[PATCH TIP 08/14] x86/dtb: add support for PCI devices backed by dtb nodes

[Grant Likely]

On Sun, Jan 23, 2011 at 9:28 PM, Sebastian Andrzej Siewior
<bigeasy at linutronix.de> wrote:
> x86_of_pci_init() does two things:
> - it provides a generic irq enable and disable function. enable queries
>  the device tree for the interrupt information, calls ->xlate on the
>  irq host and updates the pci->irq information for the device.
>
> - it walks through PCI buss(es) in the device tree and adds its children
>  (devices) nodes to appropriate pci_dev nodes in kernel. So the dtb
>  node information is available at probe time of the PCI device.
>
> Adding a PCI bus based on the information in the device tree is
> currently not supported. Right now direct access via ioports is used.
>
> Cc: devicetree-discuss at lists.ozlabs.org
> Tested-by: Dirk Brandewie <dirk.brandewie at gmail.com>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
> ---
>  arch/x86/include/asm/prom.h |   17 +++++++++
>  arch/x86/kernel/prom.c      |   82 +++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 99 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/include/asm/prom.h b/arch/x86/include/asm/prom.h
> index bd67ab2..3ed0bd6 100644
> --- a/arch/x86/include/asm/prom.h
> +++ b/arch/x86/include/asm/prom.h
> @@ -16,6 +16,7 @@
>
>  #include <linux/of.h>
>  #include <linux/types.h>
> +#include <linux/pci.h>
>  #include <asm/irq.h>
>  #include <asm/atomic.h>
>  #include <asm/setup.h>
> @@ -28,8 +29,24 @@ extern void add_dtb(u64 data);
>  void x86_dtb_find_config(void);
>  void x86_dtb_get_config(unsigned int unused);
>  void add_interrupt_host(struct irq_domain *ih);
> +void __cpuinit x86_of_pci_init(void);
> +
> +static inline struct device_node *pci_device_to_OF_node(struct pci_dev *pdev)
> +{
> +       return pdev->dev.of_node;
> +}
> +
> +static inline struct device_node *pci_bus_to_OF_node(struct pci_bus *bus)
> +{
> +       if (bus->self)
> +               return pci_device_to_OF_node(bus->self);
> +       else
> +               return NULL;
> +}

Nit: could simply be:

static inline struct device_node *pci_device_to_OF_node(struct pci_dev *pdev)
{
       return pdev ? pdev->dev.of_node : NULL;
}

static inline struct device_node *pci_bus_to_OF_node(struct pci_bus *bus)
{
       return pci_device_to_OF_node(bus->self);
}


> +
>  #else
>  static inline void add_dtb(u64 data) { }
> +static inline void x86_of_pci_init(void) { }
>  #define x86_dtb_find_config x86_init_noop
>  #define x86_dtb_get_config x86_init_uint_noop
>  #define of_ioapic 0
> diff --git a/arch/x86/kernel/prom.c b/arch/x86/kernel/prom.c
> index 16c124e..8525ca0 100644
> --- a/arch/x86/kernel/prom.c
> +++ b/arch/x86/kernel/prom.c
> @@ -9,10 +9,13 @@
>  #include <linux/of_address.h>
>  #include <linux/of_platform.h>
>  #include <linux/slab.h>
> +#include <linux/pci.h>
> +#include <linux/of_pci.h>
>
>  #include <asm/hpet.h>
>  #include <asm/irq_controller.h>
>  #include <asm/io_apic.h>
> +#include <asm/pci_x86.h>
>
>  __initdata u64 initial_dtb;
>  char __initdata cmd_line[COMMAND_LINE_SIZE];
> @@ -99,6 +102,85 @@ void __init add_dtb(u64 data)
>        initial_dtb = data + offsetof(struct setup_data, data);
>  }
>
> +#ifdef CONFIG_PCI
> +static int x86_of_pci_irq_enable(struct pci_dev *dev)
> +{
> +       struct of_irq oirq;
> +       u32 virq;
> +       int ret;
> +       u8 pin;
> +
> +       ret = pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
> +       if (ret)
> +               return ret;
> +       if (!pin)
> +               return 0;
> +
> +       ret = of_irq_map_pci(dev, &oirq);
> +       if (ret)
> +               return ret;
> +
> +       virq = irq_create_of_mapping(oirq.controller, oirq.specifier,
> +                       oirq.size);
> +       if (virq == 0)
> +               return -EINVAL;
> +       dev->irq = virq;
> +       return 0;
> +}
> +
> +static void x86_of_pci_irq_disable(struct pci_dev *dev)
> +{
> +}
> +
> +void __cpuinit x86_of_pci_init(void)
> +{
> +       struct device_node *np;
> +
> +       pcibios_enable_irq = x86_of_pci_irq_enable;
> +       pcibios_disable_irq = x86_of_pci_irq_disable;
> +
> +       for_each_node_by_type(np, "pci") {
> +               const void *prop;
> +               struct pci_bus *bus;
> +               unsigned int bus_min;
> +               struct device_node *child;
> +
> +               prop = of_get_property(np, "bus-range", NULL);
> +               if (!prop)
> +                       continue;
> +               bus_min = be32_to_cpup(prop);
> +
> +               bus = pci_find_bus(0, bus_min);
> +               if (!bus) {
> +                       printk(KERN_ERR "Can't find a node for bus %s.\n",
> +                                       np->full_name);
> +                       continue;
> +               }
> +
> +               if (bus->self)
> +                       bus->self->dev.of_node = np;
> +               else
> +                       bus->dev.of_node = np;
> +
> +               for_each_child_of_node(np, child) {
> +                       struct pci_dev *dev;
> +                       u32 devfn;
> +
> +                       prop = of_get_property(child, "reg", NULL);
> +                       if (!prop)
> +                               continue;
> +
> +                       devfn = (be32_to_cpup(prop) >> 8) & 0xff;
> +                       dev = pci_get_slot(bus, devfn);
> +                       if (!dev)
> +                               continue;
> +                       dev->dev.of_node = child;
> +                       pci_dev_put(dev);
> +               }
> +       }
> +}
> +#endif
> +
>  static void __init dtb_setup_hpet(void)
>  {
>        struct device_node *dn;
> --
> 1.7.3.2
>
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>



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.