linux-pci.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* Re: Arm64 double PCI ECAM reservations in acpi_resource_consumer()
       [not found] <c82b61f5-00d4-182f-2bb7-3518adf2ca75@quicinc.com>
@ 2021-06-02 22:09 ` Bjorn Helgaas
  2021-06-03  0:15   ` Qian Cai
  0 siblings, 1 reply; 4+ messages in thread
From: Bjorn Helgaas @ 2021-06-02 22:09 UTC (permalink / raw)
  To: Qian Cai
  Cc: Catalin Marinas, Will Deacon, linux-arm, Lorenzo Pieralisi, Linux PCI

[+cc linux-pci]

On Wed, Jun 2, 2021 at 4:49 PM Qian Cai <quic_qiancai@quicinc.com> wrote:
>
> Bjorn, I noticed PCI ECAM could be reserved twice on arm64. Firs time through,
>
> [   19.087790][    T1]  acpi_ns_walk_namespace+0xc0/0x390
> [   19.092927][    T1]  acpi_get_devices+0x160/0x1a4
> [   19.097629][    T1]  acpi_resource_consumer+0x8c/0xc0
> [   19.102680][    T1]  pci_acpi_scan_root+0x158/0x4c8
> [   19.107555][    T1]  acpi_pci_root_add+0x450/0x8e8
> [   19.112345][    T1]  acpi_bus_attach+0x300/0x7d0
> [   19.116960][    T1]  acpi_bus_attach+0x178/0x7d0
> [   19.121576][    T1]  acpi_bus_attach+0x178/0x7d0
> [   19.126190][    T1]  acpi_bus_scan+0xa8/0x170
> [   19.130545][    T1]  acpi_scan_init+0x220/0x558
> [   19.135074][    T1]  acpi_init+0x1f4/0x270
>
> where pci_acpi_setup_ecam_mapping() confirmed all reservations are succeed. Then,
>
> [   19.880588][    T1]  acpi_ns_walk_namespace+0xc0/0x390
> [   19.885725][    T1]  acpi_get_devices+0x160/0x1a4
> [   19.890426][    T1]  pnpacpi_init+0xa0/0x10
>
> As the results, those messages are showed up during the boot in pnpacpi_init().
>
> [ 17.763968] system 00:00: [mem 0x10000000000-0x1000fffffff window] could not be reserved
> [ 17.772900] system 00:00: [mem 0x7800000000-0x780fffffff window] could not be reserved
> [ 17.781627] system 00:00: [mem 0x7000000000-0x700fffffff window] could not be reserved
> [ 17.790350] system 00:00: [mem 0x6000000000-0x600fffffff window] could not be reserved
> [ 17.799073] system 00:00: [mem 0x5800000000-0x580fffffff window] could not be reserved
> [ 17.808155] system 00:00: [mem 0x1000000000-0x100fffffff window] could not be reserved
> [ 17.816862] system 00:00: [mem 0x600000000-0x60fffffff window] could not be reserved
> [ 17.825417] system 00:00: [mem 0x400000000-0x40fffffff window] could not be reserved
>
> Looking through the x86's version of pci_acpi_scan_root(), it won't call acpi_resource_consumer(), so I suppose this bug is only affecting arm64?

This might be related to
https://lore.kernel.org/linux-acpi/20210510234020.1330087-1-luzmaximilian@gmail.com/T/#u

Can you try applying that patch to see if it is related?

Bjorn

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Arm64 double PCI ECAM reservations in acpi_resource_consumer()
  2021-06-02 22:09 ` Arm64 double PCI ECAM reservations in acpi_resource_consumer() Bjorn Helgaas
@ 2021-06-03  0:15   ` Qian Cai
  2021-06-03 14:16     ` Lorenzo Pieralisi
  0 siblings, 1 reply; 4+ messages in thread
From: Qian Cai @ 2021-06-03  0:15 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: Catalin Marinas, Will Deacon, linux-arm, Lorenzo Pieralisi, Linux PCI



