diff mbox

[v12] PCI: Xilinx-NWL-PCIe: Adding support for Xilinx NWL PCIe Host Controller

Message ID 1457281934-32068-1-git-send-email-bharatku@xilinx.com
State Accepted
Headers show

Commit Message

Bharat Kumar Gogada March 6, 2016, 4:32 p.m. UTC
Adding PCIe Root Port driver for Xilinx PCIe NWL bridge IP.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bharat Kumar Gogada <bharatku@xilinx.com>
Signed-off-by: Ravi Kiran Gummaluri <rgummal@xilinx.com>
---
Changes for v12:
-> Removed nwl_setup_sspl function, it will be added after more
testing.
-> Broke nwl_pcie_link_up into nwl_pcie_link_up, nwl_phy_link_up
functions.
-> Using generic functions for configuration read and write.
-> Removed unneccessary comments.
-> Removed unneccessary new lines.
-> Added #define for number of legacy interrupts.
-> Changed MSI interrupt handlers registering sequence.
---
 .../devicetree/bindings/pci/xilinx-nwl-pcie.txt    |  68 ++
 drivers/pci/host/Kconfig                           |  10 +
 drivers/pci/host/Makefile                          |   1 +
 drivers/pci/host/pcie-xilinx-nwl.c                 | 912 +++++++++++++++++++++
 4 files changed, 991 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt
 create mode 100644 drivers/pci/host/pcie-xilinx-nwl.c

Comments

Bjorn Helgaas March 11, 2016, 9:58 p.m. UTC | #1
Hi Bharat,

I forgot I still have one question here:

On Sun, Mar 06, 2016 at 10:02:14PM +0530, Bharat Kumar Gogada wrote:
> Adding PCIe Root Port driver for Xilinx PCIe NWL bridge IP.

> +static bool nwl_pcie_valid_device(struct pci_bus *bus, unsigned int devfn)
> +{
> +	struct nwl_pcie *pcie = bus->sysdata;
> +
> +	/* Check link,before accessing downstream ports */
> +	if (bus->number != pcie->root_busno) {
> +		if (!nwl_pcie_link_up(pcie))
> +			return false;
> +	}

This seems racy.  What if we check, and the link is up, but the link
goes down before we actually complete the config access?

I'm suggesting that this check for the link being up might be
superfluous.

The hardware should do something reasonable with the config access if
it can't send it down the link.

> +
> +	/* Only one device down on each root port */
> +	if (bus->number == pcie->root_busno && devfn > 0)
> +		return false;
> +
> +	return true;
> +}
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Bharat Kumar Gogada March 14, 2016, 3:51 p.m. UTC | #2
Hi Bjorn,
 
> I forgot I still have one question here:
> 
> On Sun, Mar 06, 2016 at 10:02:14PM +0530, Bharat Kumar Gogada wrote:
> > Adding PCIe Root Port driver for Xilinx PCIe NWL bridge IP.
> 
> > +static bool nwl_pcie_valid_device(struct pci_bus *bus, unsigned int
> > +devfn) {
> > +	struct nwl_pcie *pcie = bus->sysdata;
> > +
> > +	/* Check link,before accessing downstream ports */
> > +	if (bus->number != pcie->root_busno) {
> > +		if (!nwl_pcie_link_up(pcie))
> > +			return false;
> > +	}
> 
> This seems racy.  What if we check, and the link is up, but the link goes down
> before we actually complete the config access?
> 
> I'm suggesting that this check for the link being up might be superfluous.
Without the above check and also if there is no EP then we are getting kernel stack as follows,
[    2.654105] PCI host bridge /amba/pcie@fd0e0000 ranges:
[    2.659268]   No bus range found for /amba/pcie@fd0e0000, using [bus 00-ff]
[    2.666195]   MEM 0xe1000000..0xefffffff -> 0xe1000000
[    2.671410] nwl-pcie fd0e0000.pcie: PCI host bridge to bus 0000:00
[    2.677436] pci_bus 0000:00: root bus resource [bus 00-ff]
[    2.682883] pci_bus 0000:00: root bus resource [mem 0xe1000000-0xefffffff]
[    2.690031] Unhandled fault: synchronous external abort (0x96000210) at 0xffffff8000200000
[    2.690036] nwl-pcie fd0e0000.pcie: Slave error
[    2.702582] Internal error: : 96000210 [#1] SMP
[    2.707078] Modules linked in:
[    2.710108] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.5.0-rc6+ #5
[    2.716332] Hardware name: ZynqMP (DT)
[    2.720659] task: ffffffc0798bed00 ti: ffffffc0798c0000 task.ti: ffffffc0798c0000
[    2.728102] PC is at pci_generic_config_read+0x38/0x9c
[    2.733202] LR is at pci_generic_config_read+0x1c/0x9c
.......
[    3.322701] [<ffffffc000498b1c>] pci_generic_config_read+0x38/0x9c
[    3.328842] [<ffffffc000498f54>] pci_bus_read_config_dword+0x80/0xb0
[    3.335156] [<ffffffc00049abd4>] pci_bus_read_dev_vendor_id+0x30/0x104
[    3.341643] [<ffffffc00049c5b0>] pci_scan_single_device+0x50/0xc4
[    3.347698] [<ffffffc00049c674>] pci_scan_slot+0x50/0xe8
[    3.352974] [<ffffffc00049d530>] pci_scan_child_bus+0x30/0xd8
[    3.358683] [<ffffffc00049d210>] pci_scan_bridge+0x1fc/0x4ec
[    3.364306] [<ffffffc00049d58c>] pci_scan_child_bus+0x8c/0xd8
[    3.370016] [<ffffffc0004b2d9c>] nwl_pcie_probe+0x6c4/0x8e0
.....

> The hardware should do something reasonable with the config access if it
> can't send it down the link.
When Link is down and H/W gets a ECAM access request for downstream ports, hardware responds by DECERR (decode error) status on AXI Interface.

So without any EP and without this condition, Linux kernel cannot determine above response from H/W. So the above condition is useful only when no EP is connected.

Now even if the link is up initially, but the link goes down before we actually complete the config access, then H/W responds by DECERR, then Linux kernel might throw similar stack. (We haven't observed this condition yet)

It looks like we need a different type of hardware response to get rid of this situation, but it's not easy way. 
Have you come across this/similar kind of problem anywhere else? 
Can you suggest if there is any other way to handle this.

Thanks
Bharat
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Bjorn Helgaas March 14, 2016, 5:04 p.m. UTC | #3
On Mon, Mar 14, 2016 at 03:51:01PM +0000, Bharat Kumar Gogada wrote:
> > On Sun, Mar 06, 2016 at 10:02:14PM +0530, Bharat Kumar Gogada wrote:
> > > Adding PCIe Root Port driver for Xilinx PCIe NWL bridge IP.
> > 
> > > +static bool nwl_pcie_valid_device(struct pci_bus *bus, unsigned int
> > > +devfn) {
> > > +	struct nwl_pcie *pcie = bus->sysdata;
> > > +
> > > +	/* Check link,before accessing downstream ports */
> > > +	if (bus->number != pcie->root_busno) {
> > > +		if (!nwl_pcie_link_up(pcie))
> > > +			return false;
> > > +	}
> > 
> > This seems racy.  What if we check, and the link is up, but the
> > link goes down before we actually complete the config access?
> > 
> > I'm suggesting that this check for the link being up might be
> > superfluous.

> Without the above check and also if there is no EP then we are getting kernel stack as follows,
> [    2.654105] PCI host bridge /amba/pcie@fd0e0000 ranges:
> [    2.659268]   No bus range found for /amba/pcie@fd0e0000, using [bus 00-ff]
> [    2.666195]   MEM 0xe1000000..0xefffffff -> 0xe1000000
> [    2.671410] nwl-pcie fd0e0000.pcie: PCI host bridge to bus 0000:00
> [    2.677436] pci_bus 0000:00: root bus resource [bus 00-ff]
> [    2.682883] pci_bus 0000:00: root bus resource [mem 0xe1000000-0xefffffff]
> [    2.690031] Unhandled fault: synchronous external abort (0x96000210) at 0xffffff8000200000
> [    2.690036] nwl-pcie fd0e0000.pcie: Slave error
> [    2.702582] Internal error: : 96000210 [#1] SMP
> [    2.707078] Modules linked in:
> [    2.710108] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.5.0-rc6+ #5
> [    2.716332] Hardware name: ZynqMP (DT)
> [    2.720659] task: ffffffc0798bed00 ti: ffffffc0798c0000 task.ti: ffffffc0798c0000
> [    2.728102] PC is at pci_generic_config_read+0x38/0x9c
> [    2.733202] LR is at pci_generic_config_read+0x1c/0x9c
> .......
> [    3.322701] [<ffffffc000498b1c>] pci_generic_config_read+0x38/0x9c
> [    3.328842] [<ffffffc000498f54>] pci_bus_read_config_dword+0x80/0xb0
> [    3.335156] [<ffffffc00049abd4>] pci_bus_read_dev_vendor_id+0x30/0x104
> [    3.341643] [<ffffffc00049c5b0>] pci_scan_single_device+0x50/0xc4
> [    3.347698] [<ffffffc00049c674>] pci_scan_slot+0x50/0xe8
> [    3.352974] [<ffffffc00049d530>] pci_scan_child_bus+0x30/0xd8
> [    3.358683] [<ffffffc00049d210>] pci_scan_bridge+0x1fc/0x4ec
> [    3.364306] [<ffffffc00049d58c>] pci_scan_child_bus+0x8c/0xd8
> [    3.370016] [<ffffffc0004b2d9c>] nwl_pcie_probe+0x6c4/0x8e0
> .....
> 
> > The hardware should do something reasonable with the config access if it
> > can't send it down the link.
>
> When Link is down and H/W gets a ECAM access request for downstream
> ports, hardware responds by DECERR (decode error) status on AXI
> Interface.

DECERR isn't a PCIe concept, so I assume it's something specific to
Xilinx.  In the general case of a PCIe switch, a config access that
targets a device where the link is down should cause an Unsupported
Request completion (see PCIe spec r3.0, section 2.9.1, quoted below).
Possibly your Root Complex turns Unsupported Request completions into
DECERR.

  2.9 Link Status Dependencies
  2.9.1 Transaction Layer Behavior in DL_Down Status

  DL_Down status indicates that there is no connection with another
  component on the Link, or that the connection with the other
  component has been lost and is not recoverable by the Physical or
  Data Link Layers.

  For a Downstream Port, DL_Down status is handled by:
  
   for Non-Posted Requests, forming completions for any Requests
   submitted by the device core for Transmission, returning
   Unsupported Request Completion Status, then discarding the Requests

Linux expects reads with Unsupported Request completion status to
return all 1's data to the CPU as in section 2.3.2:

  2.3.2 Completion Handling Rules

  Read Data Values with UR Completion Status

  Some system configuration software depends on reading a data value
  of all 1’s when a Configuration Read Request is terminated as an
  Unsupported Request, particularly when probing to determine the
  existence of a device in the system.  A Root Complex intended for
  use with software that depends on a read-data value of all 1’s must
  synthesize this value when UR Completion Status is returned for a
  Configuration Read Request.

> So without any EP and without this condition, Linux kernel cannot
> determine above response from H/W. So the above condition is useful
> only when no EP is connected.
> 
> Now even if the link is up initially, but the link goes down before
> we actually complete the config access, then H/W responds by DECERR,
> then Linux kernel might throw similar stack. (We haven't observed
> this condition yet)

It'd be hard to hit this race unless you added delay in
nwl_pcie_map_bus() after nwl_pcie_valid_device(), then removed the
device during that delay.

> It looks like we need a different type of hardware response to get
> rid of this situation, but it's not easy way.  Have you come across
> this/similar kind of problem anywhere else?  Can you suggest if
> there is any other way to handle this.

I'm not a hardware designer, so I don't know what to suggest here.
The current design does seem like a robustness issue: surprise removal
of a device may cause this external abort in rare cases.

Bjorn
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Pali Rohár May 29, 2021, 3:18 p.m. UTC | #4
On Monday 14 March 2016 12:04:37 Bjorn Helgaas wrote:
> On Mon, Mar 14, 2016 at 03:51:01PM +0000, Bharat Kumar Gogada wrote:
> > > On Sun, Mar 06, 2016 at 10:02:14PM +0530, Bharat Kumar Gogada wrote:
> > > > Adding PCIe Root Port driver for Xilinx PCIe NWL bridge IP.
> > > 
> > > > +static bool nwl_pcie_valid_device(struct pci_bus *bus, unsigned int
> > > > +devfn) {
> > > > +	struct nwl_pcie *pcie = bus->sysdata;
> > > > +
> > > > +	/* Check link,before accessing downstream ports */
> > > > +	if (bus->number != pcie->root_busno) {
> > > > +		if (!nwl_pcie_link_up(pcie))
> > > > +			return false;
> > > > +	}
> > > 
> > > This seems racy.  What if we check, and the link is up, but the
> > > link goes down before we actually complete the config access?
> > > 
> > > I'm suggesting that this check for the link being up might be
> > > superfluous.
> 
> > Without the above check and also if there is no EP then we are getting kernel stack as follows,

Hello! Now I found this old thread... And I would like to ask, have you
solved this issue somehow? Because very similar problem I observe with
pci-aardvark.c, just it cause Synchronous External Abort on CPU.

> > [    2.654105] PCI host bridge /amba/pcie@fd0e0000 ranges:
> > [    2.659268]   No bus range found for /amba/pcie@fd0e0000, using [bus 00-ff]
> > [    2.666195]   MEM 0xe1000000..0xefffffff -> 0xe1000000
> > [    2.671410] nwl-pcie fd0e0000.pcie: PCI host bridge to bus 0000:00
> > [    2.677436] pci_bus 0000:00: root bus resource [bus 00-ff]
> > [    2.682883] pci_bus 0000:00: root bus resource [mem 0xe1000000-0xefffffff]
> > [    2.690031] Unhandled fault: synchronous external abort (0x96000210) at 0xffffff8000200000
> > [    2.690036] nwl-pcie fd0e0000.pcie: Slave error
> > [    2.702582] Internal error: : 96000210 [#1] SMP
> > [    2.707078] Modules linked in:
> > [    2.710108] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.5.0-rc6+ #5
> > [    2.716332] Hardware name: ZynqMP (DT)
> > [    2.720659] task: ffffffc0798bed00 ti: ffffffc0798c0000 task.ti: ffffffc0798c0000
> > [    2.728102] PC is at pci_generic_config_read+0x38/0x9c
> > [    2.733202] LR is at pci_generic_config_read+0x1c/0x9c
> > .......
> > [    3.322701] [<ffffffc000498b1c>] pci_generic_config_read+0x38/0x9c
> > [    3.328842] [<ffffffc000498f54>] pci_bus_read_config_dword+0x80/0xb0
> > [    3.335156] [<ffffffc00049abd4>] pci_bus_read_dev_vendor_id+0x30/0x104
> > [    3.341643] [<ffffffc00049c5b0>] pci_scan_single_device+0x50/0xc4
> > [    3.347698] [<ffffffc00049c674>] pci_scan_slot+0x50/0xe8
> > [    3.352974] [<ffffffc00049d530>] pci_scan_child_bus+0x30/0xd8
> > [    3.358683] [<ffffffc00049d210>] pci_scan_bridge+0x1fc/0x4ec
> > [    3.364306] [<ffffffc00049d58c>] pci_scan_child_bus+0x8c/0xd8
> > [    3.370016] [<ffffffc0004b2d9c>] nwl_pcie_probe+0x6c4/0x8e0
> > .....
> > 
> > > The hardware should do something reasonable with the config access if it
> > > can't send it down the link.
> >
> > When Link is down and H/W gets a ECAM access request for downstream
> > ports, hardware responds by DECERR (decode error) status on AXI
> > Interface.
> 
> DECERR isn't a PCIe concept, so I assume it's something specific to
> Xilinx.  In the general case of a PCIe switch, a config access that
> targets a device where the link is down should cause an Unsupported
> Request completion (see PCIe spec r3.0, section 2.9.1, quoted below).
> Possibly your Root Complex turns Unsupported Request completions into
> DECERR.

This looks like same design as with pci aardvark hw. PCIe Unsupported
Request or Completion Abort is converted to AXI DECERR (or SLVERR)
which is then reported to CPU. In my case AXI DECERR/SLVERR cause
Synchronous External Abort on CPU.

>   2.9 Link Status Dependencies
>   2.9.1 Transaction Layer Behavior in DL_Down Status
> 
>   DL_Down status indicates that there is no connection with another
>   component on the Link, or that the connection with the other
>   component has been lost and is not recoverable by the Physical or
>   Data Link Layers.
> 
>   For a Downstream Port, DL_Down status is handled by:
>   
>    for Non-Posted Requests, forming completions for any Requests
>    submitted by the device core for Transmission, returning
>    Unsupported Request Completion Status, then discarding the Requests
> 
> Linux expects reads with Unsupported Request completion status to
> return all 1's data to the CPU as in section 2.3.2:
> 
>   2.3.2 Completion Handling Rules
> 
>   Read Data Values with UR Completion Status
> 
>   Some system configuration software depends on reading a data value
>   of all 1’s when a Configuration Read Request is terminated as an
>   Unsupported Request, particularly when probing to determine the
>   existence of a device in the system.  A Root Complex intended for
>   use with software that depends on a read-data value of all 1’s must
>   synthesize this value when UR Completion Status is returned for a
>   Configuration Read Request.
> 
> > So without any EP and without this condition, Linux kernel cannot
> > determine above response from H/W. So the above condition is useful
> > only when no EP is connected.
> > 
> > Now even if the link is up initially, but the link goes down before
> > we actually complete the config access, then H/W responds by DECERR,
> > then Linux kernel might throw similar stack. (We haven't observed
> > this condition yet)
> 
> It'd be hard to hit this race unless you added delay in
> nwl_pcie_map_bus() after nwl_pcie_valid_device(), then removed the
> device during that delay.
> 
> > It looks like we need a different type of hardware response to get
> > rid of this situation, but it's not easy way.  Have you come across
> > this/similar kind of problem anywhere else?  Can you suggest if
> > there is any other way to handle this.
> 
> I'm not a hardware designer, so I don't know what to suggest here.
> The current design does seem like a robustness issue: surprise removal
> of a device may cause this external abort in rare cases.

With pci aardvark I'm able to reproduce this issue with surprise removal
of device.

Bharat, have you somehow resolved this issue? Seems that this kind of HW
design is not rare.
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt b/Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt
new file mode 100644
index 0000000..90e8f32
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt
@@ -0,0 +1,68 @@ 
+* Xilinx NWL PCIe Root Port Bridge DT description
+
+Required properties:
+- compatible: Should contain "xlnx,nwl-pcie-2.11"
+- #address-cells: Address representation for root ports, set to <3>
+- #size-cells: Size representation for root ports, set to <2>
+- #interrupt-cells: specifies the number of cells needed to encode an
+	interrupt source. The value must be 1.
+- reg: Should contain Bridge, PCIe Controller registers location,
+	configuration sapce, and length
+- reg-names: Must include the following entries:
+	"breg": bridge registers
+	"pcireg": PCIe controller registers
+	"cfg": configuration space region
+- device_type: must be "pci"
+- interrupts: Should contain NWL PCIe interrupt
+- interrupt-names: Must include the following entries:
+	"msi1, msi0": interrupt asserted when msi is received
+	"intx": interrupt that is asserted when an legacy interrupt is received
+	"misc": interrupt asserted when miscellaneous is received
+- interrupt-map-mask and interrupt-map: standard PCI properties to define the
+	mapping of the PCI interface to interrupt numbers.
+- ranges: ranges for the PCI memory regions (I/O space region is not
+	supported by hardware)
+	Please refer to the standard PCI bus binding document for a more
+	detailed explanation
+- msi-controller: indicates that this is MSI controller node
+- msi-parent:  MSI parent of the root complex itself
+- legacy-interrupt-controller: Interrupt controller device node for Legacy interrupts
+	- interrupt-controller: identifies the node as an interrupt controller
+	- #interrupt-cells: should be set to 1
+	- #address-cells: specifies the number of cells needed to encode an
+		address. The value must be 0.
+
+
+Example:
+++++++++
+
+nwl_pcie: pcie@fd0e0000 {
+	#address-cells = <3>;
+	#size-cells = <2>;
+	compatible = "xlnx,nwl-pcie-2.11";
+	#interrupt-cells = <1>;
+	msi-controller;
+	device_type = "pci";
+	interrupt-parent = <&gic>;
+	interrupts = <0 114 4>, <0 115 4>, <0 116 4>, <0 117 4>, <0 118 4>;
+	interrupt-names = "msi0", "msi1", "intx", "dummy", "misc";
+	interrupt-map-mask = <0x0 0x0 0x0 0x7>;
+	interrupt-map = <0x0 0x0 0x0 0x1 &pcie_intc 0x1>,
+			<0x0 0x0 0x0 0x2 &pcie_intc 0x2>,
+			<0x0 0x0 0x0 0x3 &pcie_intc 0x3>,
+			<0x0 0x0 0x0 0x4 &pcie_intc 0x4>;
+
+	msi-parent = <&nwl_pcie>;
+	reg = <0x0 0xfd0e0000 0x0 0x1000>,
+	      <0x0 0xfd480000 0x0 0x1000>,
+	      <0x0 0xe0000000 0x0 0x1000000>;
+	reg-names = "breg", "pcireg", "cfg";
+	ranges = <0x02000000 0x00000000 0xe1000000 0x00000000 0xe1000000 0 0x0f000000>;
+
+	pcie_intc: legacy-interrupt-controller {
+		interrupt-controller;
+		#address-cells = <0>;
+		#interrupt-cells = <1>;
+	};
+
+};
diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index d1cdd9c..ba6d77c 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -17,6 +17,16 @@  config PCI_MVEBU
 	depends on ARM
 	depends on OF
 
+config PCIE_XILINX_NWL
+	bool "NWL PCIe Core"
+	depends on ARCH_ZYNQMP
+	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
+	help
+	 Say 'Y' here if you want kernel to support for Xilinx
+	 NWL PCIe controller. The controller can act as Root Port
+	 or End Point. The current option selection will only
+	 support root port enabling.
+
 config PCIE_DW
 	bool
 
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 7b2f20c..d0b7d85 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -10,6 +10,7 @@  obj-$(CONFIG_PCI_HOST_GENERIC) += pci-host-generic.o
 obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o
 obj-$(CONFIG_PCI_KEYSTONE) += pci-keystone-dw.o pci-keystone.o
 obj-$(CONFIG_PCIE_XILINX) += pcie-xilinx.o
+obj-$(CONFIG_PCIE_XILINX_NWL) += pcie-xilinx-nwl.o
 obj-$(CONFIG_PCI_XGENE) += pci-xgene.o
 obj-$(CONFIG_PCI_XGENE_MSI) += pci-xgene-msi.o
 obj-$(CONFIG_PCI_LAYERSCAPE) += pci-layerscape.o
diff --git a/drivers/pci/host/pcie-xilinx-nwl.c b/drivers/pci/host/pcie-xilinx-nwl.c
new file mode 100644
index 0000000..e5774dc
--- /dev/null
+++ b/drivers/pci/host/pcie-xilinx-nwl.c
@@ -0,0 +1,912 @@ 
+/*
+ * PCIe host controller driver for NWL PCIe Bridge
+ * Based on pcie-xilinx.c, pci-tegra.c
+ *
+ * (C) Copyright 2014 - 2015, Xilinx, Inc.
+ *
+ * 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/delay.h>
+#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>
+#include <linux/irqchip/chained_irq.h>
+
+/* Bridge core config registers */
+#define BRCFG_PCIE_RX0			0x00000000
+#define BRCFG_PCIE_RX1			0x00000004
+#define BRCFG_AXI_MASTER		0x00000008
+#define BRCFG_PCIE_TX			0x0000000C
+#define BRCFG_INTERRUPT			0x00000010
+#define BRCFG_RAM_DISABLE0		0x00000014
+#define BRCFG_RAM_DISABLE1		0x00000018
+#define BRCFG_PCIE_RELAXED_ORDER	0x0000001C
+#define BRCFG_PCIE_RX_MSG_FILTER	0x00000020
+
+/* Attribute registers */
+#define NWL_ATTRIB_100			0x00000190
+
+/* Egress - Bridge translation registers */
+#define E_BREG_CAPABILITIES		0x00000200
+#define E_BREG_STATUS			0x00000204
+#define E_BREG_CONTROL			0x00000208
+#define E_BREG_BASE_LO			0x00000210
+#define E_BREG_BASE_HI			0x00000214
+#define E_ECAM_CAPABILITIES		0x00000220
+#define E_ECAM_STATUS			0x00000224
+#define E_ECAM_CONTROL			0x00000228
+#define E_ECAM_BASE_LO			0x00000230
+#define E_ECAM_BASE_HI			0x00000234
+
+/* Ingress - address translations */
+#define I_MSII_CAPABILITIES		0x00000300
+#define I_MSII_CONTROL			0x00000308
+#define I_MSII_BASE_LO			0x00000310
+#define I_MSII_BASE_HI			0x00000314
+
+#define I_ISUB_CONTROL			0x000003E8
+#define SET_ISUB_CONTROL		BIT(0)
+/* Rxed msg fifo  - Interrupt status registers */
+#define MSGF_MISC_STATUS		0x00000400
+#define MSGF_MISC_MASK			0x00000404
+#define MSGF_LEG_STATUS			0x00000420
+#define MSGF_LEG_MASK			0x00000424
+#define MSGF_MSI_STATUS_LO		0x00000440
+#define MSGF_MSI_STATUS_HI		0x00000444
+#define MSGF_MSI_MASK_LO		0x00000448
+#define MSGF_MSI_MASK_HI		0x0000044C
+#define MSGF_RX_FIFO_POP		0x00000484
+#define MSGF_RX_FIFO_TYPE		0x00000488
+#define MSGF_RX_FIFO_ADDRLO		0x00000490
+#define MSGF_RX_FIFO_ADDRHI		0x00000494
+#define MSGF_RX_FIFO_DATA		0x00000498
+
+/* Msg filter mask bits */
+#define CFG_ENABLE_PM_MSG_FWD		BIT(1)
+#define CFG_ENABLE_INT_MSG_FWD		BIT(2)
+#define CFG_ENABLE_ERR_MSG_FWD		BIT(3)
+#define CFG_ENABLE_SLT_MSG_FWD		BIT(5)
+#define CFG_ENABLE_VEN_MSG_FWD		BIT(7)
+#define CFG_ENABLE_OTH_MSG_FWD		BIT(13)
+#define CFG_ENABLE_VEN_MSG_EN		BIT(14)
+#define CFG_ENABLE_VEN_MSG_VEN_INV	BIT(15)
+#define CFG_ENABLE_VEN_MSG_VEN_ID	GENMASK(31, 16)
+#define CFG_ENABLE_MSG_FILTER_MASK	(CFG_ENABLE_PM_MSG_FWD | \
+					CFG_ENABLE_INT_MSG_FWD | \
+					CFG_ENABLE_ERR_MSG_FWD | \
+					CFG_ENABLE_SLT_MSG_FWD | \
+					CFG_ENABLE_VEN_MSG_FWD | \
+					CFG_ENABLE_OTH_MSG_FWD | \
+					CFG_ENABLE_VEN_MSG_EN | \
+					CFG_ENABLE_VEN_MSG_VEN_INV | \
+					CFG_ENABLE_VEN_MSG_VEN_ID)
+
+/* Misc interrupt status mask bits */
+#define MSGF_MISC_SR_RXMSG_AVAIL	BIT(0)
+#define MSGF_MISC_SR_RXMSG_OVER		BIT(1)
+#define MSGF_MISC_SR_SLAVE_ERR		BIT(4)
+#define MSGF_MISC_SR_MASTER_ERR		BIT(5)
+#define MSGF_MISC_SR_I_ADDR_ERR		BIT(6)
+#define MSGF_MISC_SR_E_ADDR_ERR		BIT(7)
+#define MSGF_MISC_SR_UR_DETECT          BIT(20)
+
+#define MSGF_MISC_SR_PCIE_CORE		GENMASK(18, 16)
+#define MSGF_MISC_SR_PCIE_CORE_ERR	GENMASK(31, 22)
+
+#define MSGF_MISC_SR_MASKALL		(MSGF_MISC_SR_RXMSG_AVAIL | \
+					MSGF_MISC_SR_RXMSG_OVER | \
+					MSGF_MISC_SR_SLAVE_ERR | \
+					MSGF_MISC_SR_MASTER_ERR | \
+					MSGF_MISC_SR_I_ADDR_ERR | \
+					MSGF_MISC_SR_E_ADDR_ERR | \
+					MSGF_MISC_SR_UR_DETECT | \
+					MSGF_MISC_SR_PCIE_CORE | \
+					MSGF_MISC_SR_PCIE_CORE_ERR)
+
+/* Message rx fifo type mask bits */
+#define MSGF_RX_FIFO_TYPE_MSI		(1)
+#define MSGF_RX_FIFO_TYPE_TYPE		GENMASK(1, 0)
+
+/* Legacy interrupt status mask bits */
+#define MSGF_LEG_SR_INTA		BIT(0)
+#define MSGF_LEG_SR_INTB		BIT(1)
+#define MSGF_LEG_SR_INTC		BIT(2)
+#define MSGF_LEG_SR_INTD		BIT(3)
+#define MSGF_LEG_SR_MASKALL		(MSGF_LEG_SR_INTA | MSGF_LEG_SR_INTB | \
+					MSGF_LEG_SR_INTC | MSGF_LEG_SR_INTD)
+
+/* MSI interrupt status mask bits */
+#define MSGF_MSI_SR_LO_MASK		BIT(0)
+#define MSGF_MSI_SR_HI_MASK		BIT(0)
+
+#define MSII_PRESENT			BIT(0)
+#define MSII_ENABLE			BIT(0)
+#define MSII_STATUS_ENABLE		BIT(15)
+
+/* Bridge config interrupt mask */
+#define BRCFG_INTERRUPT_MASK		BIT(0)
+#define BREG_PRESENT			BIT(0)
+#define BREG_ENABLE			BIT(0)
+#define BREG_ENABLE_FORCE		BIT(1)
+
+/* E_ECAM status mask bits */
+#define E_ECAM_PRESENT			BIT(0)
+#define E_ECAM_SR_WR_PEND		BIT(16)
+#define E_ECAM_SR_RD_PEND		BIT(0)
+#define E_ECAM_SR_MASKALL		(E_ECAM_SR_WR_PEND | E_ECAM_SR_RD_PEND)
+#define E_ECAM_CR_ENABLE		BIT(0)
+#define E_ECAM_SIZE_LOC			GENMASK(20, 16)
+#define E_ECAM_SIZE_SHIFT		16
+#define ECAM_BUS_LOC_SHIFT		20
+#define ECAM_DEV_LOC_SHIFT		12
+#define NWL_ECAM_VALUE_DEFAULT		12
+#define NWL_ECAM_SIZE_MIN		4096
+
+#define ATTR_UPSTREAM_FACING		BIT(6)
+#define CFG_DMA_REG_BAR			GENMASK(2, 0)
+
+#define INT_PCI_MSI_NR			(2 * 32)
+
+#define INTX_NUM			4
+/* Readin the PS_LINKUP */
+#define PS_LINKUP_OFFSET		0x00000238
+#define PCIE_PHY_LINKUP_BIT		BIT(0)
+#define PHY_RDY_LINKUP_BIT		BIT(1)
+#define PCIE_USER_LINKUP		0
+#define PHY_RDY_LINKUP			1
+#define LINKUP_ITER_CHECK		5
+
+struct nwl_msi {			/* MSI information */
+	struct irq_domain *msi_domain;
+	unsigned long *bitmap;
+	struct irq_domain *dev_domain;
+	struct mutex lock;		/* protect bitmap variable */
+	int irq_msi0;
+	int irq_msi1;
+};
+
+struct nwl_pcie {
+	struct device *dev;
+	void __iomem *breg_base;
+	void __iomem *pcireg_base;
+	void __iomem *ecam_base;
+	phys_addr_t phys_breg_base;	/* Physical Bridge Register Base */
+	phys_addr_t phys_pcie_reg_base;	/* Physical PCIe Controller Base */
+	phys_addr_t phys_ecam_base;	/* Physical Configuration Base */
+	u32 breg_size;
+	u32 pcie_reg_size;
+	u32 ecam_size;
+	int irq_intx;
+	int irq_misc;
+	u32 ecam_value;
+	u8 last_busno;
+	u8 root_busno;
+	u8 link_up;
+	struct nwl_msi msi;
+	struct irq_domain *legacy_irq_domain;
+};
+
+static inline u32 nwl_bridge_readl(struct nwl_pcie *pcie, u32 off)
+{
+	return readl(pcie->breg_base + off);
+}
+
+static inline void nwl_bridge_writel(struct nwl_pcie *pcie, u32 val, u32 off)
+{
+	writel(val, pcie->breg_base + off);
+}
+
+static bool nwl_pcie_link_up(struct nwl_pcie *pcie)
+{
+	if (readl(pcie->pcireg_base + PS_LINKUP_OFFSET) & PCIE_PHY_LINKUP_BIT)
+		return true;
+	return false;
+}
+
+static bool nwl_phy_link_up(struct nwl_pcie *pcie)
+{
+	if (readl(pcie->pcireg_base + PS_LINKUP_OFFSET) & PHY_RDY_LINKUP_BIT)
+		return true;
+	return false;
+}
+
+static bool nwl_pcie_valid_device(struct pci_bus *bus, unsigned int devfn)
+{
+	struct nwl_pcie *pcie = bus->sysdata;
+
+	/* Check link,before accessing downstream ports */
+	if (bus->number != pcie->root_busno) {
+		if (!nwl_pcie_link_up(pcie))
+			return false;
+	}
+
+	/* Only one device down on each root port */
+	if (bus->number == pcie->root_busno && devfn > 0)
+		return false;
+
+	return true;
+}
+
+/**
+ * nwl_pcie_map_bus - Get configuration base
+ *
+ * @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 *nwl_pcie_map_bus(struct pci_bus *bus,
+						 unsigned int devfn,
+						 int where)
+{
+	struct nwl_pcie *pcie = bus->sysdata;
+	int relbus;
+
+	if (!nwl_pcie_valid_device(bus, devfn))
+		return NULL;
+
+	relbus = (bus->number << ECAM_BUS_LOC_SHIFT) |
+			(devfn << ECAM_DEV_LOC_SHIFT);
+
+	return pcie->ecam_base + relbus + where;
+}
+
+/* PCIe operations */
+static struct pci_ops nwl_pcie_ops = {
+	.map_bus = nwl_pcie_map_bus,
+	.read  = pci_generic_config_read,
+	.write = pci_generic_config_write,
+};
+
+static irqreturn_t nwl_pcie_misc_handler(int irq, void *data)
+{
+	struct nwl_pcie *pcie = data;
+	u32 misc_stat;
+
+	/* Checking for misc interrupts */
+	misc_stat = nwl_bridge_readl(pcie, MSGF_MISC_STATUS) &
+				     MSGF_MISC_SR_MASKALL;
+	if (!misc_stat)
+		return IRQ_NONE;
+
+	if (misc_stat & MSGF_MISC_SR_RXMSG_OVER)
+		dev_err(pcie->dev, "Received Message FIFO Overflow\n");
+
+	if (misc_stat & MSGF_MISC_SR_SLAVE_ERR)
+		dev_err(pcie->dev, "Slave error\n");
+
+	if (misc_stat & MSGF_MISC_SR_MASTER_ERR)
+		dev_err(pcie->dev, "Master error\n");
+
+	if (misc_stat & MSGF_MISC_SR_I_ADDR_ERR)
+		dev_err(pcie->dev,
+			"In Misc Ingress address translation error\n");
+
+	if (misc_stat & MSGF_MISC_SR_E_ADDR_ERR)
+		dev_err(pcie->dev,
+			"In Misc Egress address translation error\n");
+
+	if (misc_stat & MSGF_MISC_SR_PCIE_CORE_ERR)
+		dev_err(pcie->dev, "PCIe Core error\n");
+
+	/* Clear misc interrupt status */
+	nwl_bridge_writel(pcie, misc_stat, MSGF_MISC_STATUS);
+
+	return IRQ_HANDLED;
+}
+
+static void nwl_pcie_leg_handler(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct nwl_pcie *pcie;
+	unsigned long status;
+	u32 bit;
+	u32 virq;
+
+	chained_irq_enter(chip, desc);
+	pcie = irq_desc_get_handler_data(desc);
+
+	while ((status = nwl_bridge_readl(pcie, MSGF_LEG_STATUS) &
+				MSGF_LEG_SR_MASKALL) != 0) {
+		for_each_set_bit(bit, &status, 4) {
+
+			virq = irq_find_mapping(pcie->legacy_irq_domain,
+						bit + 1);
+			if (virq)
+				generic_handle_irq(virq);
+		}
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static void nwl_pcie_handle_msi_irq(struct nwl_pcie *pcie, u32 status_reg)
+{
+	struct nwl_msi *msi;
+	unsigned long status;
+	u32 bit;
+	u32 virq;
+
+	msi = &pcie->msi;
+
+	while ((status = nwl_bridge_readl(pcie, status_reg)) != 0) {
+		for_each_set_bit(bit, &status, 32) {
+			nwl_bridge_writel(pcie, 1 << bit, status_reg);
+			virq = irq_find_mapping(msi->dev_domain, bit);
+			if (virq)
+				generic_handle_irq(virq);
+		}
+	}
+}
+
+static void nwl_pcie_msi_handler_high(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct nwl_pcie *pcie;
+
+	chained_irq_enter(chip, desc);
+	pcie = irq_desc_get_handler_data(desc);
+	nwl_pcie_handle_msi_irq(pcie, MSGF_MSI_STATUS_HI);
+
+	chained_irq_exit(chip, desc);
+}
+
+static void nwl_pcie_msi_handler_low(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct nwl_pcie *pcie;
+
+	chained_irq_enter(chip, desc);
+	pcie = irq_desc_get_handler_data(desc);
+	nwl_pcie_handle_msi_irq(pcie, MSGF_MSI_STATUS_LO);
+
+	chained_irq_exit(chip, desc);
+}
+
+static int nwl_legacy_map(struct irq_domain *domain, unsigned int irq,
+				irq_hw_number_t hwirq)
+{
+	irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
+	irq_set_chip_data(irq, domain->host_data);
+
+	return 0;
+}
+
+static const struct irq_domain_ops legacy_domain_ops = {
+	.map = nwl_legacy_map,
+};
+
+#ifdef CONFIG_PCI_MSI
+static struct irq_chip nwl_msi_irq_chip = {
+	.name = "nwl_pcie:msi",
+	.irq_enable = unmask_msi_irq,
+	.irq_disable = mask_msi_irq,
+	.irq_mask = mask_msi_irq,
+	.irq_unmask = unmask_msi_irq,
+
+};
+
+static struct msi_domain_info nwl_msi_domain_info = {
+	.flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+		  MSI_FLAG_MULTI_PCI_MSI),
+	.chip = &nwl_msi_irq_chip,
+};
+#endif
+
+static void nwl_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
+{
+	struct nwl_pcie *pcie = irq_data_get_irq_chip_data(data);
+	phys_addr_t msi_addr = pcie->phys_pcie_reg_base;
+
+	msg->address_lo = lower_32_bits(msi_addr);
+	msg->address_hi = upper_32_bits(msi_addr);
+	msg->data = data->hwirq;
+}
+
+static int nwl_msi_set_affinity(struct irq_data *irq_data,
+				const struct cpumask *mask, bool force)
+{
+	return -EINVAL;
+}
+
+static struct irq_chip nwl_irq_chip = {
+	.name = "Xilinx MSI",
+	.irq_compose_msi_msg = nwl_compose_msi_msg,
+	.irq_set_affinity = nwl_msi_set_affinity,
+};
+
+static int nwl_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				unsigned int nr_irqs, void *args)
+{
+	struct nwl_pcie *pcie = domain->host_data;
+	struct nwl_msi *msi = &pcie->msi;
+	int bit;
+	int i;
+
+	mutex_lock(&msi->lock);
+	bit = bitmap_find_next_zero_area(msi->bitmap, INT_PCI_MSI_NR, 0,
+					 nr_irqs, 0);
+	if (bit < INT_PCI_MSI_NR)
+		bitmap_set(msi->bitmap, bit, nr_irqs);
+	else
+		bit = -ENOSPC;
+
+	if (bit < 0) {
+		mutex_unlock(&msi->lock);
+		return bit;
+	}
+
+	for (i = 0; i < nr_irqs; i++) {
+		irq_domain_set_info(domain, virq + i, bit + i, &nwl_irq_chip,
+				domain->host_data, handle_simple_irq,
+				NULL, NULL);
+	}
+	mutex_unlock(&msi->lock);
+	return 0;
+}
+
+static void nwl_irq_domain_free(struct irq_domain *domain, unsigned int virq,
+					unsigned int nr_irqs)
+{
+	struct irq_data *data = irq_domain_get_irq_data(domain, virq);
+	struct nwl_pcie *pcie = irq_data_get_irq_chip_data(data);
+	struct nwl_msi *msi = &pcie->msi;
+
+	mutex_lock(&msi->lock);
+	bitmap_clear(msi->bitmap, data->hwirq, nr_irqs);
+	mutex_unlock(&msi->lock);
+}
+
+static const struct irq_domain_ops dev_msi_domain_ops = {
+	.alloc  = nwl_irq_domain_alloc,
+	.free   = nwl_irq_domain_free,
+};
+
+static void nwl_msi_free_irq_domain(struct nwl_pcie *pcie)
+{
+	struct nwl_msi *msi = &pcie->msi;
+
+	if (msi->irq_msi0)
+		irq_set_chained_handler_and_data(msi->irq_msi0, NULL, NULL);
+	if (msi->irq_msi1)
+		irq_set_chained_handler_and_data(msi->irq_msi1, NULL, NULL);
+
+	if (msi->msi_domain)
+		irq_domain_remove(msi->msi_domain);
+	if (msi->dev_domain)
+		irq_domain_remove(msi->dev_domain);
+
+	kfree(msi->bitmap);
+	msi->bitmap = NULL;
+}
+
+static void nwl_pcie_free_irq_domain(struct nwl_pcie *pcie)
+{
+	int i;
+	u32 irq;
+
+	for (i = 0; i < INTX_NUM; i++) {
+		irq = irq_find_mapping(pcie->legacy_irq_domain, i + 1);
+		if (irq > 0)
+			irq_dispose_mapping(irq);
+	}
+	if (pcie->legacy_irq_domain)
+		irq_domain_remove(pcie->legacy_irq_domain);
+
+	nwl_msi_free_irq_domain(pcie);
+}
+
+static int nwl_pcie_init_msi_irq_domain(struct nwl_pcie *pcie)
+{
+#ifdef CONFIG_PCI_MSI
+	struct fwnode_handle *fwnode = of_node_to_fwnode(pcie->dev->of_node);
+	struct nwl_msi *msi = &pcie->msi;
+
+	msi->dev_domain = irq_domain_add_linear(NULL, INT_PCI_MSI_NR,
+					&dev_msi_domain_ops, pcie);
+	if (!msi->dev_domain) {
+		dev_err(pcie->dev, "failed to create dev IRQ domain\n");
+		return -ENOMEM;
+	}
+	msi->msi_domain = pci_msi_create_irq_domain(fwnode,
+							&nwl_msi_domain_info,
+							msi->dev_domain);
+	if (!msi->msi_domain) {
+		dev_err(pcie->dev, "failed to create msi IRQ domain\n");
+		irq_domain_remove(msi->dev_domain);
+		return -ENOMEM;
+	}
+#endif
+	return 0;
+}
+
+static int nwl_pcie_init_irq_domain(struct nwl_pcie *pcie)
+{
+	struct device_node *node = pcie->dev->of_node;
+	struct device_node *legacy_intc_node;
+
+	legacy_intc_node = of_get_next_child(node, NULL);
+	if (!legacy_intc_node) {
+		dev_err(pcie->dev, "No legacy intc node found\n");
+		return PTR_ERR(legacy_intc_node);
+	}
+
+	pcie->legacy_irq_domain = irq_domain_add_linear(legacy_intc_node,
+							INTX_NUM,
+							&legacy_domain_ops,
+							pcie);
+
+	if (!pcie->legacy_irq_domain) {
+		dev_err(pcie->dev, "failed to create IRQ domain\n");
+		return -ENOMEM;
+	}
+
+	nwl_pcie_init_msi_irq_domain(pcie);
+
+	return 0;
+}
+
+static int nwl_pcie_enable_msi(struct nwl_pcie *pcie, struct pci_bus *bus)
+{
+	struct platform_device *pdev = to_platform_device(pcie->dev);
+	struct nwl_msi *msi = &pcie->msi;
+	unsigned long base;
+	int ret;
+	int size = BITS_TO_LONGS(INT_PCI_MSI_NR) * sizeof(long);
+
+	mutex_init(&msi->lock);
+
+	msi->bitmap = kzalloc(size, GFP_KERNEL);
+	if (!msi->bitmap)
+		return -ENOMEM;
+
+	/* Get msi_1 IRQ number */
+	msi->irq_msi1 = platform_get_irq_byname(pdev, "msi1");
+	if (msi->irq_msi1 < 0) {
+		dev_err(&pdev->dev, "failed to get IRQ#%d\n", msi->irq_msi1);
+		ret = -EINVAL;
+		goto err;
+	}
+	/* Register msi handler */
+	irq_set_chained_handler_and_data(msi->irq_msi1,
+					 nwl_pcie_msi_handler_high, pcie);
+	/* Get msi_0 IRQ number */
+	msi->irq_msi0 = platform_get_irq_byname(pdev, "msi0");
+	if (msi->irq_msi0 < 0) {
+		dev_err(&pdev->dev, "failed to get IRQ#%d\n", msi->irq_msi0);
+		ret = -EINVAL;
+		goto err;
+	}
+
+	/* Register msi handler */
+	irq_set_chained_handler_and_data(msi->irq_msi0,
+					 nwl_pcie_msi_handler_low, pcie);
+	/* Check for msii_present bit */
+	ret = nwl_bridge_readl(pcie, I_MSII_CAPABILITIES) & MSII_PRESENT;
+	if (!ret) {
+		dev_err(pcie->dev, "MSI not present\n");
+		ret = -EIO;
+		goto err;
+	}
+
+	/* Enable MSII */
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, I_MSII_CONTROL) |
+			  MSII_ENABLE, I_MSII_CONTROL);
+
+	/* Enable MSII status */
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, I_MSII_CONTROL) |
+			  MSII_STATUS_ENABLE, I_MSII_CONTROL);
+
+	/* setup AFI/FPCI range */
+	base = pcie->phys_pcie_reg_base;
+	nwl_bridge_writel(pcie, lower_32_bits(base), I_MSII_BASE_LO);
+	nwl_bridge_writel(pcie, upper_32_bits(base), I_MSII_BASE_HI);
+
+	/*
+	 * For high range msi interrupts: disable, clear any pending,
+	 * and enable
+	 */
+	nwl_bridge_writel(pcie, (u32)~MSGF_MSI_SR_HI_MASK, MSGF_MSI_MASK_HI);
+
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie,  MSGF_MSI_STATUS_HI) &
+			  MSGF_MSI_SR_HI_MASK, MSGF_MSI_STATUS_HI);
+
+	nwl_bridge_writel(pcie, MSGF_MSI_SR_HI_MASK, MSGF_MSI_MASK_HI);
+
+	/*
+	 * For low range msi interrupts: disable, clear any pending,
+	 * and enable
+	 */
+	nwl_bridge_writel(pcie, (u32)~MSGF_MSI_SR_LO_MASK, MSGF_MSI_MASK_LO);
+
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, MSGF_MSI_STATUS_LO) &
+			  MSGF_MSI_SR_LO_MASK, MSGF_MSI_STATUS_LO);
+
+	nwl_bridge_writel(pcie, MSGF_MSI_SR_LO_MASK, MSGF_MSI_MASK_LO);
+
+	return 0;
+err:
+	kfree(msi->bitmap);
+	msi->bitmap = NULL;
+	return ret;
+}
+
+static int nwl_pcie_bridge_init(struct nwl_pcie *pcie)
+{
+	struct platform_device *pdev = to_platform_device(pcie->dev);
+	u32 breg_val, ecam_val, first_busno = 0;
+	int err;
+	int check_link_up = 0;
+	bool link_up;
+
+	/* Check for BREG present bit */
+	breg_val = nwl_bridge_readl(pcie, E_BREG_CAPABILITIES) & BREG_PRESENT;
+	if (!breg_val) {
+		dev_err(pcie->dev, "BREG is not present\n");
+		return breg_val;
+	}
+	/* Write bridge_off to breg base */
+	nwl_bridge_writel(pcie, lower_32_bits(pcie->phys_breg_base),
+			  E_BREG_BASE_LO);
+	nwl_bridge_writel(pcie, upper_32_bits(pcie->phys_breg_base),
+			  E_BREG_BASE_HI);
+
+	/* Enable BREG */
+	nwl_bridge_writel(pcie, ~BREG_ENABLE_FORCE & BREG_ENABLE,
+			  E_BREG_CONTROL);
+
+	/* Disable DMA channel registers */
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, BRCFG_PCIE_RX0) |
+			  CFG_DMA_REG_BAR, BRCFG_PCIE_RX0);
+
+	/* Enable Ingress subtractive decode translation */
+	nwl_bridge_writel(pcie, SET_ISUB_CONTROL, I_ISUB_CONTROL);
+
+	/* Enable msg filtering details */
+	nwl_bridge_writel(pcie, CFG_ENABLE_MSG_FILTER_MASK,
+			  BRCFG_PCIE_RX_MSG_FILTER);
+	do {
+		link_up = nwl_phy_link_up(pcie);
+		if (!link_up) {
+			check_link_up++;
+			if (check_link_up > LINKUP_ITER_CHECK)
+				return -ENODEV;
+			msleep(1000);
+		}
+	} while (!link_up);
+
+	ecam_val = nwl_bridge_readl(pcie, E_ECAM_CAPABILITIES) & E_ECAM_PRESENT;
+	if (!ecam_val) {
+		dev_err(pcie->dev, "ECAM is not present\n");
+		return ecam_val;
+	}
+
+	/* Enable ECAM */
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, E_ECAM_CONTROL) |
+			  E_ECAM_CR_ENABLE, E_ECAM_CONTROL);
+
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, E_ECAM_CONTROL) |
+			  (pcie->ecam_value << E_ECAM_SIZE_SHIFT),
+			  E_ECAM_CONTROL);
+
+	nwl_bridge_writel(pcie, lower_32_bits(pcie->phys_ecam_base),
+			  E_ECAM_BASE_LO);
+	nwl_bridge_writel(pcie, upper_32_bits(pcie->phys_ecam_base),
+			  E_ECAM_BASE_HI);
+
+	/* Get bus range */
+	ecam_val = nwl_bridge_readl(pcie, E_ECAM_CONTROL);
+	pcie->last_busno = (ecam_val & E_ECAM_SIZE_LOC) >> E_ECAM_SIZE_SHIFT;
+	/* Write primary, secondary and subordinate bus numbers */
+	ecam_val = first_busno;
+	ecam_val |= (first_busno + 1) << 8;
+	ecam_val |= (pcie->last_busno << E_ECAM_SIZE_SHIFT);
+	writel(ecam_val, (pcie->ecam_base + PCI_PRIMARY_BUS));
+
+	pcie->link_up = nwl_pcie_link_up(pcie);
+	if (pcie->link_up)
+		dev_info(pcie->dev, "Link is UP\n");
+	else
+		dev_info(pcie->dev, "Link is DOWN\n");
+
+	/* Get misc IRQ number */
+	pcie->irq_misc = platform_get_irq_byname(pdev, "misc");
+	if (pcie->irq_misc < 0) {
+		dev_err(&pdev->dev, "failed to get misc IRQ %d\n",
+			pcie->irq_misc);
+		return -EINVAL;
+	}
+	/* Register misc handler */
+	err = devm_request_irq(pcie->dev, pcie->irq_misc,
+			       nwl_pcie_misc_handler, IRQF_SHARED,
+			       "nwl_pcie:misc", pcie);
+	if (err) {
+		dev_err(pcie->dev, "fail to register misc IRQ#%d\n",
+			pcie->irq_misc);
+		return err;
+	}
+
+	/* Disable all misc interrupts */
+	nwl_bridge_writel(pcie, (u32)~MSGF_MISC_SR_MASKALL, MSGF_MISC_MASK);
+
+	/* Clear pending misc interrupts */
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, MSGF_MISC_STATUS) &
+			  MSGF_MISC_SR_MASKALL, MSGF_MISC_STATUS);
+
+	/* Enable all misc interrupts */
+	nwl_bridge_writel(pcie, MSGF_MISC_SR_MASKALL, MSGF_MISC_MASK);
+
+
+	/* Disable all legacy interrupts */
+	nwl_bridge_writel(pcie, (u32)~MSGF_LEG_SR_MASKALL, MSGF_LEG_MASK);
+
+	/* Clear pending legacy interrupts */
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, MSGF_LEG_STATUS) &
+			  MSGF_LEG_SR_MASKALL, MSGF_LEG_STATUS);
+
+	/* Enable all legacy interrupts */
+	nwl_bridge_writel(pcie, MSGF_LEG_SR_MASKALL, MSGF_LEG_MASK);
+
+	/* Enable the bridge config interrupt */
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, BRCFG_INTERRUPT) |
+			  BRCFG_INTERRUPT_MASK, BRCFG_INTERRUPT);
+
+	return 0;
+}
+
+static int nwl_pcie_parse_dt(struct nwl_pcie *pcie,
+					struct platform_device *pdev)
+{
+	struct device_node *node = pcie->dev->of_node;
+	struct resource *res;
+	const char *type;
+
+	/* Check for device type */
+	type = of_get_property(node, "device_type", NULL);
+	if (!type || strcmp(type, "pci")) {
+		dev_err(pcie->dev, "invalid \"device_type\" %s\n", type);
+		return -EINVAL;
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "breg");
+	pcie->breg_base = devm_ioremap_resource(pcie->dev, res);
+	if (IS_ERR(pcie->breg_base))
+		return PTR_ERR(pcie->breg_base);
+	pcie->phys_breg_base = res->start;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pcireg");
+	pcie->pcireg_base = devm_ioremap_resource(pcie->dev, res);
+	if (IS_ERR(pcie->pcireg_base))
+		return PTR_ERR(pcie->pcireg_base);
+	pcie->phys_pcie_reg_base = res->start;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
+	pcie->ecam_base = devm_ioremap_resource(pcie->dev, res);
+	if (IS_ERR(pcie->ecam_base))
+		return PTR_ERR(pcie->ecam_base);
+	pcie->phys_ecam_base = res->start;
+
+	/* Get intx IRQ number */
+	pcie->irq_intx = platform_get_irq_byname(pdev, "intx");
+	if (pcie->irq_intx < 0) {
+		dev_err(&pdev->dev, "failed to get intx IRQ %d\n",
+			pcie->irq_intx);
+		return -EINVAL;
+	}
+
+	/* Register intx handler */
+	irq_set_chained_handler_and_data(pcie->irq_intx,
+					 nwl_pcie_leg_handler, pcie);
+
+	return 0;
+}
+
+static const struct of_device_id nwl_pcie_of_match[] = {
+	{ .compatible = "xlnx,nwl-pcie-2.11", },
+	{}
+};
+
+static int nwl_pcie_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct nwl_pcie *pcie;
+	struct pci_bus *bus;
+	struct pci_bus *child;
+	int err;
+	resource_size_t iobase = 0;
+	LIST_HEAD(res);
+
+	pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL);
+	if (!pcie)
+		return -ENOMEM;
+
+	pcie->ecam_value = NWL_ECAM_VALUE_DEFAULT;
+
+	pcie->dev = &pdev->dev;
+
+	err = nwl_pcie_parse_dt(pcie, pdev);
+	if (err) {
+		dev_err(pcie->dev, "Parsing DT failed\n");
+		return err;
+	}
+	/* Bridge initialization */
+	err = nwl_pcie_bridge_init(pcie);
+	if (err) {
+		dev_err(pcie->dev, "HW Initalization failed\n");
+		return err;
+	}
+
+	err = of_pci_get_host_bridge_resources(node, 0, 0xff, &res, &iobase);
+	if (err) {
+		pr_err("Getting bridge resources failed\n");
+		return err;
+	}
+
+	err = nwl_pcie_init_irq_domain(pcie);
+	if (err) {
+		dev_err(pcie->dev, "Failed creating IRQ Domain\n");
+		return err;
+	}
+
+	bus = pci_create_root_bus(&pdev->dev, pcie->root_busno,
+				  &nwl_pcie_ops, pcie, &res);
+	if (!bus)
+		return -ENOMEM;
+
+	/* Enable MSI */
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		err = nwl_pcie_enable_msi(pcie, bus);
+		if (err < 0) {
+			dev_err(&pdev->dev,
+				"failed to enable MSI support: %d\n", err);
+			return err;
+		}
+	}
+	pci_scan_child_bus(bus);
+	pci_assign_unassigned_bus_resources(bus);
+	list_for_each_entry(child, &bus->children, node)
+		pcie_bus_configure_settings(child);
+	pci_bus_add_devices(bus);
+	platform_set_drvdata(pdev, pcie);
+
+	return 0;
+}
+
+static int nwl_pcie_remove(struct platform_device *pdev)
+{
+	struct nwl_pcie *pcie = platform_get_drvdata(pdev);
+
+	nwl_pcie_free_irq_domain(pcie);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver nwl_pcie_driver = {
+	.driver = {
+		.name = "nwl-pcie",
+		.of_match_table = nwl_pcie_of_match,
+	},
+	.probe = nwl_pcie_probe,
+	.remove = nwl_pcie_remove,
+};
+module_platform_driver(nwl_pcie_driver);
+
+MODULE_AUTHOR("Xilinx, Inc");
+MODULE_DESCRIPTION("NWL PCIe driver");
+MODULE_LICENSE("GPL");