13 files changed, 2057 insertions, 0 deletions
diff --git a/tools/testing/selftests/arm64/fp/.gitignore b/tools/testing/selftests/arm64/fp/.gitignore
new file mode 100644
index 000000000..d66f76d2a
--- /dev/null
+++ b/tools/testing/selftests/arm64/fp/.gitignore
@@ -0,0 +1,5 @@
+fpsimd-test
+sve-probe-vls
+sve-ptrace
+sve-test
+vlset
diff --git a/tools/testing/selftests/arm64/fp/Makefile b/tools/testing/selftests/arm64/fp/Makefile
new file mode 100644
index 000000000..a57009d3a
--- /dev/null
+++ b/tools/testing/selftests/arm64/fp/Makefile
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0
+
+CFLAGS += -I../../../../../usr/include/
+TEST_GEN_PROGS := sve-ptrace sve-probe-vls
+TEST_PROGS_EXTENDED := fpsimd-test fpsimd-stress sve-test sve-stress vlset
+
+all: $(TEST_GEN_PROGS) $(TEST_PROGS_EXTENDED)
+
+fpsimd-test: fpsimd-test.o
+	$(CC) -nostdlib $^ -o $@
+sve-ptrace: sve-ptrace.o sve-ptrace-asm.o
+sve-probe-vls: sve-probe-vls.o
+sve-test: sve-test.o
+	$(CC) -nostdlib $^ -o $@
+vlset: vlset.o
+
+include ../../lib.mk
diff --git a/tools/testing/selftests/arm64/fp/README b/tools/testing/selftests/arm64/fp/README
new file mode 100644
index 000000000..03e3dad86
--- /dev/null
+++ b/tools/testing/selftests/arm64/fp/README
@@ -0,0 +1,100 @@
+This directory contains a mix of tests integrated with kselftest and
+standalone stress tests.
+
+kselftest tests
+===============
+
+sve-probe-vls - Checks the SVE vector length enumeration interface
+sve-ptrace - Checks the SVE ptrace interface
+
+Running the non-kselftest tests
+===============================
+
+sve-stress performs an SVE context switch stress test, as described
+below.
+
+(The fpsimd-stress test works the same way; just substitute "fpsimd" for
+"sve" in the following commands.)
+
+
+The test runs until killed by the user.
+
+If no context switch error was detected, you will see output such as
+the following:
+
+$ ./sve-stress
+(wait for some time)
+^C
+Vector length:        512 bits
+PID:    1573
+Terminated by signal 15, no error, iterations=9467, signals=1014
+Vector length:  512 bits
+PID:    1575
+Terminated by signal 15, no error, iterations=9448, signals=1028
+Vector length:  512 bits
+PID:    1577
+Terminated by signal 15, no error, iterations=9436, signals=1039
+Vector length:  512 bits
+PID:    1579
+Terminated by signal 15, no error, iterations=9421, signals=1039
+Vector length:  512 bits
+PID:    1581
+Terminated by signal 15, no error, iterations=9403, signals=1039
+Vector length:  512 bits
+PID:    1583
+Terminated by signal 15, no error, iterations=9385, signals=1036
+Vector length:  512 bits
+PID:    1585
+Terminated by signal 15, no error, iterations=9376, signals=1039
+Vector length:  512 bits
+PID:    1587
+Terminated by signal 15, no error, iterations=9361, signals=1039
+Vector length:  512 bits
+PID:    1589
+Terminated by signal 15, no error, iterations=9350, signals=1039
+
+
+If an error was detected, details of the mismatch will be printed
+instead of "no error".
+
+Ideally, the test should be allowed to run for many minutes or hours
+to maximise test coverage.
+
+
+KVM stress testing
+==================
+
+To try to reproduce the bugs that we have been observing, sve-stress
+should be run in parallel in two KVM guests, while simultaneously
+running on the host.
+
+1) Start 2 guests, using the following command for each:
+
+$ lkvm run --console=virtio -pconsole=hvc0 --sve Image
+
+(Depending on the hardware GIC implementation, you may also need
+--irqchip=gicv3.  New kvmtool defaults to that if appropriate, but I
+can't remember whether my branch is new enough for that.  Try without
+the option first.)
+
+Kvmtool occupies the terminal until you kill it (Ctrl+A x),
+or until the guest terminates.  It is therefore recommended to run
+each instance in separate terminal (use screen or ssh etc.)  This
+allows multiple guests to be run in parallel while running other
+commands on the host.
+
+Within the guest, the host filesystem is accessible, mounted on /host.
+
+2) Run the sve-stress on *each* guest with the Vector-Length set to 32:
+guest$ ./vlset --inherit 32 ./sve-stress
+
+3) Run the sve-stress on the host with the maximum Vector-Length:
+host$ ./vlset --inherit --max ./sve-stress
+
+
+Again, the test should be allowed to run for many minutes or hours to
+maximise test coverage.
+
+If no error is detected, you will see output from each sve-stress
+instance similar to that illustrated above; otherwise details of the
+observed mismatches will be printed.
diff --git a/tools/testing/selftests/arm64/fp/asm-offsets.h b/tools/testing/selftests/arm64/fp/asm-offsets.h
new file mode 100644
index 000000000..a18085149
--- /dev/null
+++ b/tools/testing/selftests/arm64/fp/asm-offsets.h
@@ -0,0 +1,11 @@
+#define sa_sz 32
+#define sa_flags 8
+#define sa_handler 0
+#define sa_mask_sz 8
+#define SIGUSR1 10
+#define SIGTERM 15
+#define SIGINT 2
+#define SIGABRT 6
+#define SA_NODEFER 1073741824
+#define SA_SIGINFO 4
+#define ucontext_regs 184
diff --git a/tools/testing/selftests/arm64/fp/assembler.h b/tools/testing/selftests/arm64/fp/assembler.h
new file mode 100644
index 000000000..8944f2189
--- /dev/null
+++ b/tools/testing/selftests/arm64/fp/assembler.h
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2015-2019 ARM Limited.
+// Original author: Dave Martin <Dave.Martin@arm.com>
+
+#ifndef ASSEMBLER_H
+#define ASSEMBLER_H
+
+.macro __for from:req, to:req
+	.if (\from) == (\to)
+		_for__body %\from
+	.else
+		__for \from, %(\from) + ((\to) - (\from)) / 2
+		__for %(\from) + ((\to) - (\from)) / 2 + 1, \to
+	.endif
+.endm
+
+.macro _for var:req, from:req, to:req, insn:vararg
+	.macro _for__body \var:req
+		.noaltmacro
+		\insn
+		.altmacro
+	.endm
+
+	.altmacro
+	__for \from, \to
+	.noaltmacro
+
+	.purgem _for__body
+.endm
+
+.macro function name
+	.macro endfunction
+		.type \name, @function
+		.purgem endfunction
+	.endm
+\name:
+.endm
+
+.macro define_accessor name, num, insn
+	.macro \name\()_entry n
+		\insn \n, 1
+		ret
+	.endm
+
+function \name
+	adr	x2, .L__accessor_tbl\@
+	add	x2, x2, x0, lsl #3
+	br	x2
+
+.L__accessor_tbl\@:
+	_for x, 0, (\num) - 1, \name\()_entry \x
+endfunction
+
+	.purgem \name\()_entry
+.endm
+
+#endif /* ! ASSEMBLER_H */
diff --git a/tools/testing/selftests/arm64/fp/fpsimd-stress b/tools/testing/selftests/arm64/fp/fpsimd-stress
new file mode 100755
index 000000000..781b5b022
--- /dev/null
+++ b/tools/testing/selftests/arm64/fp/fpsimd-stress
@@ -0,0 +1,60 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0-only
+# Copyright (C) 2015-2019 ARM Limited.
