diff mbox

[RFC,V3,1/4] pci: APM X-Gene PCIe controller driver

Message ID 1390599168-13150-2-git-send-email-tinamdar@apm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Tanmay Inamdar Jan. 24, 2014, 9:32 p.m. UTC
This patch adds the AppliedMicro X-Gene SOC PCIe controller driver.
X-Gene PCIe controller supports maximum upto 8 lanes and GEN3 speed.
X-Gene has maximum 5 PCIe ports supported.

Signed-off-by: Tanmay Inamdar <tinamdar@apm.com>
---
 drivers/pci/host/Kconfig     |   10 +
 drivers/pci/host/Makefile    |    1 +
 drivers/pci/host/pci-xgene.c |  784 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 795 insertions(+)
 create mode 100644 drivers/pci/host/pci-xgene.c

Comments

Arnd Bergmann Jan. 30, 2014, 2:16 p.m. UTC | #1
On Friday 24 January 2014, Tanmay Inamdar wrote:

> +static void xgene_pcie_fixup_bridge(struct pci_dev *dev)
> +{
> +	int i;
> +
> +	/* Hide the PCI host BARs from the kernel as their content doesn't
> +	 * fit well in the resource management
> +	 */
> +	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
> +		dev->resource[i].start = dev->resource[i].end = 0;
> +		dev->resource[i].flags = 0;
> +	}
> +	dev_info(&dev->dev, "Hiding X-Gene pci host bridge resources %s\n",
> +		 pci_name(dev));
> +}
> +DECLARE_PCI_FIXUP_HEADER(XGENE_PCIE_VENDORID, XGENE_PCIE_DEVICEID,
> +			 xgene_pcie_fixup_bridge);

Shouldn't this be gone now that the host bridge is correctly shown
at the domain root?

> +static int xgene_pcie_setup(int nr, struct pci_sys_data *sys)
> +{
> +	struct xgene_pcie_port *pp = sys->private_data;
> +	struct resource *io = &pp->realio;
> +
> +	io->start = sys->domain * SZ_64K;
> +	io->end = io->start + SZ_64K;
> +	io->flags = pp->io.res.flags;
> +	io->name = "PCI IO";
> +	pci_ioremap_io(io->start, pp->io.res.start);
> +
> +	pci_add_resource_offset(&sys->resources, io, sys->io_offset);
> +	sys->mem_offset = pp->mem.res.start - pp->mem.pci_addr;
> +	pci_add_resource_offset(&sys->resources, &pp->mem.res,
> +				sys->mem_offset);
> +	return 1;
> +}

Thanks for bringing back the I/O space handling.

You don't seem to set sys->io_offset anywhere, but each of the
ports listed in your DT starts a local bus I/O register range
at port 0.

AFAICT, you need to add (somewhere)

	sys->io_offset = pp->realio.start - pp->io.pci_addr;

but there could be something else missing. You clearly haven't
tested if the I/O space actually works.

If you want to try out the I/O space, I'd suggest using an Intel
e1000 network card, which has both memory and i/o space. There
is a patch at http://www.spinics.net/lists/linux-pci/msg27684.html
that lets you check the I/O registers on it, or you can go
through /dev/port from user space.

I also haven't seen your patch that adds pci_ioremap_io() for
arm64. It would be helpful to keep it in the same patch
series, since it won't build without this patch.

	Arnd
Tanmay Inamdar Feb. 3, 2014, 7:42 p.m. UTC | #2
On Thu, Jan 30, 2014 at 6:16 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Friday 24 January 2014, Tanmay Inamdar wrote:
>
>> +static void xgene_pcie_fixup_bridge(struct pci_dev *dev)
>> +{
>> +     int i;
>> +
>> +     /* Hide the PCI host BARs from the kernel as their content doesn't
>> +      * fit well in the resource management
>> +      */
>> +     for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
>> +             dev->resource[i].start = dev->resource[i].end = 0;
>> +             dev->resource[i].flags = 0;
>> +     }
>> +     dev_info(&dev->dev, "Hiding X-Gene pci host bridge resources %s\n",
>> +              pci_name(dev));
>> +}
>> +DECLARE_PCI_FIXUP_HEADER(XGENE_PCIE_VENDORID, XGENE_PCIE_DEVICEID,
>> +                      xgene_pcie_fixup_bridge);
>
> Shouldn't this be gone now that the host bridge is correctly shown
> at the domain root?

In inbound region configuration, whole DDR space is mapped into the
BAR of RC. When Linux PCI mid-layer starts enumerating, it reads the
size of BAR of RC and tries to fit it into the memory resource. First
thing is that the outbound memory is not enough to map the inbound BAR
space. This creates problem with the resource management logic and
second thing is that, it is not required to map inbound BAR space RC
bar as no one will be accessing it further.

As Jason suggested, Bridge BAR's should be 0 size unless the bridge
itself has registers. However this is not the case with XGene PCIe
controller. It may have been inherited from the legacy design.
'arch/powerpc/sysdev/ppc4xx_pci.c' has similar fixup function.

