PCI memory BAR assigned by u-boot not honored when using recent kernel

PCI memory BAR assigned by u-boot not honored when using recent kernel

[Karicheri, Muralidharan]

All,

I am working to port our PCI driver from v3.10 to v3.13 as part of up-streaming. The end point is Marvel SATA controller and a SCSI drive. The BARs are setup by U-Boot and Kernel is expected to honor the BAR assignments. In v3.10 based driver, I see bridge window size is 2MB for pre-fetch and non prefetched memory,  where as in v3.13rc4 based driver, it assigns a window size of 1MB. There is nothing in my driver that sets up the maximum window size. Has this been changed in recent kernel (v3.13+)? Even setting pci=firmware doesn't honor the BAR settings w.r.t to the memory BAR of the EP? The driver works fine with a e1000e NIC device driver from Intel and both Ethernet ports are functional, in this case, kernel does the BAR assignments. W.r.t SATA + SCSI, if I mount the filesystem on hard disk after boot up and do some basic read write tests, it is working, however when kernel is boot with filesystem on the harddisk, then it doesn't boot. I have attached PCI BAR related logs at boot up below for your information. Do you know what could be causing this? I am assuming the problem is due to the memory BARs being re-assigned with a different range than what is setup by U-Boot causing this issue.

Logs from a non working v3.13-rc4 driver

[    0.303686] pci_bus 0000:00: root bus resource [mem 0x50000000-0x5fffffff]
[    0.303695] pci_bus 0000:00: root bus resource [io  0x0000-0x3fff]
[    0.303704] pci_bus 0000:00: No busn resource found for root bus, will use [bus 00-ff]
[    0.303733] pci 0000:00:00.0: [104c:8888] type 01 class 0x060400
[    0.303980] PCI: bus0: Fast back to back transfers disabled
[    0.304151] pci 0000:01:00.0: [1b4b:9125] type 00 class 0x010601
[    0.304176] pci 0000:01:00.0: reg 0x10: [io  0x1000-0x1007]
[    0.304195] pci 0000:01:00.0: reg 0x14: [io  0x1008-0x100b]
[    0.304213] pci 0000:01:00.0: reg 0x18: [io  0x1010-0x1017]
[    0.304231] pci 0000:01:00.0: reg 0x1c: [io  0x1018-0x101b]
[    0.304248] pci 0000:01:00.0: reg 0x20: [io  0x1020-0x102f]
[    0.304266] pci 0000:01:00.0: reg 0x24: [mem 0x50000000-0x500007ff]
[    0.304285] pci 0000:01:00.0: reg 0x30: [mem 0xd0000000-0xd000ffff pref]
[    0.304347] pci 0000:01:00.0: PME# supported from D3hot
[    0.304502] PCI: bus1: Fast back to back transfers disabled
[    0.304512] pci_bus 0000:01: busn_res: [bus 01-ff] end is updated to 01
[    0.304524] pci_bus 0000:00: busn_res: [bus 00-ff] end is updated to 01
[    0.304536] keystone-pcie: Ending PCI scan...
[    0.304550] keystone-pcie: keystone_pcie_map_irq: slot 0, pin 1
[    0.304555] keystone-pcie: keystone_pcie_map_irq: legacy_irq 512
[    0.304577] pci 0000:00:00.0: BAR 8: assigned [mem 0x50000000-0x500fffff]
[    0.304587] pci 0000:00:00.0: BAR 9: assigned [mem 0x50100000-0x501fffff pref]
[    0.304596] pci 0000:00:00.0: BAR 7: assigned [io  0x1000-0x1fff]
[    0.304608] pci 0000:01:00.0: BAR 6: assigned [mem 0x50100000-0x5010ffff pref]
[    0.304618] pci 0000:01:00.0: BAR 5: assigned [mem 0x50000000-0x500007ff]
[    0.304629] pci 0000:01:00.0: BAR 4: assigned [io  0x1000-0x100f]
[    0.304641] pci 0000:01:00.0: BAR 0: assigned [io  0x1010-0x1017]
[    0.304652] pci 0000:01:00.0: BAR 2: assigned [io  0x1018-0x101f]
[    0.304663] pci 0000:01:00.0: BAR 1: assigned [io  0x1020-0x1023]
[    0.304674] pci 0000:01:00.0: BAR 3: assigned [io  0x1024-0x1027]
[    0.304687] pci 0000:00:00.0: PCI bridge to [bus 01]
[    0.304696] pci 0000:00:00.0:   bridge window [io  0x1000-0x1fff]
[    0.304707] pci 0000:00:00.0:   bridge window [mem 0x50000000-0x500fffff]
[    0.304716] pci 0000:00:00.0:   bridge window [mem 0x50100000-0x501fffff pref]

