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From: Benjamin Herrenschmidt <bh40@calva.net>
To: Naoki Takebayashi <ntakebay@bio.indiana.edu>,
	linuxppc-dev@lists.linuxppc.org
Subject: Re: Does 2.2.14 Break SMP for PPC?
Date: Thu, 6 Jan 2000 19:16:00 +0100	[thread overview]
Message-ID: <20000106191600.011735@mailhost.mipsys.com> (raw)
In-Reply-To: <Pine.SOL.4.10.10001061137170.262-100000@sunflower.bio.indiana.edu>


On Thu, Jan 6, 2000, Naoki Takebayashi <ntakebay@bio.indiana.edu> wrote:

>From patch-2.2.14:
>
>@@ -245,13 +233,16 @@
>        bl      prom_init
>        .globl  __secondary_start
> __secondary_start:
>-/*
>- * Use the first pair of BAT registers to map the 1st 16MB
>+/* Switch MMU off, clear BATs and flush TLB */
>+       bl      mmu_off
>+       bl      clear_bats
>+       bl      flush_tlbs
>+
>+/* Use the first pair of BAT registers to map the 1st 16MB
>  * of RAM to KERNELBASE.  From this point on we can't safely
>  * call OF any more.
>  */
>        lis     r11,KERNELBASE@h
>
>Well, I don't know PPC assembly, but I commented out the three "bl ... "
>lines.  Then the 2nd CPU stack message went away and SMP was enabled.
>However it it really unstable, though.  So the problem with 2.2.14 SMP
>seems to be around here.  Probably someone who knows PPC assembly can
>help here...

I'm the one responsible for those few lines of code, I'm a bit annoyed
that it broke SMP since I don't have an SMP card to play with.

Cort, Paul, any clue about what's wrong ? I'm wondering if it's related
to the physical address returned by OF and used in mmu_off which might be
wrong for the second CPU...


** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/

      reply	other threads:[~2000-01-06 18:16 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2000-01-06 16:51 Does 2.2.14 Break SMP for PPC? Naoki Takebayashi
2000-01-06 18:16 ` Benjamin Herrenschmidt [this message]

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