Re: Info: mapping multiple BARs. Your kernel is fine.

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

[CC list rearranged]

On Monday, February 24, 2014 05:24:00 PM Borislav Petkov wrote:
> This started happening this morning after booting -rc4+tip, let's
> add *everybody* to CC :-)
> 
> We have intel_uncore_init, snb_uncore_imc_init_box, uncore_pci_probe and
> other goodies on the stack.

I've just gone throught this.

So the problem is that we have the PNP "system" driver whose only purpose seems
to be to reserve system resources so that the PCI layer doesn't assign them to
new devices on hotplug (disclaimer: I didn't invent it, I only read the code and
comments in there).

It does that for ACPI device objects having the "PNP0C02" and "PNP0C01" IDs.

Apparently, snb_uncore_imc_init_box() steps on a range already reserved by that
driver on your box.  And this doesn't seem to be a coincidence, because the ACPI
device object in question probably *does* correspond to the memory controller
that the uncore driver attempts to use.

I'm not sure how to address that right now to be honest.  Arguably, the PNP
"system" driver should be replaced with something saner, but still the
resources it claims need to be kept out of reach of the PCI's resource
allocation code.

> ...
> [    0.488998] software IO TLB [mem 0xcac30000-0xcec30000] (64MB) mapped at [ffff8800cac30000-ffff8800cec2ffff]
> [    0.489975] resource map sanity check conflict: 0xfed10000 0xfed15fff 0xfed10000 0xfed13fff pnp 00:01
> [    0.490079] ------------[ cut here ]------------
> [    0.490204] WARNING: CPU: 2 PID: 1 at arch/x86/mm/ioremap.c:171 __ioremap_caller+0x372/0x380()
> [    0.490306] Info: mapping multiple BARs. Your kernel is fine.
> [    0.490371] Modules linked in:
> [    0.490558] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 3.14.0-rc4+ #1
> [    0.490642] Hardware name: LENOVO 2320CTO/2320CTO, BIOS G2ET86WW (2.06 ) 11/13/2012
> [    0.490742]  00000000000000ab ffff880213d01ad8 ffffffff816112e3 0000000000000006
> [    0.491032]  ffff880213d01b28 ffff880213d01b18 ffffffff8104e9bc ffff880213d01b08
> [    0.491343]  ffffc90000c58000 00000000fed10000 00000000fed10000 0000000000006000
> [    0.491631] Call Trace:
> [    0.493337]  [<ffffffff816112e3>] dump_stack+0x4f/0x7c
> [    0.493420]  [<ffffffff8104e9bc>] warn_slowpath_common+0x8c/0xc0
> [    0.493503]  [<ffffffff8104eaa6>] warn_slowpath_fmt+0x46/0x50
> [    0.493588]  [<ffffffff8103f1e2>] __ioremap_caller+0x372/0x380
> [    0.493674]  [<ffffffff810211a2>] ? snb_uncore_imc_init_box+0x62/0x90
> [    0.493761]  [<ffffffff8103f247>] ioremap_nocache+0x17/0x20
> [    0.493846]  [<ffffffff810211a2>] snb_uncore_imc_init_box+0x62/0x90
> [    0.493933]  [<ffffffff81022925>] uncore_pci_probe+0xe5/0x1e0
> [    0.494020]  [<ffffffff812d487e>] local_pci_probe+0x4e/0xa0
> [    0.494104]  [<ffffffff81418a59>] ? get_device+0x19/0x20
> [    0.494213]  [<ffffffff812d5cd1>] pci_device_probe+0xe1/0x130
> [    0.494300]  [<ffffffff8141d3cb>] driver_probe_device+0x7b/0x240
> [    0.494385]  [<ffffffff8141d63b>] __driver_attach+0xab/0xb0
> [    0.494469]  [<ffffffff8141d590>] ? driver_probe_device+0x240/0x240
> [    0.494551]  [<ffffffff8141b71e>] bus_for_each_dev+0x5e/0x90
> [    0.494634]  [<ffffffff8141cede>] driver_attach+0x1e/0x20
> [    0.494718]  [<ffffffff8141ca57>] bus_add_driver+0x117/0x230
> [    0.494802]  [<ffffffff8141dd34>] driver_register+0x64/0xf0
> [    0.494884]  [<ffffffff812d4c14>] __pci_register_driver+0x64/0x70
> [    0.494972]  [<ffffffff81d0319b>] ? uncore_types_init+0x19c/0x19c
> [    0.495056]  [<ffffffff81d03312>] intel_uncore_init+0x177/0x41c
> [    0.495155]  [<ffffffff81d0319b>] ? uncore_types_init+0x19c/0x19c
> [    0.495242]  [<ffffffff8100029e>] do_one_initcall+0x4e/0x170
> [    0.495326]  [<ffffffff81071100>] ? parse_args+0x60/0x360
> [    0.495411]  [<ffffffff81cfbfb8>] kernel_init_freeable+0x106/0x19a
> [    0.495497]  [<ffffffff81cfb83b>] ? do_early_param+0x86/0x86
> [    0.495582]  [<ffffffff81607ef0>] ? rest_init+0xd0/0xd0
> [    0.495666]  [<ffffffff81607efe>] kernel_init+0xe/0xf0
> [    0.495749]  [<ffffffff81621f6c>] ret_from_fork+0x7c/0xb0
> [    0.495831]  [<ffffffff81607ef0>] ? rest_init+0xd0/0xd0
> [    0.495921] ---[ end trace 428f365c054d9a01 ]---
> [    0.496196] RAPL PMU detected, hw unit 2^-16 Joules, API unit is 2^-32 Joules, 3 fixed counters 163840 ms ovfl timer
> [    0.498598] futex hash table entries: 1024 (order: 5, 131072 bytes)
> [    0.498833] audit: initializing netlink subsys (disabled)
> [    0.499024] audit: type=2000 audit(1393259866.477:1): initialized
> ...
> 
> 

-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.