Logs from a working v3.10 driver

[  105.763092] pci_bus 0000:00: root bus resource [mem 0x50000000-0x5fffffff]
[  105.763101] pci_bus 0000:00: root bus resource [io  0x0000-0x3fff]
[  105.763110] pci_bus 0000:00: No busn resource found for root bus, will use [bus 00-ff]
[  105.763137] pci 0000:00:00.0: [104c:8888] type 01 class 0x060400
[  105.763389] PCI: bus0: Fast back to back transfers disabled
[  105.763563] pci 0000:01:00.0: [1b4b:9125] type 00 class 0x010601
[  105.763587] pci 0000:01:00.0: reg 10: [io  0x1000-0x1007]
[  105.763606] pci 0000:01:00.0: reg 14: [io  0x1008-0x100b]
[  105.763623] pci 0000:01:00.0: reg 18: [io  0x1010-0x1017]
[  105.763640] pci 0000:01:00.0: reg 1c: [io  0x1018-0x101b]
[  105.763657] pci 0000:01:00.0: reg 20: [io  0x1020-0x102f]
[  105.763674] pci 0000:01:00.0: reg 24: [mem 0x50000000-0x500007ff]
[  105.763692] pci 0000:01:00.0: reg 30: [mem 0xd0000000-0xd000ffff pref]
[  105.763754] pci 0000:01:00.0: PME# supported from D3hot
[  105.763919] PCI: bus1: Fast back to back transfers disabled
[  105.763930] pci_bus 0000:01: busn_res: [bus 01-ff] end is updated to 01
[  105.763942] pci_bus 0000:00: busn_res: [bus 00-ff] end is updated to 01
[  105.763954] keystone-pcie: Ending PCI scan...
[  105.763968] keystone-pcie: keystone_pcie_map_irq: slot 0, pin 1
[  105.763973] keystone-pcie: keystone_pcie_map_irq: legacy_irq 572
[  105.763996] pci 0000:00:00.0: BAR 8: assigned [mem 0x50000000-0x501fffff]
[  105.764006] pci 0000:00:00.0: BAR 9: assigned [mem 0x50200000-0x503fffff pref]
[  105.764015] pci 0000:00:00.0: BAR 7: assigned [io  0x1000-0x1fff]
[  105.764027] pci 0000:01:00.0: BAR 6: assigned [mem 0x50200000-0x5020ffff pref]
[  105.764037] pci 0000:01:00.0: BAR 5: assigned [mem 0x50000000-0x500007ff]
[  105.764048] pci 0000:01:00.0: BAR 4: assigned [io  0x1000-0x100f]
[  105.764060] pci 0000:01:00.0: BAR 0: assigned [io  0x1010-0x1017]
[  105.764071] pci 0000:01:00.0: BAR 2: assigned [io  0x1018-0x101f]
[  105.764082] pci 0000:01:00.0: BAR 1: assigned [io  0x1020-0x1023]
[  105.764092] pci 0000:01:00.0: BAR 3: assigned [io  0x1024-0x1027]
[  105.764105] pci 0000:00:00.0: PCI bridge to [bus 01]
[  105.764113] pci 0000:00:00.0:   bridge window [io  0x1000-0x1fff]
[  105.764124] pci 0000:00:00.0:   bridge window [mem 0x50000000-0x501fffff]
[  105.764133] pci 0000:00:00.0:   bridge window [mem 0x50200000-0x503fffff pref]


Murali Karicheri
Linux Kernel, Software Development

Re: PCI memory BAR assigned by u-boot not honored when using recent kernel

[Bjorn Helgaas]

[+cc Yinghai]

On Fri, Feb 14, 2014 at 02:51:26PM +0000, Karicheri, Muralidharan wrote:
> All,
> 
> I am working to port our PCI driver from v3.10 to v3.13 as part of
> up-streaming. The end point is Marvel SATA controller and a SCSI drive.
> The BARs are setup by U-Boot and Kernel is expected to honor the BAR
> assignments. 

