On Wed, May 2, 2018 at 1:33 PM, Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
> On Mon, Apr 23, 2018 at 06:34:23PM +0100, Ivan Kokshaysky wrote:
>> On Sun, Apr 22, 2018 at 01:07:38PM -0700, Matt Turner wrote:
>> > On Wed, Apr 18, 2018 at 1:48 PM, Ivan Kokshaysky
>> > <ink@xxxxxxxxxxxxxxxxxxxx> wrote:
>> > > On Tue, Apr 17, 2018 at 02:43:44PM -0500, Bjorn Helgaas wrote:
>> > >> On Mon, Apr 16, 2018 at 09:43:42PM -0700, Matt Turner wrote:
>> > >> > On Mon, Apr 16, 2018 at 2:50 PM, Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
>> > >> > > Hi Matt,
>> > >> > >
>> > >> > > First of all, sorry about breaking Nautilus, and thanks very much for
>> > >> > > tracking it down to this commit.
>> > >> >
>> > >> > It's a particularly weird case, as far as I've been able to discern :)
>> > >> >
>> > >> > > On Mon, Apr 16, 2018 at 07:33:57AM -0700, Matt Turner wrote:
>> > >> > >> Commit f75b99d5a77d63f20e07bd276d5a427808ac8ef6 (PCI: Enforce bus
>> > >> > >> address limits in resource allocation) broke Alpha systems using
>> > >> > >> CONFIG_ALPHA_NAUTILUS. Alpha is 64-bit, but Nautilus systems use a
>> > >> > >> 32-bit AMD 751/761 chipset. arch/alpha/kernel/sys_nautilus.c maps PCI
>> > >> > >> into the upper addresses just below 4GB.
>> > >> > >>
>> > >> > >> I can get a working kernel by ifdef'ing out the code in
>> > >> > >> drivers/pci/bus.c:pci_bus_alloc_resource. We can't tie
>> > >> > >> PCI_BUS_ADDR_T_64BIT to ALPHA_NAUTILUS without breaking generic
>> > >> > >> kernels.
>> > >> > >>
>> > >> > >> How can we get Nautilus working again?
>> > >> > >
>> > >> > > Can you collect a complete dmesg log, ideally both before and after
>> > >> > > f75b99d5a77d? I assume the problem is that after f75b99d5a77d? we
>> > >> > > erroneously assign space for something above 4GB. But if we know the
>> > >> > > correct host bridge apertures, we shouldn't assign space outside them,
>> > >> > > regardless of the PCI bus address size.
>> > >> >
>> > >> > I made a mistake in my initial report. Commit f75b99d5a77d is actually
>> > >> > the last *working* commit. My apologies. The next commit is
>> > >> > d56dbf5bab8c (PCI: Allocate 64-bit BARs above 4G when possible) and it
>> > >> > breaks Nautilus I've confirmed.
>> > >> >
>> > >> > Please find attached dmesgs from those two commits, from the commit
>> > >> > immediately before them, and another from 4.17-rc1 with my hack of #if
>> > >> > 0'ing out the pci_bus_alloc_from_region(..., &pci_high) code.
>> > >> >
>> > >> > Thanks for having a look!
>> > >>
>> > >> We're telling the PCI core that the host bridge MMIO aperture is the
>> > >> entire 64-bit address space, so when we assign BARs, some of them end
>> > >> up above 4GB:
>> > >>
>> > >> pci_bus 0000:00: root bus resource [mem 0x00000000-0xffffffffffffffff]
>> > >> pci 0000:00:09.0: BAR 0: assigned [mem 0x100000000-0x10000ffff 64bit]
>> > >>
>> > >> But it sounds like the MMIO aperture really ends at 0xffffffff, so
>> > >> that's not going to work.
