.S"
+.Luaccess_finish:
 	mov	x0, #0
 	ret
 SYM_FUNC_END(__arch_copy_in_user)
 EXPORT_SYMBOL(__arch_copy_in_user)
-
-	.section .fixup,"ax"
-	.align	2
-9998:	sub	x0, end, dst			// bytes not copied
-	ret
-	.previous
+#include "copy_user_fixup.S"
diff --git a/arch/arm64/lib/copy_template.S b/arch/arm64/lib/copy_template.S
index 488df234c49a..90b5f63ff227 100644
--- a/arch/arm64/lib/copy_template.S
+++ b/arch/arm64/lib/copy_template.S
@@ -1,13 +1,12 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * Copyright (C) 2013 ARM Ltd.
- * Copyright (C) 2013 Linaro.
+ * Copyright (c) 2012 Linaro Limited. All rights reserved.
+ * Copyright (c) 2015 ARM Ltd. All rights reserved.
  *
- * This code is based on glibc cortex strings work originally authored by Linaro
- * be found @
+ * This code is based on work originally authored by Linaro,
+ * found at:
  *
- * http://bazaar.launchpad.net/~linaro-toolchain-dev/cortex-strings/trunk/
- * files/head:/src/aarch64/
+ * https://github.com/ARM-software/optimized-routines
  */
 
 
@@ -21,161 +20,209 @@
  * Returns:
  *	x0 - dest
  */
-dstin	.req	x0
-src	.req	x1
-count	.req	x2
-tmp1	.req	x3
-tmp1w	.req	w3
-tmp2	.req	x4
-tmp2w	.req	w4
-dst	.req	x6
-
-A_l	.req	x7
-A_h	.req	x8
-B_l	.req	x9
-B_h	.req	x10
-C_l	.req	x11
-C_h	.req	x12
-D_l	.req	x13
-D_h	.req	x14
-
-	mov	dst, dstin
-	cmp	count, #16
-	/*When memory length is less than 16, the accessed are not aligned.*/
-	b.lo	.Ltiny15
-
-	neg	tmp2, src
-	ands	tmp2, tmp2, #15/* Bytes to reach alignment. */
-	b.eq	.LSrcAligned
-	sub	count, count, tmp2
-	/*
-	* Copy the leading memory data from src to dst in an increasing
-	* address order.By this way,the risk of overwriting the source
-	* memory data is eliminated when the distance between src and
-	* dst is less than 16. The memory accesses here are alignment.
-	*/
-	tbz	tmp2, #0, 1f
-	ldrb1	tmp1w, src, #1
-	strb1	tmp1w, dst, #1
-1:
-	tbz	tmp2, #1, 2f
-	ldrh1	tmp1w, src, #2
-	strh1	tmp1w, dst, #2
-2:
-	tbz	tmp2, #2, 3f
-	ldr1	tmp1w, src, #4
-	str1	tmp1w, dst, #4
-3:
-	tbz	tmp2, #3, .LSrcAligned
-	ldr1	tmp1, src, #8
-	str1	tmp1, dst, #8
-
-.LSrcAligned:
-	cmp	count, #64
-	b.ge	.Lcpy_over64
-	/*
-	* Deal with small copies quickly by dropping straight into the
-	* exit block.
-	*/
-.Ltail63:
-	/*
-	* Copy up to 48 bytes of data. At this point we only need the
-	* bottom 6 bits of count to be accurate.
-	*/
-	ands	tmp1, count, #0x30
-	b.eq	.Ltiny15
-	cmp	tmp1w, #0x20
-	b.eq	1f
-	b.lt	2f
-	ldp1	A_l, A_h, src, #16
-	stp1	A_l, A_h, dst, #16
-1:
-	ldp1	A_l, A_h, src, #16
-	stp1	A_l, A_h, dst, #16
-2:
-	ldp1	A_l, A_h, src, #16
-	stp1	A_l, A_h, dst, #16
-.Ltiny15:
-	/*
-	* Prefer to break one ldp/stp into several load/store to access
-	* memory in an increasing address order,rather than to load/store 16
-	* bytes from (src-16) to (dst-16) and to backward the src to aligned
-	* address,which way is used in original cortex memcpy. If keeping
-	* the original memcpy process here, memmove need to satisfy the
-	* precondition that src address is at least 16 bytes bigger than dst
-	* address,otherwise some source data will be overwritten when memove
-	* call memcpy directly. To make memmove simpler and decouple the
-	* memcpy's dependency on memmove, withdrew the original process.
-	*/
-	tbz	count, #3, 1f
-	ldr1	tmp1, src, #8
-	str1	tmp1, dst, #8
-1:
-	tbz	count, #2, 2f
-	ldr1	tmp1w, src, #4
-	str1	tmp1w, dst, #4
-2:
-	tbz	count, #1, 3f
-	ldrh1	tmp1w, src, #2
-	strh1	tmp1w, dst, #2
-3:
-	tbz	count, #0, .Lexitfunc
-	ldrb1	tmp1w, src, #1
-	strb1	tmp1w, dst, #1
-
-	b	.Lexitfunc
-
-.Lcpy_over64:
-	subs	count, count, #128
-	b.ge	.Lcpy_body_large
-	/*
-	* Less than 128 bytes to copy, so handle 64 here and then jump
-	* to the tail.
-	*/
-	ldp1	A_l, A_h, src, #16
-	stp1	A_l, A_h, dst, #16
-	ldp1	B_l, B_h, src, #16
-	ldp1	C_l, C_h, src, #16
-	stp1	B_l, B_h, dst, #16
-	stp1	C_l, C_h, dst, #16
-	ldp1	D_l, D_h, src, #16
-	stp1	D_l, D_h, dst, #16
-
-	tst	count, #0x3f
-	b.ne	.Ltail63
-	b	.Lexitfunc
-
-	/*
-	* Critical loop.  Start at a new cache line boundary.  Assuming
-	* 64 bytes per line this ensures the entire loop is in one line.
-	*/
-	.p2align	L1_CACHE_SHIFT
-.Lcpy_body_large:
-	/* pre-get 64 bytes data. */
-	ldp1	A_l, A_h, src, #16
-	ldp1	B_l, B_h, src, #16
-	ldp1	C_l, C_h, src, #16
-	ldp1	D_l, D_h, src, #16
-1:
-	/*
-	* interlace the load of next 64 bytes data block with store of the last
-	* loaded 64 bytes data.
-	*/
-	stp1	A_l, A_h, dst, #16
-	ldp1	A_l, A_h, src, #16
-	stp1	B_l, B_h, dst, #16
-	ldp1	B_l, B_h, src, #16
-	stp1	C_l, C_h, dst, #16
-	ldp1	C_l, C_h, src, #16
-	stp1	D_l, D_h, dst, #16
-	ldp1	D_l, D_h, src, #16
-	subs	count, count, #64
-	b.ge	1b
-	stp1	A_l, A_h, dst, #16
-	stp1	B_l, B_h, dst, #16
-	stp1	C_l, C_h, dst, #16
-	stp1	D_l, D_h, dst, #16
-
-	tst	count, #0x3f
-	b.ne	.Ltail63
-.Lexitfunc:
+ #define dstin	x0
+ #define src	x1
+ #define count	x2
+ #define dst	x3
+ #define srcend	x4
+ #define dstend	x5
+ #define A_l	x6
+ #define A_lw	w6
+ #define A_h	x7
+ #define B_l	x8
+ #define B_lw	w8
+ #define B_h	x9
+ #define C_l	x10
+ #define C_lw	w10
+ #define C_h	x11
+ #define D_l	x12
+ #define D_h	x13
+ #define E_l	x14
+ #define E_h	x15
+ #define F_l	x16
+ #define F_h	x17
+ #define G_l	count
+ #define G_h	dst
+ #define H_l	src
+ #define H_h	srcend
+ #define tmp1	x14
+
+	add	srcend, src, count
+	add	dstend, dstin, count
+	cmp	count, 128
+	b.hi	L(copy_long)
+	cmp	count, 32
+	b.hi	L(copy32_128)
+
+	/* Small copies: 0..32 bytes. */
+	cmp	count, 16
+	b.lo	L(copy16)
+	ldp1	A_l, A_h, src
+	ldp1	D_l, D_h, srcend, -16
+	stp1	A_l, A_h, dstin
+	stp1	D_l, D_h, dstend, -16
+	copy_exit
+
+	/* Copy 8-15 bytes. */
+L(copy16):
+	tbz	count, 3, L(copy8)
+	ldr1	A_l, src
+	ldr1	A_h, srcend, -8
+	str1	A_l, dstin
+	str1	A_h, dstend, -8
+	copy_exit
+
+	.p2align 3
+	/* Copy 4-7 bytes. */
+L(copy8):
+	tbz	count, 2, L(copy4)
+	ldr1	A_lw, src
+	ldr1	B_lw, srcend, -4
+	str1	A_lw, dstin
+	str1	B_lw, dstend, -4
+	copy_exit
+
+	/* Copy 0..3 bytes using a branchless sequence. */
+L(copy4):
+	cbz	count, L(copy0)
+	lsr	tmp1, count, 1
+	ldrb1	A_lw, src
+	ldrb1	C_lw, srcend, -1
+	ldrb1_reg	B_lw, src, tmp1
+	strb1	A_lw, dstin
+	strb1_reg	B_lw, dstin, tmp1
+	strb1	C_lw, dstend, -1
+L(copy0):
+	copy_exit
+
+	.p2align 4
+	/* Medium copies: 33..128 bytes. */
+L(copy32_128):
+	ldp1	A_l, A_h, src
+	ldp1	B_l, B_h, src, 16
+	ldp1	C_l, C_h, srcend, -32
+	ldp1	D_l, D_h, srcend, -16
+	cmp	count, 64
+	b.hi	L(copy128)
+	stp1	A_l, A_h, dstin
+	stp1	B_l, B_h, dstin, 16
+	stp1	C_l, C_h, dstend, -32
+	stp1	D_l, D_h, dstend, -16
+	copy_exit
+
+	.p2align 4
+	/* Copy 65..128 bytes. */
+L(copy128):
+	ldp1	E_l, E_h, src, 32
+	ldp1	F_l, F_h, src, 48
+	cmp	count, 96
+	b.ls	L(copy96)
+	ldp1	G_l, G_h, srcend, -64
+	ldp1	H_l, H_h, srcend, -48
+	stp1	G_l, G_h, dstend, -64
+	stp1	H_l, H_h, dstend, -48
+L(copy96):
+	stp1	A_l, A_h, dstin
+	stp1	B_l, B_h, dstin, 16
+	stp1	E_l, E_h, dstin, 32
+	stp1	F_l, F_h, dstin, 48
+	stp1	C_l, C_h, dstend, -32
+	stp1	D_l, D_h, dstend, -16
+	copy_exit
+
+	.p2align 4
+	/* Copy more than 128 bytes. */
+L(copy_long):
+	/* Use backwards copy if there is an overlap. */
+	sub	tmp1, dstin, src
+	cbz	tmp1, L(copy0)
+	cmp	tmp1, count
+	b.lo	L(copy_long_backwards)
+
+	/* Copy 16 bytes and then align dst to 16-byte alignment. */
+
+	ldp1	D_l, D_h, src
+	and	tmp1, dstin, 15
+	bic	dst, dstin, 15
+	sub	src, src, tmp1
+	add	count, count, tmp1	/* Count is now 16 too large. */
+	ldp1	A_l, A_h, src, 16
+	stp1	D_l, D_h, dstin
+	ldp1	B_l, B_h, src, 32
+	ldp1	C_l, C_h, src, 48
+	ldp1_pre	D_l, D_h, src, 64
+	subs	count, count, 128 + 16 /* Test and readjust count. */
+	b.ls	L(copy64_from_end)
+
+L(loop64):
+	stp1	A_l, A_h, dst, 16
+	ldp1	A_l, A_h, src, 16
+	stp1	B_l, B_h, dst, 32
+	ldp1	B_l, B_h, src, 32
+	stp1	C_l, C_h, dst, 48
+	ldp1	C_l, C_h, src, 48
+	stp1_pre	D_l, D_h, dst, 64
+	ldp1_pre	D_l, D_h, src, 64
+	subs	count, count, 64
+	b.hi	L(loop64)
+
+	/* Write the last iteration and copy 64 bytes from the end. */
+L(copy64_from_end):
+	ldp1	E_l, E_h, srcend, -64
+	stp1	A_l, A_h, dst, 16
+	ldp1	A_l, A_h, srcend, -48
+	stp1	B_l, B_h, dst, 32
+	ldp1	B_l, B_h, srcend, -32
+	stp1	C_l, C_h, dst, 48
+	ldp1	C_l, C_h, srcend, -16
+	stp1	D_l, D_h, dst, 64
+	stp1	E_l, E_h, dstend, -64
+	stp1	A_l, A_h, dstend, -48
+	stp1	B_l, B_h, dstend, -32
+	stp1	C_l, C_h, dstend, -16
+	copy_exit
+
+	.p2align 4
+	/* Large backwards copy for overlapping copies.
+	   Copy 16 bytes and then align dst to 16-byte alignment. */
+L(copy_long_backwards):
+	ldp1	D_l, D_h, srcend, -16
+	and	tmp1, dstend, 15
+	sub	srcend, srcend, tmp1
+	sub	count, count, tmp1
+	ldp1	A_l, A_h, srcend, -16
+	stp1	D_l, D_h, dstend, -16
+	ldp1	B_l, B_h, srcend, -32
+	ldp1	C_l, C_h, srcend, -48
+	ldp1_pre	D_l, D_h, srcend, -64
+	sub	dstend, dstend, tmp1
+	subs	count, count, 128
+	b.ls	L(copy64_from_start)
+
+L(loop64_backwards):
+	stp1	A_l, A_h, dstend, -16
+	ldp1	A_l, A_h, srcend, -16
+	stp1	B_l, B_h, dstend, -32
+	ldp1	B_l, B_h, srcend, -32
+	stp1	C_l, C_h, dstend, -48
+	ldp1	C_l, C_h, srcend, -48
+	stp1_pre	D_l, D_h, dstend, -64
+	ldp1_pre	D_l, D_h, srcend, -64
+	subs	count, count, 64
+	b.hi	L(loop64_backwards)
+
+	/* Write the last iteration and copy 64 bytes from the start. */
+L(copy64_from_start):
+	ldp1	G_l, G_h, src, 48
+	stp1	A_l, A_h, dstend, -16
+	ldp1	A_l, A_h, src, 32
+	stp1	B_l, B_h, dstend, -32
+	ldp1	B_l, B_h, src, 16
+	stp1	C_l, C_h, dstend, -48
+	ldp1	C_l, C_h, src
+	stp1	D_l, D_h, dstend, -64
+	stp1	G_l, G_h, dstin, 48
+	stp1	A_l, A_h, dstin, 32
+	stp1	B_l, B_h, dstin, 16
+	stp1	C_l, C_h, dstin
+	copy_exit
diff --git a/arch/arm64/lib/copy_template_user.S b/arch/arm64/lib/copy_template_user.S
new file mode 100644
index 000000000000..3db24dcdab05
--- /dev/null
+++ b/arch/arm64/lib/copy_template_user.S
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#define L(l) .L ## l
+
+	alternative_if_not ARM64_HAS_UAO
+	b	L(copy_non_uao)
+	alternative_else_nop_endif
+#include "copy_template.S"
+
+#define ldp1 ldp1_nuao
+#define ldp1_pre ldp1_pre_nuao
+#define stp1 stp1_nuao
+#define stp1_pre stp1_pre_nuao
+#define ldr1 ldr1_nuao
+#define str1 str1_nuao
+#define ldrb1 ldrb1_nuao
+#define strb1 strb1_nuao
+#define ldrb1_reg ldrb1_nuao_reg
+#define strb1_reg strb1_nuao_reg
+
+L(copy_non_uao):
+#undef L
+#define L(l) .Lnuao ## l
+#include "copy_template.S"
diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S
index 1a104d0089f3..e4629c83abb4 100644
--- a/arch/arm64/lib/copy_to_user.S
+++ b/arch/arm64/lib/copy_to_user.S
@@ -19,49 +19,112 @@
  * Returns:
  *	x0 - bytes not copied
  */
-	.macro ldrb1 ptr, regB, val
-	ldrb  \ptr, [\regB], \val
+
+	.macro ldrb1 reg, ptr, offset=0
+	ldrb \reg, [\ptr, \offset]
+	.endm
+
+	.macro strb1 reg, ptr, offset=0
+	8888: sttrb \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro ldrb1_reg reg, ptr, offset
+	ldrb \reg, [\ptr, \offset]
+	.endm
+
+	.macro strb1_reg reg, ptr, offset
+	add \ptr, \ptr, \offset
+	8888: sttrb \reg, [\ptr]
+	sub \ptr, \ptr, \offset
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro ldr1 reg, ptr, offset=0
+	ldr \reg, [\ptr, \offset]
+	.endm
+
+	.macro str1 reg, ptr, offset=0
+	8888: sttr \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro ldp1 regA, regB, ptr, offset=0
+	ldp \regA, \regB, [\ptr, \offset]
+	.endm
+
+	.macro stp1 regA, regB, ptr, offset=0
+	8888: sttr \regA, [\ptr, \offset]
+	8889: sttr \regB, [\ptr, \offset + 8]
+	_asm_extable_faultaddr	8888b,9998f;
+	_asm_extable_faultaddr	8889b,9998f;
 	.endm
 
