diff mbox

[1/6] pci, thunder: Add support for Thunder PCIe host controller

Message ID 1411573068-12952-2-git-send-email-rric@kernel.org (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Robert Richter Sept. 24, 2014, 3:37 p.m. UTC
From: Sunil Goutham <sgoutham@cavium.com>

This patch adds support for PCI host controller of Cavium Thunder
SoCs.

Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: Robert Richter <rrichter@cavium.com>
---
 drivers/pci/host/Kconfig        |   8 ++
 drivers/pci/host/Makefile       |   1 +
 drivers/pci/host/pcie-thunder.c | 246 ++++++++++++++++++++++++++++++++++++++++
 include/linux/pci_ids.h         |   2 +
 4 files changed, 257 insertions(+)
 create mode 100644 drivers/pci/host/pcie-thunder.c

Comments

Arnd Bergmann Sept. 24, 2014, 4:12 p.m. UTC | #1
On Wednesday 24 September 2014 17:37:43 Robert Richter wrote:
> From: Sunil Goutham <sgoutham@cavium.com>
> 
> This patch adds support for PCI host controller of Cavium Thunder
> SoCs.

I had expected this hardware to be SBSA compliant. Why do you need
a hardware specific driver, is this a workaround for buggy hardware
or just noncompliant?

> +/*
> + * All PCIe devices in Thunder have fixed resources, shouldn't be reassigned.
> + * Also claim the device's valid resources to set 'res->parent' hierarchy.
> + */
> +static void pci_dev_resource_fixup(struct pci_dev *dev)
> +{
> +	struct resource *res;
> +	int resno;
> +
> +	for (resno = 0; resno < PCI_NUM_RESOURCES; resno++)
> +		dev->resource[resno].flags |= IORESOURCE_PCI_FIXED;

You have listed these as relocatable in DT, why do you have to mark
them as nonrelocatable here?

> +static void __iomem *thunder_pcie_cfg_base(struct thunder_pcie *pcie,
> +				 unsigned int bus, unsigned int devfn)
> +{
> +	return  pcie->cfg_base + ((bus << THUNDER_PCIE_BUS_SHIFT)
> +		| (PCI_SLOT(devfn) << THUNDER_PCIE_DEV_SHIFT)
> +		| (PCI_FUNC(devfn) << THUNDER_PCIE_FUNC_SHIFT));
> +}
> +
> +static int thunder_pcie_read_config(struct pci_bus *bus, unsigned int devfn,
> +				  int reg, int size, u32 *val)
> +{
> +	struct thunder_pcie *pcie = bus->sysdata;
> +	void __iomem *addr;
> +	unsigned int busnr = bus->number;
> +
> +	if (busnr > 255 || devfn > 255 || reg > 4095)
> +		return PCIBIOS_DEVICE_NOT_FOUND;
> +
> +	addr = thunder_pcie_cfg_base(pcie, busnr, devfn) + reg;
> +
> +	switch (size) {
> +	case 1:
> +		*val = readb(addr);
> +		break;
> +	case 2:
> +		*val = readw(addr);
> +		break;
> +	case 4:
> +		*val = readl(addr);
> +		break;
> +	default:
> +		return PCIBIOS_BAD_REGISTER_NUMBER;
> +	}
> +
> +	return PCIBIOS_SUCCESSFUL;
> +}

This looks roughly ECAM compliant, are you sure you need a
private implementation?

> +static int thunder_pcie_msi_enable(struct thunder_pcie *pcie,
> +					struct pci_bus *bus)
> +{
> +	struct device_node *msi_node;
> +
> +	msi_node = of_parse_phandle(pcie->node, "msi-parent", 0);
> +	if (!msi_node)
> +		return -ENODEV;
> +
> +	pcie->msi = of_pci_find_msi_chip_by_node(msi_node);
> +	if (!pcie->msi)
> +		return -ENODEV;
> +
> +	pcie->msi->dev = pcie->dev;
> +	bus->msi = pcie->msi;
> +
> +	return 0;
> +}

This is probably something we should add to the generic host driver as well,
so it can work with SBSA compliant implementations that come with an MSI
controller. Maybe move it into common code so it can be shared with that
driver.

	Arnd
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Will Deacon Sept. 24, 2014, 4:49 p.m. UTC | #2
On Wed, Sep 24, 2014 at 05:12:26PM +0100, Arnd Bergmann wrote:
> On Wednesday 24 September 2014 17:37:43 Robert Richter wrote:
> > From: Sunil Goutham <sgoutham@cavium.com>
> > 
> > This patch adds support for PCI host controller of Cavium Thunder
> > SoCs.
> 
> I had expected this hardware to be SBSA compliant. Why do you need
> a hardware specific driver, is this a workaround for buggy hardware
> or just noncompliant?

