Re: [PATCH] PCI: designware-ep: Move DBI access to init_complete if notifier is used

[Vidya Sagar <vidyas@xxxxxxxxxx>]

I have a minor comment. Otherwise this patch looks fine.
I verified it on Tegra194 and it works as expected.

Reviewed-by: Vidya Sagar <vidyas@xxxxxxxxxx>
Tested-by: Vidya Sagar <vidyas@xxxxxxxxxx>

On 7/7/2022 10:27 PM, Manivannan Sadhasivam wrote:
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>
> On Wed, Apr 27, 2022 at 03:48:26PM +0530, Manivannan Sadhasivam wrote:
> > On Wed, Mar 30, 2022 at 11:35:15AM +0530, Manivannan Sadhasivam wrote:
> > > For controllers supporting the CORE_INIT notifier, the resources are
> > > supposed to be enabled in the init_complete function. Currently,
> > > these controllers are enabling the resources during probe time due to
> > > the DBI access happens in dw_pcie_ep_init().
> > >
> > > This creates the dependency with the host PCIe controller since the
> > > resource enablement like PHY depends on host PCIe to be up. For the
> > > standalone endpoint usecase, this would never work. So let's move all DBI
> > > access to init_complete function if CORE_INIT notifier is used. For the
> > > controllers those doesn't support this notifier, this change is a NO-OP.
> > >
> > > Cc: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
> > > Cc: Om Prakash Singh <omp@xxxxxxxxxx>
> > > Cc: Vidya Sagar <vidyas@xxxxxxxxxx>
> > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> >
> > A gentle ping on this patch!
>
> Ping again!
>
> Thanks,
> Mani
>
> > Thanks,
> > Mani
> >
> > > ---
> > >   .../pci/controller/dwc/pcie-designware-ep.c   | 138 ++++++++++++------
> > >   drivers/pci/controller/dwc/pcie-designware.h  |   1 +
> > >   2 files changed, 94 insertions(+), 45 deletions(-)
> > >
> > > diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > > index 0eda8236c125..fb2bf4bf5ba0 100644
> > > --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> > > +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > > @@ -636,6 +636,63 @@ static unsigned int dw_pcie_ep_find_ext_capability(struct dw_pcie *pci, int cap)
> > >      return 0;
> > >   }
> > >
> > > +static int dw_pcie_iatu_config(struct dw_pcie_ep *ep)

How about using dw_pcie_ep_iatu_config() name? Just added 'ep' to be in 
sync with other API names in this file.

