diff mbox

[v2] pcie: Add Xilinx PCIe Host Bridge IP driver

Message ID 1393854036-5244-1-git-send-email-sthokal@xilinx.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Srikanth Thokala March 3, 2014, 1:40 p.m. UTC
This is the driver for Xilinx AXI PCIe Host Bridge Soft IP

Signed-off-by: Srikanth Thokala <sthokal@xilinx.com>
---
- Rebased on v3.14.0-rc5
- Removed IP specific DT properties like include-rc, axibar-num etc.,
  as suggested by Jason and Bjorn, Thanks
---
 .../devicetree/bindings/pci/xilinx-pcie.txt        |   23 +
 drivers/pci/host/Kconfig                           |    7 +
 drivers/pci/host/Makefile                          |    1 +
 drivers/pci/host/pci-xilinx.c                      |  940 ++++++++++++++++++++
 4 files changed, 971 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pci/xilinx-pcie.txt
 create mode 100644 drivers/pci/host/pci-xilinx.c

Comments

Jason Gunthorpe March 3, 2014, 5:43 p.m. UTC | #1
On Mon, Mar 03, 2014 at 07:10:36PM +0530, Srikanth Thokala wrote:

> +Required properties:
> +- #address-cells: Address representation for root ports, set to <3>
> +- #size-cells: Size representation for root ports, set to <2>
> +- compatible: Should contain "xlnx,axi-pcie-host-1.00.a"
> +- reg: Should contain AXI PCIe registers location and length
> +- interrupts: Should contain AXI PCIe interrupt
> +- ranges: ranges for the PCI memory regions
> +	Please refer to the standard PCI bus binding document for a more
> +	detailed explanation
> +
> +Example:
> +++++++++
> +
> +	pci_express: axi-pcie@50000000 {
> +		#address-cells = <3>;
> +		#size-cells = <2>;
> +		compatible = "xlnx,axi-pcie-host-1.00.a";
> +		reg = < 0x50000000 0x10000000 >;
> +		interrupts = < 0 52 4 >;
> +		ranges = < 0x02000000 0 0x60000000 0x60000000 0 0x10000000 >;
> +	};

That is much shorter, more notes:
 - It looks like the driver (HW?) has no support for IO space?
 - How are INTA/B/C/D handled? Typically I'd like to see an
   interrupt-mapping block describing them.

   There are a few options here, if the HW can decode A/B/C/D then
   it probably needs another irq_domain for INTx, and have the IRQ
   handler decode like it does for MSI.
- The stanza needs a
    device_type = "pci";

> +	for (i = 0; i < port->mem_resno; i++)
> +		pci_add_resource_offset(&sys->resources, &port->mem[i],
> +					sys->mem_offset);

The sys->mem_offset is probably wrong, please review Arnd's comments
on the recent threads with Will and Liviu regarding how this is
supposed to work with DT.

You may want to work with Liviu to use his patch set which provides
more generic support. Also, the driver needs to put every one of these
ports in a PCI domain, Liviu is working on generic support for that
too.

> +static struct pci_bus __init *xilinx_pcie_scan_bus(int nr,
> +				struct pci_sys_data *sys)
> +{
> +	struct xilinx_pcie_port *port = sys_to_pcie(sys);
> +	struct pci_bus *bus;
> +
> +	if (port) {
> +		port->root_busno = sys->busnr;
> +		bus = pci_scan_root_bus(NULL, sys->busnr, &xilinx_pcie_ops,
> +					sys, &sys->resources);

The NULL is probably wrong, please review the recent thread with Lucas
and Jingoo 'PCI irq mapping fixes and cleanups'

> +static int xilinx_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
> +{
> +	struct xilinx_pcie_port *port = sys_to_pcie(dev->bus->sysdata);
> +
> +	if (!port)
> +		return -EINVAL;
> +
> +	return port->irq;
> +}

It is preferred to use DT mechanisms via of_irq_parse_and_map_pci
(interrupt-mapping, etc) to define the slot IRQ, drivers should not
provide a map_irq unless absolutely necessary.

> +	/* make sure it is root port before touching header */
> +	pcie_write(port, PCI_COMMAND_MASTER, PCI_COMMAND);

Bit of a confusing comment

> +	/* Check if PCIe link is up? */
> +	port->link_up = xilinx_pcie_is_link_up(port);
> +	if (!port->link_up)
> +		dev_info(port->dev, "PCIe Link is DOWN\n");
> +	else
> +		dev_info(port->dev, "PCIe Link is UP\n");

Don't forget to think about hot plug

> +	/* Register Interrupt Handler */
> +	err = request_irq(port->irq, xilinx_pcie_intr_handler,
> +				IRQF_SHARED, "xilinx-pcie", port);

Use devm? This is leaking on error cases.

Review other resources too...

> +	/* Request and map I/O memory */
> +	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	port->phys_reg_base = io->start;
> +	port->reg_size = resource_size(io);

Here it uses the platform resource..

> +	/* Map the IRQ */
> +	port->irq = irq_of_parse_and_map(node, 0);

.. And here it doesn't, probably should be consistent and just use the
platform resources.

Jason
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Srikanth Thokala March 3, 2014, 6:13 p.m. UTC | #2
On Mon, Mar 3, 2014 at 11:13 PM, Jason Gunthorpe
<jgunthorpe@obsidianresearch.com> wrote:
> On Mon, Mar 03, 2014 at 07:10:36PM +0530, Srikanth Thokala wrote:
>
>> +Required properties:
>> +- #address-cells: Address representation for root ports, set to <3>
>> +- #size-cells: Size representation for root ports, set to <2>
>> +- compatible: Should contain "xlnx,axi-pcie-host-1.00.a"
>> +- reg: Should contain AXI PCIe registers location and length
>> +- interrupts: Should contain AXI PCIe interrupt
>> +- ranges: ranges for the PCI memory regions
>> +     Please refer to the standard PCI bus binding document for a more
>> +     detailed explanation
>> +
>> +Example:
>> +++++++++
>> +
>> +     pci_express: axi-pcie@50000000 {
>> +             #address-cells = <3>;
>> +             #size-cells = <2>;
>> +             compatible = "xlnx,axi-pcie-host-1.00.a";
>> +             reg = < 0x50000000 0x10000000 >;
>> +             interrupts = < 0 52 4 >;
>> +             ranges = < 0x02000000 0 0x60000000 0x60000000 0 0x10000000 >;
>> +     };
>
> That is much shorter, more notes:
>  - It looks like the driver (HW?) has no support for IO space?

Yes, there is no support for IO space.

>  - How are INTA/B/C/D handled? Typically I'd like to see an
>    interrupt-mapping block describing them.

                                  /
                                 /
CPU   <--- PCIe IP  <---



>
>    There are a few options here, if the HW can decode A/B/C/D then
>    it probably needs another irq_domain for INTx, and have the IRQ
>    handler decode like it does for MSI.
> - The stanza needs a
>     device_type = "pci";
>
>> +     for (i = 0; i < port->mem_resno; i++)
>> +             pci_add_resource_offset(&sys->resources, &port->mem[i],
>> +                                     sys->mem_offset);
>
> The sys->mem_offset is probably wrong, please review Arnd's comments
> on the recent threads with Will and Liviu regarding how this is
> supposed to work with DT.
>
> You may want to work with Liviu to use his patch set which provides
> more generic support. Also, the driver needs to put every one of these
> ports in a PCI domain, Liviu is working on generic support for that
> too.

Sure, I will check and come back to you.