On 6/2/2021 6:09 PM, Bjorn Helgaas wrote:
> [+cc linux-pci]
> 
> On Wed, Jun 2, 2021 at 4:49 PM Qian Cai <quic_qiancai@quicinc.com> wrote:
>>
>> Bjorn, I noticed PCI ECAM could be reserved twice on arm64. Firs time through,
>>
>> [   19.087790][    T1]  acpi_ns_walk_namespace+0xc0/0x390
>> [   19.092927][    T1]  acpi_get_devices+0x160/0x1a4
>> [   19.097629][    T1]  acpi_resource_consumer+0x8c/0xc0
>> [   19.102680][    T1]  pci_acpi_scan_root+0x158/0x4c8
>> [   19.107555][    T1]  acpi_pci_root_add+0x450/0x8e8
>> [   19.112345][    T1]  acpi_bus_attach+0x300/0x7d0
>> [   19.116960][    T1]  acpi_bus_attach+0x178/0x7d0
>> [   19.121576][    T1]  acpi_bus_attach+0x178/0x7d0
>> [   19.126190][    T1]  acpi_bus_scan+0xa8/0x170
>> [   19.130545][    T1]  acpi_scan_init+0x220/0x558
>> [   19.135074][    T1]  acpi_init+0x1f4/0x270
>>
>> where pci_acpi_setup_ecam_mapping() confirmed all reservations are succeed. Then,
>>
>> [   19.880588][    T1]  acpi_ns_walk_namespace+0xc0/0x390
>> [   19.885725][    T1]  acpi_get_devices+0x160/0x1a4
>> [   19.890426][    T1]  pnpacpi_init+0xa0/0x10
>>
>> As the results, those messages are showed up during the boot in pnpacpi_init().
>>
>> [ 17.763968] system 00:00: [mem 0x10000000000-0x1000fffffff window] could not be reserved
>> [ 17.772900] system 00:00: [mem 0x7800000000-0x780fffffff window] could not be reserved
>> [ 17.781627] system 00:00: [mem 0x7000000000-0x700fffffff window] could not be reserved
>> [ 17.790350] system 00:00: [mem 0x6000000000-0x600fffffff window] could not be reserved
>> [ 17.799073] system 00:00: [mem 0x5800000000-0x580fffffff window] could not be reserved
>> [ 17.808155] system 00:00: [mem 0x1000000000-0x100fffffff window] could not be reserved
>> [ 17.816862] system 00:00: [mem 0x600000000-0x60fffffff window] could not be reserved
>> [ 17.825417] system 00:00: [mem 0x400000000-0x40fffffff window] could not be reserved
>>
>> Looking through the x86's version of pci_acpi_scan_root(), it won't call acpi_resource_consumer(), so I suppose this bug is only affecting arm64?
> 
> This might be related to
> https://lore.kernel.org/linux-acpi/20210510234020.1330087-1-luzmaximilian@gmail.com/T/#u
> 
> Can you try applying that patch to see if it is related?

Unfortunately, that revert patch does not help. FYI, here is the first reservation from acpi_resource_consumer().

[   16.224306] acpi PNP0A08:00: ECAM area [mem 0x10000000000-0x1000fffffff] reserved by PNP0C02:00
[   16.241027] acpi PNP0A08:00: ECAM at [mem 0x10000000000-0x1000fffffff] for [bus 00-ff]
[   16.810172] acpi PNP0A08:01: ECAM area [mem 0x7800000000-0x780fffffff] reserved by PNP0C02:00
[   16.826701] acpi PNP0A08:01: ECAM at [mem 0x7800000000-0x780fffffff] for [bus 00-ff]
[   17.289302] acpi PNP0A08:02: ECAM area [mem 0x1000000000-0x100fffffff] reserved by PNP0C02:00
[   17.305840] acpi PNP0A08:02: ECAM at [mem 0x1000000000-0x100fffffff] for [bus 00-ff]
[   17.641917] acpi PNP0A08:03: ECAM area [mem 0x5800000000-0x580fffffff] reserved by PNP0C02:00
[   17.658445] acpi PNP0A08:03: ECAM at [mem 0x5800000000-0x580fffffff] for [bus 00-ff]
[   18.059837] acpi PNP0A08:04: ECAM area [mem 0x6000000000-0x600fffffff] reserved by PNP0C02:00
[   18.076368] acpi PNP0A08:04: ECAM at [mem 0x6000000000-0x600fffffff] for [bus 00-ff]
[   18.413220] acpi PNP0A08:05: ECAM area [mem 0x7000000000-0x700fffffff] reserved by PNP0C02:00
[   18.429745] acpi PNP0A08:05: ECAM at [mem 0x7000000000-0x700fffffff] for [bus 00-ff]
[   18.767189] acpi PNP0A08:06: ECAM area [mem 0x600000000-0x60fffffff] reserved by PNP0C02:00
[   18.783559] acpi PNP0A08:06: ECAM at [mem 0x600000000-0x60fffffff] for [bus 00-ff]
[   19.201613] acpi PNP0A08:07: ECAM area [mem 0x400000000-0x40fffffff] reserved by PNP0C02:00
[   19.217965] acpi PNP0A08:07: ECAM at [mem 0x400000000-0x40fffffff] for [bus 00-ff]