+# Original author: Dave Martin <Dave.Martin@arm.com>
+
+set -ue
+
+NR_CPUS=`nproc`
+
+pids=
+logs=
+
+cleanup () {
+	trap - INT TERM CHLD
+	set +e
+
+	if [ -n "$pids" ]; then
+		kill $pids
+		wait $pids
+		pids=
+	fi
+
+	if [ -n "$logs" ]; then
+		cat $logs
+		rm $logs
+		logs=
+	fi
+}
+
+interrupt () {
+	cleanup
+	exit 0
+}
+
+child_died () {
+	cleanup
+	exit 1
+}
+
+trap interrupt INT TERM EXIT
+trap child_died CHLD
+
+for x in `seq 0 $((NR_CPUS * 4))`; do
+	log=`mktemp`
+	logs=$logs\ $log
+	./fpsimd-test >$log &
+	pids=$pids\ $!
+done
+
+# Wait for all child processes to be created:
+sleep 10
+
+while :; do
+	kill -USR1 $pids
+done &
+pids=$pids\ $!
+
+wait
+
+exit 1
diff --git a/tools/testing/selftests/arm64/fp/fpsimd-test.S b/tools/testing/selftests/arm64/fp/fpsimd-test.S
new file mode 100644
index 000000000..1c5556bdd
--- /dev/null
+++ b/tools/testing/selftests/arm64/fp/fpsimd-test.S
@@ -0,0 +1,482 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2015-2019 ARM Limited.
+// Original author: Dave Martin <Dave.Martin@arm.com>
+//
+// Simple FPSIMD context switch test
+// Repeatedly writes unique test patterns into each FPSIMD register
+// and reads them back to verify integrity.
+//
+// for x in `seq 1 NR_CPUS`; do fpsimd-test & pids=$pids\ $! ; done
+// (leave it running for as long as you want...)
+// kill $pids
+
+#include <asm/unistd.h>
+#include "assembler.h"
+#include "asm-offsets.h"
+
+#define NVR	32
+#define MAXVL_B	(128 / 8)
+
+.macro _vldr Vn:req, Xt:req
+	ld1	{v\Vn\().2d}, [x\Xt]
+.endm
+
+.macro _vstr Vn:req, Xt:req
+	st1	{v\Vn\().2d}, [x\Xt]
+.endm
+
+// Generate accessor functions to read/write programmatically selected
+// FPSIMD registers.
+// x0 is the register index to access
+// x1 is the memory address to read from (getv,setp) or store to (setv,setp)
+// All clobber x0-x2
+define_accessor setv, NVR, _vldr
+define_accessor getv, NVR, _vstr
+
+// Print a single character x0 to stdout
+// Clobbers x0-x2,x8
+function putc
+	str	x0, [sp, #-16]!
+
+	mov	x0, #1			// STDOUT_FILENO
+	mov	x1, sp
+	mov	x2, #1
+	mov	x8, #__NR_write
+	svc	#0
+
+	add	sp, sp, #16
+	ret
+endfunction
+
+// Print a NUL-terminated string starting at address x0 to stdout
+// Clobbers x0-x3,x8
+function puts
+	mov	x1, x0
+
+	mov	x2, #0
+0:	ldrb	w3, [x0], #1
+	cbz	w3, 1f
+	add	x2, x2, #1
+	b	0b
+
+1:	mov	w0, #1			// STDOUT_FILENO
+	mov	x8, #__NR_write
+	svc	#0
+
+	ret
+endfunction
+
+// Utility macro to print a literal string
+// Clobbers x0-x4,x8
+.macro puts string
+	.pushsection .rodata.str1.1, "aMS", 1
+.L__puts_literal\@: .string "\string"
+	.popsection
+
+	ldr	x0, =.L__puts_literal\@
+	bl	puts
+.endm
+
+// Print an unsigned decimal number x0 to stdout
+// Clobbers x0-x4,x8
+function putdec
+	mov	x1, sp
+	str	x30, [sp, #-32]!	// Result can't be > 20 digits
+
+	mov	x2, #0
+	strb	w2, [x1, #-1]!		// Write the NUL terminator
+
+	mov	x2, #10
+0:	udiv	x3, x0, x2		// div-mod loop to generate the digits
+	msub	x0, x3, x2, x0
+	add	w0, w0, #'0'
+	strb	w0, [x1, #-1]!
+	mov	x0, x3
+	cbnz	x3, 0b
+
+	ldrb	w0, [x1]
+	cbnz	w0, 1f
+	mov	w0, #'0'		// Print "0" for 0, not ""
+	strb	w0, [x1, #-1]!
+
+1:	mov	x0, x1
+	bl	puts
+
+	ldr	x30, [sp], #32
+	ret
+endfunction
+
+// Print an unsigned decimal number x0 to stdout, followed by a newline
+// Clobbers x0-x5,x8
+function putdecn
+	mov	x5, x30
+
+	bl	putdec
+	mov	x0, #'\n'
+	bl	putc
+
+	ret	x5
+endfunction
+
+
+// Clobbers x0-x3,x8
+function puthexb
+	str	x30, [sp, #-0x10]!
+
+	mov	w3, w0
+	lsr	w0, w0, #4
+	bl	puthexnibble
+	mov	w0, w3
+
+	ldr	x30, [sp], #0x10
+	// fall through to puthexnibble
+endfunction
+// Clobbers x0-x2,x8
+function puthexnibble
+	and	w0, w0, #0xf
+	cmp	w0, #10
+	blo	1f
+	add	w0, w0, #'a' - ('9' + 1)
+1:	add	w0, w0, #'0'
+	b	putc
+endfunction
+
+// x0=data in, x1=size in, clobbers x0-x5,x8
+function dumphex
+	str	x30, [sp, #-0x10]!
+
+	mov	x4, x0
+	mov	x5, x1
+
+0:	subs	x5, x5, #1
+	b.lo	1f
+	ldrb	w0, [x4], #1
+	bl	puthexb
+	b	0b
+
+1:	ldr	x30, [sp], #0x10
+	ret
+endfunction
+
+// Declare some storate space to shadow the SVE register contents:
+.pushsection .text
+.data
+.align 4
+vref:
+	.space	MAXVL_B * NVR
+scratch:
+	.space	MAXVL_B
+.popsection
+
+// Trivial memory copy: copy x2 bytes, starting at address x1, to address x0.
+// Clobbers x0-x3
+function memcpy
+	cmp	x2, #0
+	b.eq	1f
+0:	ldrb	w3, [x1], #1
+	strb	w3, [x0], #1
+	subs	x2, x2, #1
+	b.ne	0b
+1:	ret
+endfunction
+
+// Generate a test pattern for storage in SVE registers
+// x0: pid	(16 bits)
+// x1: register number (6 bits)
+// x2: generation (4 bits)
+function pattern
+	orr	w1, w0, w1, lsl #16
+	orr	w2, w1, w2, lsl #28
+
+	ldr	x0, =scratch
+	mov	w1, #MAXVL_B / 4
+
+0:	str	w2, [x0], #4
+	add	w2, w2, #(1 << 22)
+	subs	w1, w1, #1
+	bne	0b
+
+	ret
+endfunction
+
+// Get the address of shadow data for FPSIMD V-register V<xn>
+.macro _adrv xd, xn, nrtmp
+	ldr	\xd, =vref
+	mov	x\nrtmp, #16
+	madd	\xd, x\nrtmp, \xn, \xd
+.endm
+
+// Set up test pattern in a FPSIMD V-register
+// x0: pid
+// x1: register number
+// x2: generation
+function setup_vreg
+	mov	x4, x30
+
+	mov	x6, x1
+	bl	pattern
+	_adrv	x0, x6, 2
+	mov	x5, x0
+	ldr	x1, =scratch
+	bl	memcpy
+
+	mov	x0, x6
+	mov	x1, x5
+	bl	setv
+
+	ret	x4
+endfunction
+
+// Fill x1 bytes starting at x0 with 0xae (for canary purposes)
+// Clobbers x1, x2.