>
>> +static struct pci_bus __init *xilinx_pcie_scan_bus(int nr,
>> +                             struct pci_sys_data *sys)
>> +{
>> +     struct xilinx_pcie_port *port = sys_to_pcie(sys);
>> +     struct pci_bus *bus;
>> +
>> +     if (port) {
>> +             port->root_busno = sys->busnr;
>> +             bus = pci_scan_root_bus(NULL, sys->busnr, &xilinx_pcie_ops,
>> +                                     sys, &sys->resources);
>
> The NULL is probably wrong, please review the recent thread with Lucas
> and Jingoo 'PCI irq mapping fixes and cleanups'

Ok.

>
>> +static int xilinx_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
>> +{
>> +     struct xilinx_pcie_port *port = sys_to_pcie(dev->bus->sysdata);
>> +
>> +     if (!port)
>> +             return -EINVAL;
>> +
>> +     return port->irq;
>> +}
>
> It is preferred to use DT mechanisms via of_irq_parse_and_map_pci
> (interrupt-mapping, etc) to define the slot IRQ, drivers should not
> provide a map_irq unless absolutely necessary.

Ok.

>
>> +     /* make sure it is root port before touching header */
>> +     pcie_write(port, PCI_COMMAND_MASTER, PCI_COMMAND);
>
> Bit of a confusing comment

I will correct it.

>
>> +     /* Check if PCIe link is up? */
>> +     port->link_up = xilinx_pcie_is_link_up(port);
>> +     if (!port->link_up)
>> +             dev_info(port->dev, "PCIe Link is DOWN\n");
>> +     else
>> +             dev_info(port->dev, "PCIe Link is UP\n");
>
> Don't forget to think about hot plug

Ok, you mean using the 'rescan' correct?

>
>> +     /* Register Interrupt Handler */
>> +     err = request_irq(port->irq, xilinx_pcie_intr_handler,
>> +                             IRQF_SHARED, "xilinx-pcie", port);
>
> Use devm? This is leaking on error cases.
>
> Review other resources too...
>
>> +     /* Request and map I/O memory */
>> +     io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +     port->phys_reg_base = io->start;
>> +     port->reg_size = resource_size(io);
>
> Here it uses the platform resource..
>
>> +     /* Map the IRQ */
>> +     port->irq = irq_of_parse_and_map(node, 0);
>
> .. And here it doesn't, probably should be consistent and just use the
> platform resources.

Ok, I will correct it.

Srikanth

>
> Jason
> --
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Srikanth Thokala March 3, 2014, 6:14 p.m. UTC | #3
Please ignore the last message,  accidentally it was sent.  Apologies.

Srikanth

On Mon, Mar 3, 2014 at 11:43 PM, Srikanth Thokala <sthokal@xilinx.com> wrote:
> On Mon, Mar 3, 2014 at 11:13 PM, Jason Gunthorpe
> <jgunthorpe@obsidianresearch.com> wrote:
>> On Mon, Mar 03, 2014 at 07:10:36PM +0530, Srikanth Thokala wrote:
>>
>>> +Required properties:
>>> +- #address-cells: Address representation for root ports, set to <3>
>>> +- #size-cells: Size representation for root ports, set to <2>
>>> +- compatible: Should contain "xlnx,axi-pcie-host-1.00.a"
>>> +- reg: Should contain AXI PCIe registers location and length
>>> +- interrupts: Should contain AXI PCIe interrupt
>>> +- ranges: ranges for the PCI memory regions
>>> +     Please refer to the standard PCI bus binding document for a more
>>> +     detailed explanation
>>> +
>>> +Example:
>>> +++++++++
>>> +
>>> +     pci_express: axi-pcie@50000000 {
>>> +             #address-cells = <3>;
>>> +             #size-cells = <2>;
>>> +             compatible = "xlnx,axi-pcie-host-1.00.a";
>>> +             reg = < 0x50000000 0x10000000 >;
>>> +             interrupts = < 0 52 4 >;
>>> +             ranges = < 0x02000000 0 0x60000000 0x60000000 0 0x10000000 >;
>>> +     };
>>
>> That is much shorter, more notes:
>>  - It looks like the driver (HW?) has no support for IO space?
>
> Yes, there is no support for IO space.
>
>>  - How are INTA/B/C/D handled? Typically I'd like to see an
>>    interrupt-mapping block describing them.
>
>                                   /
>                                  /
> CPU   <--- PCIe IP  <---
>
>
>
>>
>>    There are a few options here, if the HW can decode A/B/C/D then
>>    it probably needs another irq_domain for INTx, and have the IRQ
>>    handler decode like it does for MSI.
>> - The stanza needs a
>>     device_type = "pci";
>>
>>> +     for (i = 0; i < port->mem_resno; i++)
>>> +             pci_add_resource_offset(&sys->resources, &port->mem[i],
>>> +                                     sys->mem_offset);
>>
>> The sys->mem_offset is probably wrong, please review Arnd's comments
>> on the recent threads with Will and Liviu regarding how this is
>> supposed to work with DT.
>>
>> You may want to work with Liviu to use his patch set which provides
>> more generic support. Also, the driver needs to put every one of these
>> ports in a PCI domain, Liviu is working on generic support for that
>> too.
>
> Sure, I will check and come back to you.
>
>>
>>> +static struct pci_bus __init *xilinx_pcie_scan_bus(int nr,
>>> +                             struct pci_sys_data *sys)
>>> +{
>>> +     struct xilinx_pcie_port *port = sys_to_pcie(sys);
>>> +     struct pci_bus *bus;
>>> +
>>> +     if (port) {
>>> +             port->root_busno = sys->busnr;
>>> +             bus = pci_scan_root_bus(NULL, sys->busnr, &xilinx_pcie_ops,
>>> +                                     sys, &sys->resources);
>>
>> The NULL is probably wrong, please review the recent thread with Lucas
>> and Jingoo 'PCI irq mapping fixes and cleanups'
>
> Ok.
>
>>
>>> +static int xilinx_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
>>> +{
>>> +     struct xilinx_pcie_port *port = sys_to_pcie(dev->bus->sysdata);
>>> +
>>> +     if (!port)
>>> +             return -EINVAL;
>>> +
>>> +     return port->irq;
>>> +}
>>
>> It is preferred to use DT mechanisms via of_irq_parse_and_map_pci
>> (interrupt-mapping, etc) to define the slot IRQ, drivers should not
>> provide a map_irq unless absolutely necessary.
>
> Ok.
>
>>
>>> +     /* make sure it is root port before touching header */
>>> +     pcie_write(port, PCI_COMMAND_MASTER, PCI_COMMAND);
>>
>> Bit of a confusing comment
>
> I will correct it.
>
>>
>>> +     /* Check if PCIe link is up? */
>>> +     port->link_up = xilinx_pcie_is_link_up(port);
>>> +     if (!port->link_up)
>>> +             dev_info(port->dev, "PCIe Link is DOWN\n");
>>> +     else
>>> +             dev_info(port->dev, "PCIe Link is UP\n");
>>
>> Don't forget to think about hot plug
>
> Ok, you mean using the 'rescan' correct?
>
>>
>>> +     /* Register Interrupt Handler */
>>> +     err = request_irq(port->irq, xilinx_pcie_intr_handler,
>>> +                             IRQF_SHARED, "xilinx-pcie", port);
>>
>> Use devm? This is leaking on error cases.
>>
>> Review other resources too...
>>
>>> +     /* Request and map I/O memory */
>>> +     io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> +     port->phys_reg_base = io->start;
>>> +     port->reg_size = resource_size(io);
>>
>> Here it uses the platform resource..
>>
>>> +     /* Map the IRQ */
>>> +     port->irq = irq_of_parse_and_map(node, 0);
>>
>> .. And here it doesn't, probably should be consistent and just use the
>> platform resources.
>
> Ok, I will correct it.
>
> Srikanth
>
>>
>> Jason
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
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Srikanth Thokala March 3, 2014, 6:51 p.m. UTC | #4
On Mon, Mar 3, 2014 at 11:13 PM, Jason Gunthorpe
<jgunthorpe@obsidianresearch.com> wrote:
> On Mon, Mar 03, 2014 at 07:10:36PM +0530, Srikanth Thokala wrote:
>
>> +Required properties:
>> +- #address-cells: Address representation for root ports, set to <3>
>> +- #size-cells: Size representation for root ports, set to <2>
>> +- compatible: Should contain "xlnx,axi-pcie-host-1.00.a"
>> +- reg: Should contain AXI PCIe registers location and length
>> +- interrupts: Should contain AXI PCIe interrupt
>> +- ranges: ranges for the PCI memory regions
>> +     Please refer to the standard PCI bus binding document for a more
>> +     detailed explanation
>> +
>> +Example:
>> +++++++++
>> +
>> +     pci_express: axi-pcie@50000000 {
>> +             #address-cells = <3>;
>> +             #size-cells = <2>;
>> +             compatible = "xlnx,axi-pcie-host-1.00.a";
>> +             reg = < 0x50000000 0x10000000 >;
>> +             interrupts = < 0 52 4 >;
>> +             ranges = < 0x02000000 0 0x60000000 0x60000000 0 0x10000000 >;
>> +     };
>
> That is much shorter, more notes:
>  - It looks like the driver (HW?) has no support for IO space?

