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From: Chris Friesen <cfriesen@nortel.com>
To: Marcelo Tosatti <marcelo.tosatti@cyclades.com>
Cc: linuxppc64-dev@ozlabs.org, linuxppc-dev@ozlabs.org,
	Linux kernel <linux-kernel@vger.kernel.org>,
	Arjan van de Ven <arjan@infradead.org>
Subject: Re: question on symbol exports
Date: Fri, 04 Feb 2005 14:14:11 -0600	[thread overview]
Message-ID: <4203D793.1040604@nortel.com> (raw)
In-Reply-To: <20050204203050.GA5889@dmt.cnet>

I've added the ppc64 list to the addressees, in case they are interested.


Marcelo Tosatti wrote:
> On Tue, Feb 01, 2005 at 04:50:16PM +0100, Arjan van de Ven wrote:

>>afaik one doesn't need to do a tlb flush in code that clears the dirty
>>bit, as long as you use the proper vm functions to do so. 
>>(if those need a tlb flush, those are supposed to do that for you
>>afaik).

> Yep, and "proper VM function" is include/asm-generic/pgtable.h::ptep_clear_flush_dirty(),
> which on PPC flushes the TLB.

It turns out that to call ptep_clear_flush_dirty() on ppc64 from a 
module I needed to export the following symbols:

__flush_tlb_pending
ppc64_tlb_batch
hpte_update

>>Also note that your code isn't dealing with 4 level pagetables.... And
>>pagetable walking in drivers is basically almost always a mistake and a
>>sign that something is wrong.

> Or a sign that the core kernel lacks helper functions :) 

Absolutely.  It'd be so nice if there was a simple va_to_ptep() helper 
function available.

Chris

WARNING: multiple messages have this Message-ID (diff)
From: Chris Friesen <cfriesen@nortel.com>
To: Marcelo Tosatti <marcelo.tosatti@cyclades.com>
Cc: Arjan van de Ven <arjan@infradead.org>,
	linuxppc-dev@ozlabs.org,
	Linux kernel <linux-kernel@vger.kernel.org>,
	linuxppc64-dev@ozlabs.org
Subject: Re: question on symbol exports
Date: Fri, 04 Feb 2005 14:14:11 -0600	[thread overview]
Message-ID: <4203D793.1040604@nortel.com> (raw)
In-Reply-To: <20050204203050.GA5889@dmt.cnet>

I've added the ppc64 list to the addressees, in case they are interested.


Marcelo Tosatti wrote:
> On Tue, Feb 01, 2005 at 04:50:16PM +0100, Arjan van de Ven wrote:

>>afaik one doesn't need to do a tlb flush in code that clears the dirty
>>bit, as long as you use the proper vm functions to do so. 
>>(if those need a tlb flush, those are supposed to do that for you
>>afaik).

> Yep, and "proper VM function" is include/asm-generic/pgtable.h::ptep_clear_flush_dirty(),
> which on PPC flushes the TLB.

It turns out that to call ptep_clear_flush_dirty() on ppc64 from a 
module I needed to export the following symbols:

__flush_tlb_pending
ppc64_tlb_batch
hpte_update

>>Also note that your code isn't dealing with 4 level pagetables.... And
>>pagetable walking in drivers is basically almost always a mistake and a
>>sign that something is wrong.

> Or a sign that the core kernel lacks helper functions :) 

Absolutely.  It'd be so nice if there was a simple va_to_ptep() helper 
function available.

Chris

  parent reply	other threads:[~2005-02-04 20:14 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-02-01  0:15 question on symbol exports Chris Friesen
2005-02-01  7:36 ` Arjan van de Ven
2005-02-01 15:37   ` Chris Friesen
2005-02-01 15:50     ` Arjan van de Ven
2005-02-01 17:00       ` Chris Friesen
     [not found]       ` <20050204203050.GA5889@dmt.cnet>
2005-02-04 20:14         ` Chris Friesen [this message]
2005-02-04 20:14           ` Chris Friesen
2005-02-05  9:19           ` Benjamin Herrenschmidt
2005-02-05  9:19             ` Benjamin Herrenschmidt
2005-02-07 14:44             ` Chris Friesen
2005-02-07 14:44               ` Chris Friesen
2005-02-07 21:35               ` Benjamin Herrenschmidt
2005-02-07 21:35                 ` Benjamin Herrenschmidt
2005-02-07 23:02                 ` Chris Friesen
2005-02-07 23:02                   ` Chris Friesen
2005-02-07 23:42                 ` Dan Malek
2005-02-07 23:42                   ` Dan Malek
2005-02-08 15:36                   ` Chris Friesen
2005-02-08 15:36                     ` Chris Friesen

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