+function memfill_ae
+	mov	w2, #0xae
+	b	memfill
+endfunction
+
+// Fill x1 bytes starting at x0 with 0.
+// Clobbers x1, x2.
+function memclr
+	mov	w2, #0
+endfunction
+	// fall through to memfill
+
+// Trivial memory fill: fill x1 bytes starting at address x0 with byte w2
+// Clobbers x1
+function memfill
+	cmp	x1, #0
+	b.eq	1f
+
+0:	strb	w2, [x0], #1
+	subs	x1, x1, #1
+	b.ne	0b
+
+1:	ret
+endfunction
+
+// Trivial memory compare: compare x2 bytes starting at address x0 with
+// bytes starting at address x1.
+// Returns only if all bytes match; otherwise, the program is aborted.
+// Clobbers x0-x5.
+function memcmp
+	cbz	x2, 1f
+
+	mov	x5, #0
+0:	ldrb	w3, [x0, x5]
+	ldrb	w4, [x1, x5]
+	add	x5, x5, #1
+	cmp	w3, w4
+	b.ne	barf
+	subs	x2, x2, #1
+	b.ne	0b
+
+1:	ret
+endfunction
+
+// Verify that a FPSIMD V-register matches its shadow in memory, else abort
+// x0: reg number
+// Clobbers x0-x5.
+function check_vreg
+	mov	x3, x30
+
+	_adrv	x5, x0, 6
+	mov	x4, x0
+	ldr	x7, =scratch
+
+	mov	x0, x7
+	mov	x1, x6
+	bl	memfill_ae
+
+	mov	x0, x4
+	mov	x1, x7
+	bl	getv
+
+	mov	x0, x5
+	mov	x1, x7
+	mov	x2, x6
+	mov	x30, x3
+	b	memcmp
+endfunction
+
+// Any SVE register modified here can cause corruption in the main
+// thread -- but *only* the registers modified here.
+function irritator_handler
+	// Increment the irritation signal count (x23):
+	ldr	x0, [x2, #ucontext_regs + 8 * 23]
+	add	x0, x0, #1
+	str	x0, [x2, #ucontext_regs + 8 * 23]
+
+	// Corrupt some random V-regs
+	adr	x0, .text + (irritator_handler - .text) / 16 * 16
+	movi	v0.8b, #7
+	movi	v9.16b, #9
+	movi	v31.8b, #31
+
+	ret
+endfunction
+
+function terminate_handler
+	mov	w21, w0
+	mov	x20, x2
+
+	puts	"Terminated by signal "
+	mov	w0, w21
+	bl	putdec
+	puts	", no error, iterations="
+	ldr	x0, [x20, #ucontext_regs + 8 * 22]
+	bl	putdec
+	puts	", signals="
+	ldr	x0, [x20, #ucontext_regs + 8 * 23]
+	bl	putdecn
+
+	mov	x0, #0
+	mov	x8, #__NR_exit
+	svc	#0
+endfunction
+
+// w0: signal number
+// x1: sa_action
+// w2: sa_flags
+// Clobbers x0-x6,x8
+function setsignal
+	str	x30, [sp, #-((sa_sz + 15) / 16 * 16 + 16)]!
+
+	mov	w4, w0
+	mov	x5, x1
+	mov	w6, w2
+
+	add	x0, sp, #16
+	mov	x1, #sa_sz
+	bl	memclr
+
+	mov	w0, w4
+	add	x1, sp, #16
+	str	w6, [x1, #sa_flags]
+	str	x5, [x1, #sa_handler]
+	mov	x2, #0
+	mov	x3, #sa_mask_sz
+	mov	x8, #__NR_rt_sigaction
+	svc	#0
+
+	cbz	w0, 1f
+
+	puts	"sigaction failure\n"
+	b	.Labort
+
+1:	ldr	x30, [sp], #((sa_sz + 15) / 16 * 16 + 16)
+	ret
+endfunction
+
+// Main program entry point
+.globl _start
+function _start
+_start:
+	// Sanity-check and report the vector length
+
+	mov	x19, #128
+	cmp	x19, #128
+	b.lo	1f
+	cmp	x19, #2048
+	b.hi	1f
+	tst	x19, #(8 - 1)
+	b.eq	2f
+
+1:	puts	"Bad vector length: "
+	mov	x0, x19
+	bl	putdecn
+	b	.Labort
+
+2:	puts	"Vector length:\t"
+	mov	x0, x19
+	bl	putdec
+	puts	" bits\n"
+
+	// Obtain our PID, to ensure test pattern uniqueness between processes
+
+	mov	x8, #__NR_getpid
+	svc	#0
+	mov	x20, x0
+
+	puts	"PID:\t"
+	mov	x0, x20
+	bl	putdecn
+
+	mov	x23, #0		// Irritation signal count
+
+	mov	w0, #SIGINT
+	adr	x1, terminate_handler
+	mov	w2, #SA_SIGINFO
+	bl	setsignal
+
+	mov	w0, #SIGTERM
+	adr	x1, terminate_handler
+	mov	w2, #SA_SIGINFO
+	bl	setsignal
+
+	mov	w0, #SIGUSR1
+	adr	x1, irritator_handler
+	mov	w2, #SA_SIGINFO
+	orr	w2, w2, #SA_NODEFER
+	bl	setsignal
+
+	mov	x22, #0		// generation number, increments per iteration
+.Ltest_loop:
+
+	mov	x21, #0		// Set up V-regs & shadow with test pattern
+0:	mov	x0, x20
+	mov	x1, x21
+	and	x2, x22, #0xf
+	bl	setup_vreg
+	add	x21, x21, #1
+	cmp	x21, #NVR
+	b.lo	0b
+
+// Can't do this when SVE state is volatile across SVC:
+	mov	x8, #__NR_sched_yield	// Encourage preemption
+	svc	#0
+
+	mov	x21, #0
+0:	mov	x0, x21
+	bl	check_vreg
+	add	x21, x21, #1
+	cmp	x21, #NVR
+	b.lo	0b
+
+	add	x22, x22, #1
+	b	.Ltest_loop
+
+.Labort:
+	mov	x0, #0
+	mov	x1, #SIGABRT
+	mov	x8, #__NR_kill
+	svc	#0
+endfunction
+
+function barf
+	mov	x10, x0	// expected data
+	mov	x11, x1	// actual data
+	mov	x12, x2	// data size
+
+	puts	"Mistatch: PID="
+	mov	x0, x20
+	bl	putdec
+	puts	", iteration="
+	mov	x0, x22
+	bl	putdec
+	puts	", reg="
+	mov	x0, x21
+	bl	putdecn
+	puts	"\tExpected ["
+	mov	x0, x10
+	mov	x1, x12
+	bl	dumphex
+	puts	"]\n\tGot      ["
+	mov	x0, x11
+	mov	x1, x12
+	bl	dumphex
+	puts	"]\n"
+
+	mov	x8, #__NR_exit
+	mov	x1, #1
+	svc	#0
+endfunction
diff --git a/tools/testing/selftests/arm64/fp/sve-probe-vls.c b/tools/testing/selftests/arm64/fp/sve-probe-vls.c
new file mode 100644
index 000000000..b29cbc642
--- /dev/null
+++ b/tools/testing/selftests/arm64/fp/sve-probe-vls.c
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2015-2020 ARM Limited.