It doesnt support IO space, I will add notes.

>  - How are INTA/B/C/D handled? Typically I'd like to see an
>    interrupt-mapping block describing them.
>
>    There are a few options here, if the HW can decode A/B/C/D then
>    it probably needs another irq_domain for INTx, and have the IRQ
>    handler decode like it does for MSI.

The core provides a single interrupt for both INTx/MSI messages.  The
core decodes the TLP messages and accordingly assert the INTx/MSI
bits.  It provides two registers Interrupt FIFO Read 1 and Read 2 to get
more information of these.

    -------                -----------
   | CPU |  <------  | PCIe IP |   <--  MSI/INTx Message (INTA, INTB,
INTC, INTD)
    -------       IRQ   -----------

   Reading Interrupt Status Reg -> MSI/INTx bit set/not set
   Reading Root Port FIFO Read Register1 -> Mentions which interrupt
(INTx) is received
   Reading Root Port FIFO Read Register2 -> MSI Data

I will add this information to DT notes.

> - The stanza needs a
>     device_type = "pci";

Ok.

>
>> +     for (i = 0; i < port->mem_resno; i++)
>> +             pci_add_resource_offset(&sys->resources, &port->mem[i],
>> +                                     sys->mem_offset);
>
> The sys->mem_offset is probably wrong, please review Arnd's comments
> on the recent threads with Will and Liviu regarding how this is
> supposed to work with DT.
>
> You may want to work with Liviu to use his patch set which provides
> more generic support. Also, the driver needs to put every one of these
> ports in a PCI domain, Liviu is working on generic support for that
> too.

I will check and come back to you.

>
>> +static struct pci_bus __init *xilinx_pcie_scan_bus(int nr,
>> +                             struct pci_sys_data *sys)
>> +{
>> +     struct xilinx_pcie_port *port = sys_to_pcie(sys);
>> +     struct pci_bus *bus;
>> +
>> +     if (port) {
>> +             port->root_busno = sys->busnr;
>> +             bus = pci_scan_root_bus(NULL, sys->busnr, &xilinx_pcie_ops,
>> +                                     sys, &sys->resources);
>
> The NULL is probably wrong, please review the recent thread with Lucas
> and Jingoo 'PCI irq mapping fixes and cleanups'

Ok.

>
>> +static int xilinx_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
>> +{
>> +     struct xilinx_pcie_port *port = sys_to_pcie(dev->bus->sysdata);
>> +
>> +     if (!port)
>> +             return -EINVAL;
>> +
>> +     return port->irq;
>> +}
>
> It is preferred to use DT mechanisms via of_irq_parse_and_map_pci
> (interrupt-mapping, etc) to define the slot IRQ, drivers should not
> provide a map_irq unless absolutely necessary.

Ok.

>
>> +     /* make sure it is root port before touching header */
>> +     pcie_write(port, PCI_COMMAND_MASTER, PCI_COMMAND);
>
> Bit of a confusing comment

I will correct it, Thanks.

>
>> +     /* Check if PCIe link is up? */
>> +     port->link_up = xilinx_pcie_is_link_up(port);
>> +     if (!port->link_up)
>> +             dev_info(port->dev, "PCIe Link is DOWN\n");
>> +     else
>> +             dev_info(port->dev, "PCIe Link is UP\n");
>
> Don't forget to think about hot plug

Did you mean using 'rescan' (from sysfs), correct?

>
>> +     /* Register Interrupt Handler */
>> +     err = request_irq(port->irq, xilinx_pcie_intr_handler,
>> +                             IRQF_SHARED, "xilinx-pcie", port);
>
> Use devm? This is leaking on error cases.
>
> Review other resources too...

Ok.

>
>> +     /* Request and map I/O memory */
>> +     io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +     port->phys_reg_base = io->start;
>> +     port->reg_size = resource_size(io);
>
> Here it uses the platform resource..
>
>> +     /* Map the IRQ */
>> +     port->irq = irq_of_parse_and_map(node, 0);
>
> .. And here it doesn't, probably should be consistent and just use the
> platform resources.

I will correct.

Thanks
Srikanth

>
> Jason
> --
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Jason Gunthorpe March 3, 2014, 7:09 p.m. UTC | #5
On Tue, Mar 04, 2014 at 12:21:55AM +0530, Srikanth Thokala wrote:

> >> +     pci_express: axi-pcie@50000000 {
> >> +             #address-cells = <3>;
> >> +             #size-cells = <2>;
> >> +             compatible = "xlnx,axi-pcie-host-1.00.a";
> >> +             reg = < 0x50000000 0x10000000 >;
> >> +             interrupts = < 0 52 4 >;
> >> +             ranges = < 0x02000000 0 0x60000000 0x60000000 0 0x10000000 >;
> >> +     };

> >  - How are INTA/B/C/D handled? Typically I'd like to see an
> >    interrupt-mapping block describing them.
> >
> >    There are a few options here, if the HW can decode A/B/C/D then
> >    it probably needs another irq_domain for INTx, and have the IRQ
> >    handler decode like it does for MSI.
> 
> The core provides a single interrupt for both INTx/MSI messages.  The
> core decodes the TLP messages and accordingly assert the INTx/MSI
> bits.  It provides two registers Interrupt FIFO Read 1 and Read 2 to get
> more information of these.
> 
>    | CPU |  <------  | PCIe IP |   <--  MSI/INTx Message (INTA, INTB,
> INTC, INTD)
> 
>    Reading Interrupt Status Reg -> MSI/INTx bit set/not set
>    Reading Root Port FIFO Read Register1 -> Mentions which interrupt
> (INTx) is received
>    Reading Root Port FIFO Read Register2 -> MSI Data

Okay, that matches my guess based on the code.

