Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754606AbbEUJMT (ORCPT ); Thu, 21 May 2015 05:12:19 -0400 Received: from mailapp01.imgtec.com ([195.59.15.196]:33031 "EHLO imgpgp01.kl.imgtec.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754009AbbEUJMM (ORCPT ); Thu, 21 May 2015 05:12:12 -0400 X-PGP-Universal: processed; by imgpgp01.kl.imgtec.org on Thu, 21 May 2015 10:12:10 +0100 Date: Thu, 21 May 2015 10:12:04 +0100 From: Paul Burton To: Leonid Yegoshin CC: , , , , , , , , , , , , Subject: Re: [PATCH 1/2] MIPS: MSA: bugfix - disable MSA during thread switch correctly Message-ID: <20150521090741.GG13811@NP-P-BURTON> References: <20150519211222.35859.52798.stgit@ubuntu-yegoshin> <20150519211351.35859.80332.stgit@ubuntu-yegoshin> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="8GpibOaaTibBMecb" Content-Disposition: inline In-Reply-To: <20150519211351.35859.80332.stgit@ubuntu-yegoshin> User-Agent: Mutt/1.5.23 (2014-03-12) X-Originating-IP: [192.168.159.137] X-ESG-ENCRYPT-TAG: b93fcccb Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3398 Lines: 95 --8GpibOaaTibBMecb Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, May 19, 2015 at 02:13:51PM -0700, Leonid Yegoshin wrote: > During thread cloning the new (child) thread should have MSA disabled even > at first thread entry. So, the code to disable MSA is moved from macro > 'switch_to' to assembler function 'resume' before it switches kernel stack > to 'next' (new) thread. Call of 'disable_msa' after 'resume' in 'switch_t= o' > macro never called a first time entry into thread. Hi Leonid, I'm not sure I understand what you're trying to say here. Do you have an example of a program that demonstrates the behaviour you believe to be broken? Thanks, Paul > Signed-off-by: Leonid Yegoshin > --- > arch/mips/include/asm/switch_to.h | 1 - > arch/mips/kernel/r4k_switch.S | 6 ++++++ > 2 files changed, 6 insertions(+), 1 deletion(-) >=20 > diff --git a/arch/mips/include/asm/switch_to.h b/arch/mips/include/asm/sw= itch_to.h > index e92d6c4b5ed1..0d0f7f8f8b3a 100644 > --- a/arch/mips/include/asm/switch_to.h > +++ b/arch/mips/include/asm/switch_to.h > @@ -104,7 +104,6 @@ do { \ > if (test_and_clear_tsk_thread_flag(prev, TIF_USEDMSA)) \ > __fpsave =3D FP_SAVE_VECTOR; \ > (last) =3D resume(prev, next, task_thread_info(next), __fpsave); \ > - disable_msa(); \ > } while (0) > =20 > #define finish_arch_switch(prev) \ > diff --git a/arch/mips/kernel/r4k_switch.S b/arch/mips/kernel/r4k_switch.S > index 04cbbde3521b..7dbb64656bfe 100644 > --- a/arch/mips/kernel/r4k_switch.S > +++ b/arch/mips/kernel/r4k_switch.S > @@ -25,6 +25,7 @@ > /* preprocessor replaces the fp in ".set fp=3D64" with $30 otherwise */ > #undef fp > =20 > +#define t4 $12 > /* > * Offset to the current process status flags, the first 32 bytes of the > * stack are not used. > @@ -73,6 +74,11 @@ > cfc1 t1, fcr31 > msa_save_all a0 > .set pop /* SET_HARDFLOAT */ > + li t4, MIPS_CONF5_MSAEN > + mfc0 t3, CP0_CONFIG, 5 > + or t3, t3, t4 > + xor t3, t3, t4 > + mtc0 t3, CP0_CONFIG, 5 > =20 > sw t1, THREAD_FCR31(a0) > b 2f >=20 --8GpibOaaTibBMecb Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJVXaFjAAoJENzvn0paErs54s0QALkfjnLE9AcoHbf3nPdg1XKK /oDZNKa8lydX6NlX+m1rLChcM9qvMp+fhDgZTvyWV0rrg4gBWxww9S79JvGtqB/E 9cdXu7cER7GQGnxd/u12tedgf1R2OgL1c/IdbVIndcdSDGNpS4qAuHTGUS1YaRU9 lU7Vai9pZAmmno3Lcb9Dx4dheoaw9pgTyIwEiUkaNHGMY+HKgLJGo8CojlhfzJj1 hgun3BEhu13TTVQboyHPvKqGjI7PZFTFkuLNUeudm7k0iC77YcVgg3HV73c8g/ks ygF/SiG2vqlapJl/n4cmSMZnc8/FMVrd5EriNPjzhxo9Xl3ScuRI87oKuTZReCdK J2s8c0ryRPjiNUWExNtKe2NhUxKRSJ1HJfpd9jheotd4z/QRUObxpLW2vJxVirMc uteKW2lGTUnLbfzChlEVhIVt5mHXiiHFOdm//TSoGP7WDhARt/OQuAkvI84yPwk7 TQ8hb6/AMOzK38nd1e8S1ebWrNvpEKU7omgZS+18Z+zrfr9oshMrkHg/CzPgaXke PrVp8Gt2FskzAZCntF2n2agE83BudiJXT/Q6b+xa4xye7Wm01Z/Kw9tI/lKp2VIl QzilzI83Ey7twp/u3bwM6p14/kwOlOsGiroUXxE2JoUeciq0MNzlhE1oU7AQVHIy CsEhemWDG1dHlxV8qwCg =yGJG -----END PGP SIGNATURE----- --8GpibOaaTibBMecb-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/