From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 429FAC6FD18 for ; Wed, 29 Mar 2023 06:55:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229706AbjC2Gzz (ORCPT ); Wed, 29 Mar 2023 02:55:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56922 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229462AbjC2Gzw (ORCPT ); Wed, 29 Mar 2023 02:55:52 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CD018211D for ; Tue, 28 Mar 2023 23:55:51 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-54629ed836aso6038957b3.10 for ; Tue, 28 Mar 2023 23:55:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1680072951; h=content-transfer-encoding:cc:to:from:subject:message-id :mime-version:date:from:to:cc:subject:date:message-id:reply-to; bh=Yb6T5Nix/3hrpi04qTRDKmlC5J5N+Z2zQezjqCwHQSc=; b=I70iBO8V621lm+2OBg9UTLn3NwNxaOjH81/kUFD8B1L+O1fwBhekEA+10JCdKiD3tA kECwcwUJvSNC88bYchl5stnbjXXBAo59zC+OgGa1lyXqpdfSBAdKUplbtKbZ6b4sx+Io fOQ63v3lHvtOi4jdjxoivD4NQGgJEUDTIXFSDL+0qLQm7CfslCBvEOlc6kmoSJRnTYhx pEEhi7f4mATzlqPFiW1w4VEErXrG7EzcULjUI2XpAcYsYU34pW9Tn9qbtYIEjkN0lEZr djC+4bkDVcIBW8KqxkB9oMzR05gvvb+gdeHsobNc5dq91YSjLozfTnVS9sd8c8258dDQ ayIA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680072951; h=content-transfer-encoding:cc:to:from:subject:message-id :mime-version:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Yb6T5Nix/3hrpi04qTRDKmlC5J5N+Z2zQezjqCwHQSc=; b=LqdZuR+n4lt142LZVFnSf1hPzegTqDYeKL5zmWdyAWquig7mjonzv/IHyRffLdoHuf o63PUU8mwSFHkkI5OxveavCM9IWbQMUpR0sKhUHNYHp3O4M60TqXH/CRJVO+NHnZlp/D YhiSEhIc8P6gFnclZnTQot5ehlzIsfdUMcJ957gRPaU+Z0yRPJbu3Cpglu1C57FTRMle a9rDlsETJVhi2sWCuGrLua0hZl4s5qIGmJlKcWogl6NlaWbCZbl/39FdIPhQrqK1ok4D Hut9439sE94/WsY3y2hqrr/eZqkWx+/Ol6bjEPgla9/oYii8cIDHw/bYeUjyUDMjB8Kk XSrA== X-Gm-Message-State: AAQBX9feUbY7uTZIEN1l51KnleIhPMKXscrppirgdeTzej0MeHAuEYvB OhBjmGa/3WSBXx8CYBIZ4PGTtLcy/pAYRw== X-Google-Smtp-Source: AKy350bNaANkNE4LgBYqCLQFYMuy5mciHvuGb6vV8PhgtV00DdwwHufAEgSeA7hH9hghIP+DtRXhzI8HE8iwTQ== X-Received: from slicestar.c.googlers.com ([fda3:e722:ac3:cc00:4f:4b78:c0a8:20a1]) (user=davidgow job=sendgmr) by 2002:a05:6902:1003:b0:b1d:5061:98e3 with SMTP id w3-20020a056902100300b00b1d506198e3mr12429289ybt.6.1680072951072; Tue, 28 Mar 2023 23:55:51 -0700 (PDT) Date: Wed, 29 Mar 2023 14:55:32 +0800 Mime-Version: 1.0 X-Mailer: git-send-email 2.40.0.348.gf938b09366-goog Message-ID: <20230329065532.2122295-1-davidgow@google.com> Subject: [PATCH 1/2] drm: buddy_allocator: Fix buddy allocator init on 32-bit systems From: David Gow To: "=?UTF-8?q?Lu=C3=ADs=20Mendes?=" , "=?UTF-8?q?Christian=20K=C3=B6nig?=" , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , "=?UTF-8?q?Ma=C3=ADra=20Canal?=" , Arthur Grillo Cc: David Gow , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The drm buddy allocator tests were broken on 32-bit systems, as rounddown_pow_of_two() takes a long, and the buddy allocator handles 64-bit sizes even on 32-bit systems. This can be reproduced with the drm_buddy_allocator KUnit tests on i386: ./tools/testing/kunit/kunit.py run --arch i386 \ --kunitconfig ./drivers/gpu/drm/tests drm_buddy (It results in kernel BUG_ON() when too many blocks are created, due to the block size being too small.) This was independently uncovered (and fixed) by Lu=C3=ADs Mendes, whose pat= ch added a new u64 variant of rounddown_pow_of_two(). This version instead recalculates the size based on the order. Reported-by: Lu=C3=ADs Mendes Link: https://lore.kernel.org/lkml/CAEzXK1oghXAB_KpKpm=3D-CviDQbNaH0qfgYTSS= jZgvvyj4U78AA@mail.gmail.com/T/ Signed-off-by: David Gow --- drivers/gpu/drm/drm_buddy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c index 3d1f50f481cf..7098f125b54a 100644 --- a/drivers/gpu/drm/drm_buddy.c +++ b/drivers/gpu/drm/drm_buddy.c @@ -146,8 +146,8 @@ int drm_buddy_init(struct drm_buddy *mm, u64 size, u64 = chunk_size) unsigned int order; u64 root_size; =20 - root_size =3D rounddown_pow_of_two(size); - order =3D ilog2(root_size) - ilog2(chunk_size); + order =3D ilog2(size) - ilog2(chunk_size); + root_size =3D chunk_size << order; =20 root =3D drm_block_alloc(mm, NULL, order, offset); if (!root) --=20 2.40.0.348.gf938b09366-goog