From: Yongcai Huang <anson.huang@nxp.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: "linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"shawnguo@kernel.org" <shawnguo@kernel.org>,
"kernel@pengutronix.de" <kernel@pengutronix.de>,
Fabio Estevam <fabio.estevam@nxp.com>,
"robh+dt@kernel.org" <robh+dt@kernel.org>,
"mark.rutland@arm.com" <mark.rutland@arm.com>,
"linux@armlinux.org.uk" <linux@armlinux.org.uk>
Subject: RE: [PATCH 3/3] ARM: imx: add SMP support for i.MX7D
Date: Fri, 26 Aug 2016 10:28:15 +0000 [thread overview]
Message-ID: <AM3PR04MB1315EF67563EFA9F9B8450E4F5EC0@AM3PR04MB1315.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <3283479.PKRDjkX0Md@wuerfel>
Best Regards!
Anson Huang
> -----Original Message-----
> From: Arnd Bergmann [mailto:arnd@arndb.de]
> Sent: 2016-08-26 4:59 PM
> To: Yongcai Huang <anson.huang@nxp.com>
> Cc: linux-arm-kernel@lists.infradead.org; devicetree@vger.kernel.org; linux-
> kernel@vger.kernel.org; shawnguo@kernel.org; kernel@pengutronix.de;
> Fabio Estevam <fabio.estevam@nxp.com>; robh+dt@kernel.org;
> mark.rutland@arm.com; linux@armlinux.org.uk
> Subject: Re: [PATCH 3/3] ARM: imx: add SMP support for i.MX7D
>
> On Friday, August 26, 2016 7:12:51 PM CEST Anson Huang wrote:
> > i.MX7D has 2 cortex-a7 ARM core, add support for booting up SMP kernel
> > with 2 CPUs.
> >
> > The existing i.MX SMP code is designed for i.MX6 series SoCs which
> > have cortex-a9 ARM core, but i.MX7D has 2 cortex-a7 ARM core, so we
> > need to add runtime check for those differences between cortex-a9 and
> > cortex-a7.
> >
> > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> >
>
> Can't you just point i.MX7D to start from secondary_startup rather than
> v7_secondary_startup?
>
> ENTRY(v7_secondary_startup)
> + .word 0xc070 @ 0xc07 is cortex-a7 id
> + .word 0xfff0 @ mask for core type
> +
>
> This looks like you are trying to execute instructions that are actually data. Does
> this work?
>
> On a side note, could you rename v7_secondary_startup to
> imx6_secondary_startup? The name sounds overly generic on a multiplatform
> kernel.
>
> Arnd
Thanks for review, yes, I made a mistake here, the data should put in another place,
but it accidently can work and boot up secondary CPU (see below the objdump),
and also, I can just use secondary_startup for i.MX7D. So I will
leave this file untouched, will verify the function next Mon and send out a V2 patch.
10 00000004 <v7_secondary_startup>:
11 4: 0000c070 andeq ip, r0, r0, ror r0
12 8: 0000fff0 strdeq pc, [r0], -r0
Anson.
next prev parent reply other threads:[~2016-08-26 10:43 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-26 11:12 [PATCH 0/3] Add SMP support for i.MX7D Anson Huang
2016-08-26 11:12 ` [PATCH 1/3] ARM: dts: imx7: support SMP boot up Anson Huang
2016-08-26 11:12 ` [PATCH 2/3] ARM: imx: add gpcv2 support Anson Huang
2016-08-26 11:17 ` Russell King - ARM Linux
2016-08-26 12:25 ` Yongcai Huang
2016-08-26 11:12 ` [PATCH 3/3] ARM: imx: add SMP support for i.MX7D Anson Huang
2016-08-26 8:59 ` Arnd Bergmann
2016-08-26 10:28 ` Yongcai Huang [this message]
2016-08-26 11:13 ` Russell King - ARM Linux
2016-08-26 12:20 ` Yongcai Huang
2016-08-26 12:35 ` Russell King - ARM Linux
2016-08-26 13:48 ` Arnd Bergmann
2016-08-26 13:00 ` kbuild test robot
2016-08-26 12:43 ` [PATCH 0/3] Add " Fabio Estevam
2016-08-26 13:02 ` Yongcai Huang
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