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/auxv.h>
+#include <sys/prctl.h>
+#include <asm/sigcontext.h>
+
+#include "../../kselftest.h"
+
+int main(int argc, char **argv)
+{
+	unsigned int vq;
+	int vl;
+	static unsigned int vqs[SVE_VQ_MAX];
+	unsigned int nvqs = 0;
+
+	ksft_print_header();
+	ksft_set_plan(2);
+
+	if (!(getauxval(AT_HWCAP) & HWCAP_SVE))
+		ksft_exit_skip("SVE not available");
+
+	/*
+	 * Enumerate up to SVE_VQ_MAX vector lengths
+	 */
+	for (vq = SVE_VQ_MAX; vq > 0; --vq) {
+		vl = prctl(PR_SVE_SET_VL, vq * 16);
+		if (vl == -1)
+			ksft_exit_fail_msg("PR_SVE_SET_VL failed: %s (%d)\n",
+					   strerror(errno), errno);
+
+		vl &= PR_SVE_VL_LEN_MASK;
+
+		if (!sve_vl_valid(vl))
+			ksft_exit_fail_msg("VL %d invalid\n", vl);
+		vq = sve_vq_from_vl(vl);
+
+		if (!(nvqs < SVE_VQ_MAX))
+			ksft_exit_fail_msg("Too many VLs %u >= SVE_VQ_MAX\n",
+					   nvqs);
+		vqs[nvqs++] = vq;
+	}
+	ksft_test_result_pass("Enumerated %d vector lengths\n", nvqs);
+	ksft_test_result_pass("All vector lengths valid\n");
+
+	/* Print out the vector lengths in ascending order: */
+	while (nvqs--)
+		ksft_print_msg("%u\n", 16 * vqs[nvqs]);
+
+	ksft_exit_pass();
+}
diff --git a/tools/testing/selftests/arm64/fp/sve-ptrace-asm.S b/tools/testing/selftests/arm64/fp/sve-ptrace-asm.S
new file mode 100644
index 000000000..3e81f9fab
--- /dev/null
+++ b/tools/testing/selftests/arm64/fp/sve-ptrace-asm.S
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2015-2019 ARM Limited.
+// Original author: Dave Martin <Dave.Martin@arm.com>
+#include <asm/unistd.h>
+
+.arch_extension sve
+
+.globl sve_store_patterns
+
+sve_store_patterns:
+	mov	x1, x0
+
+	index	z0.b, #0, #1
+	str	q0, [x1]
+
+	mov	w8, #__NR_getpid
+	svc	#0
+	str	q0, [x1, #0x10]
+
+	mov	z1.d, z0.d
+	str	q0, [x1, #0x20]
+
+	mov	w8, #__NR_getpid
+	svc	#0
+	str	q0, [x1, #0x30]
+
+	mov	z1.d, z0.d
+	str	q0, [x1, #0x40]
+
+	ret
+
+.size	sve_store_patterns, . - sve_store_patterns
+.type	sve_store_patterns, @function
diff --git a/tools/testing/selftests/arm64/fp/sve-ptrace.c b/tools/testing/selftests/arm64/fp/sve-ptrace.c
new file mode 100644
index 000000000..612d38996
--- /dev/null
+++ b/tools/testing/selftests/arm64/fp/sve-ptrace.c
@@ -0,0 +1,336 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2015-2020 ARM Limited.
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+#include <errno.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/auxv.h>
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/wait.h>
+#include <asm/sigcontext.h>
+#include <asm/ptrace.h>
+
+#include "../../kselftest.h"
+
+/* <linux/elf.h> and <sys/auxv.h> don't like each other, so: */
+#ifndef NT_ARM_SVE
+#define NT_ARM_SVE 0x405
+#endif
+
+/* Number of registers filled in by sve_store_patterns */
+#define NR_VREGS 5
+
+void sve_store_patterns(__uint128_t v[NR_VREGS]);
+
+static void dump(const void *buf, size_t size)
+{
+	size_t i;
+	const unsigned char *p = buf;
+
+	for (i = 0; i < size; ++i)
+		printf(" %.2x", *p++);
+}
+
+static int check_vregs(const __uint128_t vregs[NR_VREGS])
+{
+	int i;
+	int ok = 1;
+
+	for (i = 0; i < NR_VREGS; ++i) {
+		printf("# v[%d]:", i);
+		dump(&vregs[i], sizeof vregs[i]);
+		putchar('\n');
+
+		if (vregs[i] != vregs[0])
+			ok = 0;
+	}
+
+	return ok;
+}
+
+static int do_child(void)
+{
+	if (ptrace(PTRACE_TRACEME, -1, NULL, NULL))
+		ksft_exit_fail_msg("PTRACE_TRACEME", strerror(errno));
+
+	if (raise(SIGSTOP))
+		ksft_exit_fail_msg("raise(SIGSTOP)", strerror(errno));
+
+	return EXIT_SUCCESS;
+}
+
+static struct user_sve_header *get_sve(pid_t pid, void **buf, size_t *size)
+{
+	struct user_sve_header *sve;
+	void *p;
+	size_t sz = sizeof *sve;
+	struct iovec iov;
+
+	while (1) {
+		if (*size < sz) {
+			p = realloc(*buf, sz);
+			if (!p) {
+				errno = ENOMEM;
+				goto error;
+			}
+
+			*buf = p;
+			*size = sz;
+		}
+
+		iov.iov_base = *buf;
+		iov.iov_len = sz;
+		if (ptrace(PTRACE_GETREGSET, pid, NT_ARM_SVE, &iov))
+			goto error;
+
+		sve = *buf;
+		if (sve->size <= sz)
+			break;
+
+		sz = sve->size;
+	}
+
+	return sve;
+
+error:
+	return NULL;
+}
+
+static int set_sve(pid_t pid, const struct user_sve_header *sve)
+{
+	struct iovec iov;
+
+	iov.iov_base = (void *)sve;
+	iov.iov_len = sve->size;
+	return ptrace(PTRACE_SETREGSET, pid, NT_ARM_SVE, &iov);
+}
+
+static void dump_sve_regs(const struct user_sve_header *sve, unsigned int num,
+			  unsigned int vlmax)
+{
+	unsigned int vq;
+	unsigned int i;
+
+	if ((sve->flags & SVE_PT_REGS_MASK) != SVE_PT_REGS_SVE)
+		ksft_exit_fail_msg("Dumping non-SVE register\n");
+
+	if (vlmax > sve->vl)
+		vlmax = sve->vl;
+
+	vq = sve_vq_from_vl(sve->vl);
+	for (i = 0; i < num; ++i) {
+		printf("# z%u:", i);
+		dump((const char *)sve + SVE_PT_SVE_ZREG_OFFSET(vq, i),
+		     vlmax);
+		printf("%s\n", vlmax == sve->vl ? "" : " ...");
+	}
+}
+
+static int do_parent(pid_t child)
+{
+	int ret = EXIT_FAILURE;
+	pid_t pid;
+	int status;
+	siginfo_t si;
+	void *svebuf = NULL, *newsvebuf;
+	size_t svebufsz = 0, newsvebufsz;
+	struct user_sve_header *sve, *new_sve;
+	struct user_fpsimd_state *fpsimd;
+	unsigned int i, j;
+	unsigned char *p;
+	unsigned int vq;
+
+	/* Attach to the child */
+	while (1) {
+		int sig;
+
+		pid = wait(&status);
+		if (pid == -1) {
+			perror("wait");
+			goto error;
+		}
+
+		/*
+		 * This should never happen but it's hard to flag in
+		 * the framework.
