Re: [PATCH 2/2] powerpc/selftests/copyloops: extend selftest to exercise __copy_tofrom_user_power7_vmx

[Venkat <venkat88@linux.ibm.com>]

> On 17 Feb 2026, at 6:14 PM, Sayali Patil <sayalip@linux.ibm.com> wrote:
> 
> The new PowerPC VMX fast path (__copy_tofrom_user_power7_vmx) is not
> exercised by existing copyloops selftests. This patch updates
> the selftest to exercise the VMX variant, ensuring the VMX copy path
> is validated.
> 
> Changes include:
>  - COPY_LOOP=test___copy_tofrom_user_power7_vmx with -D VMX_TEST is used
>    in existing selftest build targets.
>  - Inclusion of ../utils.c to provide get_auxv_entry() for hardware
>    feature detection.
>  - At runtime, the test skips execution if Altivec is not available.
>  - Copy sizes above VMX_COPY_THRESHOLD are used to ensure the VMX
>    path is taken.
> 
> This enables validation of the VMX fast path without affecting systems
> that do not support Altivec.
> 
> Signed-off-by: Sayali Patil <sayalip@linux.ibm.com>
> ---
> .../selftests/powerpc/copyloops/.gitignore        |  4 ++--
> .../testing/selftests/powerpc/copyloops/Makefile  | 11 ++++++++---
> tools/testing/selftests/powerpc/copyloops/stubs.S |  8 --------
> .../selftests/powerpc/copyloops/validate.c        | 15 ++++++++++++++-
> 4 files changed, 24 insertions(+), 14 deletions(-)
> 
> diff --git a/tools/testing/selftests/powerpc/copyloops/.gitignore b/tools/testing/selftests/powerpc/copyloops/.gitignore
> index 7283e8b07b75..80d4270a71ac 100644
> --- a/tools/testing/selftests/powerpc/copyloops/.gitignore
> +++ b/tools/testing/selftests/powerpc/copyloops/.gitignore
> @@ -2,8 +2,8 @@
> copyuser_64_t0
> copyuser_64_t1
> copyuser_64_t2
> -copyuser_p7_t0
> -copyuser_p7_t1
> +copyuser_p7
> +copyuser_p7_vmx
> memcpy_64_t0
> memcpy_64_t1
> memcpy_64_t2
> diff --git a/tools/testing/selftests/powerpc/copyloops/Makefile b/tools/testing/selftests/powerpc/copyloops/Makefile
> index 42940f92d832..0c8efb0bddeb 100644
> --- a/tools/testing/selftests/powerpc/copyloops/Makefile
> +++ b/tools/testing/selftests/powerpc/copyloops/Makefile
> @@ -1,6 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0
> TEST_GEN_PROGS := copyuser_64_t0 copyuser_64_t1 copyuser_64_t2 \
> - copyuser_p7_t0 copyuser_p7_t1 \
> + copyuser_p7 copyuser_p7_vmx \
> memcpy_64_t0 memcpy_64_t1 memcpy_64_t2 \
> memcpy_p7_t0 memcpy_p7_t1 copy_mc_64 \
> copyuser_64_exc_t0 copyuser_64_exc_t1 copyuser_64_exc_t2 \
> @@ -28,10 +28,15 @@ $(OUTPUT)/copyuser_64_t%: copyuser_64.S $(EXTRA_SOURCES)
> -D SELFTEST_CASE=$(subst copyuser_64_t,,$(notdir $@)) \
> -o $@ $^
> 
> -$(OUTPUT)/copyuser_p7_t%: copyuser_power7.S $(EXTRA_SOURCES)
> +$(OUTPUT)/copyuser_p7: copyuser_power7.S $(EXTRA_SOURCES)
> $(CC) $(CPPFLAGS) $(CFLAGS) \
> -D COPY_LOOP=test___copy_tofrom_user_power7 \
> - -D SELFTEST_CASE=$(subst copyuser_p7_t,,$(notdir $@)) \
> + -o $@ $^
> +
> +$(OUTPUT)/copyuser_p7_vmx:       copyuser_power7.S $(EXTRA_SOURCES) ../utils.c