-	.macro strb1 ptr, regB, val
-	uao_user_alternative 9998f, strb, sttrb, \ptr, \regB, \val
+	.macro ldp1_pre regA, regB, ptr, offset
+	ldp \regA, \regB, [\ptr, \offset]!
 	.endm
 
-	.macro ldrh1 ptr, regB, val
-	ldrh  \ptr, [\regB], \val
+	.macro stp1_pre regA, regB, ptr, offset
+	8888: sttr \regA, [\ptr, \offset]
+	8889: sttr \regB, [\ptr, \offset + 8]
+	add \ptr, \ptr, \offset
+	_asm_extable_faultaddr	8888b,9998f;
+	_asm_extable_faultaddr	8889b,9998f;
 	.endm
 
-	.macro strh1 ptr, regB, val
-	uao_user_alternative 9998f, strh, sttrh, \ptr, \regB, \val
+	.macro ldrb1_nuao reg, ptr, offset=0
+	ldrb \reg, [\ptr, \offset]
 	.endm
 
-	.macro ldr1 ptr, regB, val
-	ldr \ptr, [\regB], \val
+	.macro strb1_nuao reg, ptr, offset=0
+	8888: strb \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
 	.endm
 
-	.macro str1 ptr, regB, val
-	uao_user_alternative 9998f, str, sttr, \ptr, \regB, \val
+	.macro ldrb1_nuao_reg reg, ptr, offset=0
+	ldrb \reg, [\ptr, \offset]
 	.endm
 
-	.macro ldp1 ptr, regB, regC, val
-	ldp \ptr, \regB, [\regC], \val
+	.macro strb1_nuao_reg reg, ptr, offset=0
+	strb \reg, [\ptr, \offset]
 	.endm
 
-	.macro stp1 ptr, regB, regC, val
-	uao_stp 9998f, \ptr, \regB, \regC, \val
+	.macro ldr1_nuao reg, ptr, offset=0
+	ldr \reg, [\ptr, \offset]
+	.endm
+
+	.macro str1_nuao reg, ptr, offset=0
+	8888: str \reg, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro ldp1_nuao  regA, regB, ptr, offset=0
+	ldp \regA, \regB, [\ptr, \offset]
+	.endm
+
+	.macro ldp1_pre_nuao regA, regB, ptr, offset
+	ldp \regA, \regB, [\ptr, \offset]!
+	.endm
+
+	.macro stp1_nuao regA, regB, ptr, offset=0
+	8888: stp \regA, \regB, [\ptr, \offset]
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro stp1_pre_nuao regA, regB, ptr, offset
+	8888: stp \regA, \regB, [\ptr, \offset]!
+	_asm_extable_faultaddr	8888b,9998f;
+	.endm
+
+	.macro copy_exit
+	b	.Luaccess_finish
 	.endm
 
-end	.req	x5
 SYM_FUNC_START(__arch_copy_to_user)
-	add	end, x0, x2
-#include "copy_template.S"
+#include "copy_template_user.S"
+.Luaccess_finish:
 	mov	x0, #0
 	ret
 SYM_FUNC_END(__arch_copy_to_user)
 EXPORT_SYMBOL(__arch_copy_to_user)
-
-	.section .fixup,"ax"
-	.align	2
-9998:	sub	x0, end, dst			// bytes not copied
-	ret
-	.previous
+#include "copy_user_fixup.S"
diff --git a/arch/arm64/lib/copy_user_fixup.S b/arch/arm64/lib/copy_user_fixup.S
new file mode 100644
index 000000000000..117c37598691
--- /dev/null
+++ b/arch/arm64/lib/copy_user_fixup.S
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+addr	.req	x15
+.section .fixup,"ax"
+.align	2
+9998:
+	// TODO: add accurate fixup
+	ret
+
diff --git a/arch/arm64/lib/memcpy.S b/arch/arm64/lib/memcpy.S
index 9f382adfa88a..ee84b8847184 100644
--- a/arch/arm64/lib/memcpy.S
+++ b/arch/arm64/lib/memcpy.S
@@ -24,43 +24,57 @@
  * Returns:
  *	x0 - dest
  */
-	.macro ldrb1 ptr, regB, val
-	ldrb  \ptr, [\regB], \val
+
+ #define L(l) .L ## l
+
+	.macro ldrb1 reg, ptr, offset=0
+	ldrb \reg, [\ptr, \offset]
+	.endm
+
+	.macro strb1 reg, ptr, offset=0
+	strb \reg, [\ptr, \offset]
+	.endm
+
+	.macro ldr1 reg, ptr, offset=0
+	ldr \reg, [\ptr, \offset]
 	.endm
 
-	.macro strb1 ptr, regB, val
-	strb \ptr, [\regB], \val
+	.macro str1 reg, ptr, offset=0
+	str \reg, [\ptr, \offset]
 	.endm
 
-	.macro ldrh1 ptr, regB, val
-	ldrh  \ptr, [\regB], \val
+	.macro ldp1 regA, regB, ptr, offset=0
+	ldp \regA, \regB, [\ptr, \offset]
 	.endm
 
-	.macro strh1 ptr, regB, val
-	strh \ptr, [\regB], \val
+	.macro stp1 regA, regB, ptr, offset=0
+	stp \regA, \regB, [\ptr, \offset]
 	.endm
 
-	.macro ldr1 ptr, regB, val
-	ldr \ptr, [\regB], \val
+	.macro ldrb1_reg reg, ptr, offset
+	ldrb1 \reg, \ptr, \offset
 	.endm
 
-	.macro str1 ptr, regB, val
-	str \ptr, [\regB], \val
+	.macro strb1_reg reg, ptr, offset
+	strb1 \reg, \ptr, \offset
 	.endm
 
-	.macro ldp1 ptr, regB, regC, val
-	ldp \ptr, \regB, [\regC], \val
+	.macro ldp1_pre regA, regB, ptr, offset
+	ldp \regA, \regB, [\ptr, \offset]!
 	.endm
 
-	.macro stp1 ptr, regB, regC, val
-	stp \ptr, \regB, [\regC], \val
+	.macro stp1_pre regA, regB, ptr, offset
+	stp \regA, \regB, [\ptr, \offset]!
+	.endm
+
+	.macro copy_exit
+	ret
 	.endm
 
 	.weak memcpy
 SYM_FUNC_START_ALIAS(__memcpy)
 SYM_FUNC_START_PI(memcpy)
 #include "copy_template.S"
-	ret
 SYM_FUNC_END_PI(memcpy)
 EXPORT_SYMBOL(memcpy)
 SYM_FUNC_END_ALIAS(__memcpy)
-- 
2.17.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v3 09/13] arm64: Tidy up _asm_extable_faultaddr usage

[Oliver Swede]

From: Robin Murphy <robin.murphy@arm.com>

To match the way the USER() shorthand wraps _asm_extable entries,
introduce USER_F() to wrap _asm_extable_faultaddr and clean up a bit.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Oliver Swede <oli.swede@arm.com>
---
 arch/arm64/include/asm/assembler.h |  4 ++
 arch/arm64/lib/copy_from_user.S    | 36 +++++----------
 arch/arm64/lib/copy_in_user.S      | 72 ++++++++++--------------------
 arch/arm64/lib/copy_to_user.S      | 33 +++++---------
 4 files changed, 51 insertions(+), 94 deletions(-)

diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 7017aeb4b29a..384b6584b27f 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -142,6 +142,10 @@ alternative_endif
 9999:	x;					\
 	_asm_extable	9999b, l
 
+#define USER_F(l, x...)				\
+9999:	x;					\
+	_asm_extable_faultaddr	9999b, l
+
 /*
  * Register aliases.
  */
diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S
index dbf768cc7650..9c3805725bea 100644
--- a/arch/arm64/lib/copy_from_user.S
+++ b/arch/arm64/lib/copy_from_user.S
@@ -21,8 +21,7 @@
  */
 
 	.macro ldrb1 reg, ptr, offset=0
-	8888: ldtrb \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, ldtrb \reg, [\ptr, \offset])
 	.endm
 
 	.macro strb1 reg, ptr, offset=0
@@ -31,9 +30,8 @@
 
 	.macro ldrb1_reg reg, ptr, offset
 	add \ptr, \ptr, \offset
-	8888: ldtrb \reg, [\ptr]
+	USER_F(9998f, ldtrb \reg, [\ptr])
 	sub \ptr, \ptr, \offset
-	_asm_extable_faultaddr	8888b,9998f;
 	.endm
 
 	.macro strb1_reg reg, ptr, offset
@@ -41,8 +39,7 @@
 	.endm
 
 	.macro ldr1 reg, ptr, offset=0
-	8888: ldtr \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, ldtr \reg, [\ptr, \offset])
 	.endm
 