There is no guarantee that the kernel will keep the BAR assignments done
by firmware or a bootloader.  Usually the kernel *does* keep them, as long
as they are valid, but you can not rely on that.

> In v3.10 based driver, I see bridge window size is 2MB for
> pre-fetch and non prefetched memory,  where as in v3.13rc4 based driver,
> it assigns a window size of 1MB. There is nothing in my driver that sets
> up the maximum window size.

Drivers are only responsible for their device; they don't control other
devices, including upstream bridges.  Bridge configuration is done before
the driver is even bound to the device.

Does U-Boot program the windows of the 00:00.0 bridge?  From the logs
below, it looks like it does not.

> Has this been changed in recent kernel
> (v3.13+)? Even setting pci=firmware doesn't honor the BAR settings w.r.t
> to the memory BAR of the EP? The driver works fine with a e1000e NIC
> device driver from Intel and both Ethernet ports are functional, in this
> case, kernel does the BAR assignments. W.r.t SATA + SCSI, if I mount the
> filesystem on hard disk after boot up and do some basic read write tests,
> it is working, however when kernel is boot with filesystem on the
> harddisk, then it doesn't boot. I have attached PCI BAR related logs at
> boot up below for your information. Do you know what could be causing
> this? I am assuming the problem is due to the memory BARs being
> re-assigned with a different range than what is setup by U-Boot causing
> this issue.

I don't see anything in the logs below that would explain the problem
you're seeing.  It's true that v3.13-rc4 assigns a smaller prefetchable
window to 00:00.0, but it's still big enough to contain the 01:00.0 ROM
(reg 30/BAR 6), so that shouldn't be a problem.

Maybe the complete logs would have a clue.