> + $(CC) $(CPPFLAGS) $(CFLAGS) \
> + -D COPY_LOOP=test___copy_tofrom_user_power7_vmx \
> + -D VMX_TEST \
> -o $@ $^
> 
> # Strictly speaking, we only need the memcpy_64 test cases for big-endian
> diff --git a/tools/testing/selftests/powerpc/copyloops/stubs.S b/tools/testing/selftests/powerpc/copyloops/stubs.S
> index ec8bcf2bf1c2..3a9cb8c9a3ee 100644
> --- a/tools/testing/selftests/powerpc/copyloops/stubs.S
> +++ b/tools/testing/selftests/powerpc/copyloops/stubs.S
> @@ -1,13 +1,5 @@
> #include <asm/ppc_asm.h>
> 
> -FUNC_START(enter_vmx_usercopy)
> - li r3,1
> - blr
> -
> -FUNC_START(exit_vmx_usercopy)
> - li r3,0
> - blr
> -
> FUNC_START(enter_vmx_ops)
> li r3,1
> blr
> diff --git a/tools/testing/selftests/powerpc/copyloops/validate.c b/tools/testing/selftests/powerpc/copyloops/validate.c
> index 0f6873618552..fb822534fbe9 100644
> --- a/tools/testing/selftests/powerpc/copyloops/validate.c
> +++ b/tools/testing/selftests/powerpc/copyloops/validate.c
> @@ -12,6 +12,10 @@
> #define BUFLEN (MAX_LEN+MAX_OFFSET+2*MIN_REDZONE)
> #define POISON 0xa5
> 
> +#ifdef VMX_TEST
> +#define VMX_COPY_THRESHOLD 3328
> +#endif
> +
> unsigned long COPY_LOOP(void *to, const void *from, unsigned long size);
> 
> static void do_one(char *src, char *dst, unsigned long src_off,
> @@ -81,8 +85,12 @@ int test_copy_loop(void)
> /* Fill with sequential bytes */
> for (i = 0; i < BUFLEN; i++)
> fill[i] = i & 0xff;
> -
> +#ifdef VMX_TEST
> + /* Force sizes above kernel VMX threshold (3328) */
> + for (len = VMX_COPY_THRESHOLD + 1; len < MAX_LEN; len++) {
> +#else
> for (len = 1; len < MAX_LEN; len++) {
> +#endif
> for (src_off = 0; src_off < MAX_OFFSET; src_off++) {
> for (dst_off = 0; dst_off < MAX_OFFSET; dst_off++) {
> do_one(src, dst, src_off, dst_off, len,
> @@ -96,5 +104,10 @@ int test_copy_loop(void)
> 
> int main(void)
> {
> +#ifdef VMX_TEST
> + /* Skip if Altivec not present */
> + SKIP_IF_MSG(!have_hwcap(PPC_FEATURE_HAS_ALTIVEC), "ALTIVEC not supported");
> +#endif
> +
> return test_harness(test_copy_loop, str(COPY_LOOP));
> }
> -- 
> 2.52.0
> 
> 

Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>

# timeout set to 130
# selftests: powerpc/copyloops: copyuser_64_t2
# test: test___copy_tofrom_user_base
# tags: git_version:v6.19-2410-g27ede8cb60bb
# success: test___copy_tofrom_user_base
ok 3 selftests: powerpc/copyloops: copyuser_64_t2
# timeout set to 130
# selftests: powerpc/copyloops: copyuser_p7
# test: test___copy_tofrom_user_power7
# tags: git_version:v6.19-2410-g27ede8cb60bb
# success: test___copy_tofrom_user_power7
ok 4 selftests: powerpc/copyloops: copyuser_p7
# timeout set to 130
# selftests: powerpc/copyloops: copyuser_p7_vmx
# test: test___copy_tofrom_user_power7_vmx
# tags: git_version:v6.19-2410-g27ede8cb60bb
# success: test___copy_tofrom_user_power7_vmx
ok 5 selftests: powerpc/copyloops: copyuser_p7_vmx

Regards,
Venkat.