 	.macro str1 reg, ptr, offset=0
@@ -50,10 +47,8 @@
 	.endm
 
 	.macro ldp1 regA, regB, ptr, offset=0
-	8888: ldtr \regA, [\ptr, \offset]
-	8889: ldtr \regB, [\ptr, \offset + 8]
-	_asm_extable_faultaddr	8888b,9998f;
-	_asm_extable_faultaddr	8889b,9998f;
+	USER_F(9998f, ldtr \regA, [\ptr, \offset])
+	USER_F(9998f, ldtr \regB, [\ptr, \offset + 8])
 	.endm
 
 	.macro stp1 regA, regB, ptr, offset=0
@@ -61,11 +56,9 @@
 	.endm
 
 	.macro ldp1_pre regA, regB, ptr, offset
-	8888: ldtr \regA, [\ptr, \offset]
-	8889: ldtr \regB, [\ptr, \offset + 8]
+	USER_F(9998f, ldtr \regA, [\ptr, \offset])
+	USER_F(9998f, ldtr \regB, [\ptr, \offset + 8])
 	add \ptr, \ptr, \offset
-	_asm_extable_faultaddr	8888b,9998f;
-	_asm_extable_faultaddr	8889b,9998f;
 	.endm
 
 	.macro stp1_pre regA, regB, ptr, offset
@@ -73,8 +66,7 @@
 	.endm
 
 	.macro ldrb1_nuao reg, ptr, offset=0
-	8888: ldrb \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, ldrb \reg, [\ptr, \offset])
 	.endm
 
 	.macro strb1_nuao reg, ptr, offset=0
@@ -82,8 +74,7 @@
 	.endm
 
 	.macro ldrb1_nuao_reg reg, ptr, offset=0
-	8888: ldrb \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, ldrb \reg, [\ptr, \offset])
 	.endm
 
 	.macro strb1_nuao_reg reg, ptr, offset=0
@@ -91,8 +82,7 @@
 	.endm
 
 	.macro ldr1_nuao reg, ptr, offset=0
-	8888: ldr \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, ldr \reg, [\ptr, \offset])
 	.endm
 
 	.macro str1_nuao reg, ptr, offset=0
@@ -100,8 +90,7 @@
 	.endm
 
 	.macro ldp1_nuao  regA, regB, ptr, offset=0
-	8888: ldp \regA, \regB, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, ldp \regA, \regB, [\ptr, \offset])
 	.endm
 
 	.macro stp1_nuao regA, regB, ptr, offset=0
@@ -109,8 +98,7 @@
 	.endm
 
 	.macro ldp1_pre_nuao regA, regB, ptr, offset
-	8888: ldp \regA, \regB, [\ptr, \offset]!
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, ldp \regA, \regB, [\ptr, \offset]!)
 	.endm
 
 	.macro stp1_pre_nuao regA, regB, ptr, offset
diff --git a/arch/arm64/lib/copy_in_user.S b/arch/arm64/lib/copy_in_user.S
index f08d4b36a857..bdf9bfecf31f 100644
--- a/arch/arm64/lib/copy_in_user.S
+++ b/arch/arm64/lib/copy_in_user.S
@@ -23,117 +23,93 @@
  */
 
 	.macro ldrb1 reg, ptr, offset=0
-	8888: ldtrb \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, ldtrb \reg, [\ptr, \offset])
 	.endm
 
 	.macro strb1 reg, ptr, offset=0
-	8888: sttrb \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, sttrb \reg, [\ptr, \offset])
 	.endm
 
 	.macro ldrb1_reg reg, ptr, offset
 	add \ptr, \ptr, \offset
-	8888: ldtrb \reg, [\ptr]
+	USER_F(9998f, ldtrb \reg, [\ptr])
 	sub \ptr, \ptr, \offset
-	_asm_extable_faultaddr	8888b,9998f;
 	.endm
 
 	.macro strb1_reg reg, ptr, offset
 	add \ptr, \ptr, \offset
-	8888: sttrb \reg, [\ptr]
+	USER_F(9998f, sttrb \reg, [\ptr])
 	sub \ptr, \ptr, \offset
-	_asm_extable_faultaddr	8888b,9998f;
 	.endm
 
 	.macro ldr1 reg, ptr, offset=0
-	8888: ldtr \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, ldtr \reg, [\ptr, \offset])
 	.endm
 
 	.macro str1 reg, ptr, offset=0
-	8888: sttr \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, sttr \reg, [\ptr, \offset])
 	.endm
 
 	.macro ldp1 regA, regB, ptr, offset=0
-	8888: ldtr \regA, [\ptr, \offset]
-	8889: ldtr \regB, [\ptr, \offset + 8]
-	_asm_extable_faultaddr	8888b,9998f;
-	_asm_extable_faultaddr	8889b,9998f;
+	USER_F(9998f, ldtr \regA, [\ptr, \offset])
+	USER_F(9998f, ldtr \regB, [\ptr, \offset + 8])
 	.endm
 
 	.macro stp1 regA, regB, ptr, offset=0
-	8888: sttr \regA, [\ptr, \offset]
-	8889: sttr \regB, [\ptr, \offset + 8]
-	_asm_extable_faultaddr	8888b,9998f;
-	_asm_extable_faultaddr	8889b,9998f;
+	USER_F(9998f, sttr \regA, [\ptr, \offset])
+	USER_F(9998f, sttr \regB, [\ptr, \offset + 8])
 	.endm
 
 	.macro ldp1_pre regA, regB, ptr, offset
-	8888: ldtr \regA, [\ptr, \offset]
-	8889: ldtr \regB, [\ptr, \offset + 8]
+	USER_F(9998f, ldtr \regA, [\ptr, \offset])
+	USER_F(9998f, ldtr \regB, [\ptr, \offset + 8])
 	add \ptr, \ptr, \offset
-	_asm_extable_faultaddr	8888b,9998f;
-	_asm_extable_faultaddr	8889b,9998f;
 	.endm
 
 	.macro stp1_pre regA, regB, ptr, offset
-	8888: sttr \regA, [\ptr, \offset]
-	8889: sttr \regB, [\ptr, \offset + 8]
+	USER_F(9998f, sttr \regA, [\ptr, \offset])
+	USER_F(9998f, sttr \regB, [\ptr, \offset + 8])
 	add \ptr, \ptr, \offset
-	_asm_extable_faultaddr	8888b,9998f;
-	_asm_extable_faultaddr	8889b,9998f;
 	.endm
 
 	.macro ldrb1_nuao reg, ptr, offset=0
-	8888: ldrb \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, ldrb \reg, [\ptr, \offset])
 	.endm
 
 	.macro strb1_nuao reg, ptr, offset=0
-	8888: strb \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, strb \reg, [\ptr, \offset])
 	.endm
 
 	.macro ldrb1_nuao_reg reg, ptr, offset=0
-	8888: ldrb \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, ldrb \reg, [\ptr, \offset])
 	.endm
 
 	.macro strb1_nuao_reg reg, ptr, offset=0
-	8888: strb \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, strb \reg, [\ptr, \offset])
 	.endm
 
 	.macro ldr1_nuao reg, ptr, offset=0
-	8888: ldr \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, ldr \reg, [\ptr, \offset])
 	.endm
 
 	.macro str1_nuao reg, ptr, offset=0
-	8888: str \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, str \reg, [\ptr, \offset])
 	.endm
 
 	.macro ldp1_nuao  regA, regB, ptr, offset=0
-	8888: ldp \regA, \regB, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, ldp \regA, \regB, [\ptr, \offset])
 	.endm
 
 	.macro stp1_nuao regA, regB, ptr, offset=0
-	8888: stp \regA, \regB, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, stp \regA, \regB, [\ptr, \offset])
 	.endm
 
 	.macro ldp1_pre_nuao regA, regB, ptr, offset
-	8888: ldp \regA, \regB, [\ptr, \offset]!
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, ldp \regA, \regB, [\ptr, \offset]!)
 	.endm
 
 	.macro stp1_pre_nuao regA, regB, ptr, offset
-	8888: stp \regA, \regB, [\ptr, \offset]!
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, stp \regA, \regB, [\ptr, \offset]!)
 	.endm
 
 	.macro copy_exit
diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S
index e4629c83abb4..b936bc10594e 100644
--- a/arch/arm64/lib/copy_to_user.S
+++ b/arch/arm64/lib/copy_to_user.S
@@ -25,8 +25,7 @@
 	.endm
 
 	.macro strb1 reg, ptr, offset=0
-	8888: sttrb \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, sttrb \reg, [\ptr, \offset])
 	.endm
 
 	.macro ldrb1_reg reg, ptr, offset
@@ -35,9 +34,8 @@
 
 	.macro strb1_reg reg, ptr, offset
 	add \ptr, \ptr, \offset
-	8888: sttrb \reg, [\ptr]
+	USER_F(9998f, sttrb \reg, [\ptr])
 	sub \ptr, \ptr, \offset
-	_asm_extable_faultaddr	8888b,9998f;
 	.endm
 
 	.macro ldr1 reg, ptr, offset=0
@@ -45,8 +43,7 @@
 	.endm
 
 	.macro str1 reg, ptr, offset=0
-	8888: sttr \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, sttr \reg, [\ptr, \offset])
 	.endm
 
 	.macro ldp1 regA, regB, ptr, offset=0
@@ -54,10 +51,8 @@
 	.endm
 
 	.macro stp1 regA, regB, ptr, offset=0
-	8888: sttr \regA, [\ptr, \offset]
-	8889: sttr \regB, [\ptr, \offset + 8]
-	_asm_extable_faultaddr	8888b,9998f;
-	_asm_extable_faultaddr	8889b,9998f;
+	USER_F(9998f, sttr \regA, [\ptr, \offset])
+	USER_F(9998f, sttr \regB, [\ptr, \offset + 8])
 	.endm
 
 	.macro ldp1_pre regA, regB, ptr, offset
@@ -65,11 +60,9 @@
 	.endm
 
 	.macro stp1_pre regA, regB, ptr, offset
-	8888: sttr \regA, [\ptr, \offset]
-	8889: sttr \regB, [\ptr, \offset + 8]
+	USER_F(9998f, sttr \regA, [\ptr, \offset])
+	USER_F(9998f, sttr \regB, [\ptr, \offset + 8])
 	add \ptr, \ptr, \offset
-	_asm_extable_faultaddr	8888b,9998f;
-	_asm_extable_faultaddr	8889b,9998f;
 	.endm
 
 	.macro ldrb1_nuao reg, ptr, offset=0
@@ -77,8 +70,7 @@
 	.endm
 
 	.macro strb1_nuao reg, ptr, offset=0
-	8888: strb \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, strb \reg, [\ptr, \offset])
 	.endm
 
 	.macro ldrb1_nuao_reg reg, ptr, offset=0
@@ -94,8 +86,7 @@
 	.endm
 
 	.macro str1_nuao reg, ptr, offset=0
-	8888: str \reg, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, str \reg, [\ptr, \offset])
 	.endm
 
 	.macro ldp1_nuao  regA, regB, ptr, offset=0
@@ -107,13 +98,11 @@
 	.endm
 
 	.macro stp1_nuao regA, regB, ptr, offset=0
-	8888: stp \regA, \regB, [\ptr, \offset]
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, stp \regA, \regB, [\ptr, \offset])
 	.endm
 
 	.macro stp1_pre_nuao regA, regB, ptr, offset
-	8888: stp \regA, \regB, [\ptr, \offset]!
-	_asm_extable_faultaddr	8888b,9998f;
+	USER_F(9998f, stp \regA, \regB, [\ptr, \offset]!)
 	.endm
 
 	.macro copy_exit
-- 
2.17.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v3 10/13] arm64: Store the arguments to copy_*_user on the stack

[Oliver Swede]

This preserves the initial arguments of the user copy calls so that
they can be restored by the fixup routines.

The values in the relevant three registers (x0/dstin, x1/src,
x2/count) may be modified by the optimized memcpy algorithm for large
copy sizes, and this stores them before it begins executing.

The stack is used instead of other general-purpose registers due to
resource constraints: the algorithm is optimized with respect to the
Procedure Call Standard in the Arm ABI, which assumes that x0-x17
can be used as scratch registers and utilizes all of them during
copying, but leaves alone the rest that have specific uses in the
broader system. As there are no more temporary registers, the stack
can be used to preserve the initial arguments to provide fixup
routines with more information to use in the calculation of the
number of bytes that failed to copy.

The stack pointer is restored to its initial position, either from
the fixup code in the case of a fault, or at the end of the copy
algorithm otherwise (uaccess_finish is extended to restore the sp,
and this code is also moved to copy_template_user.S as it is common
to all of the copy routines that access userspace memory).

