From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <39F8B44B.7980796@mvista.com> Date: Thu, 26 Oct 2000 15:46:35 -0700 From: "Mark A. Greer" Reply-To: mgreer@mvista.com MIME-Version: 1.0 To: linuxppc-dev@lists.linuxppc.org Subject: Early PCI auto-configuration Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: [The discussion below is based on the latest fsmlabs 5005 repository code] Disclaimer: I'm fairly new to linux PPC so my apologies if this has been discussed before. My problem: The firmware on a couple platform I need to support do absolutely _no_ PCI device initialization. To make things work for these boards in the current setup, I need to use one of the pcibios_fixup() or pcibios_fixup_bus() hooks to walk the entire bus tree, setup the devices (including bridges), and sort out all the stuff that's already been put in the the "resource" entries--or am I missing something?? I would prefer to run a "pci auto-configurator" that sets up all the devices and bridges before pci_init() runs so I don't waste as much time reading bad info and they trying to fix it all up later. The "fixup" routines can still be used for minor tweaks and interrupt routing, etc. I was thinking of doing it this ways... >>From the xxx_find_bridges() routine, call "pci_auto_scan_hose()" which walks the entire bus hierarchy under each "hose" sorting out resources, enumerating the buses, setting up bridges and their bounds, etc. pci_init() will run some time later and pick up reasonable BAR values. To make this work, I will add 4 fields to the pci_controller [or "hose"] structure that have the upper and lower bounds for PCI I/O and memory space for each hose. This is what the auto-configurator will use to constrain his resource allocations. Also, while I'm at it, add 2 more fields to pci_controller, one an array of 32*8 int's that contian the devfn value of any devfn's that the auto-configurator should skip. The other is the number of valid entries in the array. This is useful--to me anyway--because I want the auto-configurator to skip the host bridge itself. Also, on some platforms, the host bridge also has an external IDSEL line that is hooked up to a PCI address line. Some bridges can not handle having themselves selected so that device needs to be skipped. Any comments? Is there a better way? Am I getting carried away? Thanks, Mark -- Mark A. Greer (mgreer@mvista.com; 480-517-0287) MontaVista Software, Inc. 2141 E. Broadway Road, Suite 108 Tempe, AZ 85282 ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/