From 3281366a8e79a512956382885091565db1036b64 Mon Sep 17 00:00:00 2001 From: Peter Bergner Date: Wed, 14 Feb 2024 16:34:06 -0600 Subject: [PATCH] uapi/auxvec: Define AT_HWCAP3 and AT_HWCAP4 aux vector, entries The powerpc toolchain keeps a copy of the HWCAP bit masks in the TCB for fast access by the __builtin_cpu_supports() built-in function. The TCB space for the HWCAP entries - which are created in pairs - is an ABI extension, so waiting to create the space for HWCAP3 and HWCAP4 until they are needed is problematic. Define AT_HWCAP3 and AT_HWCAP4 in the generic uapi header so they can be used in glibc to reserve space in the powerpc TCB for their future use. I scanned through the Linux and GLIBC source codes looking for unused AT_* values and 29 and 30 did not seem to be used, so they are what I went with. Signed-off-by: Peter Bergner Acked-by: Adhemerval Zanella Acked-by: Nicholas Piggin Acked-by: Szabolcs Nagy Acked-by: Arnd Bergmann Signed-off-by: Michael Ellerman Link: https://msgid.link/a406b535-dc55-4856-8ae9-5a063644a1af@linux.ibm.com --- include/uapi/linux/auxvec.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/uapi/linux/auxvec.h b/include/uapi/linux/auxvec.h index 6991c4b8ab18..cc61cb9b3e9a 100644 --- a/include/uapi/linux/auxvec.h +++ b/include/uapi/linux/auxvec.h @@ -32,6 +32,8 @@ #define AT_HWCAP2 26 /* extension of AT_HWCAP */ #define AT_RSEQ_FEATURE_SIZE 27 /* rseq supported feature size */ #define AT_RSEQ_ALIGN 28 /* rseq allocation alignment */ +#define AT_HWCAP3 29 /* extension of AT_HWCAP */ +#define AT_HWCAP4 30 /* extension of AT_HWCAP */ #define AT_EXECFN 31 /* filename of program */