Signed-off-by: Oliver Swede <oli.swede@arm.com>
---
 arch/arm64/lib/copy_from_user.S     | 3 ---
 arch/arm64/lib/copy_in_user.S       | 3 ---
 arch/arm64/lib/copy_template_user.S | 6 ++++++
 arch/arm64/lib/copy_to_user.S       | 3 ---
 arch/arm64/lib/copy_user_fixup.S    | 1 +
 5 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S
index 9c3805725bea..45009fb07081 100644
--- a/arch/arm64/lib/copy_from_user.S
+++ b/arch/arm64/lib/copy_from_user.S
@@ -111,9 +111,6 @@
 
 SYM_FUNC_START(__arch_copy_from_user)
 #include "copy_template_user.S"
-.Luaccess_finish:
-	mov	x0, #0
-	ret
 SYM_FUNC_END(__arch_copy_from_user)
 EXPORT_SYMBOL(__arch_copy_from_user)
 #include "copy_user_fixup.S"
diff --git a/arch/arm64/lib/copy_in_user.S b/arch/arm64/lib/copy_in_user.S
index bdf9bfecf31f..c1647a9b3a22 100644
--- a/arch/arm64/lib/copy_in_user.S
+++ b/arch/arm64/lib/copy_in_user.S
@@ -118,9 +118,6 @@
 
 SYM_FUNC_START(__arch_copy_in_user)
 #include "copy_template_user.S"
-.Luaccess_finish:
-	mov	x0, #0
-	ret
 SYM_FUNC_END(__arch_copy_in_user)
 EXPORT_SYMBOL(__arch_copy_in_user)
 #include "copy_user_fixup.S"
diff --git a/arch/arm64/lib/copy_template_user.S b/arch/arm64/lib/copy_template_user.S
index 3db24dcdab05..1d13daf314b0 100644
--- a/arch/arm64/lib/copy_template_user.S
+++ b/arch/arm64/lib/copy_template_user.S
@@ -21,4 +21,10 @@
 L(copy_non_uao):
 #undef L
 #define L(l) .Lnuao ## l
+	str     x2, [sp, #-16]!		// count
+	stp     x0, x1, [sp, #-16]!	// dstin, src
 #include "copy_template.S"
+.Luaccess_finish:
+	add	sp, sp, 32
+	mov	x0, #0
+	ret
diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S
index b936bc10594e..ac10d2d32b03 100644
--- a/arch/arm64/lib/copy_to_user.S
+++ b/arch/arm64/lib/copy_to_user.S
@@ -111,9 +111,6 @@
 
 SYM_FUNC_START(__arch_copy_to_user)
 #include "copy_template_user.S"
-.Luaccess_finish:
-	mov	x0, #0
-	ret
 SYM_FUNC_END(__arch_copy_to_user)
 EXPORT_SYMBOL(__arch_copy_to_user)
 #include "copy_user_fixup.S"
diff --git a/arch/arm64/lib/copy_user_fixup.S b/arch/arm64/lib/copy_user_fixup.S
index 117c37598691..fe9f5ac19605 100644
--- a/arch/arm64/lib/copy_user_fixup.S
+++ b/arch/arm64/lib/copy_user_fixup.S
@@ -5,5 +5,6 @@ addr	.req	x15
 .align	2
 9998:
 	// TODO: add accurate fixup
+	add	sp, sp, 32
 	ret
 
-- 
2.17.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v3 11/13] arm64: Use additional memcpy macros and fixups

[Oliver Swede]

The Arm-provided memcpy routine has been updated with more recent
optimizations. The kernel's helper functions for copying to/from
user space memory, which import this algorithm and create
exception table entries for instructions that reference user
space, require new recovery code to accurately determine the number
of bytes that successfully copied before a page fault.

This adds new macro instantiations in the copy template, and
corresponding definitions to each of the copy_*_user() functions.
This allows more fixup routines to be added so that an accurate value
for the number of bytes that failed to copy can be returned.

This increases the flexibility of the fixup code, as certain
propertes can be encapsulated by the mapping to implicitly provide
the routines with more information than would otherwise be available.

In the case of the current memcpy, the number of bytes already copied
depends highly on the type of instruction that caused the fault (load
vs. store), so the use of separate fixups enables specific routines
for each case. This is an alternative to (for instance) using a
single fixup for both the loads and stores, as this would be subject
to issues relating to overlapping src and dst buffers in
copy_in_user().
The outcome also depends largely on other factors, such as if the
target address is specified relative to the start or end of the buffer,
and whether or not this access is guaranteed to be aligned with 16B.

These distinctions, obtained from analysis of the copy algorithm,
enable fixups to be written that are modular and accurate for each
case. In this way the fixup logic should be straightforward to
modify in the future, e.g. if there are further improvements to the
memcpy routine.

Signed-off-by: Oliver Swede <oli.swede@arm.com>
---
 arch/arm64/lib/copy_from_user.S     | 196 ++++++++++++++++++++++++--
 arch/arm64/lib/copy_in_user.S       | 204 ++++++++++++++++++++++++++--
 arch/arm64/lib/copy_template.S      | 126 ++++++++---------
 arch/arm64/lib/copy_template_user.S |  20 +++
 arch/arm64/lib/copy_to_user.S       | 178 +++++++++++++++++++++++-
 arch/arm64/lib/copy_user_fixup.S    |  13 +-
 arch/arm64/lib/memcpy.S             |  80 +++++++++++
 7 files changed, 725 insertions(+), 92 deletions(-)

diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S
index 45009fb07081..0056d1fc06eb 100644
--- a/arch/arm64/lib/copy_from_user.S
+++ b/arch/arm64/lib/copy_from_user.S
@@ -21,16 +21,44 @@
  */
 
 	.macro ldrb1 reg, ptr, offset=0
-	USER_F(9998f, ldtrb \reg, [\ptr, \offset])
+	USER_F(9993f, ldtrb \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldrb2 reg, ptr, offset=0
+	USER_F(9994f, ldtrb \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldrb3 reg, ptr, offset=0
+	USER_F(9995f, ldtrb \reg, [\ptr, \offset])
 	.endm
 
 	.macro strb1 reg, ptr, offset=0
 	strb \reg, [\ptr, \offset]
 	.endm
 
+	.macro strb2 reg, ptr, offset=0
+	strb \reg, [\ptr, \offset]
+	.endm
+
+	.macro strb3 reg, ptr, offset=0
+	strb \reg, [\ptr, \offset]
+	.endm
+
 	.macro ldrb1_reg reg, ptr, offset
 	add \ptr, \ptr, \offset
-	USER_F(9998f, ldtrb \reg, [\ptr])
+	USER_F(9993f, ldtrb \reg, [\ptr])
+	sub \ptr, \ptr, \offset
+	.endm
+
+	.macro ldrb2_reg reg, ptr, offset
+	add \ptr, \ptr, \offset
+	USER_F(9994f, ldtrb \reg, [\ptr])
+	sub \ptr, \ptr, \offset
+	.endm
+
+	.macro ldrb3_reg reg, ptr, offset
+	add \ptr, \ptr, \offset
+	USER_F(9995f, ldtrb \reg, [\ptr])
 	sub \ptr, \ptr, \offset
 	.endm
 
@@ -38,26 +66,80 @@
 	strb \reg, [\ptr, \offset]
 	.endm
 
+	.macro strb2_reg reg, ptr, offset
+	strb \reg, [\ptr, \offset]
+	.endm
+
+	.macro strb3_reg reg, ptr, offset
+	strb \reg, [\ptr, \offset]
+	.endm
+
 	.macro ldr1 reg, ptr, offset=0
-	USER_F(9998f, ldtr \reg, [\ptr, \offset])
+	USER_F(9993f, ldtr \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldr2 reg, ptr, offset=0
+	USER_F(9994f, ldtr \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldr3 reg, ptr, offset=0
+	USER_F(9995f, ldtr \reg, [\ptr, \offset])
 	.endm
 
 	.macro str1 reg, ptr, offset=0
 	str \reg, [\ptr, \offset]
 	.endm
 
+	.macro str2 reg, ptr, offset=0
+	str \reg, [\ptr, \offset]
+	.endm
+
+	.macro str3 reg, ptr, offset=0
+	str \reg, [\ptr, \offset]
+	.endm
+
 	.macro ldp1 regA, regB, ptr, offset=0
-	USER_F(9998f, ldtr \regA, [\ptr, \offset])
-	USER_F(9998f, ldtr \regB, [\ptr, \offset + 8])
+	USER_F(9993f, ldtr \regA, [\ptr, \offset])
+	USER_F(9993f, ldtr \regB, [\ptr, \offset + 8])
+	.endm
+
+	.macro ldp2 regA, regB, ptr, offset=0
+	USER_F(9994f, ldtr \regA, [\ptr, \offset])
+	USER_F(9994f, ldtr \regB, [\ptr, \offset + 8])
+	.endm
+
+	.macro ldp3 regA, regB, ptr, offset=0
+	USER_F(9995f, ldtr \regA, [\ptr, \offset])
+	USER_F(9995f, ldtr \regB, [\ptr, \offset + 8])
 	.endm
 
 	.macro stp1 regA, regB, ptr, offset=0
 	stp \regA, \regB, [\ptr, \offset]
 	.endm
 
+	.macro stp2 regA, regB, ptr, offset=0
+	stp \regA, \regB, [\ptr, \offset]
+	.endm
+
+	.macro stp3 regA, regB, ptr, offset=0
+	stp \regA, \regB, [\ptr, \offset]
+	.endm
+
 	.macro ldp1_pre regA, regB, ptr, offset
-	USER_F(9998f, ldtr \regA, [\ptr, \offset])
-	USER_F(9998f, ldtr \regB, [\ptr, \offset + 8])
+	USER_F(9993f, ldtr \regA, [\ptr, \offset])
+	USER_F(9993f, ldtr \regB, [\ptr, \offset + 8])
+	add \ptr, \ptr, \offset
+	.endm
+
+	.macro ldp2_pre regA, regB, ptr, offset
+	USER_F(9994f, ldtr \regA, [\ptr, \offset])
+	USER_F(9994f, ldtr \regB, [\ptr, \offset + 8])
+	add \ptr, \ptr, \offset
+	.endm
+
+	.macro ldp3_pre regA, regB, ptr, offset
+	USER_F(9995f, ldtr \regA, [\ptr, \offset])
+	USER_F(9995f, ldtr \regB, [\ptr, \offset + 8])
 	add \ptr, \ptr, \offset
 	.endm
 
@@ -65,46 +147,134 @@
 	stp \regA, \regB, [\ptr, \offset]!
 	.endm
 
+	.macro stp2_pre regA, regB, ptr, offset
+	stp \regA, \regB, [\ptr, \offset]!
+	.endm
+
+	.macro stp3_pre regA, regB, ptr, offset
+	stp \regA, \regB, [\ptr, \offset]!
+	.endm
+
 	.macro ldrb1_nuao reg, ptr, offset=0
-	USER_F(9998f, ldrb \reg, [\ptr, \offset])
+	USER_F(9993f, ldrb \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldrb2_nuao reg, ptr, offset=0
+	USER_F(9994f, ldrb \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldrb3_nuao reg, ptr, offset=0
+	USER_F(9995f, ldrb \reg, [\ptr, \offset])
 	.endm
 
 	.macro strb1_nuao reg, ptr, offset=0
 	strb \reg, [\ptr, \offset]
 	.endm
 
+	.macro strb2_nuao reg, ptr, offset=0
+	strb \reg, [\ptr, \offset]
+	.endm
+
+	.macro strb3_nuao reg, ptr, offset=0
+	strb \reg, [\ptr, \offset]
+	.endm
+
 	.macro ldrb1_nuao_reg reg, ptr, offset=0
-	USER_F(9998f, ldrb \reg, [\ptr, \offset])
+	USER_F(9993f, ldrb \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldrb2_nuao_reg reg, ptr, offset=0
+	USER_F(9994f, ldrb \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldrb3_nuao_reg reg, ptr, offset=0
+	USER_F(9995f, ldrb \reg, [\ptr, \offset])
 	.endm
 
 	.macro strb1_nuao_reg reg, ptr, offset=0
 	strb \reg, [\ptr, \offset]
 	.endm
 
+	.macro strb2_nuao_reg reg, ptr, offset=0
+	strb \reg, [\ptr, \offset]
+	.endm
+
+	.macro strb3_nuao_reg reg, ptr, offset=0
+	strb \reg, [\ptr, \offset]
+	.endm
+
 	.macro ldr1_nuao reg, ptr, offset=0
-	USER_F(9998f, ldr \reg, [\ptr, \offset])
+	USER_F(9993f, ldr \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldr2_nuao reg, ptr, offset=0
+	USER_F(9994f, ldr \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldr3_nuao reg, ptr, offset=0
+	USER_F(9995f, ldr \reg, [\ptr, \offset])
 	.endm
 
 	.macro str1_nuao reg, ptr, offset=0
 	str \reg, [\ptr, \offset]
 	.endm
 
-	.macro ldp1_nuao  regA, regB, ptr, offset=0
-	USER_F(9998f, ldp \regA, \regB, [\ptr, \offset])
+	.macro str2_nuao reg, ptr, offset=0
+	str \reg, [\ptr, \offset]
+	.endm
+
+	.macro str3_nuao reg, ptr, offset=0
+	str \reg, [\ptr, \offset]
+	.endm
+
+	.macro ldp1_nuao regA, regB, ptr, offset=0
+	USER_F(9993f, ldp \regA, \regB, [\ptr, \offset])
+	.endm
+
+	.macro ldp2_nuao regA, regB, ptr, offset=0
+	USER_F(9994f, ldp \regA, \regB, [\ptr, \offset])
+	.endm
+
+	.macro ldp3_nuao regA, regB, ptr, offset=0
+	USER_F(9995f, ldp \regA, \regB, [\ptr, \offset])
 	.endm
 
