From mboxrd@z Thu Jan 1 00:00:00 1970 From: maxime.ripard@free-electrons.com (maxime.ripard) Date: Thu, 19 Mar 2015 10:18:43 +0100 Subject: [linux-sunxi] Re: [PATCH 2/3] ARM: sun8i: Add SMP support for the Allwinner A23 In-Reply-To: <2015031912050362587032@gmail.com> References: <1426649042-30547-1-git-send-email-wens@csie.org> <1426649042-30547-3-git-send-email-wens@csie.org> <20150318102939.GP4638@lukather> <2015031912050362587032@gmail.com> Message-ID: <20150319091843.GA4255@lukather> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Kevin, On Thu, Mar 19, 2015 at 12:05:06PM +0800, kevin.z.m.zh at gmail.com wrote: > >> One question I couldn't find any answer to is that does the SMP bit is > >> set in secondary_startup? > >> > >> I couldn't find where it was set, but it still looks like the right > >> thing to do, so I would expect the code to do that. > > > > I don't see it either. The sun8i code is just the sun6i code with the > > power clamps removed. And sun6i secondary_startup was removed some time > > ago in commit 1146b600044d ("ARM: sunxi: fix build for THUMB2_KERNEL"). > > > > ChenYu > > The SMP bit should be set in the function of "__v7_ca7mp_setup", which is located > in the file: > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/arm/mm/proc-v7.S?id=refs/tags/v4.0-rc4 > I'm not sure if this is your discussion. It is, but I wasn't seeing it called anywhere in the secondary_startup code path. I was expecting a direct call, but it looks like it's a dynamic call, with a function-pointer like call, that is indeed run both in the kernel entry point and the secondary_startup. https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/arm/kernel/head.S?id=refs/tags/v4.0-rc4#n389 Thanks! Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: Digital signature URL: