From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Eric Van Hensbergen <ericvh@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
bg-linux@lists.anl-external.org
Subject: Re: [PATCH 6/7] [RFC] enable early TLBs for BG/P
Date: Fri, 20 May 2011 10:39:01 +1000 [thread overview]
Message-ID: <1305851941.7481.92.camel@pasglop> (raw)
In-Reply-To: <1305753895-24845-6-git-send-email-ericvh@gmail.com>
On Wed, 2011-05-18 at 16:24 -0500, Eric Van Hensbergen wrote:
> BG/P maps firmware with an early TLB
That's a bit gross. How often do you call that firmware in practice ?
Aren't you better off instead inserting a TLB entry for it when you call
it instead ? A simple tlbsx. + tlbwe sequence would do. That would free
up a TLB entry for normal use.
Cheers,
Ben.
> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
> ---
> arch/powerpc/include/asm/mmu-44x.h | 6 +++++-
> 1 files changed, 5 insertions(+), 1 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/mmu-44x.h b/arch/powerpc/include/asm/mmu-44x.h
> index ca1b90c..2807d6e 100644
> --- a/arch/powerpc/include/asm/mmu-44x.h
> +++ b/arch/powerpc/include/asm/mmu-44x.h
> @@ -115,8 +115,12 @@ typedef struct {
> #endif /* !__ASSEMBLY__ */
>
> #ifndef CONFIG_PPC_EARLY_DEBUG_44x
> +#ifndef CONFIG_BGP
> #define PPC44x_EARLY_TLBS 1
> -#else
> +#else /* CONFIG_BGP */
> +#define PPC44x_EARLY_TLBS 2
> +#endif /* CONFIG_BGP */
> +#else /* CONFIG_PPC_EARLY_DEBUG_44x */
> #define PPC44x_EARLY_TLBS 2
> #define PPC44x_EARLY_DEBUG_VIRTADDR (ASM_CONST(0xf0000000) \
> | (ASM_CONST(CONFIG_PPC_EARLY_DEBUG_44x_PHYSLOW) & 0xffff))
next prev parent reply other threads:[~2011-05-20 0:39 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-18 21:24 [PATCH 1/7] [RFC] Mainline BG/P platform support Eric Van Hensbergen
2011-05-18 21:24 ` [PATCH 2/7] [RFC] add bluegene entry to cputable Eric Van Hensbergen
2011-05-20 0:35 ` Benjamin Herrenschmidt
2011-05-20 1:08 ` Eric Van Hensbergen
2011-05-20 1:50 ` Benjamin Herrenschmidt
2011-05-18 21:24 ` [PATCH 3/7] [RFC] add support for BlueGene/P FPU Eric Van Hensbergen
2011-05-19 5:58 ` Michael Neuling
2011-05-19 13:53 ` Eric Van Hensbergen
2011-05-19 15:22 ` [bg-linux] " Kazutomo Yoshii
2011-05-19 21:36 ` Michael Neuling
2011-05-19 21:55 ` Eric Van Hensbergen
2011-05-19 23:16 ` Michael Neuling
2011-05-20 0:30 ` Eric Van Hensbergen
2011-05-20 0:43 ` Michael Neuling
2011-05-20 0:53 ` Benjamin Herrenschmidt
2011-05-20 0:52 ` Benjamin Herrenschmidt
2011-05-19 21:41 ` [PATCH 3/7] [RFC][V2] add support for BlueGene/P Double FPU Eric Van Hensbergen
2011-05-18 21:24 ` [PATCH 4/7] [RFC] enable L1_WRITETHROUGH mode for BG/P Eric Van Hensbergen
2011-05-19 10:43 ` Josh Boyer
2011-05-19 12:53 ` Eric Van Hensbergen
2011-05-19 21:42 ` [PATCH 4/7] [RFC][V2] enable BGP_L1_WRITETHROUGH " Eric Van Hensbergen
2011-05-20 1:01 ` [PATCH 4/7] [RFC] enable L1_WRITETHROUGH " Benjamin Herrenschmidt
2011-05-18 21:24 ` [PATCH 5/7] [RFC] force 32-byte aligned kmallocs Eric Van Hensbergen
2011-05-20 0:36 ` Benjamin Herrenschmidt
2011-05-20 0:47 ` Eric Van Hensbergen
2011-05-20 1:50 ` Benjamin Herrenschmidt
2011-05-20 1:32 ` [bg-linux] " Kazutomo Yoshii
2011-05-20 2:08 ` Benjamin Herrenschmidt
2011-05-20 2:13 ` Benjamin Herrenschmidt
2011-05-20 3:02 ` Kazutomo Yoshii
2011-05-20 3:13 ` Benjamin Herrenschmidt
2011-05-18 21:24 ` [PATCH 6/7] [RFC] enable early TLBs for BG/P Eric Van Hensbergen
2011-05-20 0:39 ` Benjamin Herrenschmidt [this message]
2011-05-20 1:21 ` Eric Van Hensbergen
2011-05-20 1:54 ` Benjamin Herrenschmidt
2011-05-20 3:38 ` [bg-linux] " Kazutomo Yoshii
2011-05-20 3:52 ` Benjamin Herrenschmidt
2011-05-20 13:01 ` Eric Van Hensbergen
2011-05-20 22:20 ` Benjamin Herrenschmidt
2011-05-18 21:24 ` [PATCH 7/7] [RFC] SMP support code Eric Van Hensbergen
2011-05-20 1:05 ` Benjamin Herrenschmidt
2011-05-19 11:01 ` [PATCH 1/7] [RFC] Mainline BG/P platform support Josh Boyer
2011-05-19 12:35 ` Eric Van Hensbergen
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