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Arm64 double PCI ECAM reservations in acpi_resource_consumer()
  2021-06-03  0:15   ` Qian Cai
@ 2021-06-03 14:16     ` Lorenzo Pieralisi
  2021-06-03 15:44       ` Qian Cai
  0 siblings, 1 reply; 4+ messages in thread
From: Lorenzo Pieralisi @ 2021-06-03 14:16 UTC (permalink / raw)
  To: Qian Cai
  Cc: Bjorn Helgaas, Catalin Marinas, Will Deacon, linux-arm, Linux PCI

On Wed, Jun 02, 2021 at 08:15:20PM -0400, Qian Cai wrote:
> 
> 
> On 6/2/2021 6:09 PM, Bjorn Helgaas wrote:
> > [+cc linux-pci]
> > 
> > On Wed, Jun 2, 2021 at 4:49 PM Qian Cai <quic_qiancai@quicinc.com> wrote:
> >>
> >> Bjorn, I noticed PCI ECAM could be reserved twice on arm64. Firs time through,
> >>
> >> [   19.087790][    T1]  acpi_ns_walk_namespace+0xc0/0x390
> >> [   19.092927][    T1]  acpi_get_devices+0x160/0x1a4
> >> [   19.097629][    T1]  acpi_resource_consumer+0x8c/0xc0
> >> [   19.102680][    T1]  pci_acpi_scan_root+0x158/0x4c8
> >> [   19.107555][    T1]  acpi_pci_root_add+0x450/0x8e8
> >> [   19.112345][    T1]  acpi_bus_attach+0x300/0x7d0
> >> [   19.116960][    T1]  acpi_bus_attach+0x178/0x7d0
> >> [   19.121576][    T1]  acpi_bus_attach+0x178/0x7d0
> >> [   19.126190][    T1]  acpi_bus_scan+0xa8/0x170
> >> [   19.130545][    T1]  acpi_scan_init+0x220/0x558
> >> [   19.135074][    T1]  acpi_init+0x1f4/0x270
> >>
> >> where pci_acpi_setup_ecam_mapping() confirmed all reservations are succeed. Then,
> >>
> >> [   19.880588][    T1]  acpi_ns_walk_namespace+0xc0/0x390
> >> [   19.885725][    T1]  acpi_get_devices+0x160/0x1a4
> >> [   19.890426][    T1]  pnpacpi_init+0xa0/0x10
> >>
> >> As the results, those messages are showed up during the boot in pnpacpi_init().
> >>
> >> [ 17.763968] system 00:00: [mem 0x10000000000-0x1000fffffff window] could not be reserved
> >> [ 17.772900] system 00:00: [mem 0x7800000000-0x780fffffff window] could not be reserved
> >> [ 17.781627] system 00:00: [mem 0x7000000000-0x700fffffff window] could not be reserved
> >> [ 17.790350] system 00:00: [mem 0x6000000000-0x600fffffff window] could not be reserved
> >> [ 17.799073] system 00:00: [mem 0x5800000000-0x580fffffff window] could not be reserved
> >> [ 17.808155] system 00:00: [mem 0x1000000000-0x100fffffff window] could not be reserved
> >> [ 17.816862] system 00:00: [mem 0x600000000-0x60fffffff window] could not be reserved
> >> [ 17.825417] system 00:00: [mem 0x400000000-0x40fffffff window] could not be reserved
> >>
> >> Looking through the x86's version of pci_acpi_scan_root(), it won't call acpi_resource_consumer(), so I suppose this bug is only affecting arm64?
> > 
> > This might be related to
> > https://lore.kernel.org/linux-acpi/20210510234020.1330087-1-luzmaximilian@gmail.com/T/#u
> > 
> > Can you try applying that patch to see if it is related?
> 
> Unfortunately, that revert patch does not help. FYI, here is the first reservation from acpi_resource_consumer().

This is not the "reservation". AFAICS acpi_resource_consumer() checks
whether the ECAM region is part of _a_ given ACPI device _CRS in the
namespace, it does not "reserve" anything.

IIUC the issue here is that we request the ECAM region in
pci_ecam_create() and later the code in:

drivers/pnp/system.c

tries to request the ECAM region (that lives in the PNP0C02 _CRS) and
fails (see reserve_range() and request_mem_region()).

