Messages in this thread Patch in this message | | | Date | Thu, 20 Dec 2007 07:25:11 -0500 | From | Tony Camuso <> | Subject | [Fwd: Re: [PATCH 2/5]PCI: x86 MMCONFIG: add legacy pci conf functions] |
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-------- Original Message -------- Subject: Re: [PATCH 2/5]PCI: x86 MMCONFIG: add legacy pci conf functions Date: Wed, 19 Dec 2007 19:07:27 -0500 From: Tony Camuso <tcamuso@redhat.com> Reply-To: tcamuso@redhat.com To: Greg KH <gregkh@suse.de> References: <20071219221746.20362.39243.sendpatchset@dhcp83-188.boston.redhat.com> <20071219221756.20362.84805.sendpatchset@dhcp83-188.boston.redhat.com> <20071219230615.GB24219@suse.de>
Greg KH wrote:
>> +struct pci_ops pci_legacy_ops = { >> + .read = pci_ops_legacy_read, >> + .write = pci_ops_legacy_write, >> +}; > > This whole structure is never used in this patch, why add it now?
It gets used by the routine pcibios_fix_bus_scan_quirk in arch/x86/pci/common.c
> >> /* >> * Before we decide to use direct hardware access mechanisms, we try to do some >> @@ -258,18 +284,28 @@ void __init pci_direct_init(int type) >> { >> if (type == 0) >> return; >> - printk(KERN_INFO "PCI: Using configuration type %d\n", type); >> - if (type == 1) >> + if (type == 1) { >> raw_pci_ops = &pci_direct_conf1; >> - else >> + pci_legacy_conf = &pci_direct_conf1; >> + } else { >> raw_pci_ops = &pci_direct_conf2; >> + pci_legacy_conf = &pci_direct_conf2; > > Why have two pointers to the same thing? What is pci_legacy_conf going > to be used for? Why not just use raw_pci_ops? > > thanks, > > greg k-h
The way the code works today, when raw_pci_ops is set to use mmconf, it is platform-wide. Legacy pci config reads are not available.
I would have simply used the pci_direct_conf1, but because there can also be a pci_direct_conf2, I thought it best to abstract it as pci_legacy_conf.
A pointer to struct pci_ops pci_legacy_ops data is written into the pci_bus.ops field for buses that must use legacy pci config access.
The other busses can continue to use the pointer to the mmconf pci_ops.
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