Re: [PATCH v2 2/9] PCI: dwc: Add support for endpoint mode
From: Kishon Vijay Abraham I
Date: Tue Apr 10 2018 - 07:10:15 EST
Hi,
On Tuesday 10 April 2018 04:06 PM, Gustavo Pimentel wrote:
> Hi Kishon,
>
> On 10/04/2018 06:12, Kishon Vijay Abraham I wrote:
>> 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.
>
> Ok. I'll revert it.
>
>>>
>>> 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.
>
> I have looked on [1] and [2] and both implementations uses devm_ioremap
> function, they are also wrong?
>
> [1] -> https://elixir.bootlin.com/linux/latest/source/drivers/pci/dwc/pcie-artpec6.c
> [2] -> https://elixir.bootlin.com/linux/latest/source/drivers/pci/dwc/pci-dra7xx.c
yes, they are wrong. There was a patch to fix it but somehow dropped
https://patchwork.kernel.org/patch/10173831/.
I'll resend them.
Thanks
Kishon