+		 */
+		if (pid != child)
+			continue;
+
+		if (WIFEXITED(status) || WIFSIGNALED(status))
+			ksft_exit_fail_msg("Child died unexpectedly\n");
+
+		ksft_test_result(WIFSTOPPED(status), "WIFSTOPPED(%d)\n",
+				 status);
+		if (!WIFSTOPPED(status))
+			goto error;
+
+		sig = WSTOPSIG(status);
+
+		if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &si)) {
+			if (errno == ESRCH)
+				goto disappeared;
+
+			if (errno == EINVAL) {
+				sig = 0; /* bust group-stop */
+				goto cont;
+			}
+
+			ksft_test_result_fail("PTRACE_GETSIGINFO: %s\n",
+					      strerror(errno));
+			goto error;
+		}
+
+		if (sig == SIGSTOP && si.si_code == SI_TKILL &&
+		    si.si_pid == pid)
+			break;
+
+	cont:
+		if (ptrace(PTRACE_CONT, pid, NULL, sig)) {
+			if (errno == ESRCH)
+				goto disappeared;
+
+			ksft_test_result_fail("PTRACE_CONT: %s\n",
+					      strerror(errno));
+			goto error;
+		}
+	}
+
+	sve = get_sve(pid, &svebuf, &svebufsz);
+	if (!sve) {
+		int e = errno;
+
+		ksft_test_result_fail("get_sve: %s\n", strerror(errno));
+		if (e == ESRCH)
+			goto disappeared;
+
+		goto error;
+	} else {
+		ksft_test_result_pass("get_sve\n");
+	}
+
+	ksft_test_result((sve->flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_FPSIMD,
+			 "FPSIMD registers\n");
+	if ((sve->flags & SVE_PT_REGS_MASK) != SVE_PT_REGS_FPSIMD)
+		goto error;
+
+	fpsimd = (struct user_fpsimd_state *)((char *)sve +
+					      SVE_PT_FPSIMD_OFFSET);
+	for (i = 0; i < 32; ++i) {
+		p = (unsigned char *)&fpsimd->vregs[i];
+
+		for (j = 0; j < sizeof fpsimd->vregs[i]; ++j)
+			p[j] = j;
+	}
+
+	if (set_sve(pid, sve)) {
+		int e = errno;
+
+		ksft_test_result_fail("set_sve(FPSIMD): %s\n",
+				      strerror(errno));
+		if (e == ESRCH)
+			goto disappeared;
+
+		goto error;
+	}
+
+	vq = sve_vq_from_vl(sve->vl);
+
+	newsvebufsz = SVE_PT_SVE_ZREG_OFFSET(vq, 1);
+	new_sve = newsvebuf = malloc(newsvebufsz);
+	if (!new_sve) {
+		errno = ENOMEM;
+		perror(NULL);
+		goto error;
+	}
+
+	*new_sve = *sve;
+	new_sve->flags &= ~SVE_PT_REGS_MASK;
+	new_sve->flags |= SVE_PT_REGS_SVE;
+	memset((char *)new_sve + SVE_PT_SVE_ZREG_OFFSET(vq, 0),
+	       0, SVE_PT_SVE_ZREG_SIZE(vq));
+	new_sve->size = SVE_PT_SVE_ZREG_OFFSET(vq, 1);
+	if (set_sve(pid, new_sve)) {
+		int e = errno;
+
+		ksft_test_result_fail("set_sve(ZREG): %s\n", strerror(errno));
+		if (e == ESRCH)
+			goto disappeared;
+
+		goto error;
+	}
+
+	new_sve = get_sve(pid, &newsvebuf, &newsvebufsz);
+	if (!new_sve) {
+		int e = errno;
+
+		ksft_test_result_fail("get_sve(ZREG): %s\n", strerror(errno));
+		if (e == ESRCH)
+			goto disappeared;
+
+		goto error;
+	}
+
+	ksft_test_result((new_sve->flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_SVE,
+			 "SVE registers\n");
+	if ((new_sve->flags & SVE_PT_REGS_MASK) != SVE_PT_REGS_SVE)
+		goto error;
+
+	dump_sve_regs(new_sve, 3, sizeof fpsimd->vregs[0]);
+
+	p = (unsigned char *)new_sve + SVE_PT_SVE_ZREG_OFFSET(vq, 1);
+	for (i = 0; i < sizeof fpsimd->vregs[0]; ++i) {
+		unsigned char expected = i;
+
+		if (__BYTE_ORDER == __BIG_ENDIAN)
+			expected = sizeof fpsimd->vregs[0] - 1 - expected;
+
+		ksft_test_result(p[i] == expected, "p[%d] == expected\n", i);
+		if (p[i] != expected)
+			goto error;
+	}
+
+	ret = EXIT_SUCCESS;
+
+error:
+	kill(child, SIGKILL);
+
+disappeared:
+	return ret;
+}
+
+int main(void)
+{
+	int ret = EXIT_SUCCESS;
+	__uint128_t v[NR_VREGS];
+	pid_t child;
+
+	ksft_print_header();
+	ksft_set_plan(20);
+
+	if (!(getauxval(AT_HWCAP) & HWCAP_SVE))
+		ksft_exit_skip("SVE not available\n");
+
+	sve_store_patterns(v);
+
+	if (!check_vregs(v))
+		ksft_exit_fail_msg("Initial check_vregs() failed\n");
+
+	child = fork();
+	if (!child)
+		return do_child();
+
+	if (do_parent(child))
+		ret = EXIT_FAILURE;
+
+	ksft_print_cnts();
+
+	return ret;
+}
diff --git a/tools/testing/selftests/arm64/fp/sve-stress b/tools/testing/selftests/arm64/fp/sve-stress
new file mode 100755
index 000000000..24dd0922c
--- /dev/null
+++ b/tools/testing/selftests/arm64/fp/sve-stress
@@ -0,0 +1,59 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0-only
+# Copyright (C) 2015-2019 ARM Limited.
+# Original author: Dave Martin <Dave.Martin@arm.com>
+
+set -ue
+
+NR_CPUS=`nproc`
+
+pids=
+logs=
+
+cleanup () {
+	trap - INT TERM CHLD
+	set +e
+
+	if [ -n "$pids" ]; then
+		kill $pids
+		wait $pids
+		pids=
+	fi
+
+	if [ -n "$logs" ]; then
+		cat $logs
+		rm $logs
+		logs=
+	fi
+}
+
+interrupt () {
+	cleanup
+	exit 0
+}
+
+child_died () {
+	cleanup
+	exit 1
+}
+
+trap interrupt INT TERM EXIT
+
+for x in `seq 0 $((NR_CPUS * 4))`; do
+	log=`mktemp`
+	logs=$logs\ $log
+	./sve-test >$log &
+	pids=$pids\ $!
+done
+
+# Wait for all child processes to be created:
+sleep 10
+
+while :; do
+	kill -USR1 $pids
+done &
+pids=$pids\ $!
+
+wait
+
+exit 1
diff --git a/tools/testing/selftests/arm64/fp/sve-test.S b/tools/testing/selftests/arm64/fp/sve-test.S
new file mode 100644
index 000000000..07f14e279
--- /dev/null
+++ b/tools/testing/selftests/arm64/fp/sve-test.S
@@ -0,0 +1,684 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2015-2019 ARM Limited.
+// Original author: Dave Martin <Dave.Martin@arm.com>
+//
+// Simple Scalable Vector Extension context switch test
+// Repeatedly writes unique test patterns into each SVE register
+// and reads them back to verify integrity.
+//
+// for x in `seq 1 NR_CPUS`; do sve-test & pids=$pids\ $! ; done
+// (leave it running for as long as you want...)
