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Re: Add AArch64 HWCAPs from Linux 5.0
- From: Szabolcs Nagy <Szabolcs dot Nagy at arm dot com>
- To: Joseph Myers <joseph at codesourcery dot com>, "libc-alpha at sourceware dot org" <libc-alpha at sourceware dot org>
- Cc: nd <nd at arm dot com>
- Date: Tue, 19 Mar 2019 09:51:37 +0000
- Subject: Re: Add AArch64 HWCAPs from Linux 5.0
- References: <alpine.DEB.2.21.1903182130020.28623@digraph.polyomino.org.uk>
On 18/03/2019 21:30, Joseph Myers wrote:
> This patch adds new AArch64 HWCAPs from Linux 5.0 to the AArch64
> bits/hwcap.h and dl-procinfo.c.
>
> Tested (compilation only) with build-many-glibcs.py for
> aarch64-linux-gnu.
>
> 2019-03-18 Joseph Myers <joseph@codesourcery.com>
>
> * sysdeps/unix/sysv/linux/aarch64/bits/hwcap.h (HWCAP_SB): New
> macro.
> (HWCAP_PACA): Likewise.
> (HWCAP_PACG): Likewise.
> * sysdeps/unix/sysv/linux/aarch64/dl-procinfo.c (_DL_HWCAP_COUNT):
> Increase to 32.
> (_dl_aarch64_cap_flags): Add new entries for new HWCAPs.
This is OK.
thanks.
> diff --git a/sysdeps/unix/sysv/linux/aarch64/bits/hwcap.h b/sysdeps/unix/sysv/linux/aarch64/bits/hwcap.h
> index 9a395c597f..5f50623953 100644
> --- a/sysdeps/unix/sysv/linux/aarch64/bits/hwcap.h
> +++ b/sysdeps/unix/sysv/linux/aarch64/bits/hwcap.h
> @@ -51,3 +51,6 @@
> #define HWCAP_ILRCPC (1 << 26)
> #define HWCAP_FLAGM (1 << 27)
> #define HWCAP_SSBS (1 << 28)
> +#define HWCAP_SB (1 << 29)
> +#define HWCAP_PACA (1 << 30)
> +#define HWCAP_PACG (1UL << 31)
Note: we ran out of 32bit hwcaps, so further flags here
would not be compatible with ilp32 auxv.
the plan is to introduce hwcap2 and keep adding flags
there, however that will require a change in ifunc
resolver abi if we want to pass down hwcap2.
i will try to come up with a fix for that in this
release cycle.