PCI: x86 MMCONFIG: add legacy pci conf functions]
PATCH 2/5 PCI: x86 MMCONFIG: add legacy pci conf functions]
-------- 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 <[email protected]>
Reply-To: [email protected]
To: Greg KH <[email protected]>
References: <20071219221746.20362.39243.sendpatchset@dhcp83-188.boston.redhat.com> <20071219221756.20362.84805.sendpatchset@dhcp83-188.boston.redhat.com> <[email protected]>
Quoted 6 lines · Greg KH
Review
Quoted 4 lines
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-0+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
Quoted 20 lines
Quoted 6 lines
/*
* Before we decide to use direct hardware access mechanisms, we try to do some(quoted diff) +0
-0@@ -258,18 +284,28 @@ void __init pci_direct_init(int type) { if (type == 0)Review void __init pci_direct_init(int type) · line 292
Quoted 10 lines
(quoted diff) +4
-3return; - 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_confgoing to be used for? Why not just useraw_pci_ops?
Quoted 3 lines
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.