+// kill $pids
+
+#include <asm/unistd.h>
+#include "assembler.h"
+#include "asm-offsets.h"
+
+#define NZR	32
+#define NPR	16
+#define MAXVL_B	(2048 / 8)
+
+.arch_extension sve
+
+.macro _sve_ldr_v zt, xn
+	ldr	z\zt, [x\xn]
+.endm
+
+.macro _sve_str_v zt, xn
+	str	z\zt, [x\xn]
+.endm
+
+.macro _sve_ldr_p pt, xn
+	ldr	p\pt, [x\xn]
+.endm
+
+.macro _sve_str_p pt, xn
+	str	p\pt, [x\xn]
+.endm
+
+// Generate accessor functions to read/write programmatically selected
+// SVE registers.
+// x0 is the register index to access
+// x1 is the memory address to read from (getz,setp) or store to (setz,setp)
+// All clobber x0-x2
+define_accessor setz, NZR, _sve_ldr_v
+define_accessor getz, NZR, _sve_str_v
+define_accessor setp, NPR, _sve_ldr_p
+define_accessor getp, NPR, _sve_str_p
+
+// Print a single character x0 to stdout
+// Clobbers x0-x2,x8
+function putc
+	str	x0, [sp, #-16]!
+
+	mov	x0, #1			// STDOUT_FILENO
+	mov	x1, sp
+	mov	x2, #1
+	mov	x8, #__NR_write
+	svc	#0
+
+	add	sp, sp, #16
+	ret
+endfunction
+
+// Print a NUL-terminated string starting at address x0 to stdout
+// Clobbers x0-x3,x8
+function puts
+	mov	x1, x0
+
+	mov	x2, #0
+0:	ldrb	w3, [x0], #1
+	cbz	w3, 1f
+	add	x2, x2, #1
+	b	0b
+
+1:	mov	w0, #1			// STDOUT_FILENO
+	mov	x8, #__NR_write
+	svc	#0
+
+	ret
+endfunction
+
+// Utility macro to print a literal string
+// Clobbers x0-x4,x8
+.macro puts string
+	.pushsection .rodata.str1.1, "aMS", 1
+.L__puts_literal\@: .string "\string"
+	.popsection
+
+	ldr	x0, =.L__puts_literal\@
+	bl	puts
+.endm
+
+// Print an unsigned decimal number x0 to stdout
+// Clobbers x0-x4,x8
+function putdec
+	mov	x1, sp
+	str	x30, [sp, #-32]!	// Result can't be > 20 digits
+
+	mov	x2, #0
+	strb	w2, [x1, #-1]!		// Write the NUL terminator
+
+	mov	x2, #10
+0:	udiv	x3, x0, x2		// div-mod loop to generate the digits
+	msub	x0, x3, x2, x0
+	add	w0, w0, #'0'
+	strb	w0, [x1, #-1]!
+	mov	x0, x3
+	cbnz	x3, 0b
+
+	ldrb	w0, [x1]
+	cbnz	w0, 1f
+	mov	w0, #'0'		// Print "0" for 0, not ""
+	strb	w0, [x1, #-1]!
+
+1:	mov	x0, x1
+	bl	puts
+
+	ldr	x30, [sp], #32
+	ret
+endfunction
+
+// Print an unsigned decimal number x0 to stdout, followed by a newline
+// Clobbers x0-x5,x8
+function putdecn
+	mov	x5, x30
+
+	bl	putdec
+	mov	x0, #'\n'
+	bl	putc
+
+	ret	x5
+endfunction
+
+// Clobbers x0-x3,x8
+function puthexb
+	str	x30, [sp, #-0x10]!
+
+	mov	w3, w0
+	lsr	w0, w0, #4
+	bl	puthexnibble
+	mov	w0, w3
+
+	ldr	x30, [sp], #0x10
+	// fall through to puthexnibble
+endfunction
+// Clobbers x0-x2,x8
+function puthexnibble
+	and	w0, w0, #0xf
+	cmp	w0, #10
+	blo	1f
+	add	w0, w0, #'a' - ('9' + 1)
+1:	add	w0, w0, #'0'
+	b	putc
+endfunction
+
+// x0=data in, x1=size in, clobbers x0-x5,x8
+function dumphex
+	str	x30, [sp, #-0x10]!
+
+	mov	x4, x0
+	mov	x5, x1
+
+0:	subs	x5, x5, #1
+	b.lo	1f
+	ldrb	w0, [x4], #1
+	bl	puthexb
+	b	0b
+
+1:	ldr	x30, [sp], #0x10
+	ret
+endfunction
+
+// Declare some storate space to shadow the SVE register contents:
+.pushsection .text
+.data
+.align 4
+zref:
+	.space	MAXVL_B * NZR
+pref:
+	.space	MAXVL_B / 8 * NPR
+ffrref:
+	.space	MAXVL_B / 8
+scratch:
+	.space	MAXVL_B
+.popsection
+
+// Trivial memory copy: copy x2 bytes, starting at address x1, to address x0.
+// Clobbers x0-x3
+function memcpy
+	cmp	x2, #0
+	b.eq	1f
+0:	ldrb	w3, [x1], #1
+	strb	w3, [x0], #1
+	subs	x2, x2, #1
+	b.ne	0b
+1:	ret
+endfunction
+
+// Generate a test pattern for storage in SVE registers
+// x0: pid	(16 bits)
+// x1: register number (6 bits)
+// x2: generation (4 bits)
+
+// These values are used to constuct a 32-bit pattern that is repeated in the
+// scratch buffer as many times as will fit:
+// bits 31:28	generation number (increments once per test_loop)
+// bits 27:22	32-bit lane index
+// bits 21:16	register number
+// bits 15: 0	pid
+
+function pattern
+	orr	w1, w0, w1, lsl #16
+	orr	w2, w1, w2, lsl #28
+
+	ldr	x0, =scratch
+	mov	w1, #MAXVL_B / 4
+
+0:	str	w2, [x0], #4
+	add	w2, w2, #(1 << 22)
+	subs	w1, w1, #1
+	bne	0b
+
+	ret
+endfunction
+
+// Get the address of shadow data for SVE Z-register Z<xn>
+.macro _adrz xd, xn, nrtmp
+	ldr	\xd, =zref
+	rdvl	x\nrtmp, #1
+	madd	\xd, x\nrtmp, \xn, \xd
+.endm
+
+// Get the address of shadow data for SVE P-register P<xn - NZR>
+.macro _adrp xd, xn, nrtmp
+	ldr	\xd, =pref
+	rdvl	x\nrtmp, #1
+	lsr	x\nrtmp, x\nrtmp, #3
+	sub	\xn, \xn, #NZR
+	madd	\xd, x\nrtmp, \xn, \xd
+.endm
+
+// Set up test pattern in a SVE Z-register
+// x0: pid
+// x1: register number
+// x2: generation
+function setup_zreg
+	mov	x4, x30
+
+	mov	x6, x1
+	bl	pattern
+	_adrz	x0, x6, 2
+	mov	x5, x0
+	ldr	x1, =scratch
+	bl	memcpy
+
+	mov	x0, x6
+	mov	x1, x5
+	bl	setz
+
+	ret	x4
+endfunction
+
+// Set up test pattern in a SVE P-register
+// x0: pid
+// x1: register number
+// x2: generation
+function setup_preg
+	mov	x4, x30
+
+	mov	x6, x1
+	bl	pattern
+	_adrp	x0, x6, 2
+	mov	x5, x0
+	ldr	x1, =scratch
+	bl	memcpy
+
+	mov	x0, x6
+	mov	x1, x5
+	bl	setp
+
+	ret	x4
+endfunction
+
+// Set up test pattern in the FFR
+// x0: pid
+// x2: generation
+//
+// We need to generate a canonical FFR value, which consists of a number of
+// low "1" bits, followed by a number of zeros. This gives us 17 unique values
+// per 16 bits of FFR, so we create a 4 bit signature out of the PID and
+// generation, and use that as the initial number of ones in the pattern.
+// We fill the upper lanes of FFR with zeros.
+// Beware: corrupts P0.
