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From: "Jacky Lam" <jackylam@astri.org>
To: <linuxppc-embedded@lists.linuxppc.org>
Subject: Re: General porting question
Date: Thu, 9 Oct 2003 14:18:28 +0800	[thread overview]
Message-ID: <008c01c38e2d$27feac20$2803050a@JackyLam> (raw)
In-Reply-To: 20031008223518.A10052@home.com


> A quick inspection shows that es1371 does some things that won't work on
> a 405.  It takes a pci_alloc_consistent buffer and does a virt_to_page.
> That will be bogus since the buffer's virtual address is in vmalloc
> space on 4xx.  In addition, it performs a virt_to_phys and then uses
> remap_page_range on that...that will be bogus as well.  A bus_to_virt
> on the pci_alloc_consistent buffer's dma_addr will work and then
> virt_to_page() can be used on that virtual address.  In the same
> fashion one could do a virt_to_phys(bus_to_virt(dma_addr) to get
> the correct physical address to be passed to remap_page_range.
>

    That means in short:

    pci_alloc_consistent() ->virt_to_page() should be replaced by
pci_alloc_consistent()->bus_to_virt()->virt_to_page().

    Similarly, for any PCI related memory space. Before using
virt_to_*/*_to_virt(), I should use bus_to_*/*_to_bus() on the argument
first.

    Is it right?

    Thanks for your help.

Best regards,
Jacky


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

  reply	other threads:[~2003-10-09  6:18 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-10-09  4:11 General porting question Jacky Lam
2003-10-09  4:24 ` Bret Indrelee
2003-10-09  5:35 ` Matt Porter
2003-10-09  6:18   ` Jacky Lam [this message]
2003-10-09 13:38     ` Matt Porter
2003-10-09 15:36       ` Jacky Lam
2003-10-09 16:37         ` Matt Porter
2003-10-09 17:23           ` Jacky Lam

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