 	.macro stp1_nuao regA, regB, ptr, offset=0
 	stp \regA, \regB, [\ptr, \offset]
 	.endm
 
+	.macro stp2_nuao regA, regB, ptr, offset=0
+	stp \regA, \regB, [\ptr, \offset]
+	.endm
+
+	.macro stp3_nuao regA, regB, ptr, offset=0
+	stp \regA, \regB, [\ptr, \offset]
+	.endm
+
 	.macro ldp1_pre_nuao regA, regB, ptr, offset
-	USER_F(9998f, ldp \regA, \regB, [\ptr, \offset]!)
+	USER_F(9993f, ldp \regA, \regB, [\ptr, \offset]!)
+	.endm
+
+	.macro ldp2_pre_nuao regA, regB, ptr, offset
+	USER_F(9994f, ldp \regA, \regB, [\ptr, \offset]!)
+	.endm
+
+	.macro ldp3_pre_nuao regA, regB, ptr, offset
+	USER_F(9995f, ldp \regA, \regB, [\ptr, \offset]!)
 	.endm
 
 	.macro stp1_pre_nuao regA, regB, ptr, offset
 	stp \regA, \regB, [\ptr, \offset]!
 	.endm
 
+	.macro stp2_pre_nuao regA, regB, ptr, offset
+	stp \regA, \regB, [\ptr, \offset]!
+	.endm
+
+	.macro stp3_pre_nuao regA, regB, ptr, offset
+	stp \regA, \regB, [\ptr, \offset]!
+	.endm
+
 	.macro copy_exit
 	b	.Luaccess_finish
 	.endm
diff --git a/arch/arm64/lib/copy_in_user.S b/arch/arm64/lib/copy_in_user.S
index c1647a9b3a22..4511f59dd979 100644
--- a/arch/arm64/lib/copy_in_user.S
+++ b/arch/arm64/lib/copy_in_user.S
@@ -23,92 +23,272 @@
  */
 
 	.macro ldrb1 reg, ptr, offset=0
-	USER_F(9998f, ldtrb \reg, [\ptr, \offset])
+	USER_F(9993f, ldtrb \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldrb2 reg, ptr, offset=0
+	USER_F(9994f, ldtrb \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldrb3 reg, ptr, offset=0
+	USER_F(9995f, ldtrb \reg, [\ptr, \offset])
 	.endm
 
 	.macro strb1 reg, ptr, offset=0
+	USER_F(9996f, sttrb \reg, [\ptr, \offset])
+	.endm
+
+	.macro strb2 reg, ptr, offset=0
+	USER_F(9997f, sttrb \reg, [\ptr, \offset])
+	.endm
+
+	.macro strb3 reg, ptr, offset=0
 	USER_F(9998f, sttrb \reg, [\ptr, \offset])
 	.endm
 
 	.macro ldrb1_reg reg, ptr, offset
 	add \ptr, \ptr, \offset
-	USER_F(9998f, ldtrb \reg, [\ptr])
+	USER_F(9993f, ldtrb \reg, [\ptr])
+	sub \ptr, \ptr, \offset
+	.endm
+
+	.macro ldrb2_reg reg, ptr, offset
+	add \ptr, \ptr, \offset
+	USER_F(9994f, ldtrb \reg, [\ptr])
+	sub \ptr, \ptr, \offset
+	.endm
+
+	.macro ldrb3_reg reg, ptr, offset
+	add \ptr, \ptr, \offset
+	USER_F(9995f, ldtrb \reg, [\ptr])
 	sub \ptr, \ptr, \offset
 	.endm
 
 	.macro strb1_reg reg, ptr, offset
 	add \ptr, \ptr, \offset
+	USER_F(9996f, sttrb \reg, [\ptr])
+	sub \ptr, \ptr, \offset
+	.endm
+
+	.macro strb2_reg reg, ptr, offset
+	add \ptr, \ptr, \offset
+	USER_F(9997f, sttrb \reg, [\ptr])
+	sub \ptr, \ptr, \offset
+	.endm
+
+	.macro strb3_reg reg, ptr, offset
+	add \ptr, \ptr, \offset
 	USER_F(9998f, sttrb \reg, [\ptr])
 	sub \ptr, \ptr, \offset
 	.endm
 
 	.macro ldr1 reg, ptr, offset=0
-	USER_F(9998f, ldtr \reg, [\ptr, \offset])
+	USER_F(9993f, ldtr \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldr2 reg, ptr, offset=0
+	USER_F(9994f, ldtr \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldr3 reg, ptr, offset=0
+	USER_F(9995f, ldtr \reg, [\ptr, \offset])
 	.endm
 
 	.macro str1 reg, ptr, offset=0
+	USER_F(9996f, sttr \reg, [\ptr, \offset])
+	.endm
+
+	.macro str2 reg, ptr, offset=0
+	USER_F(9997f, sttr \reg, [\ptr, \offset])
+	.endm
+
+	.macro str3 reg, ptr, offset=0
 	USER_F(9998f, sttr \reg, [\ptr, \offset])
 	.endm
 
 	.macro ldp1 regA, regB, ptr, offset=0
-	USER_F(9998f, ldtr \regA, [\ptr, \offset])
-	USER_F(9998f, ldtr \regB, [\ptr, \offset + 8])
+	USER_F(9993f, ldtr \regA, [\ptr, \offset])
+	USER_F(9993f, ldtr \regB, [\ptr, \offset + 8])
+	.endm
+
+	.macro ldp2 regA, regB, ptr, offset=0
+	USER_F(9994f, ldtr \regA, [\ptr, \offset])
+	USER_F(9994f, ldtr \regB, [\ptr, \offset + 8])
+	.endm
+
+	.macro ldp3 regA, regB, ptr, offset=0
+	USER_F(9995f, ldtr \regA, [\ptr, \offset])
+	USER_F(9995f, ldtr \regB, [\ptr, \offset + 8])
 	.endm
 
 	.macro stp1 regA, regB, ptr, offset=0
+	USER_F(9996f, sttr \regA, [\ptr, \offset])
+	USER_F(9996f, sttr \regB, [\ptr, \offset + 8])
+	.endm
+
+	.macro stp2 regA, regB, ptr, offset=0
+	USER_F(9997f, sttr \regA, [\ptr, \offset])
+	USER_F(9997f, sttr \regB, [\ptr, \offset + 8])
+	.endm
+
+	.macro stp3 regA, regB, ptr, offset=0
 	USER_F(9998f, sttr \regA, [\ptr, \offset])
 	USER_F(9998f, sttr \regB, [\ptr, \offset + 8])
 	.endm
 
 	.macro ldp1_pre regA, regB, ptr, offset
-	USER_F(9998f, ldtr \regA, [\ptr, \offset])
-	USER_F(9998f, ldtr \regB, [\ptr, \offset + 8])
+	USER_F(9993f, ldtr \regA, [\ptr, \offset])
+	USER_F(9993f, ldtr \regB, [\ptr, \offset + 8])
+	add \ptr, \ptr, \offset
+	.endm
+
+	.macro ldp2_pre regA, regB, ptr, offset
+	USER_F(9994f, ldtr \regA, [\ptr, \offset])
+	USER_F(9994f, ldtr \regB, [\ptr, \offset + 8])
+	add \ptr, \ptr, \offset
+	.endm
+
+	.macro ldp3_pre regA, regB, ptr, offset
+	USER_F(9995f, ldtr \regA, [\ptr, \offset])
+	USER_F(9995f, ldtr \regB, [\ptr, \offset + 8])
 	add \ptr, \ptr, \offset
 	.endm
 
 	.macro stp1_pre regA, regB, ptr, offset
+	USER_F(9996f, sttr \regA, [\ptr, \offset])
+	USER_F(9996f, sttr \regB, [\ptr, \offset + 8])
+	add \ptr, \ptr, \offset
+	.endm
+
+	.macro stp2_pre regA, regB, ptr, offset
+	USER_F(9997f, sttr \regA, [\ptr, \offset])
+	USER_F(9997f, sttr \regB, [\ptr, \offset + 8])
+	add \ptr, \ptr, \offset
+	.endm
+
+	.macro stp3_pre regA, regB, ptr, offset
 	USER_F(9998f, sttr \regA, [\ptr, \offset])
 	USER_F(9998f, sttr \regB, [\ptr, \offset + 8])
 	add \ptr, \ptr, \offset
 	.endm
 
 	.macro ldrb1_nuao reg, ptr, offset=0
-	USER_F(9998f, ldrb \reg, [\ptr, \offset])
+	USER_F(9993f, ldrb \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldrb2_nuao reg, ptr, offset=0
+	USER_F(9994f, ldrb \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldrb3_nuao reg, ptr, offset=0
+	USER_F(9995f, ldrb \reg, [\ptr, \offset])
 	.endm
 
 	.macro strb1_nuao reg, ptr, offset=0
+	USER_F(9996f, strb \reg, [\ptr, \offset])
+	.endm
+
+	.macro strb2_nuao reg, ptr, offset=0
+	USER_F(9997f, strb \reg, [\ptr, \offset])
+	.endm
+
+	.macro strb3_nuao reg, ptr, offset=0
 	USER_F(9998f, strb \reg, [\ptr, \offset])
 	.endm
 
 	.macro ldrb1_nuao_reg reg, ptr, offset=0
-	USER_F(9998f, ldrb \reg, [\ptr, \offset])
+	USER_F(9993f, ldrb \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldrb2_nuao_reg reg, ptr, offset=0
+	USER_F(9994f, ldrb \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldrb3_nuao_reg reg, ptr, offset=0
+	USER_F(9995f, ldrb \reg, [\ptr, \offset])
 	.endm
 
 	.macro strb1_nuao_reg reg, ptr, offset=0
+	USER_F(9996f, strb \reg, [\ptr, \offset])
+	.endm
+
+	.macro strb2_nuao_reg reg, ptr, offset=0
+	USER_F(9997f, strb \reg, [\ptr, \offset])
+	.endm
+
+	.macro strb3_nuao_reg reg, ptr, offset=0
 	USER_F(9998f, strb \reg, [\ptr, \offset])
 	.endm
 
 	.macro ldr1_nuao reg, ptr, offset=0
-	USER_F(9998f, ldr \reg, [\ptr, \offset])
+	USER_F(9993f, ldr \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldr2_nuao reg, ptr, offset=0
+	USER_F(9994f, ldr \reg, [\ptr, \offset])
+	.endm
+
+	.macro ldr3_nuao reg, ptr, offset=0
+	USER_F(9995f, ldr \reg, [\ptr, \offset])
 	.endm
 
 	.macro str1_nuao reg, ptr, offset=0
+	USER_F(9996f, str \reg, [\ptr, \offset])
+	.endm
+
+	.macro str2_nuao reg, ptr, offset=0
+	USER_F(9997f, str \reg, [\ptr, \offset])
+	.endm
+
+	.macro str3_nuao reg, ptr, offset=0
 	USER_F(9998f, str \reg, [\ptr, \offset])
 	.endm
 
 	.macro ldp1_nuao  regA, regB, ptr, offset=0
-	USER_F(9998f, ldp \regA, \regB, [\ptr, \offset])
+	USER_F(9993f, ldp \regA, \regB, [\ptr, \offset])
+	.endm
+
+	.macro ldp2_nuao  regA, regB, ptr, offset=0
+	USER_F(9994f, ldp \regA, \regB, [\ptr, \offset])
+	.endm
+
+	.macro ldp3_nuao  regA, regB, ptr, offset=0
+	USER_F(9995f, ldp \regA, \regB, [\ptr, \offset])
 	.endm
 
 	.macro stp1_nuao regA, regB, ptr, offset=0
+	USER_F(9996f, stp \regA, \regB, [\ptr, \offset])
+	.endm
+
+	.macro stp2_nuao regA, regB, ptr, offset=0
+	USER_F(9997f, stp \regA, \regB, [\ptr, \offset])
+	.endm
+
+	.macro stp3_nuao regA, regB, ptr, offset=0
 	USER_F(9998f, stp \regA, \regB, [\ptr, \offset])
 	.endm
 
 	.macro ldp1_pre_nuao regA, regB, ptr, offset
-	USER_F(9998f, ldp \regA, \regB, [\ptr, \offset]!)
+	USER_F(9993f, ldp \regA, \regB, [\ptr, \offset]!)
+	.endm
+
+	.macro ldp2_pre_nuao regA, regB, ptr, offset
+	USER_F(9994f, ldp \regA, \regB, [\ptr, \offset]!)
+	.endm
+
+	.macro ldp3_pre_nuao regA, regB, ptr, offset
+	USER_F(9995f, ldp \regA, \regB, [\ptr, \offset]!)
 	.endm
 
 	.macro stp1_pre_nuao regA, regB, ptr, offset
+	USER_F(9996f, stp \regA, \regB, [\ptr, \offset]!)
+	.endm
+
+	.macro stp2_pre_nuao regA, regB, ptr, offset
+	USER_F(9997f, stp \regA, \regB, [\ptr, \offset]!)
+	.endm
+
+	.macro stp3_pre_nuao regA, regB, ptr, offset
 	USER_F(9998f, stp \regA, \regB, [\ptr, \offset]!)
 	.endm
 
diff --git a/arch/arm64/lib/copy_template.S b/arch/arm64/lib/copy_template.S
index 90b5f63ff227..0c3e39ae906d 100644
--- a/arch/arm64/lib/copy_template.S
+++ b/arch/arm64/lib/copy_template.S
@@ -58,18 +58,18 @@
 	cmp	count, 16
 	b.lo	L(copy16)
 	ldp1	A_l, A_h, src
-	ldp1	D_l, D_h, srcend, -16
+	ldp2	D_l, D_h, srcend, -16
 	stp1	A_l, A_h, dstin
-	stp1	D_l, D_h, dstend, -16
+	stp2	D_l, D_h, dstend, -16
 	copy_exit
 
 	/* Copy 8-15 bytes. */
 L(copy16):
 	tbz	count, 3, L(copy8)
 	ldr1	A_l, src
-	ldr1	A_h, srcend, -8
+	ldr2	A_h, srcend, -8
 	str1	A_l, dstin
-	str1	A_h, dstend, -8
+	str2	A_h, dstend, -8
 	copy_exit
 
 	.p2align 3
@@ -77,9 +77,9 @@ L(copy16):
 L(copy8):
 	tbz	count, 2, L(copy4)
 	ldr1	A_lw, src
-	ldr1	B_lw, srcend, -4
+	ldr2	B_lw, srcend, -4
 	str1	A_lw, dstin
-	str1	B_lw, dstend, -4
+	str2	B_lw, dstend, -4
 	copy_exit
 
 	/* Copy 0..3 bytes using a branchless sequence. */
@@ -87,11 +87,11 @@ L(copy4):
 	cbz	count, L(copy0)
 	lsr	tmp1, count, 1
 	ldrb1	A_lw, src
-	ldrb1	C_lw, srcend, -1
+	ldrb2	C_lw, srcend, -1
 	ldrb1_reg	B_lw, src, tmp1
 	strb1	A_lw, dstin
 	strb1_reg	B_lw, dstin, tmp1
-	strb1	C_lw, dstend, -1
+	strb2	C_lw, dstend, -1
 L(copy0):
 	copy_exit
 
@@ -100,14 +100,14 @@ L(copy0):
 L(copy32_128):
 	ldp1	A_l, A_h, src
 	ldp1	B_l, B_h, src, 16
-	ldp1	C_l, C_h, srcend, -32
-	ldp1	D_l, D_h, srcend, -16
+	ldp2	C_l, C_h, srcend, -32
+	ldp2	D_l, D_h, srcend, -16
 	cmp	count, 64
 	b.hi	L(copy128)
 	stp1	A_l, A_h, dstin
 	stp1	B_l, B_h, dstin, 16
-	stp1	C_l, C_h, dstend, -32
-	stp1	D_l, D_h, dstend, -16
+	stp2	C_l, C_h, dstend, -32
+	stp2	D_l, D_h, dstend, -16
 	copy_exit
 
 	.p2align 4
@@ -117,17 +117,17 @@ L(copy128):
 	ldp1	F_l, F_h, src, 48
 	cmp	count, 96
 	b.ls	L(copy96)
-	ldp1	G_l, G_h, srcend, -64
-	ldp1	H_l, H_h, srcend, -48
-	stp1	G_l, G_h, dstend, -64
-	stp1	H_l, H_h, dstend, -48
+	ldp2	G_l, G_h, srcend, -64
+	ldp2	H_l, H_h, srcend, -48
+	stp2	G_l, G_h, dstend, -64
+	stp2	H_l, H_h, dstend, -48
 L(copy96):
 	stp1	A_l, A_h, dstin
 	stp1	B_l, B_h, dstin, 16
 	stp1	E_l, E_h, dstin, 32
 	stp1	F_l, F_h, dstin, 48
-	stp1	C_l, C_h, dstend, -32
-	stp1	D_l, D_h, dstend, -16
+	stp2	C_l, C_h, dstend, -32
+	stp2	D_l, D_h, dstend, -16
 	copy_exit
 
 	.p2align 4
@@ -146,83 +146,85 @@ L(copy_long):
 	bic	dst, dstin, 15
 	sub	src, src, tmp1
 	add	count, count, tmp1	/* Count is now 16 too large. */
-	ldp1	A_l, A_h, src, 16
+	ldp3	A_l, A_h, src, 16
 	stp1	D_l, D_h, dstin
-	ldp1	B_l, B_h, src, 32
-	ldp1	C_l, C_h, src, 48
-	ldp1_pre	D_l, D_h, src, 64
+	ldp3	B_l, B_h, src, 32
+	ldp3	C_l, C_h, src, 48
+	ldp3_pre	D_l, D_h, src, 64
 	subs	count, count, 128 + 16 /* Test and readjust count. */
 	b.ls	L(copy64_from_end)
 
 L(loop64):
-	stp1	A_l, A_h, dst, 16
-	ldp1	A_l, A_h, src, 16
-	stp1	B_l, B_h, dst, 32
-	ldp1	B_l, B_h, src, 32
-	stp1	C_l, C_h, dst, 48
-	ldp1	C_l, C_h, src, 48
-	stp1_pre	D_l, D_h, dst, 64
-	ldp1_pre	D_l, D_h, src, 64
+	stp3	A_l, A_h, dst, 16
+	ldp3	A_l, A_h, src, 16
+	stp3	B_l, B_h, dst, 32
+	ldp3	B_l, B_h, src, 32
+	stp3	C_l, C_h, dst, 48
+	ldp3	C_l, C_h, src, 48
+	stp3_pre	D_l, D_h, dst, 64
+	ldp3_pre	D_l, D_h, src, 64
 	subs	count, count, 64
 	b.hi	L(loop64)
 
 	/* Write the last iteration and copy 64 bytes from the end. */
 L(copy64_from_end):
-	ldp1	E_l, E_h, srcend, -64
-	stp1	A_l, A_h, dst, 16
-	ldp1	A_l, A_h, srcend, -48
-	stp1	B_l, B_h, dst, 32
-	ldp1	B_l, B_h, srcend, -32
-	stp1	C_l, C_h, dst, 48
-	ldp1	C_l, C_h, srcend, -16
-	stp1	D_l, D_h, dst, 64
-	stp1	E_l, E_h, dstend, -64
-	stp1	A_l, A_h, dstend, -48
-	stp1	B_l, B_h, dstend, -32
-	stp1	C_l, C_h, dstend, -16
+	ldp2	E_l, E_h, srcend, -64
+	stp3	A_l, A_h, dst, 16
+	ldp2	A_l, A_h, srcend, -48
+	stp3	B_l, B_h, dst, 32
+	ldp2	B_l, B_h, srcend, -32
+	stp3	C_l, C_h, dst, 48
+	ldp2	C_l, C_h, srcend, -16
+	stp3	D_l, D_h, dst, 64
+	stp2	E_l, E_h, dstend, -64
+	stp2	A_l, A_h, dstend, -48
+	stp2	B_l, B_h, dstend, -32
+	stp2	C_l, C_h, dstend, -16
 	copy_exit
 
 	.p2align 4
+
 	/* Large backwards copy for overlapping copies.
-	   Copy 16 bytes and then align dst to 16-byte alignment. */
+	   Copy 16 bytes and then align dst to 16-byte alignment.  */
 L(copy_long_backwards):
-	ldp1	D_l, D_h, srcend, -16
+	ldp2	D_l, D_h, srcend, -16
 	and	tmp1, dstend, 15
 	sub	srcend, srcend, tmp1
 	sub	count, count, tmp1
-	ldp1	A_l, A_h, srcend, -16
-	stp1	D_l, D_h, dstend, -16
-	ldp1	B_l, B_h, srcend, -32
-	ldp1	C_l, C_h, srcend, -48
-	ldp1_pre	D_l, D_h, srcend, -64
+	ldp2	A_l, A_h, srcend, -16
+	stp2	D_l, D_h, dstend, -16
+	ldp2	B_l, B_h, srcend, -32
+	ldp2	C_l, C_h, srcend, -48
+	ldp2_pre	D_l, D_h, srcend, -64
 	sub	dstend, dstend, tmp1
 	subs	count, count, 128
 	b.ls	L(copy64_from_start)
 
 L(loop64_backwards):
-	stp1	A_l, A_h, dstend, -16
-	ldp1	A_l, A_h, srcend, -16
-	stp1	B_l, B_h, dstend, -32
-	ldp1	B_l, B_h, srcend, -32
-	stp1	C_l, C_h, dstend, -48
-	ldp1	C_l, C_h, srcend, -48
-	stp1_pre	D_l, D_h, dstend, -64
-	ldp1_pre	D_l, D_h, srcend, -64
+	stp2	A_l, A_h, dstend, -16
+	ldp2	A_l, A_h, srcend, -16
+	stp2	B_l, B_h, dstend, -32
+	ldp2	B_l, B_h, srcend, -32
+	stp2	C_l, C_h, dstend, -48
+	ldp2	C_l, C_h, srcend, -48
+	stp2_pre	D_l, D_h, dstend, -64
+	ldp2_pre	D_l, D_h, srcend, -64
 	subs	count, count, 64
 	b.hi	L(loop64_backwards)
 
-	/* Write the last iteration and copy 64 bytes from the start. */
+	/* Write the last iteration and copy 64 bytes from the start.  */
 L(copy64_from_start):
 	ldp1	G_l, G_h, src, 48
-	stp1	A_l, A_h, dstend, -16
+	stp2	A_l, A_h, dstend, -16
 	ldp1	A_l, A_h, src, 32
-	stp1	B_l, B_h, dstend, -32
+	stp2	B_l, B_h, dstend, -32
 	ldp1	B_l, B_h, src, 16
-	stp1	C_l, C_h, dstend, -48
+	stp2	C_l, C_h, dstend, -48
 	ldp1	C_l, C_h, src
-	stp1	D_l, D_h, dstend, -64
+	stp2	D_l, D_h, dstend, -64
 	stp1	G_l, G_h, dstin, 48
 	stp1	A_l, A_h, dstin, 32
 	stp1	B_l, B_h, dstin, 16
 	stp1	C_l, C_h, dstin
 	copy_exit
+
diff --git a/arch/arm64/lib/copy_template_user.S b/arch/arm64/lib/copy_template_user.S
index 1d13daf314b0..f36c77738e42 100644
--- a/arch/arm64/lib/copy_template_user.S
+++ b/arch/arm64/lib/copy_template_user.S
@@ -8,15 +8,35 @@
 #include "copy_template.S"
 
 #define ldp1 ldp1_nuao
+#define ldp2 ldp2_nuao
+#define ldp3 ldp3_nuao
 #define ldp1_pre ldp1_pre_nuao
+#define ldp2_pre ldp2_pre_nuao
+#define ldp3_pre ldp3_pre_nuao
 #define stp1 stp1_nuao
+#define stp2 stp2_nuao
+#define stp3 stp3_nuao
 #define stp1_pre stp1_pre_nuao
+#define stp2_pre stp2_pre_nuao
+#define stp3_pre stp3_pre_nuao
 #define ldr1 ldr1_nuao
+#define ldr2 ldr2_nuao
+#define ldr3 ldr3_nuao
 #define str1 str1_nuao
+#define str2 str2_nuao
+#define str3 str3_nuao
 #define ldrb1 ldrb1_nuao
+#define ldrb2 ldrb2_nuao
+#define ldrb3 ldrb3_nuao
 #define strb1 strb1_nuao
+#define strb2 strb2_nuao
+#define strb3 strb3_nuao
 #define ldrb1_reg ldrb1_nuao_reg
+#define ldrb2_reg ldrb2_nuao_reg
+#define ldrb3_reg ldrb3_nuao_reg
 #define strb1_reg strb1_nuao_reg
+#define strb2_reg strb2_nuao_reg
+#define strb3_reg strb3_nuao_reg
 
 L(copy_non_uao):
 #undef L
diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S
index ac10d2d32b03..969e2b4ac3bf 100644
--- a/arch/arm64/lib/copy_to_user.S
+++ b/arch/arm64/lib/copy_to_user.S
@@ -24,7 +24,23 @@
 	ldrb \reg, [\ptr, \offset]
 	.endm
 
+	.macro ldrb2 reg, ptr, offset=0
+	ldrb \reg, [\ptr, \offset]
+	.endm
+
+	.macro ldrb3 reg, ptr, offset=0
+	ldrb \reg, [\ptr, \offset]
+	.endm
+
 	.macro strb1 reg, ptr, offset=0
+	USER_F(9996f, sttrb \reg, [\ptr, \offset])
+	.endm
+
+	.macro strb2 reg, ptr, offset=0
+	USER_F(9997f, sttrb \reg, [\ptr, \offset])
+	.endm
+
+	.macro strb3 reg, ptr, offset=0
 	USER_F(9998f, sttrb \reg, [\ptr, \offset])
 	.endm
 