Bjorn

> Logs from a non working v3.13-rc4 driver
> 
> [    0.303686] pci_bus 0000:00: root bus resource [mem 0x50000000-0x5fffffff]
> [    0.303695] pci_bus 0000:00: root bus resource [io  0x0000-0x3fff]
> [    0.303704] pci_bus 0000:00: No busn resource found for root bus, will use [bus 00-ff]
> [    0.303733] pci 0000:00:00.0: [104c:8888] type 01 class 0x060400
> [    0.303980] PCI: bus0: Fast back to back transfers disabled
> [    0.304151] pci 0000:01:00.0: [1b4b:9125] type 00 class 0x010601
> [    0.304176] pci 0000:01:00.0: reg 0x10: [io  0x1000-0x1007]
> [    0.304195] pci 0000:01:00.0: reg 0x14: [io  0x1008-0x100b]
> [    0.304213] pci 0000:01:00.0: reg 0x18: [io  0x1010-0x1017]
> [    0.304231] pci 0000:01:00.0: reg 0x1c: [io  0x1018-0x101b]
> [    0.304248] pci 0000:01:00.0: reg 0x20: [io  0x1020-0x102f]
> [    0.304266] pci 0000:01:00.0: reg 0x24: [mem 0x50000000-0x500007ff]
> [    0.304285] pci 0000:01:00.0: reg 0x30: [mem 0xd0000000-0xd000ffff pref]
> [    0.304347] pci 0000:01:00.0: PME# supported from D3hot
> [    0.304502] PCI: bus1: Fast back to back transfers disabled
> [    0.304512] pci_bus 0000:01: busn_res: [bus 01-ff] end is updated to 01
> [    0.304524] pci_bus 0000:00: busn_res: [bus 00-ff] end is updated to 01
> [    0.304536] keystone-pcie: Ending PCI scan...
> [    0.304550] keystone-pcie: keystone_pcie_map_irq: slot 0, pin 1
> [    0.304555] keystone-pcie: keystone_pcie_map_irq: legacy_irq 512
> [    0.304577] pci 0000:00:00.0: BAR 8: assigned [mem 0x50000000-0x500fffff]
> [    0.304587] pci 0000:00:00.0: BAR 9: assigned [mem 0x50100000-0x501fffff pref]
> [    0.304596] pci 0000:00:00.0: BAR 7: assigned [io  0x1000-0x1fff]
> [    0.304608] pci 0000:01:00.0: BAR 6: assigned [mem 0x50100000-0x5010ffff pref]
> [    0.304618] pci 0000:01:00.0: BAR 5: assigned [mem 0x50000000-0x500007ff]
> [    0.304629] pci 0000:01:00.0: BAR 4: assigned [io  0x1000-0x100f]
> [    0.304641] pci 0000:01:00.0: BAR 0: assigned [io  0x1010-0x1017]
> [    0.304652] pci 0000:01:00.0: BAR 2: assigned [io  0x1018-0x101f]
> [    0.304663] pci 0000:01:00.0: BAR 1: assigned [io  0x1020-0x1023]
> [    0.304674] pci 0000:01:00.0: BAR 3: assigned [io  0x1024-0x1027]
> [    0.304687] pci 0000:00:00.0: PCI bridge to [bus 01]
> [    0.304696] pci 0000:00:00.0:   bridge window [io  0x1000-0x1fff]
> [    0.304707] pci 0000:00:00.0:   bridge window [mem 0x50000000-0x500fffff]
> [    0.304716] pci 0000:00:00.0:   bridge window [mem 0x50100000-0x501fffff pref]
> 
> Logs from a working v3.10 driver
> 
> [  105.763092] pci_bus 0000:00: root bus resource [mem 0x50000000-0x5fffffff]
> [  105.763101] pci_bus 0000:00: root bus resource [io  0x0000-0x3fff]
> [  105.763110] pci_bus 0000:00: No busn resource found for root bus, will use [bus 00-ff]
> [  105.763137] pci 0000:00:00.0: [104c:8888] type 01 class 0x060400
> [  105.763389] PCI: bus0: Fast back to back transfers disabled
> [  105.763563] pci 0000:01:00.0: [1b4b:9125] type 00 class 0x010601
> [  105.763587] pci 0000:01:00.0: reg 10: [io  0x1000-0x1007]
> [  105.763606] pci 0000:01:00.0: reg 14: [io  0x1008-0x100b]
> [  105.763623] pci 0000:01:00.0: reg 18: [io  0x1010-0x1017]
> [  105.763640] pci 0000:01:00.0: reg 1c: [io  0x1018-0x101b]
> [  105.763657] pci 0000:01:00.0: reg 20: [io  0x1020-0x102f]
> [  105.763674] pci 0000:01:00.0: reg 24: [mem 0x50000000-0x500007ff]
> [  105.763692] pci 0000:01:00.0: reg 30: [mem 0xd0000000-0xd000ffff pref]
> [  105.763754] pci 0000:01:00.0: PME# supported from D3hot
> [  105.763919] PCI: bus1: Fast back to back transfers disabled
> [  105.763930] pci_bus 0000:01: busn_res: [bus 01-ff] end is updated to 01
> [  105.763942] pci_bus 0000:00: busn_res: [bus 00-ff] end is updated to 01
> [  105.763954] keystone-pcie: Ending PCI scan...
> [  105.763968] keystone-pcie: keystone_pcie_map_irq: slot 0, pin 1
> [  105.763973] keystone-pcie: keystone_pcie_map_irq: legacy_irq 572
> [  105.763996] pci 0000:00:00.0: BAR 8: assigned [mem 0x50000000-0x501fffff]
> [  105.764006] pci 0000:00:00.0: BAR 9: assigned [mem 0x50200000-0x503fffff pref]
> [  105.764015] pci 0000:00:00.0: BAR 7: assigned [io  0x1000-0x1fff]
> [  105.764027] pci 0000:01:00.0: BAR 6: assigned [mem 0x50200000-0x5020ffff pref]
> [  105.764037] pci 0000:01:00.0: BAR 5: assigned [mem 0x50000000-0x500007ff]
> [  105.764048] pci 0000:01:00.0: BAR 4: assigned [io  0x1000-0x100f]
> [  105.764060] pci 0000:01:00.0: BAR 0: assigned [io  0x1010-0x1017]
> [  105.764071] pci 0000:01:00.0: BAR 2: assigned [io  0x1018-0x101f]
> [  105.764082] pci 0000:01:00.0: BAR 1: assigned [io  0x1020-0x1023]
> [  105.764092] pci 0000:01:00.0: BAR 3: assigned [io  0x1024-0x1027]
> [  105.764105] pci 0000:00:00.0: PCI bridge to [bus 01]
> [  105.764113] pci 0000:00:00.0:   bridge window [io  0x1000-0x1fff]
> [  105.764124] pci 0000:00:00.0:   bridge window [mem 0x50000000-0x501fffff]
> [  105.764133] pci 0000:00:00.0:   bridge window [mem 0x50200000-0x503fffff pref]
> 
> 
> Murali Karicheri
> Linux Kernel, Software Development
> 
> 
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RE: PCI memory BAR assigned by u-boot not honored when using recent kernel

[Karicheri, Muralidharan]

>-----Original Message-----
>From: Bjorn Helgaas [mailto:bhelgaas@google.com]
>Sent: Friday, February 14, 2014 11:45 AM
>To: Karicheri, Muralidharan
>Cc: linux-pci@vger.kernel.org; Yinghai Lu
>Subject: Re: PCI memory BAR assigned by u-boot not honored when using recent kernel
>
>[+cc Yinghai]
>
>On Fri, Feb 14, 2014 at 02:51:26PM +0000, Karicheri, Muralidharan wrote:
>> All,
>>
>> I am working to port our PCI driver from v3.10 to v3.13 as part of
>> up-streaming. The end point is Marvel SATA controller and a SCSI drive.
>> The BARs are setup by U-Boot and Kernel is expected to honor the BAR
>> assignments.
>
>There is no guarantee that the kernel will keep the BAR assignments done by firmware or
>a bootloader.  Usually the kernel *does* keep them, as long as they are valid, but you
>can not rely on that.
>
Bjorn,

Thanks for responding.

Doesn't pci=firmware supposed to do this? Is it broken?

>> In v3.10 based driver, I see bridge window size is 2MB for pre-fetch
>> and non prefetched memory,  where as in v3.13rc4 based driver, it
>> assigns a window size of 1MB. There is nothing in my driver that sets
>> up the maximum window size.
>
>Drivers are only responsible for their device; they don't control other devices, including
>upstream bridges.  Bridge configuration is done before the driver is even bound to the
>device.
>
>Does U-Boot program the windows of the 00:00.0 bridge?  From the logs below, it looks
>like it does not.
>

Not sure if u-boot sets up the 00.00.0 bridge, I will check and get back
and also provide more log.But is there a way I can override the default from 1MB
to 2MB to check if that resolves the issue. Which part of the pci code uses default 1MB?
Thanks in advance for your input.

Murali
>> Has this been changed in recent kernel (v3.13+)? Even setting
>> pci=firmware doesn't honor the BAR settings w.r.t to the memory BAR of
>> the EP? The driver works fine with a e1000e NIC device driver from
>> Intel and both Ethernet ports are functional, in this case, kernel
>> does the BAR assignments. W.r.t SATA + SCSI, if I mount the filesystem
>> on hard disk after boot up and do some basic read write tests, it is
>> working, however when kernel is boot with filesystem on the harddisk,
>> then it doesn't boot. I have attached PCI BAR related logs at boot up
>> below for your information. Do you know what could be causing this? I
>> am assuming the problem is due to the memory BARs being re-assigned
>> with a different range than what is setup by U-Boot causing this
>> issue.
>
>I don't see anything in the logs below that would explain the problem you're seeing.  It's
>true that v3.13-rc4 assigns a smaller prefetchable window to 00:00.0, but it's still big
>enough to contain the 01:00.0 ROM (reg 30/BAR 6), so that shouldn't be a problem.
>
>Maybe the complete logs would have a clue.
>
>Bjorn
>
>> Logs from a non working v3.13-rc4 driver
>>
>> [    0.303686] pci_bus 0000:00: root bus resource [mem 0x50000000-0x5fffffff]
>> [    0.303695] pci_bus 0000:00: root bus resource [io  0x0000-0x3fff]
>> [    0.303704] pci_bus 0000:00: No busn resource found for root bus, will use [bus 00-
>ff]
>> [    0.303733] pci 0000:00:00.0: [104c:8888] type 01 class 0x060400
>> [    0.303980] PCI: bus0: Fast back to back transfers disabled
>> [    0.304151] pci 0000:01:00.0: [1b4b:9125] type 00 class 0x010601
>> [    0.304176] pci 0000:01:00.0: reg 0x10: [io  0x1000-0x1007]
>> [    0.304195] pci 0000:01:00.0: reg 0x14: [io  0x1008-0x100b]
>> [    0.304213] pci 0000:01:00.0: reg 0x18: [io  0x1010-0x1017]
>> [    0.304231] pci 0000:01:00.0: reg 0x1c: [io  0x1018-0x101b]
>> [    0.304248] pci 0000:01:00.0: reg 0x20: [io  0x1020-0x102f]
>> [    0.304266] pci 0000:01:00.0: reg 0x24: [mem 0x50000000-0x500007ff]
>> [    0.304285] pci 0000:01:00.0: reg 0x30: [mem 0xd0000000-0xd000ffff pref]
>> [    0.304347] pci 0000:01:00.0: PME# supported from D3hot
>> [    0.304502] PCI: bus1: Fast back to back transfers disabled
>> [    0.304512] pci_bus 0000:01: busn_res: [bus 01-ff] end is updated to 01
>> [    0.304524] pci_bus 0000:00: busn_res: [bus 00-ff] end is updated to 01
>> [    0.304536] keystone-pcie: Ending PCI scan...
>> [    0.304550] keystone-pcie: keystone_pcie_map_irq: slot 0, pin 1
>> [    0.304555] keystone-pcie: keystone_pcie_map_irq: legacy_irq 512
>> [    0.304577] pci 0000:00:00.0: BAR 8: assigned [mem 0x50000000-0x500fffff]
>> [    0.304587] pci 0000:00:00.0: BAR 9: assigned [mem 0x50100000-0x501fffff pref]
>> [    0.304596] pci 0000:00:00.0: BAR 7: assigned [io  0x1000-0x1fff]
>> [    0.304608] pci 0000:01:00.0: BAR 6: assigned [mem 0x50100000-0x5010ffff pref]
>> [    0.304618] pci 0000:01:00.0: BAR 5: assigned [mem 0x50000000-0x500007ff]
>> [    0.304629] pci 0000:01:00.0: BAR 4: assigned [io  0x1000-0x100f]
>> [    0.304641] pci 0000:01:00.0: BAR 0: assigned [io  0x1010-0x1017]
>> [    0.304652] pci 0000:01:00.0: BAR 2: assigned [io  0x1018-0x101f]
>> [    0.304663] pci 0000:01:00.0: BAR 1: assigned [io  0x1020-0x1023]
>> [    0.304674] pci 0000:01:00.0: BAR 3: assigned [io  0x1024-0x1027]
>> [    0.304687] pci 0000:00:00.0: PCI bridge to [bus 01]
>> [    0.304696] pci 0000:00:00.0:   bridge window [io  0x1000-0x1fff]
>> [    0.304707] pci 0000:00:00.0:   bridge window [mem 0x50000000-0x500fffff]
>> [    0.304716] pci 0000:00:00.0:   bridge window [mem 0x50100000-0x501fffff pref]
>>
>> Logs from a working v3.10 driver
>>
>> [  105.763092] pci_bus 0000:00: root bus resource [mem
>> 0x50000000-0x5fffffff] [  105.763101] pci_bus 0000:00: root bus
>> resource [io  0x0000-0x3fff] [  105.763110] pci_bus 0000:00: No busn
>> resource found for root bus, will use [bus 00-ff] [  105.763137] pci
>> 0000:00:00.0: [104c:8888] type 01 class 0x060400 [  105.763389] PCI:
>> bus0: Fast back to back transfers disabled [  105.763563] pci
>> 0000:01:00.0: [1b4b:9125] type 00 class 0x010601 [  105.763587] pci
>> 0000:01:00.0: reg 10: [io  0x1000-0x1007] [  105.763606] pci
>> 0000:01:00.0: reg 14: [io  0x1008-0x100b] [  105.763623] pci
>> 0000:01:00.0: reg 18: [io  0x1010-0x1017] [  105.763640] pci
>> 0000:01:00.0: reg 1c: [io  0x1018-0x101b] [  105.763657] pci
>> 0000:01:00.0: reg 20: [io  0x1020-0x102f] [  105.763674] pci
>> 0000:01:00.0: reg 24: [mem 0x50000000-0x500007ff] [  105.763692] pci
>> 0000:01:00.0: reg 30: [mem 0xd0000000-0xd000ffff pref] [  105.763754]
>> pci 0000:01:00.0: PME# supported from D3hot [  105.763919] PCI: bus1:
>> Fast back to back transfers disabled [  105.763930] pci_bus 0000:01:
>> busn_res: [bus 01-ff] end is updated to 01 [  105.763942] pci_bus
>> 0000:00: busn_res: [bus 00-ff] end is updated to 01 [  105.763954] keystone-pcie:
>Ending PCI scan...
>> [  105.763968] keystone-pcie: keystone_pcie_map_irq: slot 0, pin 1 [
>> 105.763973] keystone-pcie: keystone_pcie_map_irq: legacy_irq 572 [
>> 105.763996] pci 0000:00:00.0: BAR 8: assigned [mem
>> 0x50000000-0x501fffff] [  105.764006] pci 0000:00:00.0: BAR 9:
>> assigned [mem 0x50200000-0x503fffff pref] [  105.764015] pci
>> 0000:00:00.0: BAR 7: assigned [io  0x1000-0x1fff] [  105.764027] pci
>> 0000:01:00.0: BAR 6: assigned [mem 0x50200000-0x5020ffff pref] [
>> 105.764037] pci 0000:01:00.0: BAR 5: assigned [mem
>> 0x50000000-0x500007ff] [  105.764048] pci 0000:01:00.0: BAR 4:
>> assigned [io  0x1000-0x100f] [  105.764060] pci 0000:01:00.0: BAR 0:
>> assigned [io  0x1010-0x1017] [  105.764071] pci 0000:01:00.0: BAR 2:
>> assigned [io  0x1018-0x101f] [  105.764082] pci 0000:01:00.0: BAR 1:
>> assigned [io  0x1020-0x1023] [  105.764092] pci 0000:01:00.0: BAR 3: assigned [io
>0x1024-0x1027] [  105.764105] pci 0000:00:00.0: PCI bridge to [bus 01]
>> [  105.764113] pci 0000:00:00.0:   bridge window [io  0x1000-0x1fff]
>> [  105.764124] pci 0000:00:00.0:   bridge window [mem 0x50000000-0x501fffff]
>> [  105.764133] pci 0000:00:00.0:   bridge window [mem 0x50200000-0x503fffff pref]
>>
>>
>> Murali Karicheri
>> Linux Kernel, Software Development
>>
>>
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>> info at  http://vger.kernel.org/majordomo-info.html

Re: PCI memory BAR assigned by u-boot not honored when using recent kernel

[Yinghai Lu]

On Fri, Feb 14, 2014 at 9:32 AM, Karicheri, Muralidharan
>>There is no guarantee that the kernel will keep the BAR assignments done by firmware or
>>a bootloader.  Usually the kernel *does* keep them, as long as they are valid, but you
>>can not rely on that.

Not sure what arch in your case.

You need to have code like pcibios_resource_survey() in x86 to
checking and reserve resource from firmware.

Also firmware need to make sure mmio assignments are valid otherwise
kernel will reject and reassign a new one.

Thanks

Yinghai

RE: PCI memory BAR assigned by u-boot not honored when using recent kernel

[Karicheri, Muralidharan]

>-----Original Message-----
>From: yhlu.kernel@gmail.com [mailto:yhlu.kernel@gmail.com] On Behalf Of Yinghai Lu
>Sent: Friday, February 14, 2014 2:24 PM
>To: Karicheri, Muralidharan
>Cc: Bjorn Helgaas; linux-pci@vger.kernel.org
>Subject: Re: PCI memory BAR assigned by u-boot not honored when using recent kernel
>
>On Fri, Feb 14, 2014 at 9:32 AM, Karicheri, Muralidharan
>>>There is no guarantee that the kernel will keep the BAR assignments
>>>done by firmware or a bootloader.  Usually the kernel *does* keep
>>>them, as long as they are valid, but you can not rely on that.
>
>Not sure what arch in your case.
>
Yinghai,

Thanks for the response

The arch is ARM 32bit (V7 cortex A8 processor)

>You need to have code like pcibios_resource_survey() in x86 to checking and reserve
>resource from firmware.
>
>Also firmware need to make sure mmio assignments are valid otherwise kernel will reject
>and reassign a new one.
>

I see pcibios_resource_survey() is used only on non ARM architectures. This driver works fine on
v3.10 kernel, but got issues with v3.13. So I am currently debugging this.

Murali
>Thanks
>
>Yinghai