Re: [RFC 2/4] PCI: generic: Add support for ARM64 and MSI(x)

[Sunil Kovvuri <sunil.kovvuri@gmail.com>]

How does the res->parent for devices of non-"PCI_PROBE_ONLY" controller
gets set with this patch ?

On Mon, Sep 29, 2014 at 2:23 AM,  <suravee.suthikulpanit@amd.com> wrote:
> From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
>
> This patch adds ARM64 support to the generic PCI host driver.
>
> For MSI support, it adds new device tree binding "msi-parent",
> which should point to corresponded msi-controller.
>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Liviu Dudau <Liviu.Dudau@arm.com>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
> ---
>  .../devicetree/bindings/pci/host-generic-pci.txt   |  3 +
>  drivers/pci/host/Kconfig                           |  2 +-
>  drivers/pci/host/pci-host-generic.c                | 95 ++++++++++++++++++++--
>  3 files changed, 90 insertions(+), 10 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/pci/host-generic-pci.txt b/Documentation/devicetree/bindings/pci/host-generic-pci.txt
> index f0b0436..327e5b1 100644
> --- a/Documentation/devicetree/bindings/pci/host-generic-pci.txt
> +++ b/Documentation/devicetree/bindings/pci/host-generic-pci.txt
> @@ -69,6 +69,9 @@ Practice: Interrupt Mapping' and requires the following properties:
>
>  - interrupt-map-mask : <see aforementioned specification>
>
> +Optinal Properties:
> +
> +- msi-parent     : Specify the msi-controller phandle.
>
>  Example:
>
> diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
> index 90f5cca..44bf523 100644
> --- a/drivers/pci/host/Kconfig
> +++ b/drivers/pci/host/Kconfig
> @@ -50,7 +50,7 @@ config PCI_RCAR_GEN2_PCIE
>
>  config PCI_HOST_GENERIC
>         bool "Generic PCI host controller"
> -       depends on ARM && OF
> +       depends on (ARM || ARM64) && OF
>         help
>           Say Y here if you want to support a simple generic PCI host
>           controller, such as the one emulated by kvmtool.
> diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c
> index 3d2076f..f33c547 100644
> --- a/drivers/pci/host/pci-host-generic.c
> +++ b/drivers/pci/host/pci-host-generic.c
> @@ -42,14 +42,24 @@ struct gen_pci {
>         struct pci_host_bridge                  host;
>         struct gen_pci_cfg_windows              cfg;
>         struct list_head                        resources;
> +       struct device_node *msi_parent;
>  };
>
> +#ifdef CONFIG_ARM64
> +#define bus_to_gen_pci(b) \
> +       ((struct gen_pci *)b->sysdata)
> +#else
> +#define bus_to_gen_pci(b) \
> +       ((struct gen_pci *) \
> +       (((struct pci_sys_data *) \
> +       (bus->sysdata))->private_data))
> +#endif
> +
>  static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
>                                              unsigned int devfn,
>                                              int where)
>  {
> -       struct pci_sys_data *sys = bus->sysdata;
> -       struct gen_pci *pci = sys->private_data;
> +       struct gen_pci *pci = bus_to_gen_pci(bus);
>         resource_size_t idx = bus->number - pci->cfg.bus_range.start;
>
>         return pci->cfg.win[idx] + ((devfn << 8) | where);
> @@ -64,8 +74,7 @@ static void __iomem *gen_pci_map_cfg_bus_ecam(struct pci_bus *bus,
>                                               unsigned int devfn,
>                                               int where)
>  {
> -       struct pci_sys_data *sys = bus->sysdata;
> -       struct gen_pci *pci = sys->private_data;
> +       struct gen_pci *pci = bus_to_gen_pci(bus);
>         resource_size_t idx = bus->number - pci->cfg.bus_range.start;
>
>         return pci->cfg.win[idx] + ((devfn << 12) | where);
> @@ -80,8 +89,7 @@ static int gen_pci_config_read(struct pci_bus *bus, unsigned int devfn,
>                                 int where, int size, u32 *val)
>  {
>         void __iomem *addr;
> -       struct pci_sys_data *sys = bus->sysdata;
> -       struct gen_pci *pci = sys->private_data;
> +       struct gen_pci *pci = bus_to_gen_pci(bus);
>
>         addr = pci->cfg.ops->map_bus(bus, devfn, where);
>
> @@ -103,8 +111,7 @@ static int gen_pci_config_write(struct pci_bus *bus, unsigned int devfn,
>                                  int where, int size, u32 val)
>  {
>         void __iomem *addr;
> -       struct pci_sys_data *sys = bus->sysdata;
