All of lore.kernel.org
 help / color / mirror / Atom feed
From: david laight <david.laight@runbox.com>
To: Nikolay Borisov <nik.borisov@suse.com>
Cc: linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org,
	bp@alien8.de, Yazen.Ghannam@amd.com
Subject: Re: [PATCH v2] RAS/AMD/ATL: Remove bitwise_xor_bits
Date: Tue, 25 Nov 2025 09:35:29 +0000	[thread overview]
Message-ID: <20251125093529.109c8e1e@pumpkin> (raw)
In-Reply-To: <20251124084011.1575166-1-nik.borisov@suse.com>

On Mon, 24 Nov 2025 10:40:11 +0200
Nikolay Borisov <nik.borisov@suse.com> wrote:

> Both LLVM/GCC support a __builtin_parity function which is functionally
> equivalent to the custom bitwise_xor_bits() one. Let's simplify the code by
> relying on the built-in. No functional changes.
> 

While you've got this code out on the operating table:

- Change all the locals/parameters from u8/u16 to 'unsigned int'.
  It will generate better code.
  Using u8/u16 only makes any sense if you are trying to reduce the
  size of a structure.

- Both col_xor and row_xor are masks (for the parity code).
  So the names are wrong.
  In fact I think all the 'xor' and 'XOR' are incorrectly named.

- How often is 'xor_enable' aka 'mask_enable' set?
  If set most of the time (or the code rarely runs) then if the hardware
  register says 'don't include these values' then just set the row/col
  mask values to zero and let the rest of the code just run through.

	David

      parent reply	other threads:[~2025-11-25  9:35 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-11-24  8:40 [PATCH v2] RAS/AMD/ATL: Remove bitwise_xor_bits Nikolay Borisov
2025-11-24  8:57 ` Kuan-Wei Chiu
2025-11-24 11:05   ` Borislav Petkov
2025-11-24 12:03     ` Kuan-Wei Chiu
2025-11-24 12:52       ` Borislav Petkov
2025-11-24 13:24         ` Nikolay Borisov
2025-11-24 13:34           ` Borislav Petkov
2025-11-25  9:35 ` david laight [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20251125093529.109c8e1e@pumpkin \
    --to=david.laight@runbox.com \
    --cc=Yazen.Ghannam@amd.com \
    --cc=bp@alien8.de \
    --cc=linux-edac@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=nik.borisov@suse.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.