RE: Purpose of pci_remap_iospace

[Bharat Kumar Gogada]

> > Subject: Re: Purpose of pci_remap_iospace
> >
> > On Wed, Jul 13, 2016 at 12:30:44PM +0000, Bharat Kumar Gogada wrote:
> >
> > [...]
> >
> > > err = of_pci_get_host_bridge_resources(node, 0, 0xff, &res, &iobase);
> > >         if (err) {
> > >                 pr_err("Getting bridge resources failed\n");
> > >                 return err;
> > >         }
> > > resource_list_for_each_entry(window, &res) {            //code for io
> resource
> > >                 struct resource *res = window->res;
> > >                 u64 restype = resource_type(res);
> > >
> > >                 switch (restype) {
> > >                 case IORESOURCE_IO:
> > >                         err = pci_remap_iospace(res, iobase);
> > >                         if(err)
> > >                                 pr_info("FAILED TO IPREMAP RESOURCE\n");
> > >                         break;
> > >                 default:
> > >                         dev_err(pcie->dev, "invalid resource %pR\n",
> > > res);
> > >
> > >                 }
> > >         }
> > >
> > > Other than above code I haven't done any change in driver.
> > >
> > Here is your PCI bridge mem space window assignment. I do not see an
> > IO window assignment which makes me think that IO cycles and relative
> > IO window is not enabled through the bridge, that's the reason you
> > can't assign IO space to the endpoint, because it has no parent IO window
> enabled IIUC.
> >
>
> We sorted this out, enabled the IO base limit / upper 16bit registers in the
> bridge for 32 bit decode.
> However my IO address being assigned to EP is different than what I provide
> in device tree.
>

Hi Lorenzo,

I missed something in my device tree now I corrected it.

ranges = <0x01000000 0x00000000 0xe0000000 0x00000000 0xe0000000 0 0x00010000   //io
                     0x02000000 0x00000000 0xe0100000 0x00000000 0xe0100000 0 0x0ef00000>; //non prefetchabe memory

[    2.389498] nwl-pcie fd0e0000.pcie: Link is UP
[    2.389541] PCI host bridge /amba/pcie@fd0e0000 ranges:
[    2.389558]   No bus range found for /amba/pcie@fd0e0000, using [bus 00-ff]
[    2.389583]    IO 0xe0000000..0xe000ffff -> 0xe0000000
[    2.389624]   MEM 0xe0100000..0xeeffffff -> 0xe0100000
[    2.389803] nwl-pcie fd0e0000.pcie: PCI host bridge to bus 0000:00
[    2.389822] pci_bus 0000:00: root bus resource [bus 00-ff]
[    2.389839] pci_bus 0000:00: root bus resource [io  0x0000-0xffff] (bus address [0xe0000000-0xe000ffff])
[    2.389863] pci_bus 0000:00: root bus resource [mem 0xe0100000-0xeeffffff]
[    2.390094] pci 0000:00:00.0: cannot attach to SMMU, is it on the same bus?
[    2.390110] iommu: Adding device 0000:00:00.0 to group 1
[    2.390274] pci 0000:01:00.0: reg 0x20: initial BAR value 0x00000000 invalid
[    2.390481] pci 0000:01:00.0: cannot attach to SMMU, is it on the same bus?
[    2.390496] iommu: Adding device 0000:01:00.0 to group 1
[    2.390533] in pci_bridge_check_ranges io 101
[    2.390545] in pci_bridge_check_ranges io 2 101
[    2.390575] pci 0000:00:00.0: BAR 8: assigned [mem 0xe0100000-0xe02fffff]
[    2.390592] pci 0000:00:00.0: BAR 7: assigned [io  0x1000-0x1fff]
[    2.390609] pci 0000:00:00.0: BAR 6: assigned [mem 0xe0300000-0xe03007ff pref]
[    2.390636] pci 0000:01:00.0: BAR 0: assigned [mem 0xe0100000-0xe01fffff 64bit]
[    2.390669] pci 0000:01:00.0: BAR 2: assigned [mem 0xe0200000-0xe02fffff 64bit]
[    2.390702] pci 0000:01:00.0: BAR 4: assigned [io  0x1000-0x103f]
[    2.390721] pci 0000:00:00.0: PCI bridge to [bus 01-0c]
[    2.390785] pci 0000:00:00.0:   bridge window [io  0x1000-0x1fff]
[    2.390823] pci 0000:00:00.0:   bridge window [mem 0xe0100000-0xe02fffff]

Lspci on bridge:
00:00.0 PCI bridge: Xilinx Corporation Device a024 (prog-if 00 [Normal decode])
        Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
        Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Interrupt: pin A routed to IRQ 224
        Bus: primary=00, secondary=01, subordinate=0c, sec-latency=0
        I/O behind bridge: e0001000-e0001fff
        Memory behind bridge: e0100000-e02fffff

Here my IO space is showing 4k, but what I'm providing is 4k ?(In above boot log also IO space length 4k)

Lspci on EP:
01:00.0 Memory controller: Xilinx Corporation Device d024
        Subsystem: Xilinx Corporation Device 0007
        Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
        Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Interrupt: pin A routed to IRQ 224
        Region 0: Memory at e0100000 (64-bit, non-prefetchable) [disabled] [size=1M]
        Region 2: Memory at e0200000 (64-bit, non-prefetchable) [disabled] [size=1M]
        Region 4: I/O ports at 1000 [disabled] [size=64]

On EP from where it is getting this 1000 address, it should be within I/O behind bridge range know ?


Thanks & Regards,
Bharat



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