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authorMichael Ellerman <mpe@ellerman.id.au>2023-11-28 16:27:45 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2023-12-13 05:29:08 +0300
commite5d00aaac651a69b8016d355123438387bfd37be (patch)
tree1ce836b4c94b0826e4921d4c1b2a36e84efac69a /tools/testing/selftests/powerpc/math/fpu_asm.S
parent9dbd5927408c4a0707de73ae9dd9306b184e8fee (diff)
downloadlinux-e5d00aaac651a69b8016d355123438387bfd37be.tar.xz
selftests/powerpc: Check all FPRs in fpu_preempt
There's a selftest that checks FPRs aren't corrupted by preemption, or just process scheduling. However it only checks the non-volatile FPRs, meaning corruption of the volatile FPRs could go undetected. The check_fpu function it calls is used by several other tests, so for now add a new routine to check all the FPRs. Increase the size of the array of FPRs to 32, and initialise them all with random values. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231128132748.1990179-2-mpe@ellerman.id.au
Diffstat (limited to 'tools/testing/selftests/powerpc/math/fpu_asm.S')
-rw-r--r--tools/testing/selftests/powerpc/math/fpu_asm.S41
1 files changed, 37 insertions, 4 deletions
diff --git a/tools/testing/selftests/powerpc/math/fpu_asm.S b/tools/testing/selftests/powerpc/math/fpu_asm.S
index 9dc0c158f871..051392ad3ce7 100644
--- a/tools/testing/selftests/powerpc/math/fpu_asm.S
+++ b/tools/testing/selftests/powerpc/math/fpu_asm.S
@@ -66,6 +66,40 @@ FUNC_START(check_fpu)
li r3,0 # Success!!!
1: blr
+
+// int check_all_fprs(double darray[32])
+FUNC_START(check_all_fprs)
+ PUSH_BASIC_STACK(8)
+ mr r4, r3 // r4 = darray
+ li r3, 1 // prepare for failure
+
+ stfd f31, STACK_FRAME_LOCAL(0, 0)(sp) // backup f31
+
+ // Check regs f0-f30, using f31 as scratch
+ .set i, 0
+ .rept 31
+ lfd f31, (8 * i)(r4) // load expected value
+ fcmpu cr0, i, f31 // compare
+ bne cr0, 1f // bail if mismatch
+ .set i, i + 1
+ .endr
+
+ lfd f31, STACK_FRAME_LOCAL(0, 0)(sp) // reload f31
+ stfd f30, STACK_FRAME_LOCAL(0, 0)(sp) // backup f30
+
+ lfd f30, (8 * 31)(r4) // load expected value of f31
+ fcmpu cr0, f30, f31 // compare
+ bne cr0, 1f // bail if mismatch
+
+ lfd f30, STACK_FRAME_LOCAL(0, 0)(sp) // reload f30
+
+ // Success
+ li r3, 0
+
+1: POP_BASIC_STACK(8)
+ blr
+FUNC_END(check_all_fprs)
+
FUNC_START(test_fpu)
# r3 holds pointer to where to put the result of fork
# r4 holds pointer to the pid
@@ -104,8 +138,8 @@ FUNC_START(preempt_fpu)
std r4,STACK_FRAME_PARAM(1)(sp) # int *threads_starting
std r5,STACK_FRAME_PARAM(2)(sp) # int *running
- bl load_fpu
- nop
+ // Load FPRs with expected values
+ OP_REGS lfd, 8, 0, 31, r3
sync
# Atomic DEC
@@ -116,8 +150,7 @@ FUNC_START(preempt_fpu)
bne- 1b
2: ld r3,STACK_FRAME_PARAM(0)(sp)
- bl check_fpu
- nop
+ bl check_all_fprs
cmpdi r3,0
bne 3f
ld r4,STACK_FRAME_PARAM(2)(sp)