Re: powerpc64: filling in a few more HWCAP flags

On Sun, 3 May 2026 09:42:33 -0400
Brad Smith <[email protected]> wrote:

> PPC_FEATURE2_ARCH_2_07
> 
> Noticed in FFmpeg for Power8 VSX code within libswscale and devel/orc
> and probably others.
> 
> PPC_FEATURE2_HAS_VEC_CRYPTO
> 
> OpenSSL, NSS, Nettle, and Botan

Thanks for looking for these flags.  I had a diff to add some flags,
but didn't commit it, because I forgot to finish checking it.

Some ports would do faster AES and SHA-2 if elf_aux_info(3) AT_HWCAP2
had the crypto flag.  Some ports will need a patch to start calling
elf_aux_info, but at least security/libgcrypt already calls it.  The
flag has 2 names,
  PPC_FEATURE2_HAS_VEC_CRYPTO
  PPC_FEATURE2_VEC_CRYPTO      /* no HAS_ */
Ports like the 2nd name, so my diff adds it.  (If we don't add it,
most ports will #ifndef it then #define it.)

https://www.kernel.org/doc/html/next/arch/powerpc/elf_hwcaps.html says
to set 2.06 but not 2.05.  My diff sets 2.06, 2.07, isel and crypto
for both POWER8 and POWER9.  I saw PPC_FEATURE2_ISEL in qemu.  An
example of isel in C is
  /* r = c < d ? a : b; */
  __asm ("cmpw %3, %4; isellt %0, %1, %2":
      "=r"(r): "r"(a), "r"(b), "r"(c), "r"(d): "cr0");

--gkoehler

Index: arch/powerpc/include/elf.h
===================================================================
RCS file: /cvs/src/sys/arch/powerpc/include/elf.h,v
diff -u -p -r1.3 elf.h
--- arch/powerpc/include/elf.h	19 Feb 2025 18:25:03 -0000	1.3
+++ arch/powerpc/include/elf.h	13 Jul 2026 00:32:09 -0000
@@ -54,6 +54,7 @@ extern unsigned long hwcap2;
 #define	PPC_FEATURE2_ISEL	0x08000000
 #define	PPC_FEATURE2_TAR	0x04000000
 #define	PPC_FEATURE2_HAS_VEC_CRYPTO	0x02000000
+#define	PPC_FEATURE2_VEC_CRYPTO	0x02000000
 #define	PPC_FEATURE2_HTM_NOSC	0x01000000
 #define	PPC_FEATURE2_ARCH_3_00	0x00800000
 #define	PPC_FEATURE2_HAS_IEEE128	0x00400000
Index: arch/powerpc64/include/elf.h
===================================================================
RCS file: /cvs/src/sys/arch/powerpc64/include/elf.h,v
diff -u -p -r1.3 elf.h
--- arch/powerpc64/include/elf.h	19 Feb 2025 18:25:03 -0000	1.3
+++ arch/powerpc64/include/elf.h	13 Jul 2026 00:32:09 -0000
@@ -54,6 +54,7 @@ extern unsigned long hwcap2;
 #define	PPC_FEATURE2_ISEL	0x08000000
 #define	PPC_FEATURE2_TAR	0x04000000
 #define	PPC_FEATURE2_HAS_VEC_CRYPTO	0x02000000
+#define	PPC_FEATURE2_VEC_CRYPTO	0x02000000
 #define	PPC_FEATURE2_HTM_NOSC	0x01000000
 #define	PPC_FEATURE2_ARCH_3_00	0x00800000
 #define	PPC_FEATURE2_HAS_IEEE128	0x00400000
Index: arch/powerpc64/powerpc64/cpu.c
===================================================================
RCS file: /cvs/src/sys/arch/powerpc64/powerpc64/cpu.c,v
diff -u -p -r1.30 cpu.c
--- arch/powerpc64/powerpc64/cpu.c	28 Nov 2024 18:54:36 -0000	1.30
+++ arch/powerpc64/powerpc64/cpu.c	13 Jul 2026 00:32:09 -0000
@@ -224,9 +224,11 @@ cpu_init_features(void)
 {
 	uint32_t pvr = mfpvr();
 
-	hwcap = PPC_FEATURE_32 | PPC_FEATURE_64 | PPC_FEATURE_HAS_FPU |
-	    PPC_FEATURE_HAS_MMU | PPC_FEATURE_HAS_ALTIVEC |
-	    PPC_FEATURE_HAS_VSX;
+	hwcap = PPC_FEATURE_32 | PPC_FEATURE_64 | PPC_FEATURE_HAS_ALTIVEC |
+	    PPC_FEATURE_HAS_FPU | PPC_FEATURE_HAS_MMU |
+	    PPC_FEATURE_ARCH_2_06 | PPC_FEATURE_HAS_VSX;
+	hwcap2 = PPC_FEATURE2_ARCH_2_07 | PPC_FEATURE2_ISEL |
+	    PPC_FEATURE2_VEC_CRYPTO;
 
 	switch (CPU_VERSION(pvr)) {
 	case CPU_IBMPOWER9: