From:   Vladimir Oltean <vladimir.oltean@nxp.com>
To:     Michael Ellerman <mpe@ellerman.id.au>,
        "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>
CC:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "stable@vger.kernel.org" <stable@vger.kernel.org>
Subject: Re: [PATCH] powerpc/mm: fix early initialization failure for MMUs
 with no hash table
Thread-Topic: [PATCH] powerpc/mm: fix early initialization failure for MMUs
 with no hash table
Thread-Index: AQHX4zMyTd6jC6dzkE216Yt21RNlsqwXhikA
Date:   Sat, 27 Nov 2021 15:48:55 +0000
Message-ID: <20211127154854.lnu3blrsjm6wfkni@skbuf>
References: <20211127020448.4008507-1-vladimir.oltean@nxp.com>
In-Reply-To: <20211127020448.4008507-1-vladimir.oltean@nxp.com>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?WqIjr1W+jvS/G8RQgjsWWzjVN6oF7Wzok0nZjj/1v8O7ClSx7hQIMWYUs1NX?=
 =?us-ascii?Q?V02S7yNmm4/GbbISJRq3kuk4wkSUzT9RZW8FDILdSvwee4amnp9dkjkNwMBv?=
 =?us-ascii?Q?yMAwooJkEVxke8jPNvgUUd/AFX9AxRJBCAsEV75ojizr1a10If+j/TEmGh1F?=
 =?us-ascii?Q?QZQY+s3xtyDDbCvacRZodN2U/aAVwE32+24fD4OJpD8hXDI8QqrriL4+GBn7?=
 =?us-ascii?Q?XKC1q2fS4wUCZXboStrdh7d+lo82VWi9i5+gd7gafwoXxjuuomkPqWhlSbCH?=
 =?us-ascii?Q?B3RLc7YRYydd6g8eObwIhY/iTOZtKjNS0L8XhMhx7biGf7VDxeSCkVT/x7OQ?=
 =?us-ascii?Q?3LvzUMGf+JC2b4OFwkq7WYnuqkyJv8C7OtC9Jj/KJz9zaIJGOGUUIdDfTHEQ?=
 =?us-ascii?Q?QDL/GPB1UNJKHb3UVoj8+Y2LqFRZ3DZZTbQeXO2d2XBr2wOVJneEcBhDqEY3?=
 =?us-ascii?Q?PW+0KvzYbuDsPEeVSJm/m1AzewQNUVG0Wgki3yrqk0lfVNDQyySyscC/kzyH?=
 =?us-ascii?Q?7vRjMgWLNdbKSGRV6lkVy3nEKsSQDeNqp97uys82fyS3c7M6GKY6agl9NGOA?=
 =?us-ascii?Q?tt8XJvfggzZag9eMhVJ6jRb0L4Rt5EjH+ppLnbdGFJHz4lmQUmkgClvOAazC?=
 =?us-ascii?Q?LNOwqprI8nwn8qr6e4TMNL22zLvI9lxzqTwIbq4h1PMkQ2Z5sxZOjeb6kPFZ?=
 =?us-ascii?Q?NSi1tYayYLYZS0lAhedGgDwerJQwgvEvRUp1+efe6l7/XhPeOMKBu0SZfEPS?=
 =?us-ascii?Q?YonOccoApQ3wM+vQ/CcJtesQyWh7qZVIwbMrJnVZDAxu2O8aALM/DP1N5fEj?=
 =?us-ascii?Q?GUDU9FBIvFm908l/iRS6uWgs+aVAvQcteDS70O0RVITbDtFkvVoJfJTN1Ea0?=
 =?us-ascii?Q?d+Zw9fAldDh7NuDTKNMtI+D5Ww+ywAhew5hB3RwkQXhxK2yK9o35VMu6/k4N?=
 =?us-ascii?Q?1Rp3dw0mecUALql7eiA8j3exqatrMmvSG2Y+bZEDt6vb4CC+YzG9GB+FwnGN?=
 =?us-ascii?Q?QwGQXsnj2wx1uuUALaxKn3GEHQvtcuwahZqs8Q9mfnD0JZBuoNpfVQQTz5xw?=
 =?us-ascii?Q?JRKLrtAuHgqEfPavUO7gSxGh1oN0w/N2Na768ZCD8JlvSxXhinle/NFR6Q1M?=
 =?us-ascii?Q?Y09IhT60XQ8uiPVukakGQrxt4DECm5ANN25z5GL178k19k8y+RnSb496vSpO?=
 =?us-ascii?Q?Dps9L2WoLptjlom+2mvUo3NOTO20sDBmSjzkggSUHPXy4mnY0MtkxKLZFDbX?=
 =?us-ascii?Q?PGZw2P07my/CSvvtDnHIHSS99gxd0mh9CG8ddgPIw48houajB7NOnAz1Gp1W?=
 =?us-ascii?Q?7rboRfSEbCkm7/GTcepE2sKqoFjAxJxgWfoMK6fSaX2RfLl4RrPaw+2zA2up?=
 =?us-ascii?Q?faBaB3x2aiNGRhZeRB0bWeSUwnZGngedAq0ENQzSlyWb6f6KdLyH+uXA93Ys?=
 =?us-ascii?Q?+BgSBZPOeIbT5nMlNgI8rIrW+FRrG31DiYZHUnjqw8aCOY1TynWx7CllRT9L?=
 =?us-ascii?Q?CDkQPsYqVGNkhJpWNyj7eHR6l6sNk/6C9Kcz9Nxk/CScjlDj717zpJNxDtkd?=
