From: Valentine Barshak <vbarshak@ru•mvista.com>
To: Vitaly Bordug <vitb@kernel•crashing.org>
Cc: linuxppc-dev <linuxppc-dev@ozlabs•org>
Subject: Re: [PATCH] [RFC][POWERPC] Merge 32 and 64 bit pci_process_bridge_OF_ranges() instances
Date: Tue, 18 Sep 2007 18:38:56 +0400 [thread overview]
Message-ID: <46EFE300.1090108@ru.mvista.com> (raw)
In-Reply-To: <20070918182704.640c677f@localhost.localdomain>
Vitaly Bordug wrote:
> Hello Valentine,
>
> On Tue, 18 Sep 2007 16:03:50 +0400
> Valentine Barshak wrote:
>
>> Vitaly Bordug wrote:
>>> +
>>> + hose->io_base_phys = cpu_phys_addr - pci_addr;
>> This is not gonna work on 32-bit platform (unless pci_addr == 0).
>> Should be
>> hose->io_base_phys = cpu_phys_addr;
>> The other way we should adjust io size like we do on 64-bit and rewrite
>> resource fixup functions.
>>
> I think the second sounds like a plan then. We should not "assume" where we can make things to behave properly.
>
>>> + /* handle from 0 to top of I/O window */
>>> +#ifdef CONFIG_PPC64
>>> + hose->pci_io_size = pci_addr + size;
>>> +#endif
>>> + hose->io_base_virt = ioremap(hose->io_base_phys, size);
>> Do we need to ioremap on 64-bit? I think 64-bit uses different approach
>> in handling io space.
>>
> Correct - 64 bit code does __get_vm_area() so the upper line is ppc32-specific.
>>> +#ifdef CONFIG_PPC32
>>> + if (prim)
>>> + isa_io_base = (unsigned long)hose->io_base_virt;
>>> +#endif
>> What's exactly the point of merging this single function?
>> If this was intended to add 64-bit physical address support to 32-bit
>> platforms (like ppc440), then it does not seem sufficient to make pci
>> stuff work right.
>> What about the 32-bit pcibios_fixup_resources(),
>> pcibios_resource_to_bus(), pcibios_bus_to_resource() stuff?
>> There's still no 64-bit support. You'll get
>> "PCI Cannot allocate resource region" attempting to initialize resources
>> at PCI start-up.
> Because this function is critical to get the stuff going. You can have some devices working even without PCI resources initted
> (what in fact I had with mpc8272). I am in process of moving the mentioned to the common_... domain but I suspect there are other 32-bit-stick stuff still. So if you want to assist in cleaning this up, feel free to join the club...
Well, thanks for the invitation :)
I've been trying to work on the pci support here too. But I've used a
bit different approach. I tried to add 64-bit phys addr support to
pci_32.c. The patch seems to work on Sequoia. Actually, I thought
merging was too risky at this point and might cause more problems
breaking both 64 and 32-bit pci support.
Thanks,
Valentine.
next prev parent reply other threads:[~2007-09-18 14:40 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-11 22:49 [PATCH] [RFC][POWERPC] Merge 32 and 64 bit pci_process_bridge_OF_ranges() instances Vitaly Bordug
2007-09-11 22:57 ` Arnd Bergmann
2007-09-11 23:56 ` Vitaly Bordug
2007-09-12 8:13 ` Arnd Bergmann
2007-09-12 14:51 ` Segher Boessenkool
2007-09-12 16:07 ` Vitaly Bordug
2007-09-13 5:11 ` David Gibson
2007-09-18 12:03 ` Valentine Barshak
2007-09-18 14:27 ` Vitaly Bordug
2007-09-18 14:38 ` Valentine Barshak [this message]
2007-09-19 0:09 ` Vitaly Bordug
2007-09-18 21:44 ` Benjamin Herrenschmidt
2007-09-18 21:41 ` Benjamin Herrenschmidt
2007-09-18 21:42 ` Benjamin Herrenschmidt
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