Hi Jiaxun,

On Wed, Oct 23, 2019 at 11:25:51PM +0800, Jiaxun Yang wrote:

After further discussion with userland library develpoer, we addressed another two ASEs that can be used runtimely in programs.

Export them in hwcap as well to benefit userspace programs.

Signed-off-by: Jiaxun Yang jiaxun.yang@flygoat.com Cc: stable@vger.kernel.org # 4.4+

---

arch/mips/include/uapi/asm/hwcap.h | 2 ++ arch/mips/kernel/cpu-probe.c | 7 ++++++- 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/mips/include/uapi/asm/hwcap.h b/arch/mips/include/uapi/asm/hwcap.h index 1ade1daa4921..e1a9bac62149 100644 --- a/arch/mips/include/uapi/asm/hwcap.h +++ b/arch/mips/include/uapi/asm/hwcap.h @@ -17,5 +17,7 @@ #define HWCAP_LOONGSON_MMI (1 << 11) #define HWCAP_LOONGSON_EXT (1 << 12) #define HWCAP_LOONGSON_EXT2 (1 << 13) +#define HWCAP_MIPS_MICROMIPS (1 << 14) +#define HWCAP_MIPS_VZ (1 << 15)

What's the motivation for exposing VZ? Userland can't actually use it without something like KVM, which already exposes a means of detecting whether VZ is supported (try the creating a VM of type KVM_VM_MIPS_VZ & see if it works). I'm not sure what userland would be able to do with this information in AT_HWCAP.

Thanks, Paul

#endif /* _UAPI_ASM_HWCAP_H */ diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index f521cbf934e7..11e853d88aae 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -2213,8 +2213,13 @@ void cpu_probe(void) if (cpu_has_loongson_ext2) elf_hwcap |= HWCAP_LOONGSON_EXT2;

• if (cpu_has_vz)

• if (cpu_has_mmips)

• elf_hwcap |= HWCAP_MIPS_MICROMIPS;
  

• if (cpu_has_vz) {

• elf_hwcap |= HWCAP_MIPS_VZ;
  

  cpu_probe_vz(c);
• }

cpu_probe_vmbits(c); -- 2.23.0