Re: [PATCH v2 2/9] PCI: dwc: Add support for endpoint mode

From: Kishon Vijay Abraham I
Date: Tue Apr 10 2018 - 01:12:59 EST

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In reply to: Gustavo Pimentel: "[PATCH v2 2/9] PCI: dwc: Add support for endpoint mode"
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Hi,

On Monday 09 April 2018 03:11 PM, Gustavo Pimentel wrote:
> The PCIe controller dual mode is capable of operating in host mode as well
> as endpoint mode by configuration, therefore this patch aims to add
> endpoint mode support to the designware driver.
>
> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
> ---
> Change v1->v2:
> - Removed dw_plat_pcie_stop_link empty function.
> - Implemented Kishon's suggestions about dw-pcie-rc and dw-pcie strings.
> compatibility.
> - Added second entry on pci_epf_test_ids structure.
>
> drivers/pci/dwc/Kconfig | 45 ++++++--
> drivers/pci/dwc/pcie-designware-ep.c | 4 +-
> drivers/pci/dwc/pcie-designware-plat.c | 153 ++++++++++++++++++++++++--
> drivers/pci/endpoint/functions/pci-epf-test.c | 9 ++
> 4 files changed, 190 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/pci/dwc/Kconfig b/drivers/pci/dwc/Kconfig
> index 2f3f5c5..3fd7daf 100644
> --- a/drivers/pci/dwc/Kconfig
> +++ b/drivers/pci/dwc/Kconfig
> @@ -7,8 +7,7 @@ config PCIE_DW
>
> config PCIE_DW_HOST
> bool
> - depends on PCI
> - depends on PCI_MSI_IRQ_DOMAIN
> + depends on PCI && PCI_MSI_IRQ_DOMAIN
> select PCIE_DW
>
> config PCIE_DW_EP
> @@ -52,16 +51,42 @@ config PCI_DRA7XX_EP
>
> config PCIE_DW_PLAT
> bool "Platform bus based DesignWare PCIe Controller"
> - depends on PCI
> - depends on PCI_MSI_IRQ_DOMAIN
> - select PCIE_DW_HOST
> - ---help---
> - This selects the DesignWare PCIe controller support. Select this if
> - you have a PCIe controller on Platform bus.
> + help
> + There are two instances of PCIe controller in Designware IP.
> + This controller can work either as EP or RC. In order to enable
> + host-specific features PCIE_DW_PLAT_HOST must be selected and in
> + order to enable device-specific features PCIE_DW_PLAT_EP must be
> + selected.
>
> - If you have a controller with this interface, say Y or M here.
> +config PCIE_DW_PLAT_HOST
> + bool "Platform bus based DesignWare PCIe Controller - Host mode"
> + depends on PCI && PCI_MSI_IRQ_DOMAIN
> + select PCIE_DW_HOST
> + select PCIE_DW_PLAT
> + default y
> + help
> + Enables support for the PCIe controller in the Designware IP to
> + work in host mode. There are two instances of PCIe controller in
> + Designware IP.
> + This controller can work either as EP or RC. In order to enable
> + host-specific features PCIE_DW_PLAT_HOST must be selected and in
> + order to enable device-specific features PCI_DW_PLAT_EP must be
> + selected.
>
> - If unsure, say N.
> +config PCIE_DW_PLAT_EP
> + bool "Platform bus based DesignWare PCIe Controller - Endpoint mode"
> + depends on PCI && PCI_MSI_IRQ_DOMAIN
> + depends on PCI_ENDPOINT
> + select PCIE_DW_EP
> + select PCIE_DW_PLAT
> + help
> + Enables support for the PCIe controller in the Designware IP to
> + work in endpoint mode. There are two instances of PCIe controller
> + in Designware IP.
> + This controller can work either as EP or RC. In order to enable
> + host-specific features PCIE_DW_PLAT_HOST must be selected and in
> + order to enable device-specific features PCI_DW_PLAT_EP must be
> + selected.
>
> config PCI_EXYNOS
> bool "Samsung Exynos PCIe controller"
> diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
> index f07678b..4ac135a 100644
> --- a/drivers/pci/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/dwc/pcie-designware-ep.c
> @@ -15,8 +15,10 @@
> void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
> {
> struct pci_epc *epc = ep->epc;
> + struct pci_epf *epf;
>
> - pci_epc_linkup(epc);
> + list_for_each_entry(epf, &epc->pci_epf, list)
> + pci_epf_linkup(epf);
> }

This shouldn't be required anymore.
>
> static void __dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar,
> diff --git a/drivers/pci/dwc/pcie-designware-plat.c b/drivers/pci/dwc/pcie-designware-plat.c
> index 5416aa8..5382a7a 100644
> --- a/drivers/pci/dwc/pcie-designware-plat.c
> +++ b/drivers/pci/dwc/pcie-designware-plat.c
> @@ -12,19 +12,29 @@
> #include <linux/interrupt.h>
> #include <linux/kernel.h>
> #include <linux/init.h>
> +#include <linux/of_device.h>
> #include <linux/of_gpio.h>
> #include <linux/pci.h>
> #include <linux/platform_device.h>
> #include <linux/resource.h>
> #include <linux/signal.h>
> #include <linux/types.h>
> +#include <linux/regmap.h>
>
> #include "pcie-designware.h"
>
> struct dw_plat_pcie {
> - struct dw_pcie *pci;
> + struct dw_pcie *pci;
> + struct regmap *regmap;
> + enum dw_pcie_device_mode mode;
> };
>
> +struct dw_plat_pcie_of_data {
> + enum dw_pcie_device_mode mode;
> +};
> +
> +static const struct of_device_id dw_plat_pcie_of_match[];
> +
> static int dw_plat_pcie_host_init(struct pcie_port *pp)
> {
> struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> @@ -42,9 +52,53 @@ static const struct dw_pcie_host_ops dw_plat_pcie_host_ops = {
> .host_init = dw_plat_pcie_host_init,
> };
>
> -static int dw_plat_add_pcie_port(struct pcie_port *pp,
> +static int dw_plat_pcie_establish_link(struct dw_pcie *pci)
> +{
> + return 0;
> +}
> +
> +static const struct dw_pcie_ops dw_pcie_ops = {
> + .start_link = dw_plat_pcie_establish_link,
> +};
> +
> +static void dw_plat_pcie_ep_init(struct dw_pcie_ep *ep)
> +{
> + struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> + enum pci_barno bar;
> +
> + for (bar = BAR_0; bar <= BAR_5; bar++)
> + dw_pcie_ep_reset_bar(pci, bar);
> +}
> +
> +static int dw_plat_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
> + enum pci_epc_irq_type type,
> + u8 interrupt_num)
> +{
> + struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> +
> + switch (type) {
> + case PCI_EPC_IRQ_LEGACY:
> + dev_err(pci->dev, "EP cannot trigger legacy IRQs\n");
> + return -EINVAL;
> + case PCI_EPC_IRQ_MSI:
> + return dw_pcie_ep_raise_msi_irq(ep, func_no, interrupt_num);
> + default:
> + dev_err(pci->dev, "UNKNOWN IRQ type\n");
> + }
> +
> + return 0;
> +}
> +
> +static struct dw_pcie_ep_ops pcie_ep_ops = {
> + .ep_init = dw_plat_pcie_ep_init,
> + .raise_irq = dw_plat_pcie_ep_raise_irq,
> +};
> +
> +static int dw_plat_add_pcie_port(struct dw_plat_pcie *dw_plat_pcie,
> struct platform_device *pdev)
> {
> + struct dw_pcie *pci = dw_plat_pcie->pci;
> + struct pcie_port *pp = &pci->pp;
> struct device *dev = &pdev->dev;
> int ret;
>
> @@ -63,15 +117,44 @@ static int dw_plat_add_pcie_port(struct pcie_port *pp,
>
> ret = dw_pcie_host_init(pp);
> if (ret) {
> - dev_err(dev, "failed to initialize host\n");
> + dev_err(dev, "Failed to initialize host\n");
> return ret;
> }
>
> return 0;
> }
>
> -static const struct dw_pcie_ops dw_pcie_ops = {
> -};
> +static int dw_plat_add_pcie_ep(struct dw_plat_pcie *dw_plat_pcie,
> + struct platform_device *pdev)
> +{
> + int ret;
> + struct dw_pcie_ep *ep;
> + struct resource *res;
> + struct device *dev = &pdev->dev;
> + struct dw_pcie *pci = dw_plat_pcie->pci;
> +
> + ep = &pci->ep;
> + ep->ops = &pcie_ep_ops;
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi2");
> + pci->dbi_base2 = devm_ioremap(dev, res->start, resource_size(res));

This can throw up a NULL pointer dereferencing error. Use devm_ioremap_resource
instead.

