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SubjectRe: [PATCH 2/8] PCI: dwc: designware: Add support for endpoint mode
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Hi,

On Wednesday 04 April 2018 03:50 PM, Gustavo Pimentel wrote:
> 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?

No, dw_pcie_ep_linkup is an optional function. If your platform gives a
notification when the link to the host is established, then you have to invoke
this function.

If you keep "linkup_notifier = false" in pci-epf-test.c, dw_pcie_ep_linkup
should be required.
>
>>> +
>>> + 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?

Actually that patch doesn't add any configfs attribute entry. It just creates a
new configfs directory for every entry populated in pci_epf_device_id.

For example, If you have something like this

static const struct pci_epf_test_data k2g_data = {
.test_reg_bar = BAR_1,
.linkup_notifier = false
};

static const struct pci_epf_device_id pci_epf_test_ids[] = {
{
.name = "pci_epf_test",
},
{
.name = "pci_epf_test_k2g",
.driver_data = (kernel_ulong_t)&k2g_data,
},
{},
};

after [1], there should be 2 entries in /sys/kernel/config/pci_ep/functions/
pci_epf_test and pci_epf_test_k2g.

Here if you use pci_epf_test_k2g entry then the driver data associated with
pci_epf_test_k2g will be used.

Thanks
Kishon

[1] -> https://patchwork.kernel.org/patch/10319695/
>
>>
>> Thanks
>> Kishon
>>
>
>

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