You probably want to do something like this:

     pci_express: axi-pcie@50000000 {
             #address-cells = <3>;
             #size-cells = <2>;
	     device_type ="pci";
             compatible = "xlnx,axi-pcie-host-1.00.a";
             reg = < 0x50000000 0x10000000 >;
             interrupts = < 0 52 4 >;
             ranges = < 0x02000000 0 0x60000000 0x60000000 0 0x10000000 >;

	     pcie_intc: interrupt-controller {
    		interrupt-controller;
		#address-cells = <0>;
		#interrupt-cells = <1>;
	     }

	     interrupt-map-mask = <0 0 0 7>;
	     interrupt-map = <0 0 0 1 &pcie_intc 0>, // INT A
	                     <0 0 0 2 &pcie_intc 2>, // INT B
	                     <0 0 0 3 &pcie_intc 3>, // INT C
	                     <0 0 0 4 &pcie_intc 4>; // INT D
     };

(similar to what ralink,rt3883 does for their binding)

Setup a interrupt domain like for MSI, except attach it to the
nested interrupt-controller DT node. Decode the 4 interrutps from
the core in the ISR and route them into the domain.

The generic code will take care of the rest.

This way all the interrupts are decoded and the interrupt-map DT
functionality is supported, which is important in a number of
board-specific corner cases.

> > You may want to work with Liviu to use his patch set which provides
> > more generic support. Also, the driver needs to put every one of these
> > ports in a PCI domain, Liviu is working on generic support for that
> > too.
> 
> I will check and come back to you.

Will's latest patch that was just posted is a very good example of how
the resource stuff should work correctly.

> > Don't forget to think about hot plug
> 
> Did you mean using 'rescan' (from sysfs), correct?

Yes

Jason
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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/pci/xilinx-pcie.txt b/Documentation/devicetree/bindings/pci/xilinx-pcie.txt
new file mode 100644
index 0000000..b0ea448
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/xilinx-pcie.txt
@@ -0,0 +1,23 @@ 
+* Xilinx AXI PCIe Root Port Bridge DT description
+
+Required properties:
+- #address-cells: Address representation for root ports, set to <3>
+- #size-cells: Size representation for root ports, set to <2>
+- compatible: Should contain "xlnx,axi-pcie-host-1.00.a"
+- reg: Should contain AXI PCIe registers location and length
+- interrupts: Should contain AXI PCIe interrupt
+- ranges: ranges for the PCI memory regions
+	Please refer to the standard PCI bus binding document for a more
+	detailed explanation
+
+Example:
+++++++++
+
+	pci_express: axi-pcie@50000000 {
+		#address-cells = <3>;
+		#size-cells = <2>;
+		compatible = "xlnx,axi-pcie-host-1.00.a";
+		reg = < 0x50000000 0x10000000 >;
+		interrupts = < 0 52 4 >;
+		ranges = < 0x02000000 0 0x60000000 0x60000000 0 0x10000000 >;
+	};
diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index 47d46c6..8771824 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -33,4 +33,11 @@  config PCI_RCAR_GEN2
 	  There are 3 internal PCI controllers available with a single
 	  built-in EHCI/OHCI host controller present on each one.
 