> > > +{
> > > +   struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> > > +   struct device *dev = pci->dev;
> > > +   void *addr;
> > > +
> > > +   dw_pcie_iatu_detect(pci);
> > > +
> > > +   ep->ib_window_map = devm_kcalloc(dev,
> > > +                                    BITS_TO_LONGS(pci->num_ib_windows),
> > > +                                    sizeof(long),
> > > +                                    GFP_KERNEL);
> > > +   if (!ep->ib_window_map)
> > > +           return -ENOMEM;
> > > +
> > > +   ep->ob_window_map = devm_kcalloc(dev,
> > > +                                    BITS_TO_LONGS(pci->num_ob_windows),
> > > +                                    sizeof(long),
> > > +                                    GFP_KERNEL);
> > > +   if (!ep->ob_window_map)
> > > +           return -ENOMEM;
> > > +
> > > +   addr = devm_kcalloc(dev, pci->num_ob_windows, sizeof(phys_addr_t),
> > > +                       GFP_KERNEL);
> > > +   if (!addr)
> > > +           return -ENOMEM;
> > > +
> > > +   ep->outbound_addr = addr;
> > > +
> > > +   return 0;
> > > +}
> > > +
> > > +static int dw_pcie_ep_func_init(struct dw_pcie_ep *ep)
> > > +{
> > > +   struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> > > +   struct dw_pcie_ep_func *ep_func;
> > > +   struct pci_epc *epc = ep->epc;
> > > +   struct device *dev = pci->dev;
> > > +   u8 func_no;
> > > +
> > > +   for (func_no = 0; func_no < epc->max_functions; func_no++) {
> > > +           ep_func = devm_kzalloc(dev, sizeof(*ep_func), GFP_KERNEL);
> > > +           if (!ep_func)
> > > +                   return -ENOMEM;
> > > +
> > > +           ep_func->func_no = func_no;
> > > +           ep_func->msi_cap = dw_pcie_ep_find_capability(ep, func_no,
> > > +                                                         PCI_CAP_ID_MSI);
> > > +           ep_func->msix_cap = dw_pcie_ep_find_capability(ep, func_no,
> > > +                                                          PCI_CAP_ID_MSIX);
> > > +
> > > +           list_add_tail(&ep_func->list, &ep->func_list);
> > > +   }
> > > +
> > > +   return 0;
> > > +}
> > > +
> > >   int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
> > >   {
> > >      struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> > > @@ -643,7 +700,22 @@ int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
> > >      unsigned int nbars;
> > >      u8 hdr_type;
> > >      u32 reg;
> > > -   int i;
> > > +   int ret, i;
> > > +
> > > +   if (ep->core_init_notifier) {
> > > +           ret = dw_pcie_iatu_config(ep);
> > > +           if (ret)
> > > +                   return ret;
> > > +   }
> > > +
> > > +   if (ep->core_init_notifier) {
> > > +           ret = dw_pcie_ep_func_init(ep);
> > > +           if (ret)
> > > +                   return ret;
> > > +
> > > +           if (ep->ops->ep_init)
> > > +                   ep->ops->ep_init(ep);
> > > +   }
> > >
> > >      hdr_type = dw_pcie_readb_dbi(pci, PCI_HEADER_TYPE) &
> > >                 PCI_HEADER_TYPE_MASK;
> > > @@ -677,8 +749,6 @@ EXPORT_SYMBOL_GPL(dw_pcie_ep_init_complete);
> > >   int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> > >   {
> > >      int ret;
> > > -   void *addr;
> > > -   u8 func_no;
> > >      struct resource *res;
> > >      struct pci_epc *epc;
> > >      struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> > > @@ -686,7 +756,12 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> > >      struct platform_device *pdev = to_platform_device(dev);
> > >      struct device_node *np = dev->of_node;
> > >      const struct pci_epc_features *epc_features;
> > > -   struct dw_pcie_ep_func *ep_func;
> > > +
> > > +   if (ep->ops->get_features) {
> > > +           epc_features = ep->ops->get_features(ep);
> > > +           if (epc_features->core_init_notifier)
> > > +                   ep->core_init_notifier = true;
> > > +   }
> > >
> > >      INIT_LIST_HEAD(&ep->func_list);
> > >
> > > @@ -708,7 +783,11 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> > >              }
> > >      }
> > >
> > > -   dw_pcie_iatu_detect(pci);
> > > +   if (!ep->core_init_notifier) {
> > > +           ret = dw_pcie_iatu_config(ep);
> > > +           if (ret)
> > > +                   return ret;
> > > +   }
> > >
> > >      res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "addr_space");
> > >      if (!res)
> > > @@ -717,26 +796,6 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> > >      ep->phys_base = res->start;
> > >      ep->addr_size = resource_size(res);
> > >
> > > -   ep->ib_window_map = devm_kcalloc(dev,
> > > -                                    BITS_TO_LONGS(pci->num_ib_windows),
> > > -                                    sizeof(long),
> > > -                                    GFP_KERNEL);
> > > -   if (!ep->ib_window_map)
> > > -           return -ENOMEM;
> > > -
> > > -   ep->ob_window_map = devm_kcalloc(dev,
> > > -                                    BITS_TO_LONGS(pci->num_ob_windows),
> > > -                                    sizeof(long),
> > > -                                    GFP_KERNEL);
> > > -   if (!ep->ob_window_map)
> > > -           return -ENOMEM;
> > > -
> > > -   addr = devm_kcalloc(dev, pci->num_ob_windows, sizeof(phys_addr_t),
> > > -                       GFP_KERNEL);
> > > -   if (!addr)
> > > -           return -ENOMEM;
> > > -   ep->outbound_addr = addr;
> > > -
> > >      if (pci->link_gen < 1)
> > >              pci->link_gen = of_pci_get_max_link_speed(np);
> > >
> > > @@ -753,23 +812,15 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> > >      if (ret < 0)
> > >              epc->max_functions = 1;
> > >
> > > -   for (func_no = 0; func_no < epc->max_functions; func_no++) {
> > > -           ep_func = devm_kzalloc(dev, sizeof(*ep_func), GFP_KERNEL);
> > > -           if (!ep_func)
> > > -                   return -ENOMEM;
> > > -
> > > -           ep_func->func_no = func_no;
> > > -           ep_func->msi_cap = dw_pcie_ep_find_capability(ep, func_no,
> > > -                                                         PCI_CAP_ID_MSI);
> > > -           ep_func->msix_cap = dw_pcie_ep_find_capability(ep, func_no,
> > > -                                                          PCI_CAP_ID_MSIX);
> > > +   if (!ep->core_init_notifier) {
> > > +           ret = dw_pcie_ep_func_init(ep);
> > > +           if (ret)
> > > +                   return ret;
> > >
> > > -           list_add_tail(&ep_func->list, &ep->func_list);
> > > +           if (ep->ops->ep_init)
> > > +                   ep->ops->ep_init(ep);
> > >      }
> > >
> > > -   if (ep->ops->ep_init)
> > > -           ep->ops->ep_init(ep);
> > > -
> > >      ret = pci_epc_mem_init(epc, ep->phys_base, ep->addr_size,
> > >                             ep->page_size);
> > >      if (ret < 0) {
> > > @@ -784,12 +835,9 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> > >              return -ENOMEM;
> > >      }
> > >
> > > -   if (ep->ops->get_features) {
> > > -           epc_features = ep->ops->get_features(ep);
> > > -           if (epc_features->core_init_notifier)
> > > -                   return 0;
> > > -   }
> > > +   if (!ep->core_init_notifier)
> > > +           return dw_pcie_ep_init_complete(ep);
> > >
> > > -   return dw_pcie_ep_init_complete(ep);
> > > +   return 0;
> > >   }
> > >   EXPORT_SYMBOL_GPL(dw_pcie_ep_init);
> > > diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> > > index 7d6e9b7576be..aadb14159df7 100644
> > > --- a/drivers/pci/controller/dwc/pcie-designware.h
> > > +++ b/drivers/pci/controller/dwc/pcie-designware.h
> > > @@ -242,6 +242,7 @@ struct dw_pcie_ep {
> > >      void __iomem            *msi_mem;
> > >      phys_addr_t             msi_mem_phys;
> > >      struct pci_epf_bar      *epf_bar[PCI_STD_NUM_BARS];
> > > +   bool                    core_init_notifier;
> > >   };
> > >
> > >   struct dw_pcie_ops {
> > > --
> > > 2.25.1
>
> --
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