+function setup_ffr
+	mov	x4, x30
+
+	and	w0, w0, #0x3
+	bfi	w0, w2, #2, #2
+	mov	w1, #1
+	lsl	w1, w1, w0
+	sub	w1, w1, #1
+
+	ldr	x0, =ffrref
+	strh	w1, [x0], 2
+	rdvl	x1, #1
+	lsr	x1, x1, #3
+	sub	x1, x1, #2
+	bl	memclr
+
+	mov	x0, #0
+	ldr	x1, =ffrref
+	bl	setp
+
+	wrffr	p0.b
+
+	ret	x4
+endfunction
+
+// Fill x1 bytes starting at x0 with 0xae (for canary purposes)
+// Clobbers x1, x2.
+function memfill_ae
+	mov	w2, #0xae
+	b	memfill
+endfunction
+
+// Fill x1 bytes starting at x0 with 0.
+// Clobbers x1, x2.
+function memclr
+	mov	w2, #0
+endfunction
+	// fall through to memfill
+
+// Trivial memory fill: fill x1 bytes starting at address x0 with byte w2
+// Clobbers x1
+function memfill
+	cmp	x1, #0
+	b.eq	1f
+
+0:	strb	w2, [x0], #1
+	subs	x1, x1, #1
+	b.ne	0b
+
+1:	ret
+endfunction
+
+// Trivial memory compare: compare x2 bytes starting at address x0 with
+// bytes starting at address x1.
+// Returns only if all bytes match; otherwise, the program is aborted.
+// Clobbers x0-x5.
+function memcmp
+	cbz	x2, 2f
+
+	stp	x0, x1, [sp, #-0x20]!
+	str	x2, [sp, #0x10]
+
+	mov	x5, #0
+0:	ldrb	w3, [x0, x5]
+	ldrb	w4, [x1, x5]
+	add	x5, x5, #1
+	cmp	w3, w4
+	b.ne	1f
+	subs	x2, x2, #1
+	b.ne	0b
+
+1:	ldr	x2, [sp, #0x10]
+	ldp	x0, x1, [sp], #0x20
+	b.ne	barf
+
+2:	ret
+endfunction
+
+// Verify that a SVE Z-register matches its shadow in memory, else abort
+// x0: reg number
+// Clobbers x0-x7.
+function check_zreg
+	mov	x3, x30
+
+	_adrz	x5, x0, 6
+	mov	x4, x0
+	ldr	x7, =scratch
+
+	mov	x0, x7
+	mov	x1, x6
+	bl	memfill_ae
+
+	mov	x0, x4
+	mov	x1, x7
+	bl	getz
+
+	mov	x0, x5
+	mov	x1, x7
+	mov	x2, x6
+	mov	x30, x3
+	b	memcmp
+endfunction
+
+// Verify that a SVE P-register matches its shadow in memory, else abort
+// x0: reg number
+// Clobbers x0-x7.
+function check_preg
+	mov	x3, x30
+
+	_adrp	x5, x0, 6
+	mov	x4, x0
+	ldr	x7, =scratch
+
+	mov	x0, x7
+	mov	x1, x6
+	bl	memfill_ae
+
+	mov	x0, x4
+	mov	x1, x7
+	bl	getp
+
+	mov	x0, x5
+	mov	x1, x7
+	mov	x2, x6
+	mov	x30, x3
+	b	memcmp
+endfunction
+
+// Verify that the FFR matches its shadow in memory, else abort
+// Beware -- corrupts P0.
+// Clobbers x0-x5.
+function check_ffr
+	mov	x3, x30
+
+	ldr	x4, =scratch
+	rdvl	x5, #1
+	lsr	x5, x5, #3
+
+	mov	x0, x4
+	mov	x1, x5
+	bl	memfill_ae
+
+	rdffr	p0.b
+	mov	x0, #0
+	mov	x1, x4
+	bl	getp
+
+	ldr	x0, =ffrref
+	mov	x1, x4
+	mov	x2, x5
+	mov	x30, x3
+	b	memcmp
+endfunction
+
+// Any SVE register modified here can cause corruption in the main
+// thread -- but *only* the registers modified here.
+function irritator_handler
+	// Increment the irritation signal count (x23):
+	ldr	x0, [x2, #ucontext_regs + 8 * 23]
+	add	x0, x0, #1
+	str	x0, [x2, #ucontext_regs + 8 * 23]
+
+	// Corrupt some random Z-regs
+	adr	x0, .text + (irritator_handler - .text) / 16 * 16
+	movi	v0.8b, #1
+	movi	v9.16b, #2
+	movi	v31.8b, #3
+	// And P0
+	rdffr	p0.b
+	// And FFR
+	wrffr	p15.b
+
+	ret
+endfunction
+
+function terminate_handler
+	mov	w21, w0
+	mov	x20, x2
+
+	puts	"Terminated by signal "
+	mov	w0, w21
+	bl	putdec
+	puts	", no error, iterations="
+	ldr	x0, [x20, #ucontext_regs + 8 * 22]
+	bl	putdec
+	puts	", signals="
+	ldr	x0, [x20, #ucontext_regs + 8 * 23]
+	bl	putdecn
+
+	mov	x0, #0
+	mov	x8, #__NR_exit
+	svc	#0
+endfunction
+
+// w0: signal number
+// x1: sa_action
+// w2: sa_flags
+// Clobbers x0-x6,x8
+function setsignal
+	str	x30, [sp, #-((sa_sz + 15) / 16 * 16 + 16)]!
