diff options
| author | Cyril Bur <cyrilbur@gmail.com> | 2016-09-23 16:18:13 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2016-10-04 20:10:09 +1100 |
| commit | 65ca668f58a260e144621fd93a413da67635b999 (patch) | |
| tree | a279400c17b19584e6b9bc3ecbe02d431e2b8ec1 /tools/testing/selftests/powerpc/math/vsx_asm.S | |
| parent | d11994314b2bfe028bc39be24b44298787925160 (diff) | |
| download | linux-65ca668f58a260e144621fd93a413da67635b999.tar.gz | |
selftests/powerpc: Check for VSX preservation across userspace preemption
Ensure the kernel correctly switches VSX registers correctly. VSX
registers are all volatile, and despite the kernel preserving VSX
across syscalls, it doesn't have to. Test that during interrupts and
timeslices ending the VSX regs remain the same.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'tools/testing/selftests/powerpc/math/vsx_asm.S')
| -rw-r--r-- | tools/testing/selftests/powerpc/math/vsx_asm.S | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/tools/testing/selftests/powerpc/math/vsx_asm.S b/tools/testing/selftests/powerpc/math/vsx_asm.S new file mode 100644 index 000000000000..a110dd882d5e --- /dev/null +++ b/tools/testing/selftests/powerpc/math/vsx_asm.S @@ -0,0 +1,61 @@ +/* + * Copyright 2015, Cyril Bur, IBM Corp. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include "../basic_asm.h" +#include "../vsx_asm.h" + +#long check_vsx(vector int *r3); +#This function wraps storeing VSX regs to the end of an array and a +#call to a comparison function in C which boils down to a memcmp() +FUNC_START(check_vsx) + PUSH_BASIC_STACK(32) + std r3,STACK_FRAME_PARAM(0)(sp) + addi r3, r3, 16 * 12 #Second half of array + bl store_vsx + ld r3,STACK_FRAME_PARAM(0)(sp) + bl vsx_memcmp + POP_BASIC_STACK(32) + blr +FUNC_END(check_vsx) + +# int preempt_vmx(vector int *varray, int *threads_starting, +# int *running); +# On starting will (atomically) decrement threads_starting as a signal +# that the VMX have been loaded with varray. Will proceed to check the +# validity of the VMX registers while running is not zero. +FUNC_START(preempt_vsx) + PUSH_BASIC_STACK(512) + std r3,STACK_FRAME_PARAM(0)(sp) # vector int *varray + std r4,STACK_FRAME_PARAM(1)(sp) # int *threads_starting + std r5,STACK_FRAME_PARAM(2)(sp) # int *running + + bl load_vsx + nop + + sync + # Atomic DEC + ld r3,STACK_FRAME_PARAM(1)(sp) +1: lwarx r4,0,r3 + addi r4,r4,-1 + stwcx. r4,0,r3 + bne- 1b + +2: ld r3,STACK_FRAME_PARAM(0)(sp) + bl check_vsx + nop + cmpdi r3,0 + bne 3f + ld r4,STACK_FRAME_PARAM(2)(sp) + ld r5,0(r4) + cmpwi r5,0 + bne 2b + +3: POP_BASIC_STACK(512) + blr +FUNC_END(preempt_vsx) |