As the comment in reserve_range() goes, this is harmless, not sure
whether there is anything to do about it.

Lorenzo

> [   16.224306] acpi PNP0A08:00: ECAM area [mem 0x10000000000-0x1000fffffff] reserved by PNP0C02:00
> [   16.241027] acpi PNP0A08:00: ECAM at [mem 0x10000000000-0x1000fffffff] for [bus 00-ff]
> [   16.810172] acpi PNP0A08:01: ECAM area [mem 0x7800000000-0x780fffffff] reserved by PNP0C02:00
> [   16.826701] acpi PNP0A08:01: ECAM at [mem 0x7800000000-0x780fffffff] for [bus 00-ff]
> [   17.289302] acpi PNP0A08:02: ECAM area [mem 0x1000000000-0x100fffffff] reserved by PNP0C02:00
> [   17.305840] acpi PNP0A08:02: ECAM at [mem 0x1000000000-0x100fffffff] for [bus 00-ff]
> [   17.641917] acpi PNP0A08:03: ECAM area [mem 0x5800000000-0x580fffffff] reserved by PNP0C02:00
> [   17.658445] acpi PNP0A08:03: ECAM at [mem 0x5800000000-0x580fffffff] for [bus 00-ff]
> [   18.059837] acpi PNP0A08:04: ECAM area [mem 0x6000000000-0x600fffffff] reserved by PNP0C02:00
> [   18.076368] acpi PNP0A08:04: ECAM at [mem 0x6000000000-0x600fffffff] for [bus 00-ff]
> [   18.413220] acpi PNP0A08:05: ECAM area [mem 0x7000000000-0x700fffffff] reserved by PNP0C02:00
> [   18.429745] acpi PNP0A08:05: ECAM at [mem 0x7000000000-0x700fffffff] for [bus 00-ff]
> [   18.767189] acpi PNP0A08:06: ECAM area [mem 0x600000000-0x60fffffff] reserved by PNP0C02:00
> [   18.783559] acpi PNP0A08:06: ECAM at [mem 0x600000000-0x60fffffff] for [bus 00-ff]
> [   19.201613] acpi PNP0A08:07: ECAM area [mem 0x400000000-0x40fffffff] reserved by PNP0C02:00
> [   19.217965] acpi PNP0A08:07: ECAM at [mem 0x400000000-0x40fffffff] for [bus 00-ff]

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Arm64 double PCI ECAM reservations in acpi_resource_consumer()
  2021-06-03 14:16     ` Lorenzo Pieralisi
@ 2021-06-03 15:44       ` Qian Cai
  0 siblings, 0 replies; 4+ messages in thread
From: Qian Cai @ 2021-06-03 15:44 UTC (permalink / raw)
  To: Lorenzo Pieralisi
  Cc: Bjorn Helgaas, Catalin Marinas, Will Deacon, linux-arm, Linux PCI



On 6/3/2021 10:16 AM, Lorenzo Pieralisi wrote:
> This is not the "reservation". AFAICS acpi_resource_consumer() checks
> whether the ECAM region is part of _a_ given ACPI device _CRS in the
> namespace, it does not "reserve" anything.
> 
> IIUC the issue here is that we request the ECAM region in
> pci_ecam_create() and later the code in:

Okay, I was confused by the code. I thought once acpi_resource_consumer() returned something, it is "reserved".

	adev = acpi_resource_consumer(&cfgres);
	if (adev)
		dev_info(dev, "ECAM area %pR reserved by %s\n", &cfgres,
			 dev_name(&adev->dev));
	else
		dev_warn(dev, FW_BUG "ECAM area %pR not reserved in ACPI namespace\n",
			 &cfgres);

> 
> drivers/pnp/system.c
> 
> tries to request the ECAM region (that lives in the PNP0C02 _CRS) and
> fails (see reserve_range() and request_mem_region()).
> 
> As the comment in reserve_range() goes, this is harmless, not sure
> whether there is anything to do about it.

Actually, the comment said it is "usually harmless", so it is a tricky for an average Joe to figure out if one case falls into the "usual" bracket or not at the first place.

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2021-06-03 15:44 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
     [not found] <c82b61f5-00d4-182f-2bb7-3518adf2ca75@quicinc.com>
2021-06-02 22:09 ` Arm64 double PCI ECAM reservations in acpi_resource_consumer() Bjorn Helgaas
2021-06-03  0:15   ` Qian Cai
2021-06-03 14:16     ` Lorenzo Pieralisi
2021-06-03 15:44       ` Qian Cai

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).