>> > >
>> > > Correct... This would do as a quick fix, I think:
>> > >
>> > > diff --git a/arch/alpha/kernel/sys_nautilus.c b/arch/alpha/kernel/sys_nautilus.c
>> > > index ff4f54b..477ba65 100644
>> > > --- a/arch/alpha/kernel/sys_nautilus.c
>> > > +++ b/arch/alpha/kernel/sys_nautilus.c
>> > > @@ -193,6 +193,8 @@ static struct resource irongate_io = {
>> > > };
>> > > static struct resource irongate_mem = {
>> > > .name = "Irongate PCI MEM",
>> > > + .start = 0,
>> > > + .end = 0xffffffff,
>> > > .flags = IORESOURCE_MEM,
>> > > };
>> > > static struct resource busn_resource = {
>> > > @@ -218,7 +220,7 @@ nautilus_init_pci(void)
>> > > return;
>> > >
>> > > pci_add_resource(&bridge->windows, &ioport_resource);
>> > > - pci_add_resource(&bridge->windows, &iomem_resource);
>> > > + pci_add_resource(&bridge->windows, &irongate_mem);
>> > > pci_add_resource(&bridge->windows, &busn_resource);
>> > > bridge->dev.parent = NULL;
>> > > bridge->sysdata = hose;
>> >
>> > Thanks. But with that I get
>> >
>> > PCI host bridge to bus 0000:00
>> > pci_bus 0000:00: root bus resource [io 0x0000-0xffff]
>> > pci_bus 0000:00: root bus resource [mem 0x00000000-0xffffffff]
>> > pci_bus 0000:00: root bus resource [bus 00-ff]
>> > pci 0000:00:10.0: [Firmware Bug]: reg 0x10: invalid BAR (can't size)
>> > pci 0000:00:10.0: [Firmware Bug]: reg 0x14: invalid BAR (can't size)
>> > pci 0000:00:10.0: [Firmware Bug]: reg 0x18: invalid BAR (can't size)
>> > pci 0000:00:10.0: [Firmware Bug]: reg 0x1c: invalid BAR (can't size)
>> > pci 0000:00:10.0: legacy IDE quirk: reg 0x10: [io 0x01f0-0x01f7]
>> > pci 0000:00:10.0: legacy IDE quirk: reg 0x14: [io 0x03f6]
>> > pci 0000:00:10.0: legacy IDE quirk: reg 0x18: [io 0x0170-0x0177]
>> > pci 0000:00:10.0: legacy IDE quirk: reg 0x1c: [io 0x0376]
>> > pci 0000:00:11.0: quirk: [io 0x4000-0x403f] claimed by ali7101 ACPI
>> > pci 0000:00:11.0: quirk: [io 0x5000-0x501f] claimed by ali7101 SMB
>> > pci 0000:00:01.0: BAR 9: assigned [mem 0xc0000000-0xc2ffffff pref]
>> > pci 0000:00:01.0: BAR 8: assigned [mem 0xc3000000-0xc3bfffff]
>> > pci 0000:00:0b.0: BAR 6: assigned [mem 0xc3c00000-0xc3c3ffff pref]
>> > pci 0000:00:08.0: BAR 6: assigned [mem 0xc3c40000-0xc3c5ffff pref]
>> > pci 0000:00:09.0: BAR 0: assigned [mem 0xc3c60000-0xc3c6ffff 64bit]
>> > pci 0000:00:03.0: BAR 0: assigned [mem 0xc3c70000-0xc3c70fff]
>> > pci 0000:00:06.0: BAR 1: assigned [mem 0xc3c71000-0xc3c71fff]
>> > pci 0000:00:08.0: BAR 1: assigned [mem 0xc3c72000-0xc3c72fff 64bit]
>> > pci 0000:00:14.0: BAR 0: assigned [mem 0xc3c73000-0xc3c73fff]
>> > pci 0000:00:0b.0: BAR 1: assigned [mem 0xc3c74000-0xc3c743ff]
>> > pci 0000:00:03.0: BAR 1: assigned [io 0x8000-0x80ff]
>> > pci 0000:00:06.0: BAR 0: assigned [io 0x8400-0x84ff]
>> > pci 0000:00:08.0: BAR 0: assigned [io 0x8800-0x88ff]
>> > pci 0000:00:0b.0: BAR 0: assigned [io 0x8c00-0x8c7f]
>> > pci 0000:00:10.0: BAR 4: assigned [io 0x8c80-0x8c8f]
>> > pci 0000:01:05.0: BAR 0: assigned [mem 0xc0000000-0xc1ffffff pref]
>> > pci 0000:01:05.0: BAR 2: assigned [mem 0xc3000000-0xc37fffff]
>> > pci 0000:01:05.0: BAR 6: assigned [mem 0xc2000000-0xc200ffff pref]
>> > pci 0000:01:05.0: BAR 1: assigned [mem 0xc3800000-0xc3803fff]
>> > pci 0000:00:01.0: PCI bridge to [bus 01]
>> > pci 0000:00:01.0: bridge window [mem 0xc3000000-0xc3bfffff]
>> > pci 0000:00:01.0: bridge window [mem 0xc0000000-0xc2ffffff pref]
>> >
>> > Looks like the bridge window is overlapping with some previously assigned BARs?
>>
>> No, there are no overlaps. This is AGP bridge window with AGP card BARs
>> inside it.
>>
>> > The result is the SCSI card failing to work:
>> >
>> > scsi host0: Adaptec AIC7XXX EISA/VLB/PCI SCSI HBA DRIVER, Rev 7.0
>> > <Adaptec 29160 Ultra160 SCSI adapter>
>> > aic7892: Ultra160 Wide Channel A, SCSI Id=7, 32/253 SCBs
>> >
>> > scsi0: ahc_intr - referenced scb not valid during SELTO scb(0, 255)
>> > >>>>>>>>>>>>>>>>>> Dump Card State Begins <<<<<<<<<<<<<<<<<
>> > scsi0: Dumping Card State while idle, at SEQADDR 0x18
>> > [snip endless spew]
>>
>> It looks like Irongate PCI memory window setting is completely wrong,
>> perhaps it starts at zero, so that PCI DMA doesn't work at all.
>>
>> Please try the patch below. It tries to fix things properly, but if
>> PCI bus sizing fails for some reason, it falls back to a "safe" PCI
>> memory window placement at 3GB.
>
> Ping, Matt, any feedback on this patch?
Sorry I haven't had a chance to test it and respond. I'll get to it by
this weekend at the latest.