>
>> +static int xgene_pcie_setup(int nr, struct pci_sys_data *sys)
>> +{
>> +     struct xgene_pcie_port *pp = sys->private_data;
>> +     struct resource *io = &pp->realio;
>> +
>> +     io->start = sys->domain * SZ_64K;
>> +     io->end = io->start + SZ_64K;
>> +     io->flags = pp->io.res.flags;
>> +     io->name = "PCI IO";
>> +     pci_ioremap_io(io->start, pp->io.res.start);
>> +
>> +     pci_add_resource_offset(&sys->resources, io, sys->io_offset);
>> +     sys->mem_offset = pp->mem.res.start - pp->mem.pci_addr;
>> +     pci_add_resource_offset(&sys->resources, &pp->mem.res,
>> +                             sys->mem_offset);
>> +     return 1;
>> +}
>
> Thanks for bringing back the I/O space handling.
>
> You don't seem to set sys->io_offset anywhere, but each of the
> ports listed in your DT starts a local bus I/O register range
> at port 0.
>
> AFAICT, you need to add (somewhere)
>
>         sys->io_offset = pp->realio.start - pp->io.pci_addr;
>
> but there could be something else missing. You clearly haven't
> tested if the I/O space actually works.

That is correct :-). Could not find the card. Thanks for the patch below.
>
> If you want to try out the I/O space, I'd suggest using an Intel
> e1000 network card, which has both memory and i/o space. There
> is a patch at http://www.spinics.net/lists/linux-pci/msg27684.html
> that lets you check the I/O registers on it, or you can go
> through /dev/port from user space.
>
> I also haven't seen your patch that adds pci_ioremap_io() for
> arm64. It would be helpful to keep it in the same patch
> series, since it won't build without this patch.

I will post the arm64 pci patch along with next revision of this
driver. That will cover the 'pci_ioremap_io' as well.

>
>         Arnd
Arnd Bergmann Feb. 3, 2014, 8:12 p.m. UTC | #3
On Monday 03 February 2014 11:42:22 Tanmay Inamdar wrote:
> On Thu, Jan 30, 2014 at 6:16 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> > On Friday 24 January 2014, Tanmay Inamdar wrote:
> >
> >> +static void xgene_pcie_fixup_bridge(struct pci_dev *dev)
> >> +{
> >> +     int i;
> >> +
> >> +     /* Hide the PCI host BARs from the kernel as their content doesn't
> >> +      * fit well in the resource management
> >> +      */
> >> +     for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
> >> +             dev->resource[i].start = dev->resource[i].end = 0;
> >> +             dev->resource[i].flags = 0;
> >> +     }
> >> +     dev_info(&dev->dev, "Hiding X-Gene pci host bridge resources %s\n",
> >> +              pci_name(dev));
> >> +}
> >> +DECLARE_PCI_FIXUP_HEADER(XGENE_PCIE_VENDORID, XGENE_PCIE_DEVICEID,
> >> +                      xgene_pcie_fixup_bridge);
> >
> > Shouldn't this be gone now that the host bridge is correctly shown
> > at the domain root?
> 
> In inbound region configuration, whole DDR space is mapped into the
> BAR of RC. When Linux PCI mid-layer starts enumerating, it reads the
> size of BAR of RC and tries to fit it into the memory resource. First
> thing is that the outbound memory is not enough to map the inbound BAR
> space. This creates problem with the resource management logic and
> second thing is that, it is not required to map inbound BAR space RC
> bar as no one will be accessing it further.
> 
> As Jason suggested, Bridge BAR's should be 0 size unless the bridge
> itself has registers. However this is not the case with XGene PCIe
> controller. It may have been inherited from the legacy design.
> 'arch/powerpc/sysdev/ppc4xx_pci.c' has similar fixup function.

Are you sure that is true for the root bridge as well? I don't
remember the details, but I though that for the host bridge,
we don't actually look at the BARs at all.

> > If you want to try out the I/O space, I'd suggest using an Intel
> > e1000 network card, which has both memory and i/o space. There
> > is a patch at http://www.spinics.net/lists/linux-pci/msg27684.html
> > that lets you check the I/O registers on it, or you can go
> > through /dev/port from user space.
> >
> > I also haven't seen your patch that adds pci_ioremap_io() for
> > arm64. It would be helpful to keep it in the same patch
> > series, since it won't build without this patch.
> 
> I will post the arm64 pci patch along with next revision of this
> driver. That will cover the 'pci_ioremap_io' as well.

Please note that today, Liviu Dudau has also posted patches for this,
so you should coordinate a bit.

	Arnd
Tanmay Inamdar Feb. 3, 2014, 8:14 p.m. UTC | #4
On Mon, Feb 3, 2014 at 12:12 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Monday 03 February 2014 11:42:22 Tanmay Inamdar wrote:
>> On Thu, Jan 30, 2014 at 6:16 AM, Arnd Bergmann <arnd@arndb.de> wrote:
>> > On Friday 24 January 2014, Tanmay Inamdar wrote:
>> >
>> >> +static void xgene_pcie_fixup_bridge(struct pci_dev *dev)
>> >> +{
>> >> +     int i;
>> >> +
>> >> +     /* Hide the PCI host BARs from the kernel as their content doesn't
>> >> +      * fit well in the resource management
>> >> +      */
>> >> +     for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
>> >> +             dev->resource[i].start = dev->resource[i].end = 0;
>> >> +             dev->resource[i].flags = 0;
>> >> +     }
>> >> +     dev_info(&dev->dev, "Hiding X-Gene pci host bridge resources %s\n",
>> >> +              pci_name(dev));
>> >> +}
>> >> +DECLARE_PCI_FIXUP_HEADER(XGENE_PCIE_VENDORID, XGENE_PCIE_DEVICEID,
>> >> +                      xgene_pcie_fixup_bridge);
>> >
>> > Shouldn't this be gone now that the host bridge is correctly shown
>> > at the domain root?
>>
>> In inbound region configuration, whole DDR space is mapped into the
>> BAR of RC. When Linux PCI mid-layer starts enumerating, it reads the
>> size of BAR of RC and tries to fit it into the memory resource. First
>> thing is that the outbound memory is not enough to map the inbound BAR
>> space. This creates problem with the resource management logic and
>> second thing is that, it is not required to map inbound BAR space RC
>> bar as no one will be accessing it further.
>>
>> As Jason suggested, Bridge BAR's should be 0 size unless the bridge
>> itself has registers. However this is not the case with XGene PCIe
>> controller. It may have been inherited from the legacy design.
>> 'arch/powerpc/sysdev/ppc4xx_pci.c' has similar fixup function.
>
> Are you sure that is true for the root bridge as well? I don't
> remember the details, but I though that for the host bridge,
> we don't actually look at the BARs at all.
>
>> > If you want to try out the I/O space, I'd suggest using an Intel
>> > e1000 network card, which has both memory and i/o space. There
>> > is a patch at http://www.spinics.net/lists/linux-pci/msg27684.html
>> > that lets you check the I/O registers on it, or you can go
>> > through /dev/port from user space.
>> >
>> > I also haven't seen your patch that adds pci_ioremap_io() for
>> > arm64. It would be helpful to keep it in the same patch
>> > series, since it won't build without this patch.
>>
>> I will post the arm64 pci patch along with next revision of this
>> driver. That will cover the 'pci_ioremap_io' as well.
>
> Please note that today, Liviu Dudau has also posted patches for this,
> so you should coordinate a bit.

Yes. Just looking at his patches. Looks similar to what I have. I will
wait till your solution shapes up.
>
>         Arnd
Jason Gunthorpe Feb. 3, 2014, 10:15 p.m. UTC | #5
On Mon, Feb 03, 2014 at 09:12:32PM +0100, Arnd Bergmann wrote:

> Are you sure that is true for the root bridge as well? I don't
> remember the details, but I though that for the host bridge,
> we don't actually look at the BARs at all.

That is right, but this isn't a host bridge device, it is a PCI-PCI
bridge with root complex registers. The root complex bridge is not the
same as the host bridge.

Unfortunately the implementation is non-conforming. :(

Jason
Arnd Bergmann Feb. 4, 2014, 7:22 p.m. UTC | #6
On Monday 03 February 2014, Jason Gunthorpe wrote:
> On Mon, Feb 03, 2014 at 09:12:32PM +0100, Arnd Bergmann wrote:
> 
> > Are you sure that is true for the root bridge as well? I don't
> > remember the details, but I though that for the host bridge,
> > we don't actually look at the BARs at all.
> 
> That is right, but this isn't a host bridge device, it is a PCI-PCI
> bridge with root complex registers. The root complex bridge is not the
> same as the host bridge.
> 
> Unfortunately the implementation is non-conforming. :(

Ok, I see. I was probably asking the wrong question then earlier
when I tried to find out what this is.

	Arnd
diff mbox

Patch

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index 47d46c6..19ce97d 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -33,4 +33,14 @@  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_XGENE
+	bool "X-Gene PCIe controller"
+	depends on ARCH_XGENE
+	depends on OF
+	select PCIEPORTBUS
+	help
+	  Say Y here if you want internal PCI support on APM X-Gene SoC.
+	  There are 5 internal PCIe ports available. Each port is GEN3 capable
+	  and have varied lanes from x1 to x8.
+
 endmenu
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 13fb333..34c7c36 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_XGENE) += pci-xgene.o
diff --git a/drivers/pci/host/pci-xgene.c b/drivers/pci/host/pci-xgene.c
new file mode 100644
index 0000000..650a860
--- /dev/null
+++ b/drivers/pci/host/pci-xgene.c
@@ -0,0 +1,784 @@ 
+/**
+ * APM X-Gene PCIe Driver
+ *
+ * Copyright (c) 2013 Applied Micro Circuits Corporation.
+ *
+ * Author: Tanmay Inamdar <tinamdar@apm.com>.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/clk-private.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/jiffies.h>
+#include <linux/memblock.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_pci.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <asm/pcibios.h>
+
+#define PCIECORE_LTSSM			0x4c
+#define PCIECORE_CTLANDSTATUS		0x50
+#define PIPE_PHY_RATE_RD(src)		((0xc000 & (u32)(src)) >> 0xe)
+#define INTXSTATUSMASK			0x6c
+#define PIM1_1L				0x80
+#define IBAR2				0x98
+#define IR2MSK				0x9c
+#define PIM2_1L				0xa0
+#define IBAR3L				0xb4
+#define IR3MSKL				0xbc
+#define PIM3_1L				0xc4
+#define OMR1BARL			0x100
+#define OMR2BARL			0x118
+#define CFGBARL				0x154
+#define CFGBARH				0x158
+#define CFGCTL				0x15c
+#define RTDID				0x160
+#define BRIDGE_CFG_0			0x2000
+#define BRIDGE_CFG_1			0x2004
+#define BRIDGE_CFG_4			0x2010
+#define BRIDGE_CFG_32			0x2030
+#define BRIDGE_CFG_14			0x2038
+#define BRIDGE_CTRL_1			0x2204
+#define BRIDGE_CTRL_2			0x2208
+#define BRIDGE_CTRL_5			0x2214
+#define BRIDGE_STATUS_0			0x2600
+#define MEM_RAM_SHUTDOWN                0xd070
+#define BLOCK_MEM_RDY                   0xd074
+
+#define DEVICE_PORT_TYPE_MASK		0x03c00000
+#define PM_FORCE_RP_MODE_MASK		0x00000400
+#define SWITCH_PORT_MODE_MASK		0x00000800
+#define CLASS_CODE_MASK			0xffffff00
+#define LINK_UP_MASK			0x00000100
+#define AER_OPTIONAL_ERROR_EN		0xffc00000
+#define XGENE_PCIE_DEV_CTRL		0x2f0f
+#define AXI_EP_CFG_ACCESS		0x10000
+#define ENABLE_ASPM			0x08000000
+#define XGENE_PORT_TYPE_RC		0x05000000
+#define BLOCK_MEM_RDY_VAL               0xFFFFFFFF
+#define EN_COHERENCY			0xF0000000
+#define EN_REG				0x00000001
+#define OB_LO_IO			0x00000002
+#define XGENE_PCIE_VENDORID		0xE008
+#define XGENE_PCIE_DEVICEID		0xE004
+#define XGENE_PCIE_TIMEOUT		(500*1000) /* us */
+#define XGENE_LTSSM_DETECT_WAIT		20
+#define XGENE_LTSSM_L0_WAIT		4
+#define SZ_1T				(SZ_1G*1024ULL)
+
+struct xgene_res_cfg {
+	struct resource		res;
+	u64			pci_addr;
+};
+
+struct xgene_pcie_port {
+	struct device_node	*node;
+	struct device		*dev;
+	struct clk		*clk;
+	struct xgene_res_cfg	mem;
+	struct xgene_res_cfg	io;
+	struct resource		realio;
+	void __iomem		*csr_base;
+	void __iomem		*cfg_base;
+	u8			link_up;
+};
+
+static inline u32 pcie_bar_low_val(u32 addr, u32 flags)
+{
+	return (addr & PCI_BASE_ADDRESS_MEM_MASK) | flags;
+}
+
+static inline struct xgene_pcie_port *
+xgene_pcie_bus_to_port(struct pci_bus *bus)
+{
+	struct pci_sys_data *sys = bus->sysdata;
+	return sys->private_data;
+}
+
+/* PCIE Configuration Out/In */
+static inline void xgene_pcie_cfg_out32(void __iomem *addr, u32 val)
+{
+	writel(val, addr);
+}
+
+static inline void xgene_pcie_cfg_out16(void __iomem *addr, u16 val)
+{
+	u64 temp_addr = (u64)addr & ~0x3;
+	u32 val32 = readl((void __iomem *)temp_addr);
+
+	switch ((u64) addr & 0x3) {
+	case 2:
+		val32 &= ~0xFFFF0000;
+		val32 |= (u32) val << 16;
+		break;
+	case 0:
+	default:
+		val32 &= ~0xFFFF;
+		val32 |= val;
+		break;
+	}
+	writel(val32, (void __iomem *)temp_addr);
+}
+
+static inline void xgene_pcie_cfg_out8(void __iomem *addr, u8 val)
+{
+	phys_addr_t temp_addr = (u64) addr & ~0x3;
+	u32 val32 = readl((void __iomem *)temp_addr);
+
+	switch ((u64) addr & 0x3) {
+	case 0:
+		val32 &= ~0xFF;
+		val32 |= val;
+		break;
+	case 1:
+		val32 &= ~0xFF00;
+		val32 |= (u32) val << 8;
+		break;
+	case 2:
+		val32 &= ~0xFF0000;
+		val32 |= (u32) val << 16;
+		break;
+	case 3:
+	default:
+		val32 &= ~0xFF000000;
+		val32 |= (u32) val << 24;
+		break;
+	}
+	writel(val32, (void __iomem *)temp_addr);
+}
+
+static inline void xgene_pcie_cfg_in32(void __iomem *addr, u32 *val)
+{
+	*val = readl(addr);
+}
+
+static inline void xgene_pcie_cfg_in16(void __iomem *addr, u16 *val)
+{
+	u64 temp_addr = (u64)addr & ~0x3;
+	u32 val32;
+
+	val32 = readl((void __iomem *)temp_addr);
+
+	switch ((u64)addr & 0x3) {
+	case 2:
+		*val = val32 >> 16;
+		break;
+	case 0:
+	default:
+		*val = val32;
+		break;
+	}
+}
+
+static inline void xgene_pcie_cfg_in8(void __iomem *addr, u8 *val)
+{
+	u64 temp_addr = (u64)addr & ~0x3;
+	u32 val32;
+
+	val32 = readl((void __iomem *)temp_addr);
+
+	switch ((u64)addr & 0x3) {
+	case 3:
+		*val = val32 >> 24;
+		break;
+	case 2:
+		*val = val32 >> 16;
+		break;
+	case 1:
+		*val = val32 >> 8;
+		break;
+	case 0:
+	default:
+		*val = val32;
+		break;
+	}
+}
+
+/* When the address bit [17:16] is 2'b01, the Configuration access will be
+ * treated as Type 1 and it will be forwarded to external PCIe device.
+ */
+static void __iomem *xgene_pcie_get_cfg_base(struct pci_bus *bus)
+{
+	struct xgene_pcie_port *port = xgene_pcie_bus_to_port(bus);
+
+	if (bus->number >= (bus->primary + 1))
+		return port->cfg_base + AXI_EP_CFG_ACCESS;
+
+	return port->cfg_base;
+}
+
+/* For Configuration request, RTDID register is used as Bus Number,
+ * Device Number and Function number of the header fields.
+ */
+static void xgene_pcie_set_rtdid_reg(struct pci_bus *bus, uint devfn)
+{
+	struct xgene_pcie_port *port = xgene_pcie_bus_to_port(bus);
+	unsigned int b, d, f;
+	u32 rtdid_val = 0;
+
+	b = bus->number;
+	d = PCI_SLOT(devfn);
+	f = PCI_FUNC(devfn);
+
+	if (!pci_is_root_bus(bus))
+		rtdid_val = (b << 8) | (d << 3) | f;
+
+	writel(rtdid_val, port->csr_base + RTDID);
+	/* read the register back to ensure flush */
+	readl(port->csr_base + RTDID);
+}
+
+static int xgene_pcie_read_config(struct pci_bus *bus, unsigned int devfn,
+				  int offset, int len, u32 *val)
+{
+	struct xgene_pcie_port *port = xgene_pcie_bus_to_port(bus);
+	void __iomem *addr;
+	u8 val8;
+	u16 val16;
+
+	if ((pci_is_root_bus(bus) && devfn != 0) || !port->link_up)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	xgene_pcie_set_rtdid_reg(bus, devfn);
+	addr = xgene_pcie_get_cfg_base(bus);
+	switch (len) {
+	case 1:
+		xgene_pcie_cfg_in8(addr + offset, &val8);
+		*val = val8;
+		break;
+	case 2:
+		xgene_pcie_cfg_in16(addr + offset, &val16);
+		*val = val16;
+		break;
+	default:
+		xgene_pcie_cfg_in32(addr + offset, val);
+		break;
+	}
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int xgene_pcie_write_config(struct pci_bus *bus, unsigned int devfn,
+				   int offset, int len, u32 val)
+{
+	struct xgene_pcie_port *port = xgene_pcie_bus_to_port(bus);
+	void __iomem *addr;
+
+	if ((pci_is_root_bus(bus) && devfn != 0) || !port->link_up)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	xgene_pcie_set_rtdid_reg(bus, devfn);
+	addr = xgene_pcie_get_cfg_base(bus);
+	switch (len) {
+	case 1:
+		xgene_pcie_cfg_out8(addr + offset, (u8) val);
+		break;
+	case 2:
+		xgene_pcie_cfg_out16(addr + offset, (u16) val);
+		break;
+	default:
+		xgene_pcie_cfg_out32(addr + offset, val);
+		break;
+	}
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static struct pci_ops xgene_pcie_ops = {
+	.read = xgene_pcie_read_config,
+	.write = xgene_pcie_write_config
+};
+
+static void xgene_pcie_program_core(void __iomem *csr_base)
+{
+	u32 val;
+
+	val = readl(csr_base + BRIDGE_CFG_0);
+	val |= AER_OPTIONAL_ERROR_EN;
+	writel(val, csr_base + BRIDGE_CFG_0);
+	writel(0x0, csr_base + INTXSTATUSMASK);
+	val = readl(csr_base + BRIDGE_CTRL_1);
+	val = (val & ~0xffff) | XGENE_PCIE_DEV_CTRL;
+	writel(val, csr_base + BRIDGE_CTRL_1);
+}
+
+static u64 xgene_pcie_set_ib_mask(void __iomem *csr_base, u32 addr,
+				  u32 flags, u64 size)
+{
+	u64 mask = (~(size - 1) & PCI_BASE_ADDRESS_MEM_MASK) | flags;
+	u32 val32 = 0;
+	u32 val;
+
+	val32 = readl(csr_base + addr);
+	val = (val32 & 0x0000ffff) | (lower_32_bits(mask) << 16);
+	writel(val, csr_base + addr);
+
+	val32 = readl(csr_base + addr + 0x04);
+	val = (val32 & 0xffff0000) | (lower_32_bits(mask) >> 16);
+	writel(val, csr_base + addr + 0x04);
+
+	val32 = readl(csr_base + addr + 0x04);
+	val = (val32 & 0x0000ffff) | (upper_32_bits(mask) << 16);
+	writel(val, csr_base + addr + 0x04);
+
+	val32 = readl(csr_base + addr + 0x08);
+	val = (val32 & 0xffff0000) | (upper_32_bits(mask) >> 16);
+	writel(val, csr_base + addr + 0x08);
+
+	return mask;
+}
+
+static void xgene_pcie_poll_linkup(struct xgene_pcie_port *port,
+				   u32 *lanes, u32 *speed)
+{
+	void __iomem *csr_base = port->csr_base;
+	u32 val32;
+	u64 start_time, time;
+
+	/*
+	 * A component enters the LTSSM Detect state within
+	 * 20ms of the end of fundamental core reset.
+	 */
+	msleep(XGENE_LTSSM_DETECT_WAIT);
+	port->link_up = 0;
+	start_time = jiffies;
+	do {
+		val32 = readl(csr_base + PCIECORE_CTLANDSTATUS);
+		if (val32 & LINK_UP_MASK) {
+			port->link_up = 1;
+			*speed = PIPE_PHY_RATE_RD(val32);
+			val32 = readl(csr_base + BRIDGE_STATUS_0);
+			*lanes = val32 >> 26;
+		}
+		time = jiffies_to_msecs(jiffies - start_time);
+	} while ((!port->link_up) || (time <= XGENE_LTSSM_L0_WAIT));
+}
+
+static void xgene_pcie_setup_root_complex(struct xgene_pcie_port *port)
+{
+	void __iomem *csr_base = port->csr_base;
+	u32 val;
+
+	val = (XGENE_PCIE_DEVICEID << 16) | XGENE_PCIE_VENDORID;
+	writel(val, csr_base + BRIDGE_CFG_0);
+
+	val = readl(csr_base + BRIDGE_CFG_1);
+	val &= ~CLASS_CODE_MASK;
+	val |= PCI_CLASS_BRIDGE_PCI << 16;
+	writel(val, csr_base + BRIDGE_CFG_1);
+
+	val = readl(csr_base + BRIDGE_CFG_14);
+	val |= SWITCH_PORT_MODE_MASK;
+	val &= ~PM_FORCE_RP_MODE_MASK;
+	writel(val, csr_base + BRIDGE_CFG_14);
+
+	val = readl(csr_base + BRIDGE_CTRL_5);
+	val &= ~DEVICE_PORT_TYPE_MASK;
+	val |= XGENE_PORT_TYPE_RC;
+	writel(val, csr_base + BRIDGE_CTRL_5);
+
+	val = readl(csr_base + BRIDGE_CTRL_2);
+	val |= ENABLE_ASPM;
+	writel(val, csr_base + BRIDGE_CTRL_2);
+
+	val = readl(csr_base + BRIDGE_CFG_32);
+	writel(val | (1 << 19), csr_base + BRIDGE_CFG_32);
+}
+
+/* Return 0 on success */
+static int xgene_pcie_init_ecc(struct xgene_pcie_port *port)
+{
+	void __iomem *csr_base = port->csr_base;
+	int timeout = XGENE_PCIE_TIMEOUT;
+	u32 val;
+
+	val = readl(csr_base + MEM_RAM_SHUTDOWN);
+	if (val == 0)
+		return 0;
+	writel(0x0, csr_base + MEM_RAM_SHUTDOWN);
+	do {
+		val = readl(csr_base + BLOCK_MEM_RDY);
+		udelay(1);
+	} while ((val != BLOCK_MEM_RDY_VAL) && timeout--);
+
+	return !(timeout > 0);
+}
+
+static int xgene_pcie_init_port(struct xgene_pcie_port *port)
+{
+	int rc;
+
+	port->clk = clk_get(port->dev, NULL);
+	if (IS_ERR_OR_NULL(port->clk)) {
+		dev_err(port->dev, "clock not available\n");
+		return -ENODEV;
+	}
+
+	rc = clk_prepare_enable(port->clk);
+	if (rc) {
+		dev_err(port->dev, "clock enable failed\n");
+		return rc;
+	}
+
+	rc = xgene_pcie_init_ecc(port);
+	if (rc) {
+		dev_err(port->dev, "memory init failed\n");
+		return rc;
+	}
+
+	return 0;
+}
+
+struct device_node *pcibios_get_phb_of_node(struct pci_bus *bus)
+{
+	struct xgene_pcie_port *port = xgene_pcie_bus_to_port(bus);
+
+	return of_node_get(port->node);
+}
+
+static void xgene_pcie_fixup_bridge(struct pci_dev *dev)
+{
+	int i;
+
+	/* Hide the PCI host BARs from the kernel as their content doesn't
+	 * fit well in the resource management
+	 */
+	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
+		dev->resource[i].start = dev->resource[i].end = 0;
+		dev->resource[i].flags = 0;
+	}
+	dev_info(&dev->dev, "Hiding X-Gene pci host bridge resources %s\n",
+		 pci_name(dev));
+}
+DECLARE_PCI_FIXUP_HEADER(XGENE_PCIE_VENDORID, XGENE_PCIE_DEVICEID,
+			 xgene_pcie_fixup_bridge);
+
+static int xgene_pcie_map_reg(struct xgene_pcie_port *port,
+			      struct platform_device *pdev, u64 *cfg_addr)
+{
+	struct resource *res;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "csr");
+	port->csr_base = devm_ioremap_resource(port->dev, res);
+	if (IS_ERR(port->csr_base))
+		return PTR_ERR(port->csr_base);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
+	port->cfg_base = devm_ioremap_resource(port->dev, res);
+	if (IS_ERR(port->cfg_base))
+		return PTR_ERR(port->cfg_base);
+	*cfg_addr = res->start;
+
+	return 0;
+}
+
+static void xgene_pcie_setup_ob_reg(struct xgene_pcie_port *port,
+				    u32 addr, u32 restype)
+{
+	struct resource *res;
+	void __iomem *base = port->csr_base + addr;
+	resource_size_t size;
+	u64 cpu_addr, pci_addr;
+	u64 mask = 0;
+	u32 min_size;
+	u32 flag = EN_REG;
+
+	if (restype == IORESOURCE_MEM) {
+		res = &port->mem.res;
+		pci_addr = port->mem.pci_addr;
+		min_size = SZ_128M;
+	} else {
+		res = &port->io.res;
+		pci_addr = port->io.pci_addr;
+		min_size = 128;
+		flag |= OB_LO_IO;
+	}
+	size = resource_size(res);
+	if (size >= min_size)
+		mask = ~(size - 1) | flag;
+	else
+		dev_warn(port->dev, "res size 0x%llx less than minimum 0x%x\n",
+			 (u64)size, min_size);
+	cpu_addr = res->start;
+	writel(lower_32_bits(cpu_addr), base);
+	writel(upper_32_bits(cpu_addr), base + 0x04);
+	writel(lower_32_bits(mask), base + 0x08);
+	writel(upper_32_bits(mask), base + 0x0c);
+	writel(lower_32_bits(pci_addr), base + 0x10);
+	writel(upper_32_bits(pci_addr), base + 0x14);
+}
+
+static void xgene_pcie_setup_cfg_reg(void __iomem *csr_base, u64 addr)
+{
+	writel(lower_32_bits(addr), csr_base + CFGBARL);
+	writel(upper_32_bits(addr), csr_base + CFGBARH);
+	writel(EN_REG, csr_base + CFGCTL);
+}
+
+static int xgene_pcie_parse_map_ranges(struct xgene_pcie_port *port,
+				       u64 cfg_addr)
+{
+	struct device_node *np = port->node;
+	struct of_pci_range range;
+	struct of_pci_range_parser parser;
+	struct device *dev = port->dev;
+
+	if (of_pci_range_parser_init(&parser, np)) {
+		dev_err(dev, "missing ranges property\n");
+		return -EINVAL;
+	}
+
+	/* Get the I/O, memory ranges from DT */
+	for_each_of_pci_range(&parser, &range) {
+		struct resource *res = NULL;
+		u64 restype = range.flags & IORESOURCE_TYPE_BITS;
+		u64 end = range.cpu_addr + range.size - 1;
+		dev_dbg(port->dev, "0x%08x 0x%016llx..0x%016llx -> 0x%016llx\n",
+			range.flags, range.cpu_addr, end, range.pci_addr);
+
+		switch (restype) {
+		case IORESOURCE_IO:
+			res = &port->io.res;
+			port->io.pci_addr = range.pci_addr;
+			of_pci_range_to_resource(&range, np, res);
+			xgene_pcie_setup_ob_reg(port, OMR1BARL, restype);
+			break;
+		case IORESOURCE_MEM:
+			res = &port->mem.res;
+			port->mem.pci_addr = range.pci_addr;
+			of_pci_range_to_resource(&range, np, res);
+			xgene_pcie_setup_ob_reg(port, OMR2BARL, restype);
+			break;
+		default:
+			dev_err(dev, "invalid io resource!");
+			return -EINVAL;
+		}
+	}
+	xgene_pcie_setup_cfg_reg(port->csr_base, cfg_addr);
+	return 0;
+}
+
+static void xgene_pcie_setup_pims(void *addr, u64 pim, u64 size)
+{
+	writel(lower_32_bits(pim), addr);
+	writel(upper_32_bits(pim) | EN_COHERENCY, addr + 0x04);
+	writel(lower_32_bits(size), addr + 0x10);
+	writel(upper_32_bits(size), addr + 0x14);
+}
+
+/*
+ * X-Gene PCIe support maximum 3 inbound memory regions
+ * This function helps to select a region based on size of region
+ */
+static int xgene_pcie_select_ib_reg(u8 *ib_reg_mask, u64 size)
+{
+	if ((size > 4) && (size < SZ_16M) && !(*ib_reg_mask & (1 << 1))) {
+		*ib_reg_mask |= (1 << 1);
+		return 1;
+	}
+
+	if ((size > SZ_1K) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 0))) {
+		*ib_reg_mask |= (1 << 0);
+		return 0;
+	}
+
+	if ((size > SZ_1M) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 2))) {
+		*ib_reg_mask |= (1 << 2);
+		return 2;
+	}
+	return -EINVAL;
+}
+
+static void xgene_pcie_setup_ib_reg(struct xgene_pcie_port *port,
+				    struct of_pci_range *range, u8 *ib_reg_mask)
+{
+	void __iomem *csr_base = port->csr_base;
+	void __iomem *cfg_base = port->cfg_base;
+	void *bar_addr;
+	void *pim_addr;
+	u64 restype = range->flags & IORESOURCE_TYPE_BITS;
+	u64 cpu_addr = range->cpu_addr;
+	u64 pci_addr = range->pci_addr;
+	u64 size = range->size;
+	u64 mask = ~(size - 1) | EN_REG;
+	u32 flags = PCI_BASE_ADDRESS_MEM_TYPE_64;
+	u32 bar_low;
+	int region;
+
+	region = xgene_pcie_select_ib_reg(ib_reg_mask, range->size);
+	if (region < 0) {
+		dev_warn(port->dev, "invalid pcie dma-range config\n");
+		return;
+	}
+
+	if (restype == PCI_BASE_ADDRESS_MEM_PREFETCH)
+		flags |= PCI_BASE_ADDRESS_MEM_PREFETCH;
+
+	bar_low = pcie_bar_low_val((u32)cpu_addr, flags);
+	switch (region) {
+	case 0:
+		xgene_pcie_set_ib_mask(csr_base, BRIDGE_CFG_4, flags, size);
+		bar_addr = cfg_base + PCI_BASE_ADDRESS_0;
+		writel(bar_low, bar_addr);
+		writel(upper_32_bits(cpu_addr), bar_addr + 0x4);
+		pim_addr = csr_base + PIM1_1L;
+		break;
+	case 1:
+		bar_addr = csr_base + IBAR2;
+		writel(bar_low, bar_addr);
+		writel(lower_32_bits(mask), csr_base + IR2MSK);
+		pim_addr = csr_base + PIM2_1L;
+		break;
+	case 2:
+		bar_addr = csr_base + IBAR3L;
+		writel(bar_low, bar_addr);
+		writel(upper_32_bits(cpu_addr), bar_addr + 0x4);
+		writel(lower_32_bits(mask), csr_base + IR3MSKL);
+		writel(upper_32_bits(mask), csr_base + IR3MSKL + 0x4);
+		pim_addr = csr_base + PIM3_1L;
+		break;
+	}
+
+	xgene_pcie_setup_pims(pim_addr, pci_addr, size);
+}
+
+static int pci_dma_range_parser_init(struct of_pci_range_parser *parser,
+				     struct device_node *node)
+{
+	const int na = 3, ns = 2;
+	int rlen;
+
+	parser->node = node;
+	parser->pna = of_n_addr_cells(node);
+	parser->np = parser->pna + na + ns;
+
+	parser->range = of_get_property(node, "dma-ranges", &rlen);
+	if (!parser->range)
+		return -ENOENT;
+
+	parser->end = parser->range + rlen / sizeof(__be32);
+	return 0;
+}
+
+static int xgene_pcie_parse_map_dma_ranges(struct xgene_pcie_port *port)
+{
+	struct device_node *np = port->node;
+	struct of_pci_range range;
+	struct of_pci_range_parser parser;
+	struct device *dev = port->dev;
+	u8 ib_reg_mask = 0;
+
+	if (pci_dma_range_parser_init(&parser, np)) {
+		dev_err(dev, "missing dma-ranges property\n");
+		return -EINVAL;
+	}
+
+	/* Get the dma-ranges from DT */
+	for_each_of_pci_range(&parser, &range) {
+		u64 end = range.cpu_addr + range.size - 1;
+		dev_dbg(port->dev, "0x%08x 0x%016llx..0x%016llx -> 0x%016llx\n",
+			range.flags, range.cpu_addr, end, range.pci_addr);
+		xgene_pcie_setup_ib_reg(port, &range, &ib_reg_mask);
+	}
+	return 0;
+}
+
+static int xgene_pcie_setup(int nr, struct pci_sys_data *sys)
+{
+	struct xgene_pcie_port *pp = sys->private_data;
+	struct resource *io = &pp->realio;
+
+	io->start = sys->domain * SZ_64K;
+	io->end = io->start + SZ_64K;
+	io->flags = pp->io.res.flags;
+	io->name = "PCI IO";
+	pci_ioremap_io(io->start, pp->io.res.start);
+
+	pci_add_resource_offset(&sys->resources, io, sys->io_offset);
+	sys->mem_offset = pp->mem.res.start - pp->mem.pci_addr;
+	pci_add_resource_offset(&sys->resources, &pp->mem.res,
+				sys->mem_offset);
+	return 1;
+}
+
+static int __init xgene_pcie_probe_bridge(struct platform_device *pdev)
+{
+	struct device_node *np = of_node_get(pdev->dev.of_node);
+	struct xgene_pcie_port *port;
+	struct hw_pci xgene_pcie_hw;
+	u32 lanes = 0, speed = 0;
+	u64 cfg_addr = 0;
+	static u32 domain;
+	int ret;
+
+	port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL);
+	if (!port)
+		return -ENOMEM;
+	port->node = np;
+	port->dev = &pdev->dev;
+
+	ret = xgene_pcie_map_reg(port, pdev, &cfg_addr);
+	if (ret)
+		return ret;
+
+	ret = xgene_pcie_init_port(port);
+	if (ret)
+		goto skip;
+	xgene_pcie_program_core(port->csr_base);
+	xgene_pcie_setup_root_complex(port);
+	ret = xgene_pcie_parse_map_ranges(port, cfg_addr);
+	if (ret)
+		goto skip;
+	ret = xgene_pcie_parse_map_dma_ranges(port);
+	if (ret)
+		goto skip;
+	xgene_pcie_poll_linkup(port, &lanes, &speed);
+skip:
+	if (!port->link_up)
+		dev_info(port->dev, "(rc) link down\n");
+	else
+		dev_info(port->dev, "(rc) x%d gen-%d link up\n",
+				lanes, speed + 1);
+	platform_set_drvdata(pdev, port);
+	memset(&xgene_pcie_hw, 0, sizeof(xgene_pcie_hw));
+	xgene_pcie_hw.domain = domain++;
+	xgene_pcie_hw.private_data = (void **)&port;
+	xgene_pcie_hw.nr_controllers = 1;
+	xgene_pcie_hw.setup = xgene_pcie_setup;
+	xgene_pcie_hw.map_irq = of_irq_parse_and_map_pci;
+	xgene_pcie_hw.ops = &xgene_pcie_ops;
+	pci_common_init(&xgene_pcie_hw);
+	return 0;
+}
+
+static const struct of_device_id xgene_pcie_match_table[] __initconst = {
+	{.compatible = "apm,xgene-pcie",},
+	{},
+};
+
+static struct platform_driver xgene_pcie_driver = {
+	.driver = {
+		   .name = "xgene-pcie",
+		   .owner = THIS_MODULE,
+		   .of_match_table = of_match_ptr(xgene_pcie_match_table),
+		  },
+	.probe = xgene_pcie_probe_bridge,
+};
+module_platform_driver(xgene_pcie_driver);
+
+MODULE_AUTHOR("Tanmay Inamdar <tinamdar@apm.com>");
+MODULE_DESCRIPTION("APM X-Gene PCIe driver");
+MODULE_LICENSE("GPL v2");