From: Timur Tabi <timur@freescale.com>
To: Kumar Gala <galak@kernel.crashing.org>
Cc: Li Yang-r58472 <LeoLi@freescale.com>,
netdev@vger.kernel.org, linuxppc-dev@ozlabs.org
Subject: Re: [PATCH 1/4] ucc_geth: Change private immrbar_virt_to_phys to generic iopa
Date: Thu, 08 Feb 2007 07:35:08 -0600 [thread overview]
Message-ID: <45CB270C.5090603@freescale.com> (raw)
In-Reply-To: <17A046C6-5FD3-46D5-AB96-EAEDF22FA829@kernel.crashing.org>
Kumar Gala wrote:
> Right, so when do you know if you'll be using MURAM or normal memory?
> Why not just keep around a token that is the physical address at the
> point you make the decision of MURAM vs normal memory.
That's what the original code did, kinda. It called virt_to_phys() if
it is main memory, and it called immrbar_virt_to_phys() if it is MURAM.
immrbar_virt_to_phys() did pointer math to extract the physical address.
I knew that Leo's patch was calling iopa() on main memory, but since it
worked, I didn't think much about it. But it does make some sense that
since we obtain the physical address when we allocate the BD ring, we
should store that address and use it.
That's what most drivers do, anyway, and so we should do the same thing.
So instead of p_tx_bd_ring[i], we would have p_tx_bd_ring[i].virtual
and p_tx_bd_ring[i].physical.
Besides, iopa() is slower, because it walks page tables.
WARNING: multiple messages have this Message-ID (diff)
From: Timur Tabi <timur@freescale.com>
To: Kumar Gala <galak@kernel.crashing.org>
Cc: netdev@vger.kernel.org, linuxppc-dev@ozlabs.org
Subject: Re: [PATCH 1/4] ucc_geth: Change private immrbar_virt_to_phys to generic iopa
Date: Thu, 08 Feb 2007 07:35:08 -0600 [thread overview]
Message-ID: <45CB270C.5090603@freescale.com> (raw)
In-Reply-To: <17A046C6-5FD3-46D5-AB96-EAEDF22FA829@kernel.crashing.org>
Kumar Gala wrote:
> Right, so when do you know if you'll be using MURAM or normal memory?
> Why not just keep around a token that is the physical address at the
> point you make the decision of MURAM vs normal memory.
That's what the original code did, kinda. It called virt_to_phys() if
it is main memory, and it called immrbar_virt_to_phys() if it is MURAM.
immrbar_virt_to_phys() did pointer math to extract the physical address.
I knew that Leo's patch was calling iopa() on main memory, but since it
worked, I didn't think much about it. But it does make some sense that
since we obtain the physical address when we allocate the BD ring, we
should store that address and use it.
That's what most drivers do, anyway, and so we should do the same thing.
So instead of p_tx_bd_ring[i], we would have p_tx_bd_ring[i].virtual
and p_tx_bd_ring[i].physical.
Besides, iopa() is slower, because it walks page tables.
next prev parent reply other threads:[~2007-02-08 13:35 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-02-06 11:31 [PATCH 1/4] ucc_geth: Change private immrbar_virt_to_phys to generic iopa Li Yang
2007-02-06 14:26 ` Kumar Gala
2007-02-06 14:26 ` Kumar Gala
2007-02-07 9:34 ` Li Yang-r58472
2007-02-07 9:34 ` Li Yang-r58472
2007-02-07 16:36 ` Kumar Gala
2007-02-07 16:36 ` Kumar Gala
2007-02-07 16:43 ` Timur Tabi
2007-02-07 16:43 ` Timur Tabi
2007-02-07 16:49 ` Kumar Gala
2007-02-07 16:49 ` Kumar Gala
2007-02-07 17:03 ` Timur Tabi
2007-02-07 17:03 ` Timur Tabi
2007-02-08 5:52 ` Li Yang-r58472
2007-02-08 5:52 ` Li Yang-r58472
2007-02-08 5:57 ` Kumar Gala
2007-02-08 6:48 ` Li Yang-r58472
2007-02-08 6:48 ` Li Yang-r58472
2007-02-08 6:53 ` Kumar Gala
2007-02-08 6:53 ` Kumar Gala
2007-02-08 7:06 ` Li Yang-r58472
2007-02-08 7:06 ` Li Yang-r58472
2007-02-08 7:16 ` Kumar Gala
2007-02-08 7:16 ` Kumar Gala
2007-02-08 7:36 ` Li Yang-r58472
2007-02-08 7:36 ` Li Yang-r58472
2007-02-08 7:41 ` Kumar Gala
2007-02-08 7:41 ` Kumar Gala
2007-02-08 9:22 ` Discussion about iopa() Li Yang-r58472
2007-02-08 13:41 ` Timur Tabi
2007-02-09 17:08 ` Dan Malek
2007-02-10 2:37 ` Benjamin Herrenschmidt
2007-02-10 18:04 ` Dan Malek
2007-02-10 21:40 ` Benjamin Herrenschmidt
2007-02-10 22:27 ` Dan Malek
2007-02-10 22:42 ` Benjamin Herrenschmidt
2007-02-08 21:26 ` Benjamin Herrenschmidt
2007-02-09 17:13 ` Dan Malek
2007-02-09 22:06 ` Benjamin Herrenschmidt
2007-02-09 22:46 ` Kumar Gala
2007-02-09 22:51 ` Timur Tabi
2007-02-09 23:06 ` Kumar Gala
2007-02-09 23:10 ` Timur Tabi
2007-02-09 23:19 ` Benjamin Herrenschmidt
2007-02-09 23:22 ` Kumar Gala
2007-02-09 23:33 ` Timur Tabi
2007-02-09 23:43 ` Kumar Gala
2007-02-09 17:06 ` Dan Malek
2007-02-08 13:35 ` Timur Tabi [this message]
2007-02-08 13:35 ` [PATCH 1/4] ucc_geth: Change private immrbar_virt_to_phys to generic iopa Timur Tabi
2007-02-09 17:22 ` Dan Malek
2007-02-09 17:26 ` Timur Tabi
2007-02-09 17:26 ` Timur Tabi
2007-02-08 13:27 ` Timur Tabi
2007-02-07 0:19 ` Jeff Garzik
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