From: Balbir Singh <bsingharora@gmail.com>
To: Michael Ellerman <mpe@ellerman.id.au>
Cc: <linuxppc-dev@ozlabs.org>,
alistair@popple.id.au, aneesh.kumar@linux.vnet.ibm.com
Subject: Re: [PATCH 2/2] powerpc: Fix crash at boot with CONFIG_PPC_RADIX_MMU=n
Date: Thu, 12 May 2016 11:32:36 +1000 [thread overview]
Message-ID: <20160512113236.58c0783d@cotter.ozlabs.ibm.com> (raw)
In-Reply-To: <1462949231-28355-2-git-send-email-mpe@ellerman.id.au>
On Wed, 11 May 2016 16:47:11 +1000
Michael Ellerman <mpe@ellerman.id.au> wrote:
> Currently a kernel that is built with CONFIG_PPC_RADIX_MMU=n, and then
> booted on a 64-bit Hash MMU system will crash on the first SLB miss,
> typically with an oops something like:
>
> Unrecoverable exception 4100 at c000000000969504
> cpu 0x0: Vector: 4100 at [c000000000de78e0]
> pc: c000000000969504: memmap_init_zone+0x160/0x2dc
> lr: c0000000009694b0: memmap_init_zone+0x10c/0x2dc
> ...
> [c000000000de7b60] c000000000968ec8 init_currently_empty_zone+0x3c/0x11c (unreliable)
> [c000000000de7bf0] c000000000969bc0 free_area_init_node+0x540/0x688
> [c000000000de7cf0] c000000000c4b3b4 free_area_init_nodes+0x7b4/0x864
> [c000000000de7df0] c000000000c2fce0 paging_init+0x88/0xa4
> [c000000000de7e60] c000000000c2b49c setup_arch+0x29c/0x2ec
> [c000000000de7f00] c000000000c23b7c start_kernel+0x88/0x524
> [c000000000de7f90] c000000000008c60 start_here_common+0x20/0xa0
>
> This is caused by the branch in slb_miss_realmode() that jumps directly
> to the unrecoverable case when MMU_FTR_RADIX is set:
>
> BEGIN_MMU_FTR_SECTION
> b 2f
> END_MMU_FTR_SECTION_IFSET(MMU_FTR_RADIX)
>
This makes sense and its a good way to avoid plenty of #ifdefs around code
Acked-by: Balbir Singh <bsingharora@gmail.com>
Balbir Singh
next prev parent reply other threads:[~2016-05-12 1:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-11 6:47 [PATCH 1/2] powerpc: Add mask of possible MMU features Michael Ellerman
2016-05-11 6:47 ` [PATCH 2/2] powerpc: Fix crash at boot with CONFIG_PPC_RADIX_MMU=n Michael Ellerman
2016-05-12 1:32 ` Balbir Singh [this message]
2016-05-12 2:29 ` Aneesh Kumar K.V
2016-05-12 2:28 ` [PATCH 1/2] powerpc: Add mask of possible MMU features Aneesh Kumar K.V
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160512113236.58c0783d@cotter.ozlabs.ibm.com \
--to=bsingharora@gmail.com \
--cc=alistair@popple.id.au \
--cc=aneesh.kumar@linux.vnet.ibm.com \
--cc=linuxppc-dev@ozlabs.org \
--cc=mpe@ellerman.id.au \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.