+config PCI_XILINX
+	bool "Xilinx AXI PCIe host bridge support"
+	depends on ARCH_ZYNQ
+	help
+	  Say 'Y' here if you want kernel to support the Xilinx AXI PCIe
+	  Host Bridge driver.
+
 endmenu
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 13fb333..4e9c843 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -4,3 +4,4 @@  obj-$(CONFIG_PCI_IMX6) += pci-imx6.o
 obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o
 obj-$(CONFIG_PCI_TEGRA) += pci-tegra.o
 obj-$(CONFIG_PCI_RCAR_GEN2) += pci-rcar-gen2.o
+obj-$(CONFIG_PCI_XILINX) += pci-xilinx.o
diff --git a/drivers/pci/host/pci-xilinx.c b/drivers/pci/host/pci-xilinx.c
new file mode 100644
index 0000000..209d2fb
--- /dev/null
+++ b/drivers/pci/host/pci-xilinx.c
@@ -0,0 +1,940 @@ 
+/*
+ * PCIe host controller driver for Xilinx AXI PCIe Bridge
+ *
+ * Copyright (c) 2012 - 2014 Xilinx, Inc.
+ *
+ * Based on the Tegra PCIe driver
+ *
+ * Bits taken from Synopsys Designware Host controller driver
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/of_irq.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+
+/* Register definitions */
+#define XILINX_PCIE_REG_VSECC		0x00000128
+#define XILINX_PCIE_REG_VSECH		0x0000012c
+#define XILINX_PCIE_REG_BIR		0x00000130
+#define XILINX_PCIE_REG_BSCR		0x00000134
+#define XILINX_PCIE_REG_IDR		0x00000138
+#define XILINX_PCIE_REG_IMR		0x0000013c
+#define XILINX_PCIE_REG_BLR		0x00000140
+#define XILINX_PCIE_REG_PSCR		0x00000144
+#define XILINX_PCIE_REG_RPSC		0x00000148
+#define XILINX_PCIE_REG_MSIBASE1	0x0000014c
+#define XILINX_PCIE_REG_MSIBASE2	0x00000150
+#define XILINX_PCIE_REG_RPEFR		0x00000154
+#define XILINX_PCIE_REG_RPIFR1		0x00000158
+#define XILINX_PCIE_REG_RPIFR2		0x0000015c
+#define XILINX_PCIE_REG_VSECC2		0x00000200
+#define XILINX_PCIE_REG_VSECH2		0x00000204
+
+/* Interrupt registers definitions */
+#define XILINX_PCIE_INTR_LINK_DOWN	BIT(0)
+#define XILINX_PCIE_INTR_ECRC_ERR	BIT(1)
+#define XILINX_PCIE_INTR_STR_ERR	BIT(2)
+#define XILINX_PCIE_INTR_HOT_RESET	BIT(3)
+#define XILINX_PCIE_INTR_CFG_COMPL	GENMASK(7, 5)
+#define XILINX_PCIE_INTR_CFG_TIMEOUT	BIT(8)
+#define XILINX_PCIE_INTR_CORRECTABLE	BIT(9)
+#define XILINX_PCIE_INTR_NONFATAL	BIT(10)
+#define XILINX_PCIE_INTR_FATAL		BIT(11)
+#define XILINX_PCIE_INTR_INTX		BIT(16)
+#define XILINX_PCIE_INTR_MSI		BIT(17)
+#define XILINX_PCIE_INTR_SLV_UNSUPP	BIT(20)
+#define XILINX_PCIE_INTR_SLV_UNEXP	BIT(21)
+#define XILINX_PCIE_INTR_SLV_COMPL	BIT(22)
+#define XILINX_PCIE_INTR_SLV_ERRP	BIT(23)
+#define XILINX_PCIE_INTR_SLV_CMPABT	BIT(24)
+#define XILINX_PCIE_INTR_SLV_ILLBUR	BIT(25)
+#define XILINX_PCIE_INTR_MST_DECERR	BIT(26)
+#define XILINX_PCIE_INTR_MST_SLVERR	BIT(27)
+#define XILINX_PCIE_INTR_MST_ERRP	BIT(28)
+#define XILINX_PCIE_IMR_ALL_MASK	0x1FF30FED
+#define XILINX_PCIE_IDR_ALL_MASK	0xFFFFFFFF
+
+/* Root Port Error FIFO Read Register definitions */
+#define XILINX_PCIE_RPEFR_ERR_VALID	BIT(18)
+#define XILINX_PCIE_RPEFR_REQ_ID	GENMASK(15, 0)
+#define XILINX_PCIE_RPEFR_ALL_MASK	0xFFFFFFFF
+
+/* Root Port Interrupt FIFO Read Register 1 definitions */
+#define XILINX_PCIE_RPIFR1_INTR_VALID	BIT(31)
+#define XILINX_PCIE_RPIFR1_MSI_INTR	BIT(30)
+#define XILINX_PCIE_RPIFR1_INTR_ASSRT	BIT(29)
+#define XILINX_PCIE_RPIFR1_MSI_ADR_MASK	GENMASK(26, 16)
+#define XILINX_PCIE_RPIFR1_ALL_MASK	0xFFFFFFFF
+#define XILINX_PCIE_RPIFR1_MSI_ADR_SHIFT	16
+
+/* Bridge Info Register definitions */
+#define XILINX_PCIE_BIR_ECAM_SZ_MASK	GENMASK(18, 16)
+#define XILINX_PCIE_BIR_ECAM_SZ_SHIFT	16
+
+/* Root Port Interrupt FIFO Read Register 2 definitions */
+#define XILINX_PCIE_RPIFR2_MSG_DATA	GENMASK(15, 0)
+
+/* Root Port Status/control Register definitions */
+#define XILINX_PCIE_REG_RPSC_BEN	BIT(0)
+
+/* Phy Status/Control Register definitions */
+#define XILINX_PCIE_REG_PSCR_LNKUP	BIT(11)
+
+/* ECAM definitions */
+#define ECAM_BUS_NUM_SHIFT		20
+#define ECAM_DEV_NUM_SHIFT		12
+
+/* PCI Configuration space Bus Number Register definitions */
+#define PCI_SECONDARY_BUS_NUM_SHIFT	8
+#define PCI_SUBORDINATE_BUS_NUM_SHIFT	16
+#define PCI_LATENCY_TIMER_MASK		GENMASK(31, 24)
+
+/* Number of MSI IRQs */
+#define XILINX_NUM_MSI_IRQS		128
+
+/* Number of Memory Resources */
+#define XILINX_MAX_NUM_RESOURCES	3
+
+/**
+ * struct xilinx_pcie_port - PCIe port information
+ * @reg_base: IO Mapped Register Base
+ * @phys_reg_base: Physical Register Base
+ * @reg_size: Register space
+ * @irq: Interrupt number
+ * @msg_addr: MSI message address
+ * @root_busno: Root Bus number
+ * @mem_resno: Number of memory resources
+ * @link_up: Link status flag
+ * @node: Device tree node
+ * @dev: Device pointer
+ * @irq_domain: IRQ domain pointer
+ * @mem: Memory Resources
+ */
+struct xilinx_pcie_port {
+	void __iomem *reg_base;
+	u32 phys_reg_base;
+	u32 reg_size;
+	u32 irq;
+	unsigned long msg_addr;
+	u8 root_busno;
+	u8 mem_resno;
+	bool link_up;
+	struct device_node *node;
+	struct device *dev;
+	struct irq_domain *irq_domain;
+	struct resource mem[XILINX_MAX_NUM_RESOURCES];
+};
+
+static DECLARE_BITMAP(msi_irq_in_use, XILINX_NUM_MSI_IRQS);
+
+static inline struct xilinx_pcie_port *sys_to_pcie(struct pci_sys_data *sys)
+{
+	return sys->private_data;
+}
+
+static inline u32 pcie_read(struct xilinx_pcie_port *port, u32 reg)
+{
+	return readl(port->reg_base + reg);
+}
+
+static inline void pcie_write(struct xilinx_pcie_port *port,
+					 u32 val, u32 reg)
+{
+	writel(val, port->reg_base + reg);
+}
+
+static inline bool xilinx_pcie_is_link_up(struct xilinx_pcie_port *port)
+{
+	return (pcie_read(port, XILINX_PCIE_REG_PSCR) &
+		XILINX_PCIE_REG_PSCR_LNKUP) ? 1 : 0;
+}
+
+/**
+ * xilinx_pcie_clear_err_interrupts - Clear Error Interrupts
+ * @port: PCIe port information
+ */
+static inline void
+xilinx_pcie_clear_err_interrupts(struct xilinx_pcie_port *port)
+{
+	u32 val = pcie_read(port, XILINX_PCIE_REG_RPEFR);
+
+	if (val & XILINX_PCIE_RPEFR_ERR_VALID) {
+		dev_dbg(port->dev, "Requester ID %d\n",
+			val & XILINX_PCIE_RPEFR_REQ_ID);
+		pcie_write(port, XILINX_PCIE_RPEFR_ALL_MASK,
+				XILINX_PCIE_REG_RPEFR);
+	}
+}
+
+/**
+ * xilinx_pcie_verify_config - Verify configuration
+ * @port: PCIe port information
+ * @bus: Bus structure of current bus
+ * @devfn: device/function
+ *
+ * Return: 0 on success and PCIBIOS_DEVICE_NOT_FOUND on error
+ */
+static int xilinx_pcie_verify_config(struct xilinx_pcie_port *port,
+					struct pci_bus *bus,
+					unsigned int devfn)
+{
+	/* Check if link is up when trying to access downstream ports */
+	if (bus->number != port->root_busno)
+		if (!xilinx_pcie_is_link_up(port))
+			return 0;
+
+	/* Only one device down on each root port */
+	if (bus->number == port->root_busno && devfn > 0)
+		return 0;
+
+	/*
+	 * Do not read more than one device on the bus directly attached
+	 * to RC.
+	 */
+	if (bus->primary == port->root_busno && devfn > 0)
+		return 0;
+
+	return 1;
+}
+
+/**
+ * xilinx_pcie_get_config_base - Get configuration base
+ * @port: PCIe port information
+ * @bus: Bus structure of current bus
+ * @devfn: Device/function
+ * @where: Offset from base
+ *
+ * Return: Base address of the configuration space needed to be
+ *	   accessed.
+ */
+static void __iomem *xilinx_pcie_get_config_base(struct xilinx_pcie_port *port,
+						 struct pci_bus *bus,
+						 unsigned int devfn,
+						 int where)
+{
+	int relbus;
+
+	relbus = (bus->number << ECAM_BUS_NUM_SHIFT) |
+		 (devfn << ECAM_DEV_NUM_SHIFT);
+
+	return port->reg_base + relbus + where;
+}
+
+/**
+ * xilinx_pcie_read_config - Read configuration space
+ * @bus: Bus structure of current bus
+ * @devfn: Device/function
+ * @where: Offset from base
+ * @size: Byte/word/dword
+ * @val: Value to be read
+ *
+ * Return: PCIBIOS_SUCCESSFUL on success
+ *	   EINVAL/PCIBIOS_DEVICE_NOT_FOUND/PCIBIOS_BAD_REGISTER_NUMBER
+ *	   on failure.
+ */
+static int xilinx_pcie_read_config(struct pci_bus *bus,
+				unsigned int devfn,
+				int where,
+				int size,
+				u32 *val)
+{
+	struct xilinx_pcie_port *port = sys_to_pcie(bus->sysdata);
+	void __iomem *addr;
+
+	if (!port) {
+		BUG();
+		return -EINVAL;
+	}
+
+	if (!xilinx_pcie_verify_config(port, bus, devfn)) {
+		*val = 0xFFFFFFFF;
+		return PCIBIOS_DEVICE_NOT_FOUND;
+	}
+
+	addr = xilinx_pcie_get_config_base(port, bus, devfn, where);
+	if (!addr)
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+
+	switch (size) {
+	case 1:
+		*val = readb(addr);
+		break;
+	case 2:
+		*val = readw(addr);
+		break;
+	default:
+		*val = readl(addr);
+		break;
+	}
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+/**
+ * xilinx_pcie_write_config - Write configuration space
+ * @bus: Bus structure of current bus
+ * @devfn: Device/function
+ * @where: Offset from base
+ * @size: Byte/word/dword
+ * @val: Value to be written to device
+ *
+ * Return: PCIBIOS_SUCCESSFUL on success,
+ *	   EINVAL/PCIBIOS_DEVICE_NOT_FOUND/PCIBIOS_BAD_REGISTER_NUMBER
+ *	   on failure.
+ */
+static int xilinx_pcie_write_config(struct pci_bus *bus,
+				unsigned int devfn,
+				int where,
+				int size,
+				u32 val)
+{
+	struct xilinx_pcie_port *port = sys_to_pcie(bus->sysdata);
+	void __iomem *addr;
+
+	if (!port) {
+		BUG();
+		return -EINVAL;
+	}
+
+	if (!xilinx_pcie_verify_config(port, bus, devfn))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	addr = xilinx_pcie_get_config_base(port, bus, devfn, where);
+	if (!addr)
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+
+	switch (size) {
+	case 1:
+		writeb(val, addr);
+		break;
+	case 2:
+		writew(val, addr);
+		break;
+	default:
+		writel(val, addr);
+		break;
+	}
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+/* PCIe operations */
+static struct pci_ops xilinx_pcie_ops = {
+	.read  = xilinx_pcie_read_config,
+	.write = xilinx_pcie_write_config,
+};
+
+/* MSI functions */
+
+/**
+ * xilinx_pcie_destroy_msi - Free MSI number
+ * @irq: IRQ to be freed
+ */
+static void xilinx_pcie_destroy_msi(unsigned int irq)
+{
+	struct irq_desc *desc;
+	struct msi_desc *msi;
+	struct xilinx_pcie_port *port;
+
+	desc = irq_to_desc(irq);
+	msi = irq_desc_get_msi_desc(desc);
+	port = sys_to_pcie(msi->dev->bus->sysdata);
+	if (!port) {
+		BUG();
+		return;
+	}
+
+	if (!test_bit(irq, msi_irq_in_use))
+		dev_err(port->dev, "Trying to free unused MSI#%d\n", irq);
+	else
+		clear_bit(irq, msi_irq_in_use);
+}
+
+/**
+ * xilinx_pcie_assign_msi - Allocate MSI number
+ * @port: PCIe port structure
+ *
+ * Return: A valid IRQ on success and error value on failure.
+ */
+static int xilinx_pcie_assign_msi(struct xilinx_pcie_port *port)
+{
+	int pos;
+
+	pos = find_first_zero_bit(msi_irq_in_use, XILINX_NUM_MSI_IRQS);
+	if (pos < XILINX_NUM_MSI_IRQS)
+		set_bit(pos, msi_irq_in_use);
+	else
+		return -ENOSPC;
+
+	return irq_find_mapping(port->irq_domain, pos);
+}
+
+/**
+ * xilinx_msi_teardown_irq - Destroy the MSI
+ * @chip: MSI Chip descriptor
+ * @irq: MSI IRQ to destroy
+ */
+static void xilinx_msi_teardown_irq(struct msi_chip *chip, unsigned int irq)
+{
+	xilinx_pcie_destroy_msi(irq);
+}
+
+/**
+ * xilinx_pcie_msi_setup_irq - Setup MSI request
+ * @chip: MSI chip pointer
+ * @pdev: PCIe device pointer
+ * @desc: MSI descriptor pointer
+ *
+ * Return: '0' on success and error value on failure
+ */
+static int xilinx_pcie_msi_setup_irq(struct msi_chip *chip,
+					struct pci_dev *pdev,
+					struct msi_desc *desc)
+{
+	struct xilinx_pcie_port *port = sys_to_pcie(pdev->bus->sysdata);
+	int irq;
+	struct msi_msg msg;
+
+	if (!port) {
+		BUG();
+		return -EINVAL;
+	}
+
+	irq = xilinx_pcie_assign_msi(port);
+	if (irq < 0)
+		return irq;
+
+	irq_set_msi_desc(irq, desc);
+
+	msg.address_hi = 0;
+	msg.address_lo = virt_to_phys((void *)port->msg_addr);
+	msg.data = irq;
+
+	write_msi_msg(irq, &msg);
+
+	return 0;
+}
+
+/* MSI Chip Descriptor */
+static struct msi_chip xilinx_pcie_msi_chip = {
+	.setup_irq = xilinx_pcie_msi_setup_irq,
+	.teardown_irq = xilinx_msi_teardown_irq,
+};
+
+/* HW Interrupt Chip Descriptor */
+static struct irq_chip xilinx_msi_irq_chip = {
+	.name = "Xilinx PCIe MSI",
+	.irq_enable = unmask_msi_irq,
+	.irq_disable = mask_msi_irq,
+	.irq_mask = mask_msi_irq,
+	.irq_unmask = unmask_msi_irq,
+};
+
+/**
+ * xilinx_pcie_msi_map - Set the handler for the MSI and mark IRQ as valid
+ * @domain: IRQ domain
+ * @irq: Virtual IRQ number
+ * @hwirq: HW interrupt number
+ *
+ * Return: Always returns 0.
+ */
+static int xilinx_pcie_msi_map(struct irq_domain *domain, unsigned int irq,
+				irq_hw_number_t hwirq)
+{
+	irq_set_chip_and_handler(irq, &xilinx_msi_irq_chip, handle_simple_irq);
+	irq_set_chip_data(irq, domain->host_data);
+	set_irq_flags(irq, IRQF_VALID);
+
+	return 0;
+}
+
+/* IRQ Domain operations */
+static const struct irq_domain_ops msi_domain_ops = {
+	.map = xilinx_pcie_msi_map,
+};
+
+/**
+ * xilinx_pcie_enable_msi - Enable MSI support
+ * @port: PCIe port information
+ */
+static void xilinx_pcie_enable_msi(struct xilinx_pcie_port *port)
+{
+	port->msg_addr = __get_free_pages(GFP_KERNEL, 0);
+
+	pcie_write(port, 0x0, XILINX_PCIE_REG_MSIBASE1);
+	pcie_write(port, virt_to_phys((void *)port->msg_addr),
+			XILINX_PCIE_REG_MSIBASE2);
+}
+
+/* PCIe HW Functions */
+
+/**
+ * xilinx_pcie_setup - Setup memory resources
+ * @nr: Bus number
+ * @sys: Per controller structure
+ *
+ * Return: '1' on success and '0' on failure
+ */
+static int xilinx_pcie_setup(int nr, struct pci_sys_data *sys)
+{
+	struct xilinx_pcie_port *port = sys_to_pcie(sys);
+	int i;
+
+	if (!port)
+		return 0;
+
+	for (i = 0; i < port->mem_resno; i++)
+		pci_add_resource_offset(&sys->resources, &port->mem[i],
+					sys->mem_offset);
+
+	return 1;
+}
+
+/**
+ * xilinx_pcie_add_bus - Add MSI chip info to PCIe bus
+ * @bus: PCIe bus
+ */
+static void xilinx_pcie_add_bus(struct pci_bus *bus)
+{
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		struct xilinx_pcie_port *port = sys_to_pcie(bus->sysdata);
+
+		if (!port)
+			return;
+
+		xilinx_pcie_msi_chip.dev = port->dev;
+		bus->msi = &xilinx_pcie_msi_chip;
+	}
+}
+
+/**
+ * xilinx_pcie_scan_bus - Scan PCIe bus for devices
+ * @nr: Bus number
+ * @sys: Per controller structure
+ *
+ * Return: Valid Bus pointer on success and NULL on failure
+ */
+static struct pci_bus __init *xilinx_pcie_scan_bus(int nr,
+				struct pci_sys_data *sys)
+{
+	struct xilinx_pcie_port *port = sys_to_pcie(sys);
+	struct pci_bus *bus;
+
+	if (port) {
+		port->root_busno = sys->busnr;
+		bus = pci_scan_root_bus(NULL, sys->busnr, &xilinx_pcie_ops,
+					sys, &sys->resources);
+	} else {
+		bus = NULL;
+		BUG();
+	}
+
+	return bus;
+}
+
+/**
+ * xilinx_pcie_map_irq - Get the interrupt of this port
+ * @dev: PCIe device
+ * @slot: Bridge slot
+ * @pin: Interrupt pin
+ *
+ * Return: Interrupt number on success and error value on failure
+ */
+static int xilinx_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
+{
+	struct xilinx_pcie_port *port = sys_to_pcie(dev->bus->sysdata);
+
+	if (!port)
+		return -EINVAL;
+
+	return port->irq;
+}
+
+/**
+ * xilinx_pcie_intr_handler - Interrupt Service Handler
+ * @irq: IRQ number
+ * @data: PCIe port information
+ *
+ * Return: IRQ_HANDLED on success and IRQ_NONE on failure
+ */
+static irqreturn_t xilinx_pcie_intr_handler(int irq, void *data)
+{
+	struct xilinx_pcie_port *port = (struct xilinx_pcie_port *)data;
+	u32 val, mask, status, msi_data;
+
+	/* Read interrupt decode and mask registers */
+	val = pcie_read(port, XILINX_PCIE_REG_IDR);
+	mask = pcie_read(port, XILINX_PCIE_REG_IMR);
+
+	status = val & mask;
+	if (!status)
+		return IRQ_NONE;
+
+	if (status & XILINX_PCIE_INTR_LINK_DOWN)
+		dev_warn(port->dev, "Link Down\n");
+
+	if (status & XILINX_PCIE_INTR_ECRC_ERR)
+		dev_warn(port->dev, "ECRC failed\n");
+
+	if (status & XILINX_PCIE_INTR_STR_ERR)
+		dev_warn(port->dev, "Streaming error\n");
+
+	if (status & XILINX_PCIE_INTR_HOT_RESET)
+		dev_info(port->dev, "Hot reset\n");
+
+	if (status & XILINX_PCIE_INTR_CFG_TIMEOUT)
+		dev_warn(port->dev, "ECAM access timeout\n");
+
+	if (status & XILINX_PCIE_INTR_CORRECTABLE) {
+		dev_warn(port->dev, "Correctable error message\n");
+		xilinx_pcie_clear_err_interrupts(port);
+	}
+
+	if (status & XILINX_PCIE_INTR_NONFATAL) {
+		dev_warn(port->dev, "Non fatal error message\n");
+		xilinx_pcie_clear_err_interrupts(port);
+	}
+
+	if (status & XILINX_PCIE_INTR_FATAL) {
+		dev_warn(port->dev, "Fatal error message\n");
+		xilinx_pcie_clear_err_interrupts(port);
+	}
+
+	if (status & XILINX_PCIE_INTR_INTX) {
+		/* INTx interrupt received */
+		val = pcie_read(port, XILINX_PCIE_REG_RPIFR1);
+
+		/* Check whether interrupt valid */
+		if (!(val & XILINX_PCIE_RPIFR1_INTR_VALID)) {
+			dev_warn(port->dev, "RP Intr FIFO1 read error\n");
+			return IRQ_HANDLED;
+		}
+
+		/* Check MSI or INTX */
+		if (!(val & XILINX_PCIE_RPIFR1_MSI_INTR)) {
+			if (val & XILINX_PCIE_RPIFR1_INTR_ASSRT)
+				dev_dbg(port->dev, "INTx assert\n");
+			else
+				dev_dbg(port->dev, "INTx deassert\n");
+		}
+
+		/* Clear interrupt FIFO register 1 */
+		pcie_write(port, XILINX_PCIE_RPIFR1_ALL_MASK,
+				XILINX_PCIE_REG_RPIFR1);
+	}
+
+	if (status & XILINX_PCIE_INTR_MSI) {
+		/* MSI Interrupt */
+		val = pcie_read(port, XILINX_PCIE_REG_RPIFR1);
+
+		if (!(val & XILINX_PCIE_RPIFR1_INTR_VALID)) {
+			dev_warn(port->dev, "RP Intr FIFO1 read error\n");
+			return IRQ_HANDLED;
+		}
+
+		if (val & XILINX_PCIE_RPIFR1_MSI_INTR) {
+			msi_data = pcie_read(port, XILINX_PCIE_REG_RPIFR2) &
+					XILINX_PCIE_RPIFR2_MSG_DATA;
+
+			/* Clear interrupt FIFO register 1 */
+			pcie_write(port, XILINX_PCIE_RPIFR1_ALL_MASK,
+				XILINX_PCIE_REG_RPIFR1);
+
+			if (IS_ENABLED(CONFIG_PCI_MSI)) {
+				/* Handle MSI Interrupt */
+				generic_handle_irq(msi_data);
+			}
+		}
+	}
+
+	if (status & XILINX_PCIE_INTR_SLV_UNSUPP)
+		dev_warn(port->dev, "Slave unsupported request\n");
+
+	if (status & XILINX_PCIE_INTR_SLV_UNEXP)
+		dev_warn(port->dev, "Slave unexpected completion\n");
+
+	if (status & XILINX_PCIE_INTR_SLV_COMPL)
+		dev_warn(port->dev, "Slave completion timeout\n");
+
+	if (status & XILINX_PCIE_INTR_SLV_ERRP)
+		dev_warn(port->dev, "Slave Error Poison\n");
+
+	if (status & XILINX_PCIE_INTR_SLV_CMPABT)
+		dev_warn(port->dev, "Slave Completer Abort\n");
+
+	if (status & XILINX_PCIE_INTR_SLV_ILLBUR)
+		dev_warn(port->dev, "Slave Illegal Burst\n");
+
+	if (status & XILINX_PCIE_INTR_MST_DECERR)
+		dev_warn(port->dev, "Master decode error\n");
+
+	if (status & XILINX_PCIE_INTR_MST_SLVERR)
+		dev_warn(port->dev, "Master slave error\n");
+
+	if (status & XILINX_PCIE_INTR_MST_ERRP)
+		dev_warn(port->dev, "Master error poison\n");
+
+	/* Clear the Interrupt Decode register */