> + if (IS_ERR(pci->dbi_base2))
> + return PTR_ERR(pci->dbi_base2);
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "addr_space");
> + if (!res)
> + return -EINVAL;
> +
> + ep->phys_base = res->start;
> + ep->addr_size = resource_size(res);
> +
> + ret = dw_pcie_ep_init(ep);
> + if (ret) {
> + dev_err(dev, "Failed to initialize endpoint\n");
> + return ret;
> + }
> + return 0;
> +}
>
> static int dw_plat_pcie_probe(struct platform_device *pdev)
> {
> @@ -80,6 +163,16 @@ static int dw_plat_pcie_probe(struct platform_device *pdev)
> struct dw_pcie *pci;
> struct resource *res; /* Resource from DT */
> int ret;
> + const struct of_device_id *match;
> + const struct dw_plat_pcie_of_data *data;
> + enum dw_pcie_device_mode mode;
> +
> + match = of_match_device(dw_plat_pcie_of_match, dev);
> + if (!match)
> + return -EINVAL;
> +
> + data = (struct dw_plat_pcie_of_data *)match->data;
> + mode = (enum dw_pcie_device_mode)data->mode;
>
> dw_plat_pcie = devm_kzalloc(dev, sizeof(*dw_plat_pcie), GFP_KERNEL);
> if (!dw_plat_pcie)
> @@ -93,23 +186,63 @@ static int dw_plat_pcie_probe(struct platform_device *pdev)
> pci->ops = &dw_pcie_ops;
>
> dw_plat_pcie->pci = pci;
> + dw_plat_pcie->mode = mode;
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
> + if (!res)
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>
> - res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> pci->dbi_base = devm_ioremap_resource(dev, res);
> if (IS_ERR(pci->dbi_base))
> return PTR_ERR(pci->dbi_base);
>
> platform_set_drvdata(pdev, dw_plat_pcie);
>
> - ret = dw_plat_add_pcie_port(&pci->pp, pdev);
> - if (ret < 0)
> - return ret;
> + switch (dw_plat_pcie->mode) {
> + case DW_PCIE_RC_TYPE:
> + if (!IS_ENABLED(CONFIG_PCIE_DW_PLAT_HOST))
> + return -ENODEV;
> +
> + ret = dw_plat_add_pcie_port(dw_plat_pcie, pdev);
> + if (ret < 0)
> + return ret;
> + break;
> + case DW_PCIE_EP_TYPE:
> + if (!IS_ENABLED(CONFIG_PCIE_DW_PLAT_EP))
> + return -ENODEV;
> +
> + ret = dw_plat_add_pcie_ep(dw_plat_pcie, pdev);
> + if (ret < 0)
> + return ret;
> + break;
> + default:
> + dev_err(dev, "INVALID device type %d\n", dw_plat_pcie->mode);
> + }
>
> return 0;
> }
>
> +static const struct dw_plat_pcie_of_data dw_plat_pcie_rc_of_data = {
> + .mode = DW_PCIE_RC_TYPE,
> +};
> +
> +static const struct dw_plat_pcie_of_data dw_plat_pcie_ep_of_data = {
> + .mode = DW_PCIE_EP_TYPE,
> +};
> +
> static const struct of_device_id dw_plat_pcie_of_match[] = {
> - { .compatible = "snps,dw-pcie", },
> + {
> + .compatible = "snps,dw-pcie",
> + .data = &dw_plat_pcie_rc_of_data,
> + },
> + {
> + .compatible = "snps,dw-pcie-rc",
> + .data = &dw_plat_pcie_rc_of_data,
> + },
> + {
> + .compatible = "snps,dw-pcie-ep",
> + .data = &dw_plat_pcie_ep_of_data,
> + },
> {},
> };
>
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index 7cef851..45d1c63 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c

have a separate patch for this.
> @@ -459,10 +459,19 @@ static int pci_epf_test_bind(struct pci_epf *epf)
> return 0;
> }
>
> +static const struct pci_epf_test_data data_cfg2 = {
> + .test_reg_bar = BAR_0,

default test_reg_bar is BAR_0. So you can skip this.
> + .linkup_notifier = false
> +};
> +

Thanks
Kishon

Next message: Williams, Dan J: "[GIT PULL] libnvdimm for 4.17"
Previous message: syzbot: "WARNING: kobject bug in corrupted"
In reply to: Gustavo Pimentel: "[PATCH v2 2/9] PCI: dwc: Add support for endpoint mode"
Next in thread: Gustavo Pimentel: "Re: [PATCH v2 2/9] PCI: dwc: Add support for endpoint mode"
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