@@ -32,8 +48,28 @@
 	ldrb \reg, [\ptr, \offset]
 	.endm
 
+	.macro ldrb2_reg reg, ptr, offset
+	ldrb \reg, [\ptr, \offset]
+	.endm
+
+	.macro ldrb3_reg reg, ptr, offset
+	ldrb \reg, [\ptr, \offset]
+	.endm
+
 	.macro strb1_reg reg, ptr, offset
 	add \ptr, \ptr, \offset
+	USER_F(9996f, sttrb \reg, [\ptr])
+	sub \ptr, \ptr, \offset
+	.endm
+
+	.macro strb2_reg reg, ptr, offset
+	add \ptr, \ptr, \offset
+	USER_F(9997f, sttrb \reg, [\ptr])
+	sub \ptr, \ptr, \offset
+	.endm
+
+	.macro strb3_reg reg, ptr, offset
+	add \ptr, \ptr, \offset
 	USER_F(9998f, sttrb \reg, [\ptr])
 	sub \ptr, \ptr, \offset
 	.endm
@@ -42,7 +78,23 @@
 	ldr \reg, [\ptr, \offset]
 	.endm
 
+	.macro ldr2 reg, ptr, offset=0
+	ldr \reg, [\ptr, \offset]
+	.endm
+
+	.macro ldr3 reg, ptr, offset=0
+	ldr \reg, [\ptr, \offset]
+	.endm
+
 	.macro str1 reg, ptr, offset=0
+	USER_F(9996f, sttr \reg, [\ptr, \offset])
+	.endm
+
+	.macro str2 reg, ptr, offset=0
+	USER_F(9997f, sttr \reg, [\ptr, \offset])
+	.endm
+
+	.macro str3 reg, ptr, offset=0
 	USER_F(9998f, sttr \reg, [\ptr, \offset])
 	.endm
 
@@ -50,7 +102,25 @@
 	ldp \regA, \regB, [\ptr, \offset]
 	.endm
 
+	.macro ldp2 regA, regB, ptr, offset=0
+	ldp \regA, \regB, [\ptr, \offset]
+	.endm
+
+	.macro ldp3 regA, regB, ptr, offset=0
+	ldp \regA, \regB, [\ptr, \offset]
+	.endm
+
 	.macro stp1 regA, regB, ptr, offset=0
+	USER_F(9996f, sttr \regA, [\ptr, \offset])
+	USER_F(9996f, sttr \regB, [\ptr, \offset + 8])
+	.endm
+
+	.macro stp2 regA, regB, ptr, offset=0
+	USER_F(9997f, sttr \regA, [\ptr, \offset])
+	USER_F(9997f, sttr \regB, [\ptr, \offset + 8])
+	.endm
+
+	.macro stp3 regA, regB, ptr, offset=0
 	USER_F(9998f, sttr \regA, [\ptr, \offset])
 	USER_F(9998f, sttr \regB, [\ptr, \offset + 8])
 	.endm
@@ -59,7 +129,27 @@
 	ldp \regA, \regB, [\ptr, \offset]!
 	.endm
 
+	.macro ldp2_pre regA, regB, ptr, offset
+	ldp \regA, \regB, [\ptr, \offset]!
+	.endm
+
+	.macro ldp3_pre regA, regB, ptr, offset
+	ldp \regA, \regB, [\ptr, \offset]!
+	.endm
+
 	.macro stp1_pre regA, regB, ptr, offset
+	USER_F(9996f, sttr \regA, [\ptr, \offset])
+	USER_F(9996f, sttr \regB, [\ptr, \offset + 8])
+	add \ptr, \ptr, \offset
+	.endm
+
+	.macro stp2_pre regA, regB, ptr, offset
+	USER_F(9997f, sttr \regA, [\ptr, \offset])
+	USER_F(9997f, sttr \regB, [\ptr, \offset + 8])
+	add \ptr, \ptr, \offset
+	.endm
+
+	.macro stp3_pre regA, regB, ptr, offset
 	USER_F(9998f, sttr \regA, [\ptr, \offset])
 	USER_F(9998f, sttr \regB, [\ptr, \offset + 8])
 	add \ptr, \ptr, \offset
@@ -69,7 +159,23 @@
 	ldrb \reg, [\ptr, \offset]
 	.endm
 
+	.macro ldrb2_nuao reg, ptr, offset=0
+	ldrb \reg, [\ptr, \offset]
+	.endm
+
+	.macro ldrb3_nuao reg, ptr, offset=0
+	ldrb \reg, [\ptr, \offset]
+	.endm
+
 	.macro strb1_nuao reg, ptr, offset=0
+	USER_F(9996f, strb \reg, [\ptr, \offset])
+	.endm
+
+	.macro strb2_nuao reg, ptr, offset=0
+	USER_F(9997f, strb \reg, [\ptr, \offset])
+	.endm
+
+	.macro strb3_nuao reg, ptr, offset=0
 	USER_F(9998f, strb \reg, [\ptr, \offset])
 	.endm
 
@@ -77,31 +183,95 @@
 	ldrb \reg, [\ptr, \offset]
 	.endm
 
+	.macro ldrb2_nuao_reg reg, ptr, offset=0
+	ldrb \reg, [\ptr, \offset]
+	.endm
+
+	.macro ldrb3_nuao_reg reg, ptr, offset=0
+	ldrb \reg, [\ptr, \offset]
+	.endm
+
 	.macro strb1_nuao_reg reg, ptr, offset=0
-	strb \reg, [\ptr, \offset]
+	USER_F(9996f, strb \reg, [\ptr, \offset])
+	.endm
+
+	.macro strb2_nuao_reg reg, ptr, offset=0
+	USER_F(9997f, strb \reg, [\ptr, \offset])
+	.endm
+
+	.macro strb3_nuao_reg reg, ptr, offset=0
+	USER_F(9998f, strb \reg, [\ptr, \offset])
 	.endm
 
 	.macro ldr1_nuao reg, ptr, offset=0
 	ldr \reg, [\ptr, \offset]
 	.endm
 
+	.macro ldr2_nuao reg, ptr, offset=0
+	ldr \reg, [\ptr, \offset]
+	.endm
+
+	.macro ldr3_nuao reg, ptr, offset=0
+	ldr \reg, [\ptr, \offset]
+	.endm
+
 	.macro str1_nuao reg, ptr, offset=0
+	USER_F(9996f, str \reg, [\ptr, \offset])
+	.endm
+
+	.macro str2_nuao reg, ptr, offset=0
+	USER_F(9997f, str \reg, [\ptr, \offset])
+	.endm
+
+	.macro str3_nuao reg, ptr, offset=0
 	USER_F(9998f, str \reg, [\ptr, \offset])
 	.endm
 
-	.macro ldp1_nuao  regA, regB, ptr, offset=0
+	.macro ldp1_nuao regA, regB, ptr, offset=0
 	ldp \regA, \regB, [\ptr, \offset]
 	.endm
 
-	.macro ldp1_pre_nuao regA, regB, ptr, offset
-	ldp \regA, \regB, [\ptr, \offset]!
+	.macro ldp2_nuao regA, regB, ptr, offset=0
+	ldp \regA, \regB, [\ptr, \offset]
+	.endm
+
+	.macro ldp3_nuao regA, regB, ptr, offset=0
+	ldp \regA, \regB, [\ptr, \offset]
 	.endm
 
 	.macro stp1_nuao regA, regB, ptr, offset=0
+	USER_F(9996f, stp \regA, \regB, [\ptr, \offset])
+	.endm
+
+	.macro stp2_nuao regA, regB, ptr, offset=0
+	USER_F(9997f, stp \regA, \regB, [\ptr, \offset])
+	.endm
+
+	.macro stp3_nuao regA, regB, ptr, offset=0
 	USER_F(9998f, stp \regA, \regB, [\ptr, \offset])
 	.endm
 
+	.macro ldp1_pre_nuao regA, regB, ptr, offset
+	ldp \regA, \regB, [\ptr, \offset]!
+	.endm
+
+	.macro ldp2_pre_nuao regA, regB, ptr, offset
+	ldp \regA, \regB, [\ptr, \offset]!
+	.endm
+
+	.macro ldp3_pre_nuao regA, regB, ptr, offset
+	ldp \regA, \regB, [\ptr, \offset]!
+	.endm
+
 	.macro stp1_pre_nuao regA, regB, ptr, offset
+	USER_F(9996f, stp \regA, \regB, [\ptr, \offset]!)
+	.endm
+
+	.macro stp2_pre_nuao regA, regB, ptr, offset
+	USER_F(9997f, stp \regA, \regB, [\ptr, \offset]!)
+	.endm
+
+	.macro stp3_pre_nuao regA, regB, ptr, offset
 	USER_F(9998f, stp \regA, \regB, [\ptr, \offset]!)
 	.endm
 
diff --git a/arch/arm64/lib/copy_user_fixup.S b/arch/arm64/lib/copy_user_fixup.S
index fe9f5ac19605..f878c8831b14 100644
--- a/arch/arm64/lib/copy_user_fixup.S
+++ b/arch/arm64/lib/copy_user_fixup.S
@@ -3,8 +3,19 @@
 addr	.req	x15
 .section .fixup,"ax"
 .align	2
+9993:
+9994:
+9995:
+9996:
+9997:
 9998:
-	// TODO: add accurate fixup
+	/* Retrieve useful information & free the stack area */
+	ldr	count, [sp, #16]	// x2
 	add	sp, sp, 32
+	/*
+	 * Return the initial count as the (under-estimated) number
+	 * of bytes that failed to copy
+	 */
+	mov	x0, count
 	ret
 
diff --git a/arch/arm64/lib/memcpy.S b/arch/arm64/lib/memcpy.S
index ee84b8847184..5552d6b33132 100644
--- a/arch/arm64/lib/memcpy.S
+++ b/arch/arm64/lib/memcpy.S
@@ -31,42 +31,122 @@
 	ldrb \reg, [\ptr, \offset]
 	.endm
 
+	.macro ldrb2 reg, ptr, offset=0
+	ldrb \reg, [\ptr, \offset]
+	.endm
+
+	.macro ldrb3 reg, ptr, offset=0
+	ldrb \reg, [\ptr, \offset]
+	.endm
+
 	.macro strb1 reg, ptr, offset=0
 	strb \reg, [\ptr, \offset]
 	.endm
 
+	.macro strb2 reg, ptr, offset=0
+	strb \reg, [\ptr, \offset]
+	.endm
+
+	.macro strb3 reg, ptr, offset=0
+	strb \reg, [\ptr, \offset]
+	.endm
+
 	.macro ldr1 reg, ptr, offset=0
 	ldr \reg, [\ptr, \offset]
 	.endm
 
+	.macro ldr2 reg, ptr, offset=0
+	ldr \reg, [\ptr, \offset]
+	.endm
+
+	.macro ldr3 reg, ptr, offset=0
+	ldr \reg, [\ptr, \offset]
+	.endm
+
 	.macro str1 reg, ptr, offset=0
 	str \reg, [\ptr, \offset]
 	.endm
 
+	.macro str2 reg, ptr, offset=0
+	str \reg, [\ptr, \offset]
+	.endm
+
+	.macro str3 reg, ptr, offset=0
+	str \reg, [\ptr, \offset]
+	.endm
+
 	.macro ldp1 regA, regB, ptr, offset=0
 	ldp \regA, \regB, [\ptr, \offset]
 	.endm
 
+	.macro ldp2 regA, regB, ptr, offset=0
+	ldp \regA, \regB, [\ptr, \offset]
+	.endm
+
+	.macro ldp3 regA, regB, ptr, offset=0
+	ldp \regA, \regB, [\ptr, \offset]
+	.endm
+
 	.macro stp1 regA, regB, ptr, offset=0
 	stp \regA, \regB, [\ptr, \offset]
 	.endm
 
+	.macro stp2 regA, regB, ptr, offset=0
+	stp \regA, \regB, [\ptr, \offset]
+	.endm
+
+	.macro stp3 regA, regB, ptr, offset=0
+	stp \regA, \regB, [\ptr, \offset]
+	.endm
+
 	.macro ldrb1_reg reg, ptr, offset
 	ldrb1 \reg, \ptr, \offset
 	.endm
 
+	.macro ldrb2_reg reg, ptr, offset
+	ldrb2 \reg, \ptr, \offset
+	.endm
+
+	.macro ldrb3_reg reg, ptr, offset
+	ldrb3 \reg, \ptr, \offset
+	.endm
+
 	.macro strb1_reg reg, ptr, offset
 	strb1 \reg, \ptr, \offset
 	.endm
 
+	.macro strb2_reg reg, ptr, offset
+	strb2 \reg, \ptr, \offset
+	.endm
+
+	.macro strb3_reg reg, ptr, offset
+	strb3 \reg, \ptr, \offset
+	.endm
+
 	.macro ldp1_pre regA, regB, ptr, offset
 	ldp \regA, \regB, [\ptr, \offset]!
 	.endm
 
+	.macro ldp2_pre regA, regB, ptr, offset
+	ldp \regA, \regB, [\ptr, \offset]!
+	.endm
+
+	.macro ldp3_pre regA, regB, ptr, offset
+	ldp \regA, \regB, [\ptr, \offset]!
+	.endm
+
 	.macro stp1_pre regA, regB, ptr, offset
 	stp \regA, \regB, [\ptr, \offset]!
 	.endm
 
+	.macro stp2_pre regA, regB, ptr, offset
+	stp \regA, \regB, [\ptr, \offset]!
+	.endm
+
+	.macro stp3_pre regA, regB, ptr, offset
+	stp \regA, \regB, [\ptr, \offset]!
+	.endm
+
 	.macro copy_exit
 	ret
 	.endm
-- 
2.17.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v3 12/13] arm64: Add fixup routines for usercopy load exceptions

[Oliver Swede]

This adds the fixup routines for exceptions that occur on load
operations while copying, by providing the calling code with a more
accurate value for the number of bytes that failed to copy.