Patches welcome to pci-host-generic.c :) Lorenzo already has code to port
it to Liviu's new API, so do shout if it's not suitable for your needs.

> > +static int thunder_pcie_msi_enable(struct thunder_pcie *pcie,
> > +					struct pci_bus *bus)
> > +{
> > +	struct device_node *msi_node;
> > +
> > +	msi_node = of_parse_phandle(pcie->node, "msi-parent", 0);
> > +	if (!msi_node)
> > +		return -ENODEV;
> > +
> > +	pcie->msi = of_pci_find_msi_chip_by_node(msi_node);
> > +	if (!pcie->msi)
> > +		return -ENODEV;
> > +
> > +	pcie->msi->dev = pcie->dev;
> > +	bus->msi = pcie->msi;
> > +
> > +	return 0;
> > +}
> 
> This is probably something we should add to the generic host driver as well,
> so it can work with SBSA compliant implementations that come with an MSI
> controller. Maybe move it into common code so it can be shared with that
> driver.

Agreed. I've been carrying something similar [1] (based on a hacked-up version
of bios32, so not bothered to post it) whilst I've been waiting for the
arm64 core PCI code to get merged.

Will

[1] https://git.kernel.org/cgit/linux/kernel/git/will/linux.git/commit/drivers/pci/host/pci-host-generic.c?h=iommu/pci&id=b719acf062ceccfbd79ee7b1ae0b7904ea4da27e
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Sunil Kovvuri Sept. 30, 2014, 9:14 a.m. UTC | #3
Will/Arnd

Thanks for the comments.
There is another patch submitted for adding MSI controller to Generic driver.
https://lkml.org/lkml/2014/9/28/150

Will go through these and comeback.

On Wed, Sep 24, 2014 at 10:19 PM, Will Deacon <will.deacon@arm.com> wrote:
> On Wed, Sep 24, 2014 at 05:12:26PM +0100, Arnd Bergmann wrote:
>> On Wednesday 24 September 2014 17:37:43 Robert Richter wrote:
>> > From: Sunil Goutham <sgoutham@cavium.com>
>> >
>> > This patch adds support for PCI host controller of Cavium Thunder
>> > SoCs.
>>
>> I had expected this hardware to be SBSA compliant. Why do you need
>> a hardware specific driver, is this a workaround for buggy hardware
>> or just noncompliant?
>
> Patches welcome to pci-host-generic.c :) Lorenzo already has code to port
> it to Liviu's new API, so do shout if it's not suitable for your needs.
>
>> > +static int thunder_pcie_msi_enable(struct thunder_pcie *pcie,
>> > +                                   struct pci_bus *bus)
>> > +{
>> > +   struct device_node *msi_node;
>> > +
>> > +   msi_node = of_parse_phandle(pcie->node, "msi-parent", 0);
>> > +   if (!msi_node)
>> > +           return -ENODEV;
>> > +
>> > +   pcie->msi = of_pci_find_msi_chip_by_node(msi_node);
>> > +   if (!pcie->msi)
>> > +           return -ENODEV;
>> > +
>> > +   pcie->msi->dev = pcie->dev;
>> > +   bus->msi = pcie->msi;
>> > +
>> > +   return 0;
>> > +}
>>
>> This is probably something we should add to the generic host driver as well,
>> so it can work with SBSA compliant implementations that come with an MSI
>> controller. Maybe move it into common code so it can be shared with that
>> driver.
>
> Agreed. I've been carrying something similar [1] (based on a hacked-up version
> of bios32, so not bothered to post it) whilst I've been waiting for the
> arm64 core PCI code to get merged.
>
> Will
>
> [1] https://git.kernel.org/cgit/linux/kernel/git/will/linux.git/commit/drivers/pci/host/pci-host-generic.c?h=iommu/pci&id=b719acf062ceccfbd79ee7b1ae0b7904ea4da27e
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diff mbox

Patch

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index 90f5ccacce4b..269c3ff786bc 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -63,4 +63,12 @@  config PCIE_SPEAR13XX
 	help
 	  Say Y here if you want PCIe support on SPEAr13XX SoCs.
 
+config PCI_THUNDER
+	bool "Thunder PCIe host controller"
+	depends on ARM64 || COMPILE_TEST
+	depends on OF_PCI
+	depends on PCI_MSI
+	help
+	  Say Y here if you want internal PCI support on Thunder SoC.
+
 endmenu
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index d0e88f114ff9..fd8041da1719 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -8,3 +8,4 @@  obj-$(CONFIG_PCI_RCAR_GEN2) += pci-rcar-gen2.o
 obj-$(CONFIG_PCI_RCAR_GEN2_PCIE) += pcie-rcar.o
 obj-$(CONFIG_PCI_HOST_GENERIC) += pci-host-generic.o
 obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o
+obj-$(CONFIG_PCI_THUNDER) += pcie-thunder.o
diff --git a/drivers/pci/host/pcie-thunder.c b/drivers/pci/host/pcie-thunder.c
new file mode 100644
index 000000000000..947fad3b1980
--- /dev/null
+++ b/drivers/pci/host/pcie-thunder.c
@@ -0,0 +1,246 @@ 
+/*
+ * PCIe host controller driver for Cavium Thunder SOC
+ *
+ * Copyright (C) 2014, Cavium 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/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/of_irq.h>
+#include <linux/of_pci.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/msi.h>
+
+#define PCI_DEVICE_ID_THUNDER_BRIDGE	0xa002
+
+#define THUNDER_PCIE_BUS_SHIFT		20
+#define THUNDER_PCIE_DEV_SHIFT		15
+#define THUNDER_PCIE_FUNC_SHIFT		12
+
+struct thunder_pcie {
+	struct device_node	*node;
+	struct device		*dev;
+	void __iomem		*cfg_base;
+	struct msi_chip		*msi;
+};
+
+/*
+ * This bridge is just for the sake of supporting ARI for
+ * downstream devices. No resources are attached to it.
+ * Copy upstream root bus resources to bridge which aide in
+ * resource claiming for downstream devices
+ */
+static void pci_bridge_resource_fixup(struct pci_dev *dev)
+{
+	struct pci_bus *bus;
+	int resno;
+
+	bus = dev->subordinate;
+	for (resno = 0; resno < PCI_BRIDGE_RESOURCE_NUM; resno++) {
+		bus->resource[resno] = pci_bus_resource_n(bus->parent,
+			PCI_BRIDGE_RESOURCE_NUM + resno);
+	}
+
+	for (resno = PCI_BRIDGE_RESOURCES;
+		resno <= PCI_BRIDGE_RESOURCE_END; resno++) {
+		dev->resource[resno].start = dev->resource[resno].end = 0;
+		dev->resource[resno].flags = 0;
+	}
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_CAVIUM, PCI_DEVICE_ID_THUNDER_BRIDGE,
+			pci_bridge_resource_fixup);
+
+/*
+ * All PCIe devices in Thunder have fixed resources, shouldn't be reassigned.
+ * Also claim the device's valid resources to set 'res->parent' hierarchy.
+ */
+static void pci_dev_resource_fixup(struct pci_dev *dev)
+{
+	struct resource *res;
+	int resno;
+
+	for (resno = 0; resno < PCI_NUM_RESOURCES; resno++)
+		dev->resource[resno].flags |= IORESOURCE_PCI_FIXED;
+
+	for (resno = 0; resno < PCI_BRIDGE_RESOURCES; resno++) {
+		res = &dev->resource[resno];
+		if (res->parent || !(res->flags & IORESOURCE_MEM))
+			continue;
+		pci_claim_resource(dev, resno);
+	}
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_CAVIUM, PCI_ANY_ID,
+			pci_dev_resource_fixup);
+
+static void __iomem *thunder_pcie_cfg_base(struct thunder_pcie *pcie,
+				 unsigned int bus, unsigned int devfn)
+{
+	return  pcie->cfg_base + ((bus << THUNDER_PCIE_BUS_SHIFT)
+		| (PCI_SLOT(devfn) << THUNDER_PCIE_DEV_SHIFT)
+		| (PCI_FUNC(devfn) << THUNDER_PCIE_FUNC_SHIFT));
+}
+
+static int thunder_pcie_read_config(struct pci_bus *bus, unsigned int devfn,
+				  int reg, int size, u32 *val)
+{
+	struct thunder_pcie *pcie = bus->sysdata;
+	void __iomem *addr;
+	unsigned int busnr = bus->number;
+
+	if (busnr > 255 || devfn > 255 || reg > 4095)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	addr = thunder_pcie_cfg_base(pcie, busnr, devfn) + reg;
+
+	switch (size) {
+	case 1:
+		*val = readb(addr);
+		break;
+	case 2:
+		*val = readw(addr);
+		break;
+	case 4:
+		*val = readl(addr);
+		break;
+	default:
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+	}
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int thunder_pcie_write_config(struct pci_bus *bus, unsigned int devfn,
+				  int reg, int size, u32 val)
+{
+	struct thunder_pcie *pcie = bus->sysdata;
+	void __iomem *addr;
+	unsigned int busnr = bus->number;
+
+	if (busnr > 255 || devfn > 255 || reg > 4095)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	addr = thunder_pcie_cfg_base(pcie, busnr, devfn) + reg;
+
+	switch (size) {
+	case 1:
+		writeb(val, addr);
+		break;
+	case 2:
+		writew(val, addr);
+		break;
+	case 4:
+		writel(val, addr);
+		break;
+	default:
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+	}
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static struct pci_ops thunder_pcie_ops = {
+	.read	= thunder_pcie_read_config,
+	.write	= thunder_pcie_write_config,
+};
+
+static int thunder_pcie_msi_enable(struct thunder_pcie *pcie,
+					struct pci_bus *bus)
+{
+	struct device_node *msi_node;
+
+	msi_node = of_parse_phandle(pcie->node, "msi-parent", 0);
+	if (!msi_node)
+		return -ENODEV;
+
+	pcie->msi = of_pci_find_msi_chip_by_node(msi_node);
+	if (!pcie->msi)
+		return -ENODEV;
+
+	pcie->msi->dev = pcie->dev;
+	bus->msi = pcie->msi;
+
+	return 0;
+}
+
+static int thunder_pcie_probe(struct platform_device *pdev)
+{
+	struct thunder_pcie *pcie;
+	struct resource *cfg_base;
+	struct pci_bus *bus;
+	int ret;
+	LIST_HEAD(res);
+
+	pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL);
+	if (!pcie)
+		return -ENOMEM;
+
+	pcie->node = of_node_get(pdev->dev.of_node);
+	pcie->dev = &pdev->dev;
+
+	/* Get controller's configuration space range */
+	cfg_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pcie->cfg_base = devm_ioremap_resource(&pdev->dev, cfg_base);
+	if (IS_ERR(pcie->cfg_base)) {
+		ret = PTR_ERR(pcie->cfg_base);
+		goto err_ioremap;
+	}
+
+	ret = of_pci_get_host_bridge_resources(pdev->dev.of_node,
+					       0, 255, &res, NULL);
+	if (ret)
+		goto err_get_host;
+
+	bus = pci_create_root_bus(&pdev->dev, 0, &thunder_pcie_ops, pcie, &res);
+	if (!bus) {
+		ret = -ENODEV;
+		goto err_root_bus;
+	}
+
+	/* Set reference to MSI chip */
+	ret = thunder_pcie_msi_enable(pcie, bus);
+	if (ret)
+		goto err_msi;
+
+	platform_set_drvdata(pdev, pcie);
+
+	pci_scan_child_bus(bus);
+	pci_bus_add_devices(bus);
+
+	return 0;
+err_msi:
+	pci_remove_root_bus(bus);
+err_root_bus:
+	pci_free_resource_list(&res);
+err_get_host:
+	devm_ioremap_release(pcie->dev, pcie->cfg_base);
+err_ioremap:
+	of_node_put(pcie->node);
+	kfree(pcie);
+	return ret;
+}
+
+static const struct of_device_id thunder_pcie_of_match[] = {
+	{ .compatible = "cavium,thunder-pcie", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, thunder_pcie_of_match);
+
+static struct platform_driver thunder_pcie_driver = {
+	.driver = {
+		.name = "thunder-pcie",
+		.owner = THIS_MODULE,
+		.of_match_table = thunder_pcie_of_match,
+	},
+	.probe = thunder_pcie_probe,
+};
+module_platform_driver(thunder_pcie_driver);
+
+MODULE_AUTHOR("Sunil Goutham");
+MODULE_DESCRIPTION("Cavium Thunder PCIe host controller driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index 6ed0bb73a864..60f16b888c9d 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -2322,6 +2322,8 @@ 
 #define PCI_DEVICE_ID_ALTIMA_AC9100	0x03ea
 #define PCI_DEVICE_ID_ALTIMA_AC1003	0x03eb
 
+#define PCI_VENDOR_ID_CAVIUM		0x177d
+
 #define PCI_VENDOR_ID_BELKIN		0x1799
 #define PCI_DEVICE_ID_BELKIN_F5D7010V7	0x701f