+	pcie_write(port, status, XILINX_PCIE_REG_IDR);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * xilinx_pcie_init_port - Initialize hardware
+ * @port: PCIe port information
+ *
+ * Return: '0' on success and error value on failure
+ */
+static int xilinx_pcie_init_port(struct xilinx_pcie_port *port)
+{
+	int err;
+	u32 val, last, first = 0;
+
+	port->reg_base = devm_ioremap(port->dev, port->phys_reg_base,
+					port->reg_size);
+	if (!port->reg_base)
+		return -ENOMEM;
+
+	/* make sure it is root port before touching header */
+	pcie_write(port, PCI_COMMAND_MASTER, PCI_COMMAND);
+
+	/* Check if PCIe link is up? */
+	port->link_up = xilinx_pcie_is_link_up(port);
+	if (!port->link_up)
+		dev_info(port->dev, "PCIe Link is DOWN\n");
+	else
+		dev_info(port->dev, "PCIe Link is UP\n");
+
+	/* Disable all interrupts*/
+	pcie_write(port, ~XILINX_PCIE_IDR_ALL_MASK,
+				XILINX_PCIE_REG_IMR);
+
+	/* Clear pending interrupts */
+	pcie_write(port, pcie_read(port, XILINX_PCIE_REG_IDR) &
+			XILINX_PCIE_IMR_ALL_MASK,
+			XILINX_PCIE_REG_IDR);
+
+	/* Enable all interrupts*/
+	pcie_write(port, XILINX_PCIE_IMR_ALL_MASK,
+			XILINX_PCIE_REG_IMR);
+
+	/* Enable the 'Bridge enable' bit */
+	pcie_write(port, pcie_read(port, XILINX_PCIE_REG_RPSC) |
+			XILINX_PCIE_REG_RPSC_BEN, XILINX_PCIE_REG_RPSC);
+
+	/* Register Interrupt Handler */
+	err = request_irq(port->irq, xilinx_pcie_intr_handler,
+				IRQF_SHARED, "xilinx-pcie", port);
+	if (err) {
+		dev_err(port->dev,
+			"Could not allocate interrupt %d\n", port->irq);
+		return err;
+	}
+
+	/* Get last bus number */
+	val = pcie_read(port, XILINX_PCIE_REG_BIR);
+	last = (val & XILINX_PCIE_BIR_ECAM_SZ_MASK) >>
+		XILINX_PCIE_BIR_ECAM_SZ_SHIFT;
+
+	/* Write primary, secondary and subordinate bus numbers */
+	val = pcie_read(port, PCI_PRIMARY_BUS) & PCI_LATENCY_TIMER_MASK;
+	val |= first;
+	val |= (first + 1) << PCI_SECONDARY_BUS_NUM_SHIFT;
+	val |= last << PCI_SUBORDINATE_BUS_NUM_SHIFT;
+	pcie_write(port, val, PCI_PRIMARY_BUS);
+
+	return 0;
+}
+
+/**
+ * xilinx_pcie_parse_dt - Parse Device tree
+ * @port: PCIe port information
+ *
+ * Return: '0' on success and error value on failure
+ */
+static int xilinx_pcie_parse_dt(struct xilinx_pcie_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+	struct device_node *node = port->dev->of_node;
+	struct resource *io, res;
+	struct of_pci_range_parser parser;
+	struct of_pci_range range;
+
+	/* Request and map I/O memory */
+	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	port->phys_reg_base = io->start;
+	port->reg_size = resource_size(io);
+
+	/* Map the IRQ */
+	port->irq = irq_of_parse_and_map(node, 0);
+	if (!port->irq) {
+		dev_err(port->dev, "Unable to get IRQ\n");
+		return -EINVAL;
+	}
+
+	if (of_pci_range_parser_init(&parser, node)) {
+		dev_err(port->dev, "missing \"ranges\" property\n");
+		return -EINVAL;
+	}
+
+	for_each_of_pci_range(&parser, &range) {
+		if (port->mem_resno >= XILINX_MAX_NUM_RESOURCES) {
+			dev_err(port->dev, "Maximum memory resources exceeded\n");
+			return -EINVAL;
+		}
+
+		of_pci_range_to_resource(&range, node, &res);
+
+		switch (res.flags & IORESOURCE_TYPE_BITS) {
+		case IORESOURCE_MEM:
+			if (res.flags & IORESOURCE_PREFETCH)
+				port->mem[port->mem_resno].name = "PREFETCH";
+			else
+				port->mem[port->mem_resno].name = "MEM";
+
+			memcpy(&port->mem[port->mem_resno], &res, sizeof(res));
+			port->mem_resno++;
+		/* Fallthrough */
+		default:
+			break;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * xilinx_pcie_probe - Probe function
+ * @pdev: Platform device pointer
+ *
+ * Return: '0' on success and error value on failure
+ */
+static int xilinx_pcie_probe(struct platform_device *pdev)
+{
+	struct xilinx_pcie_port *port;
+	struct hw_pci hw;
+	int err;
+
+	port = devm_kzalloc(&pdev->dev, sizeof(struct xilinx_pcie_port *),
+				 GFP_KERNEL);
+	if (!port)
+		return -ENOMEM;
+
+	port->dev = &pdev->dev;
+
+	/* Parse the device tree */
+	err = xilinx_pcie_parse_dt(port);
+	if (err) {
+		dev_err(port->dev, "Parsing DT failed\n");
+		return err;
+	}
+
+	/* Initialize the hardware */
+	err = xilinx_pcie_init_port(port);
+	if (err) {
+		dev_err(port->dev, "HW Initalization failed\n");
+		return err;
+	}
+
+	/* Setup MSI */
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		int i;
+
+		port->irq_domain = irq_domain_add_linear(port->dev->of_node,
+					XILINX_NUM_MSI_IRQS, &msi_domain_ops,
+					&xilinx_pcie_msi_chip);
+		if (!port->irq_domain) {
+			dev_err(port->dev, "Failed to get an IRQ domain\n");
+			return -ENXIO;
+		}
+
+		for (i = 0; i < XILINX_NUM_MSI_IRQS; i++)
+			irq_create_mapping(port->irq_domain, i);
+
+		xilinx_pcie_enable_msi(port);
+	}
+
+	memset(&hw, 0, sizeof(hw));
+
+	hw.nr_controllers = 1;
+	hw.private_data = (void **)&port;
+	hw.setup = xilinx_pcie_setup;
+	hw.map_irq = xilinx_pcie_map_irq;
+	hw.add_bus = xilinx_pcie_add_bus;
+	hw.scan = xilinx_pcie_scan_bus;
+	hw.ops = &xilinx_pcie_ops;
+
+	/* Register the device */
+	pci_common_init_dev(port->dev, &hw);
+
+	platform_set_drvdata(pdev, port);
+
+	return 0;
+}
+
+/**
+ * xilinx_pcie_remove - Remove function
+ * @pdev: Platform device pointer
+ *
+ * Return: '0' always
+ */
+static int xilinx_pcie_remove(struct platform_device *pdev)
+{
+	struct xilinx_pcie_port *port = platform_get_drvdata(pdev);
+
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		int i;
+		u32 irq;
+
+		free_pages(port->msg_addr, 0);
+
+		for (i = 0; i < XILINX_NUM_MSI_IRQS; i++) {
+			irq = irq_find_mapping(port->irq_domain, i);
+			if (irq > 0)
+				irq_dispose_mapping(irq);
+		}
+
+		irq_domain_remove(port->irq_domain);
+	}
+
+	if (port->irq > 0)
+		free_irq(port->irq, port);
+
+	return 0;
+}
+
+static struct of_device_id xilinx_pcie_of_match[] = {
+	{ .compatible = "xlnx,axi-pcie-host-1.00.a" ,},
+	{}
+};
+
+static struct platform_driver xilinx_pcie_driver = {
+	.driver = {
+		.name = "xilinx-pcie",
+		.owner = THIS_MODULE,
+		.of_match_table = xilinx_pcie_of_match,
+		.suppress_bind_attrs = true,
+	},
+	.probe = xilinx_pcie_probe,
+	.remove = xilinx_pcie_remove,
+};
+module_platform_driver(xilinx_pcie_driver);
+
+MODULE_AUTHOR("Xilinx Inc");
+MODULE_DESCRIPTION("Xilinx AXI PCIe driver");
+MODULE_LICENSE("GPLv2");