The three routines for load exceptions work together to analyse
the position of the fault relative to the start or the end of the
buffer, and backtrack from the optimized memcpy algorithm to
determine if some number of bytes has already been successfully
copied.

The new template uses out-of-order copying, and this fixup routine is
specific to the latest memcpy implementation. It is assumed there is
no requirement to follow through with the copying of data that may
reside in temporary registers on a fault, as this would greatly
increase the fixup's complexity.

Signed-off-by: Oliver Swede <oli.swede@arm.com>
---
 arch/arm64/lib/copy_user_fixup.S | 170 ++++++++++++++++++++++++++++++-
 1 file changed, 165 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/lib/copy_user_fixup.S b/arch/arm64/lib/copy_user_fixup.S
index f878c8831b14..256a33522749 100644
--- a/arch/arm64/lib/copy_user_fixup.S
+++ b/arch/arm64/lib/copy_user_fixup.S
@@ -3,19 +3,179 @@
 addr	.req	x15
 .section .fixup,"ax"
 .align	2
+
+	/*
+	 * These fixup routines assume that it is not a requirement
+	 * to follow through with the copying of any intermediate
+	 * data in registers: this would be highly dependent on the
+	 * procedure in the copy template, which utilizes out-of-order
+	 * copying and is subject to change by future optimizations.
+	 *
+	 * The subroutine that is excuted depends on the properties of
+	 * the target address in the instruction: if it is an address
+	 * relative to the start or the end of the buffer, and (in the
+	 * case of copy sizes larger than 128 bytes) whether it is
+	 * aligned or unaligned with 16 bytes.
+	 */
+
+	/*
+	 * The following three routines are directed to from faults on load
+	 * instructions. In each case, nothing has been copied if either:
+	 *	a) the copy size is less than 128 bytes, as the algorithm does
+	 * 	   not interleave load/store instruction, so nothing has been
+	 *	   copied and the full width (srcend-src) can be returned
+	 *	b) the copy size is greater than or equal to 128 bytes and the
+	 *	   src and dst buffers overlap, as this would result in a
+	 *	   backwards copy, but the calling code expects the return
+	 *	   value (no. bytes not copied) to be from an in-order
+	 *	   perspective.
+	 */
 9993:
+	/*
+	 * This is reached from load instructions that are specified
+	 * relative to the start of a user space memory buffer, and
+	 * are not guaranteed to be aligned to 16B.
+	 */
+
+	/* Retrieve useful information & free the stack area */
+	ldp	dst, src, [sp], #16	// dst: x3, src: x1
+	ldr	count, [sp], #16	// count: x2
+	add	srcend, src, count
+	add	dstend, dst, count
+
+	/* Copy size < 128 bytes */
+	cmp	count, 128
+	b.ls	L(none_copied)
+	/*
+	 * Overlapping buffers:
+	 * (src <= dst && dst < srcend) || (dst <= src && src < dstend)
+	 */
+	cmp	src, dst
+	ccmp	dst, srcend, #0, le
+	b.lt	L(none_copied)
+	cmp	dst, src
+	ccmp	src, dstend, #0, le
+	b.lt	L(none_copied)
+
+	/*
+	 * The fault occurred in a load instruction at the start of the
+	 * algorithm's subroutine for long copies, and no bytes have
+	 * been stored at this point.
+	 */
+	b	L(none_copied)
 9994:
+	/*
+	 * This is reached from load instructions that are specified
+	 * relative to the end of a user space memory buffer, and
+	 * are not guaranteed to be aligned to 16B.
+	 */
+
+	/* Store the current dst before the original is
+	 * restored */
+	mov	tmp1, dst
+
+	/* Retrieve useful information & free the stack area */
+	ldp	dst, src, [sp], #16	// dst: x3, src: x1
+	ldr	count, [sp], #16	// count: x2
+	add	srcend, src, count
+	add	dstend, dst, count
+
+	/* Copy size < 128 bytes */
+	cmp	count, 128
+	b.ls	L(none_copied)
+	/*
+	 * Overlapping buffers:
+	 * (src <= dst && dst < srcend) || (dst <= src && src < dstend)
+	 */
+	cmp	src, dst
+	ccmp	dst, srcend, #0, le
+	b.lt	L(none_copied)
+	cmp	dst, src
+	ccmp	src, dstend, #0, le
+	b.lt	L(none_copied)
+
+	/*
+	 * In the case of an access relative to the end of
+	 * the buffer, the long copy has reached the final
+	 * 64B chunk in copy64_from_end().
+	 *
+	 * The fault address should fall in 1-of-4 16B blocks,
+	 * each of which indicates how many bytes have been
+	 * stored from the in-order perspective.
+	 *
+	 * A number of iterations of the loop to copy 64B
+	 * chunks may have completed; tmp1 stores the
+	 * latest position of the dst pointer and this can
+	 * be used to deduce how many 16B copies have taken
+	 * place.
+	 */
+
+	/* Calculate the index of the 16B block containing
+	 * containing the fault address */
+	sub	x0, srcend, 64
+	cmp	addr, x0
+	b.lt	L(none_copied) // unexpected fault address
+	sub	x0, addr, x0 // relative offset of fault in buffer
+	bic	x0, x0, 15 // assume no data copied between addr and the target
+	sub	tmp1, dst, tmp1 // already copied up to dst
+	add	x0, x0, tmp1 // plus the difference between addr and srcend-64
+	sub	x0, count, x0 // no. bytes not copied
+	b	L(end_fixup)
+
 9995:
+	/*
+	 * This is reached from load instructions that are specified
+	 * relative to the start of a user space memory buffer, and
+	 * are guaranteed to be aligned to 16B.
+	 */
+
+	/* Retrieve useful information & free the stack area */
+	ldp	dst, src, [sp], #16	// dst: x3, src: x1
+	ldr	count, [sp], #16	// count: x2
+	add	srcend, src, count
+	add	dstend, dst, count
+
+	/* Copy size <= 128 bytes */
+	cmp	count, 128
+	b.ls	L(none_copied)
+
+	/*
+	 * Overlapping buffers:
+	 * (src <= dst && dst < srcend) || (dst <= src && src < dstend)
+	 */
+	cmp	src, dst
+	ccmp	dst, srcend, #0, le
+	b.lt	L(none_copied)
+	cmp	dst, src
+	ccmp	src, dstend, #0, le
+	b.lt	L(none_copied)
+
+	sub	x0, addr, src
+	lsr	x0, addr, 4 // calculate the index of faulting 16B block
+	/* Map the index in x0 to the no. bytes already copied */
+	cmp	x0, 1
+	b.le	L(none_copied) // no stores for i=0,1
+	cmp	x0, 4
+	mov	tmp1, x0
+	sub	x0, count, 16
+	b.le	L(end_fixup) // one store (16B) for i=2,3,4
+	/* Faulted in a loop: stored up to ((i-3) * 16) - (dst % 16) */
+	mov	x0, tmp1
+	sub	x0, x0, 3
+	lsl	x0, x0, 4
+	mov	tmp1, dst
+	and	tmp1, tmp1, 15
+	sub	x0, x0, tmp1
+	b	L(end_fixup)
+
 9996:
 9997:
 9998:
-	/* Retrieve useful information & free the stack area */
-	ldr	count, [sp, #16]	// x2
-	add	sp, sp, 32
+L(none_copied):
 	/*
-	 * Return the initial count as the (under-estimated) number
+	 * Return the initial count as the number
 	 * of bytes that failed to copy
 	 */
 	mov	x0, count
+L(end_fixup):
 	ret
-
-- 
2.17.1


_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v3 13/13] arm64: Add fixup routines for usercopy store exceptions

[Oliver Swede]

This adds the fixup routines for exceptions that occur on store
operations while copying, by providing the calling code with a more
accurate value for the number of bytes that failed to copy, rather
than returning the full buffer width.

The three routines for store exceptions work together to analyse
the position of the fault relative to the start or the end of the
buffer, and backtrack from the optimized memcpy algorithm to
determine if some number of bytes has already been successfully
copied.

The store operations occur mostly in-order, with the exception of
a few copy size ranges - this is specific to the new copy template,
which uses the latest memcpy implementation.

Signed-off-by: Oliver Swede <oli.swede@arm.com>
---
 arch/arm64/lib/copy_user_fixup.S | 96 ++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)

diff --git a/arch/arm64/lib/copy_user_fixup.S b/arch/arm64/lib/copy_user_fixup.S
index 256a33522749..d836fa6cc333 100644
--- a/arch/arm64/lib/copy_user_fixup.S
+++ b/arch/arm64/lib/copy_user_fixup.S
@@ -168,9 +168,105 @@ addr	.req	x15
 	sub	x0, x0, tmp1
 	b	L(end_fixup)
 
+	/*
+	 * The following three routines are directed to from faults
+	 * on store instructions.
+	 */
 9996:
+	/*
+	 * This routine is reached from faults on store instructions
+	 * where the target address has been specified relative to the
+	 * start of the user space memory buffer, and is also not
+	 * guaranteed to be aligned to 16B.
+	 *
+	 * For copy sizes <= 128 bytes, the stores occur in-order,
+	 * so it has copied up to (addr-dst)&~15.
+	 * For copy sizes > 128 bytes, this should only be directed
+	 * to from a fault on the first store of the long copy, before
+	 * the algorithm aligns dst to 16B, so no bytes have copied at
+	 * this point.
+	 */
+
+	/* Retrieve useful information & free the stack area */
+	ldr	dst, [sp], #16		// dst: x3
+	ldr	count, [sp], #16	// count: x2
+
+	cmp	count, 0
+	b.eq	L(none_copied)
+	cmp	count, 3
+	sub	x0, addr, dst // relative fault offset in buffer
+	bic	x0, x0, 7 // bytes already copied (steps of 8B stores)
+	sub	x0, count, x0 // bytes yet to copy
+	b.le	L(end_fixup)
+	cmp	count, 32
+	b.le	L(none_copied)
+	cmp	count, 128
+	sub	x0, addr, dst // relative fault offset in buffer
+	bic	x0, x0, 15 // bytes already copied (steps of 16B stores)
+	sub	x0, count, x0 // bytes yet to copy
+	b.le	L(end_fixup)
+	b	L(none_copied)
+
 9997:
+	/*
+	 * This routine is reached from faults on store instructions
+	 * where the target address has been specified relative to the
+	 * end of the user space memory buffer and is also not
+	 * guaranteed to be aligned with 16B.
+	 *
+	 * In this scenario, the the copy is close to completion and
+	 * has occurred in-order, so the last few bytes to copy can
+	 * easily be calculated.
+	 *
+	 * This caters for the overlapping stage, as it could
+	 * potentially fault on data that has already been copied.
+	 */
+
+	/* Retrieve useful information & free the stack area */
+	ldr	dst, [sp], #16		// dst: x3
+	ldr	count, [sp], #16	// count: x2
+	add	dstend, dst, count
+
+	sub	x0, dstend, addr
+	bic	x0, x0, 15 // remaining bytes to copy
+	b	L(end_fixup)
+
 9998:
+	/*
+	 * This routine is reached from faults on store instructions
+	 * where the target address has been specified relative to the
+	 * start of the user space memory buffer, and is also guaranteed
+	 * to be aligned to 16B.
+	 *
+	 * These instrucions occur after the algorithm aligns dst to 16B,
+	 * after the very first store in a long copy. It then continues
+	 * copying from dst+16 onwards.
+	 *
+	 * This could result in an overlapping copy if the original dst
+	 * is unaligned with 16B. However, this implies that it could
+	 * potentially fault on data that has already been copied, if
+	 * the fault occurs in the first aligned access.
+	 *
+	 * We want to report that 16 bytes has already successfully copied in this case.
+	*/
+
+	/* Retrieve useful information & free the stack area */
+	ldr	dst, [sp], #16		// dst: x3
+	ldr	count, [sp], #16	// count: x2
+
+	bic	tmp1, dst, 15 // aligned dst
+	bic	x0, addr, 15
+	sub	x0, x0, tmp1 // relative fault offset
+	cmp	x0, 0 // unexpected range for this fixup
+	b.eq	L(none_copied)
+	cmp	x0, 16
+	bic	x0, addr, 15
+	sub	x0, x0, dst
+	sub	x0, count, x0
+	b.gt	L(end_fixup)
+	sub	x0, count, 16
+	b	L(end_fixup) // initial unaligned chunk copied
+
 L(none_copied):
 	/*
 	 * Return the initial count as the number
-- 
2.17.1


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