> -       struct gen_pci *pci = sys->private_data;
> +       struct gen_pci *pci = bus_to_gen_pci(bus);
>
>         addr = pci->cfg.ops->map_bus(bus, devfn, where);
>
> @@ -144,8 +151,11 @@ static int gen_pci_calc_io_offset(struct device *dev,
>                                   resource_size_t *offset)
>  {
>         static atomic_t wins = ATOMIC_INIT(0);
> -       int err, idx, max_win;
> +       int idx, max_win;
>         unsigned int window;
> +#ifndef CONFIG_ARM64
> +       int err;
> +#endif
>
>         if (!PAGE_ALIGNED(range->cpu_addr))
>                 return -EINVAL;
> @@ -156,9 +166,12 @@ static int gen_pci_calc_io_offset(struct device *dev,
>                 return -ENOSPC;
>
>         window = (idx - 1) * SZ_64K;
> +
> +#ifndef CONFIG_ARM64
>         err = pci_ioremap_io(window, range->cpu_addr);
>         if (err)
>                 return err;
> +#endif
>
>         of_pci_range_to_resource(range, dev->of_node, res);
>         res->start = window;
> @@ -310,12 +323,58 @@ static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
>         return 0;
>  }
>
> +#ifndef CONFIG_ARM64
>  static int gen_pci_setup(int nr, struct pci_sys_data *sys)
>  {
>         struct gen_pci *pci = sys->private_data;
>         list_splice_init(&pci->resources, &sys->resources);
>         return 1;
>  }
> +#endif
> +
> +#ifdef CONFIG_ARM64
> +struct pci_bus *gen_scan_root_bus(struct device *parent, int bus,
> +                                      struct pci_ops *ops, void *sysdata,
> +                                      struct list_head *resources)
> +{
> +       struct pci_host_bridge_window *window;
> +       bool found = false;
> +       struct pci_bus *b;
> +       int max;
> +       struct gen_pci *pci = sysdata;
> +
> +       list_for_each_entry(window, resources, list)
> +               if (window->res->flags & IORESOURCE_BUS) {
> +                       found = true;
> +                       break;
> +               }
> +
> +       b = pci_create_root_bus(parent, bus, ops, sysdata, resources);
> +       if (!b)
> +               return NULL;
> +
> +       /* TODO:
> +        * This is probably should be done in the core pci driver somewhere
> +        */
> +       if (pci->msi_parent)
> +               b->msi = of_pci_find_msi_chip_by_node(pci->msi_parent);
> +
> +       if (!found) {
> +               dev_info(&b->dev,
> +                "No busn resource found for root bus, will use [bus %02x-ff]\n",
> +                       bus);
> +               pci_bus_insert_busn_res(b, bus, 255);
> +       }
> +
> +       max = pci_scan_child_bus(b);
> +
> +       if (!found)
> +               pci_bus_update_busn_res_end(b, max);
> +
> +       pci_bus_add_devices(b);
> +       return b;
> +}
> +#endif
>
>  static int gen_pci_probe(struct platform_device *pdev)
>  {
> @@ -326,6 +385,7 @@ static int gen_pci_probe(struct platform_device *pdev)
>         struct device *dev = &pdev->dev;
>         struct device_node *np = dev->of_node;
>         struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
> +#ifndef CONFIG_ARM64
>         struct hw_pci hw = {
>                 .nr_controllers = 1,
>                 .private_data   = (void **)&pci,
> @@ -333,6 +393,7 @@ static int gen_pci_probe(struct platform_device *pdev)
>                 .map_irq        = of_irq_parse_and_map_pci,
>                 .ops            = &gen_pci_ops,
>         };
> +#endif
>
>         if (!pci)
>                 return -ENOMEM;
> @@ -368,8 +429,24 @@ static int gen_pci_probe(struct platform_device *pdev)
>                 gen_pci_release_of_pci_ranges(pci);
>                 return err;
>         }
> +#ifdef CONFIG_ARM64
>
> +#ifdef CONFIG_PCI_MSI
> +       pci->msi_parent = of_parse_phandle(np, "msi-parent", 0);
> +       if (!pci->msi_parent) {
> +               dev_err(&pdev->dev, "Failed to allocate msi-parent.\n");
> +               return -EINVAL;
> +       }
> +#endif
> +
> +       if (!gen_scan_root_bus(&pdev->dev, pci->cfg.bus_range.start,
> +                              &gen_pci_ops, pci, &pci->resources)) {
> +               dev_err(&pdev->dev, "failed to enable PCIe ports\n");
> +               return -ENODEV;
> +       }
> +#else
>         pci_common_init_dev(dev, &hw);
> +#endif /* CONFIG_ARM64 */
>         return 0;
>  }
>
> --
> 1.9.3
>
> --
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