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SubjectRe: [PATCH 2/8] PCI: dwc: designware: Add support for endpoint mode
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Date
On 02/04/2018 06:34, Kishon Vijay Abraham I wrote:
> Hi,
>
> On Wednesday 28 March 2018 05:08 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@synopsys.com>
>> ---
>> drivers/pci/dwc/Kconfig | 45 ++++++--
>> drivers/pci/dwc/pcie-designware-plat.c | 157 ++++++++++++++++++++++++--
>> drivers/pci/endpoint/functions/pci-epf-test.c | 5 +
>> 3 files changed, 187 insertions(+), 20 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-plat.c b/drivers/pci/dwc/pcie-designware-plat.c
>> index 5416aa8..921ab07 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 +52,61 @@ 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)
>> +{
>> + dw_pcie_ep_linkup(&pci->ep);
>
> .start_link ops is used incorrectly here. .start_link is used when all the
> endpoint side configuration is done and "is ready" to establish a link with the
> host. But dw_pcie_ep_linkup is used to inform the function devices that the
> link "has been" established.

If I move the dw_pcie_ep_linkup call from the dw_plat_pcie_establish_link to the
dw_plat_pcie_ep_init function it would be more correct in your perspective? If
not, where you suggest?

>> +
>> + return 0;
>> +}
>> +
>> +static void dw_plat_pcie_stop_link(struct dw_pcie *pci)
>> +{
>> +
>> +}
>
> Not necessary to have empty function here. pci-epc-core will not try to invoke
> ops which are not populated.

Ok, I'll remove it.

>> +
>> +static const struct dw_pcie_ops dw_pcie_ops = {
>> + .start_link = dw_plat_pcie_establish_link,
>> + .stop_link = dw_plat_pcie_stop_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 +125,44 @@ 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));
>> + 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 +171,16 @@ 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 +194,59 @@ 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-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 64d8a17..d7de684 100644
>> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
>> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
>> @@ -451,9 +451,14 @@ static int pci_epf_test_bind(struct pci_epf *epf)
>> return 0;
>> }
>>
>> +static const struct pci_epf_test_data pci_epf_data = {
>> + .linkup_notifier = false
>> +};
>> +
>> static const struct pci_epf_device_id pci_epf_test_ids[] = {
>> {
>> .name = "pci_epf_test",
>> + .driver_data = (kernel_ulong_t)&pci_epf_data,
>
> This will disable linkup_notifier for existing devices. Please add a new entry
> to the table to make any modifications to driver data. (I have a configfs fix
> for this to work. Will post that today).

Are you refering to this patch? https://patchwork.kernel.org/patch/10319695/
Let's see if I understood it right, this patch will expose the some configfs
(something like /sys/kernel/config/pci_ep/functions/pci_epf_test/func1/...) that
ables me to disable the linkup notifier for existing devices without the need to
change the code like I did, right?

>
> Thanks
> Kishon
>


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