From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 4/4] ARM: idmap: use idmap_pgd when setting up mm for reboot
Date: Fri, 18 Nov 2011 17:21:07 +0000 [thread overview]
Message-ID: <20111118172107.GC17991@mudshark.cambridge.arm.com> (raw)
In-Reply-To: <CAHkRjk4c1Q7+q9-fc+KXc3ySwnVPXbfBGJbqL2QvpHCqtNK_Tw@mail.gmail.com>
On Fri, Nov 18, 2011 at 04:56:24PM +0000, Catalin Marinas wrote:
> On 16 November 2011 16:48, Will Deacon <will.deacon@arm.com> wrote:
> > ?void setup_mm_for_reboot(char mode)
> > ?{
> > - ? ? ? /*
> > - ? ? ? ?* We need to access to user-mode page tables here. For kernel threads
> > - ? ? ? ?* we don't have any user-mode mappings so we use the context that we
> > - ? ? ? ?* "borrowed".
> > - ? ? ? ?*/
> > - ? ? ? identity_mapping_add(current->active_mm->pgd, 0, TASK_SIZE);
> > + ? ? ? /* Clean and invalidate L1. */
> > + ? ? ? flush_cache_all();
>
> Is the cache flushing needed here? The setup_mm_for_reboot callers do
> it after this function anyway (unless this is needed for VIVT
> caches?).
I initially added the cache flushing because we used to manipulate the page
tables at this point. We don't do that anymore, but as you say, if we have
a VIVT D-side then we do need that flush before switching to the new pgd.
One thing I will change is the following comment (/* Switch exclusively to kernel
mappings. */) because that's a bit confusing now.
Will
next prev parent reply other threads:[~2011-11-18 17:21 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-16 16:48 [PATCH 0/4] Consolidate identity mapping code in idmap.c Will Deacon
2011-11-16 16:48 ` [PATCH 1/4] ARM: idmap: populate identity map pgd at init time using .init.text Will Deacon
2011-11-18 12:02 ` Catalin Marinas
2011-11-18 12:08 ` Will Deacon
2011-11-16 16:48 ` [PATCH 2/4] ARM: suspend: use idmap_pgd instead of suspend_pgd Will Deacon
2011-11-18 16:43 ` Catalin Marinas
2011-11-18 17:26 ` Will Deacon
2011-11-16 16:48 ` [PATCH 3/4] ARM: proc-*.S: place cpu_reset functions into .idmap.text section Will Deacon
2011-11-16 16:48 ` [PATCH 4/4] ARM: idmap: use idmap_pgd when setting up mm for reboot Will Deacon
2011-11-18 16:56 ` Catalin Marinas
2011-11-18 17:21 ` Will Deacon [this message]
2011-11-17 13:47 ` [PATCH 0/4] Consolidate identity mapping code in idmap.c Dave Martin
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