selftests/powerpc: Test preservation of FPU and VMX regs across preemption
Loop in assembly checking the registers with many threads.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/tools/testing/selftests/powerpc/math/vmx_asm.S b/tools/testing/selftests/powerpc/math/vmx_asm.S
index 4ce6421..1b8c248 100644
--- a/tools/testing/selftests/powerpc/math/vmx_asm.S
+++ b/tools/testing/selftests/powerpc/math/vmx_asm.S
@@ -9,6 +9,7 @@
#include "../basic_asm.h"
+# POS MUST BE 16 ALIGNED!
#define PUSH_VMX(pos,reg) \
li reg,pos; \
stvx v20,reg,sp; \
@@ -35,6 +36,7 @@
addi reg,reg,16; \
stvx v31,reg,sp;
+# POS MUST BE 16 ALIGNED!
#define POP_VMX(pos,reg) \
li reg,pos; \
lvx v20,reg,sp; \
@@ -93,7 +95,7 @@
# Should be safe from C, only touches r4, r5 and v0,v1,v2
FUNC_START(check_vmx)
- PUSH_BASIC_STACK(16)
+ PUSH_BASIC_STACK(32)
mr r4,r3
li r3,1 # assume a bad result
li r5,0
@@ -162,7 +164,7 @@
cmpdi r0,0xffffffffffffffff
bne 1f
li r3,0
-1: POP_BASIC_STACK(16)
+1: POP_BASIC_STACK(32)
blr
FUNC_END(check_vmx)
@@ -193,3 +195,41 @@
POP_BASIC_STACK(512)
blr
FUNC_END(test_vmx)
+
+# 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_vmx)
+ 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
+ # VMX need to write to 16 byte aligned addresses, skip STACK_FRAME_LOCAL(3,0)
+ PUSH_VMX(STACK_FRAME_LOCAL(4,0),r4)
+
+ bl load_vmx
+ 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_vmx
+ nop
+ cmpdi r3,0
+ bne 3f
+ ld r4,STACK_FRAME_PARAM(2)(sp)
+ ld r5,0(r4)
+ cmpwi r5,0
+ bne 2b
+
+3: POP_VMX(STACK_FRAME_LOCAL(4,0),r4)
+ POP_BASIC_STACK(512)
+ blr
+FUNC_END(preempt_vmx)