Date: Fri, 7 Feb 2014 15:26:10 -0500 From: John Baldwin <jhb@freebsd.org> To: freebsd-current@freebsd.org Cc: David Shane Holden <dpejesh@yahoo.com> Subject: Re: [PATCH] PCI bus number management Message-ID: <201402071526.10129.jhb@freebsd.org> In-Reply-To: <ld1ekh$4pe$1@ger.gmane.org> References: <201402061437.53355.jhb@freebsd.org> <ld1ekh$4pe$1@ger.gmane.org>
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On Thursday, February 06, 2014 8:58:42 pm David Shane Holden wrote: > On 02/06/14 14:37, John Baldwin wrote: > > I have a patch to teach the PCI bus code and PCI-PCI bridge driver to > > manage PCI bus numbers. The approach is somewhat similar to how > > NEW_PCIB manages I/O windows for briges. Each bridge creates an rman > > to manage the bus numbers for all buses and bridges that live below > > it. Each bus allocates a bus resource from its parent bridge, and > > child bridges allocate their ranges from their parent devices. At the > > "top" of the PCI tree, the Host-PCI bridges allocate their respective > > bus ranges from their PCI domain/segment. There isn't really a > > device node for PCI domains, so I created a helper API that basically > > auto- creates a PCI bus rman for each domain on first use and then > > sub-allocates from that for Host-PCI bridges. > > > > The current patch (with some extra debugging) is at > > http://people.FreeBSD.org/~jhb/patches/pci_bus_rman.3.patch > > > > I would like to commit this to HEAD soon but thought I would post it > > for some pre-commit testing for the brave. :) If you are really > > brave, try booting with 'hw.pci.clear_buses=1' which will force the > > kernel to renumber all buses in the system. If you are really, > > really brave, try booting with 'hw.pci.clear_bars=1', > > 'hw.pci.clear_buses=1', and 'hw.pci.clear_pcib=1'. (My laptop > > survives with all those set) > > > > Note that the patch only enables bus number management on amd64 and > > i386. I believe ia64 just needs to define PCI_RES_BUS for this to > > work since it mandates ACPI. Porting this to other platforms > > requires handling PCI_RES_BUS rseources for Host-PCI bridges in > > bus_alloc_resource(), bus_adjust_resource(), and > > bus_release_resource(). > > > > Setting all 3 on an Atom D510MO works fine. On a Lenovo W520 though > hw.pci.clear_bars=1 causes a lockup during boot. The last few lines > with a normal boot are: > > pcib0: <ACPI Host-PCI bridge> port 0xcf8-0xcff on acpi0 > pcib0: decoding 5 range 0-0xfe > pci0: <ACPI PCI bus> on pcib0 > secbus=1, subbus=1 > pci0:0:1:0: allocated initial secbus range > > While a verbose boot produces: > > pcib0: allocated type 3 (0xc0000400-0xc00007ff) for rid 10 of pci:0:0:26:0 > pcib0: matched entry for 0x26.INTA > pcib0: slot 26 INTA hardwired to IRQ 26 > > And it ends there. Setting the other 2 are fine though. Ok, I think this may be a bit of a known issue in that some video cards really don't like having their framebuffer disabled, even temporarily. Thanks for testing! -- John Baldwin
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