+
+	mov	w4, w0
+	mov	x5, x1
+	mov	w6, w2
+
+	add	x0, sp, #16
+	mov	x1, #sa_sz
+	bl	memclr
+
+	mov	w0, w4
+	add	x1, sp, #16
+	str	w6, [x1, #sa_flags]
+	str	x5, [x1, #sa_handler]
+	mov	x2, #0
+	mov	x3, #sa_mask_sz
+	mov	x8, #__NR_rt_sigaction
+	svc	#0
+
+	cbz	w0, 1f
+
+	puts	"sigaction failure\n"
+	b	.Labort
+
+1:	ldr	x30, [sp], #((sa_sz + 15) / 16 * 16 + 16)
+	ret
+endfunction
+
+// Main program entry point
+.globl _start
+function _start
+_start:
+	// Sanity-check and report the vector length
+
+	rdvl	x19, #8
+	cmp	x19, #128
+	b.lo	1f
+	cmp	x19, #2048
+	b.hi	1f
+	tst	x19, #(8 - 1)
+	b.eq	2f
+
+1:	puts	"Bad vector length: "
+	mov	x0, x19
+	bl	putdecn
+	b	.Labort
+
+2:	puts	"Vector length:\t"
+	mov	x0, x19
+	bl	putdec
+	puts	" bits\n"
+
+	// Obtain our PID, to ensure test pattern uniqueness between processes
+
+	mov	x8, #__NR_getpid
+	svc	#0
+	mov	x20, x0
+
+	puts	"PID:\t"
+	mov	x0, x20
+	bl	putdecn
+
+	mov	x23, #0		// Irritation signal count
+
+	mov	w0, #SIGINT
+	adr	x1, terminate_handler
+	mov	w2, #SA_SIGINFO
+	bl	setsignal
+
+	mov	w0, #SIGTERM
+	adr	x1, terminate_handler
+	mov	w2, #SA_SIGINFO
+	bl	setsignal
+
+	mov	w0, #SIGUSR1
+	adr	x1, irritator_handler
+	mov	w2, #SA_SIGINFO
+	orr	w2, w2, #SA_NODEFER
+	bl	setsignal
+
+	mov	x22, #0		// generation number, increments per iteration
+.Ltest_loop:
+	rdvl	x0, #8
+	cmp	x0, x19
+	b.ne	vl_barf
+
+	mov	x21, #0		// Set up Z-regs & shadow with test pattern
+0:	mov	x0, x20
+	mov	x1, x21
+	and	x2, x22, #0xf
+	bl	setup_zreg
+	add	x21, x21, #1
+	cmp	x21, #NZR
+	b.lo	0b
+
+	mov	x0, x20		// Set up FFR & shadow with test pattern
+	mov	x1, #NZR + NPR
+	and	x2, x22, #0xf
+	bl	setup_ffr
+
+0:	mov	x0, x20		// Set up P-regs & shadow with test pattern
+	mov	x1, x21
+	and	x2, x22, #0xf
+	bl	setup_preg
+	add	x21, x21, #1
+	cmp	x21, #NZR + NPR
+	b.lo	0b
+
+// Can't do this when SVE state is volatile across SVC:
+//	mov	x8, #__NR_sched_yield	// Encourage preemption
+//	svc	#0
+
+	mov	x21, #0
+0:	mov	x0, x21
+	bl	check_zreg
+	add	x21, x21, #1
+	cmp	x21, #NZR
+	b.lo	0b
+
+0:	mov	x0, x21
+	bl	check_preg
+	add	x21, x21, #1
+	cmp	x21, #NZR + NPR
+	b.lo	0b
+
+	bl	check_ffr
+
+	add	x22, x22, #1
+	b	.Ltest_loop
+
+.Labort:
+	mov	x0, #0
+	mov	x1, #SIGABRT
+	mov	x8, #__NR_kill
+	svc	#0
+endfunction
+
+function barf
+// fpsimd.c acitivty log dump hack
+//	ldr	w0, =0xdeadc0de
+//	mov	w8, #__NR_exit
+//	svc	#0
+// end hack
+	mov	x10, x0	// expected data
+	mov	x11, x1	// actual data
+	mov	x12, x2	// data size
+
+	puts	"Mistatch: PID="
+	mov	x0, x20
+	bl	putdec
+	puts	", iteration="
+	mov	x0, x22
+	bl	putdec
+	puts	", reg="
+	mov	x0, x21
+	bl	putdecn
+	puts	"\tExpected ["
+	mov	x0, x10
+	mov	x1, x12
+	bl	dumphex
+	puts	"]\n\tGot      ["
+	mov	x0, x11
+	mov	x1, x12
+	bl	dumphex
+	puts	"]\n"
+
+	mov	x8, #__NR_getpid
+	svc	#0
+// fpsimd.c acitivty log dump hack
+//	ldr	w0, =0xdeadc0de
+//	mov	w8, #__NR_exit
+//	svc	#0
+// ^ end of hack
+	mov	x1, #SIGABRT
+	mov	x8, #__NR_kill
+	svc	#0
+//	mov	x8, #__NR_exit
+//	mov	x1, #1
+//	svc	#0
+endfunction
+
+function vl_barf
+	mov	x10, x0
+
+	puts	"Bad active VL: "
+	mov	x0, x10
+	bl	putdecn
+
+	mov	x8, #__NR_exit
+	mov	x1, #1
+	svc	#0
+endfunction
diff --git a/tools/testing/selftests/arm64/fp/vlset.c b/tools/testing/selftests/arm64/fp/vlset.c
new file mode 100644
index 000000000..308d27a68
--- /dev/null
+++ b/tools/testing/selftests/arm64/fp/vlset.c
@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2015-2019 ARM Limited.
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+#define _GNU_SOURCE
+#include <assert.h>
+#include <errno.h>
+#include <limits.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <getopt.h>
+#include <unistd.h>
+#include <sys/auxv.h>
+#include <sys/prctl.h>
+#include <asm/hwcap.h>
+#include <asm/sigcontext.h>
+
+static int inherit = 0;
+static int no_inherit = 0;
+static int force = 0;
+static unsigned long vl;
+
+static const struct option options[] = {
+	{ "force",	no_argument, NULL, 'f' },
+	{ "inherit",	no_argument, NULL, 'i' },
+	{ "max",	no_argument, NULL, 'M' },
+	{ "no-inherit",	no_argument, &no_inherit, 1 },
+	{ "help",	no_argument, NULL, '?' },
+	{}
+};
+
+static char const *program_name;
+
+static int parse_options(int argc, char **argv)
+{
+	int c;
+	char *rest;
+
+	program_name = strrchr(argv[0], '/');
+	if (program_name)
+		++program_name;
+	else
+		program_name = argv[0];
+
+	while ((c = getopt_long(argc, argv, "Mfhi", options, NULL)) != -1)
+		switch (c) {
+		case 'M':	vl = SVE_VL_MAX; break;
+		case 'f':	force = 1; break;
+		case 'i':	inherit = 1; break;
+		case 0:		break;
+		default:	goto error;
+		}
+
+	if (inherit && no_inherit)
+		goto error;
+
+	if (!vl) {
+		/* vector length */
+		if (optind >= argc)
+			goto error;
+
+		errno = 0;
+		vl = strtoul(argv[optind], &rest, 0);
+		if (*rest) {
+			vl = ULONG_MAX;
+			errno = EINVAL;
+		}
+		if (vl == ULONG_MAX && errno) {
+			fprintf(stderr, "%s: %s: %s\n",
+				program_name, argv[optind], strerror(errno));
+			goto error;
+		}
+
+		++optind;
+	}
+
+	/* command */
+	if (optind >= argc)
+		goto error;
+
+	return 0;
+
+error:
+	fprintf(stderr,
+		"Usage: %s [-f | --force] "
+		"[-i | --inherit | --no-inherit] "
+		"{-M | --max | <vector length>} "
+		"<command> [<arguments> ...]\n",
+		program_name);
+	return -1;
+}
+
+int main(int argc, char **argv)
+{
+	int ret = 126;	/* same as sh(1) command-not-executable error */
+	long flags;
+	char *path;
+	int t, e;
+
+	if (parse_options(argc, argv))
+		return 2;	/* same as sh(1) builtin incorrect-usage */
+
+	if (vl & ~(vl & PR_SVE_VL_LEN_MASK)) {
+		fprintf(stderr, "%s: Invalid vector length %lu\n",
+			program_name, vl);
+		return 2;	/* same as sh(1) builtin incorrect-usage */
+	}
+
+	if (!(getauxval(AT_HWCAP) & HWCAP_SVE)) {
+		fprintf(stderr, "%s: Scalable Vector Extension not present\n",
+			program_name);
+
+		if (!force)
+			goto error;
+
+		fputs("Going ahead anyway (--force):  "
+		      "This is a debug option.  Don't rely on it.\n",
+		      stderr);
+	}
+
+	flags = PR_SVE_SET_VL_ONEXEC;
+	if (inherit)
+		flags |= PR_SVE_VL_INHERIT;
+
+	t = prctl(PR_SVE_SET_VL, vl | flags);
+	if (t < 0) {
+		fprintf(stderr, "%s: PR_SVE_SET_VL: %s\n",
+			program_name, strerror(errno));
+		goto error;
+	}
+
+	t = prctl(PR_SVE_GET_VL);
+	if (t == -1) {
+		fprintf(stderr, "%s: PR_SVE_GET_VL: %s\n",
+			program_name, strerror(errno));
+		goto error;
+	}
+	flags = PR_SVE_VL_LEN_MASK;
+	flags = t & ~flags;
+
+	assert(optind < argc);
+	path = argv[optind];
+
+	execvp(path, &argv[optind]);
+	e = errno;
+	if (errno == ENOENT)
+		ret = 127;	/* same as sh(1) not-found error */
+	fprintf(stderr, "%s: %s: %s\n", program_name, path, strerror(e));
+
+error:
+	return ret;		/* same as sh(1) not-executable error */
+}