 =?us-ascii?Q?/IPx2XskLOoZBc4NoxkM6UzIsHVSEFjGszsWu8M2PoSXfLEa/t2REMoIzPvJ?=
 =?us-ascii?Q?5QpaVHvC43pyIEwEAEf3VlI=3D?=
Content-Type: text/plain; charset="us-ascii"
Content-ID: <69EB1757AD0D804CA152119CAE4E3861@eurprd04.prod.outlook.com>
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-OriginatorOrg: nxp.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: VI1PR04MB5136.eurprd04.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 96fecbbc-6409-408a-66e5-08d9b1bd6b63
X-MS-Exchange-CrossTenant-originalarrivaltime: 27 Nov 2021 15:48:55.7318
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: ph/124n/+dRsIV6UU4nlD/bU3dFebkA/WlxSp5cba19mVRS+wi067WEPBbip/6FUqGRXzzzVHak2CYFqRAYfEA==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR04MB5296
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Sat, Nov 27, 2021 at 04:04:48AM +0200, Vladimir Oltean wrote:
> The blamed patch attempted to do a trivial conversion of
> map_mem_in_cams() by adding an extra "bool init" argument, but by
> mistake, changed the way in which two call sites pass the other boolean
> argument, "bool dry_run".
>=20
> As a result, early_init_this_mmu() now calls map_mem_in_cams() with
> dry_run=3Dtrue, and setup_initial_memory_limit() calls with dry_run=3Dfal=
se,
> both of which are unintended changes.
>=20
> This makes the kernel boot process hang here:
>=20
> [    0.045211] e500 family performance monitor hardware support registere=
d
> [    0.051891] rcu: Hierarchical SRCU implementation.
> [    0.057791] smp: Bringing up secondary CPUs ...
>=20
> Issue noticed on a Freescale T1040.
>=20
> Fixes: 52bda69ae8b5 ("powerpc/fsl_booke: Tell map_mem_in_cams() if init i=
s done")
> Cc: stable@vger.kernel.org
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> ---
>  arch/powerpc/mm/nohash/tlb.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>=20
> diff --git a/arch/powerpc/mm/nohash/tlb.c b/arch/powerpc/mm/nohash/tlb.c
> index 89353d4f5604..647bf454a0fa 100644
> --- a/arch/powerpc/mm/nohash/tlb.c
> +++ b/arch/powerpc/mm/nohash/tlb.c
> @@ -645,7 +645,7 @@ static void early_init_this_mmu(void)
> =20
>  		if (map)
>  			linear_map_top =3D map_mem_in_cams(linear_map_top,
> -							 num_cams, true, true);
> +							 num_cams, false, true);
>  	}
>  #endif
> =20
> @@ -766,7 +766,7 @@ void setup_initial_memory_limit(phys_addr_t first_mem=
block_base,
>  		num_cams =3D (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
> =20
>  		linear_sz =3D map_mem_in_cams(first_memblock_size, num_cams,
> -					    false, true);
> +					    true, true);
> =20
>  		ppc64_rma_size =3D min_t(u64, linear_sz, 0x40000000);
>  	} else
> --=20
> 2.25.1
>

This is a duplicate of commit 5b54860943dc ("powerpc/book3e: Fix TLBCAM pre=
set at boot"),
looks like I'm late to the party. That commit unbricks my board, so
please drop this patch.=