Re: [PATCH 11/11] ARM64 / PCI / ACPI: support for ACPI based PCI hostbridge init

[Will Deacon <will.deacon@arm.com>]

On Tue, May 26, 2015 at 01:49:24PM +0100, Hanjun Guo wrote:
> Based on Jiang Liu's common interface to support PCI host bridge
> init and refactoring of MMCONFIG, this patch using information
> from ACPI MCFG table and IO/irq resources from _CRS to init
> ARM64 PCI hostbridge, then PCI will work on ARM64.
> 
> This patch is based on Mark Salter and Tomasz Nowicki's work.
> 
> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
> Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
> CC: Arnd Bergmann <arnd@arndb.de>
> CC: Catalin Marinas <catalin.marinas@arm.com>
> CC: Liviu Dudau <Liviu.Dudau@arm.com>
> CC: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
> CC: Will Deacon <will.deacon@arm.com>
> ---
>  arch/arm64/Kconfig      |   7 ++
>  arch/arm64/kernel/pci.c | 245 +++++++++++++++++++++++++++++++++++++++++++++---
>  drivers/pci/pci.c       |  26 +++--
>  3 files changed, 257 insertions(+), 21 deletions(-)
> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 9b80428..8e4b789 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -276,6 +276,13 @@ config PCI_DOMAINS_GENERIC
>  config PCI_SYSCALL
>         def_bool PCI
> 
> +config PCI_MMCONFIG
> +       def_bool y
> +       select PCI_ECAM
> +       select HAVE_PCI_ECAM
> +       select GENERIC_PCI_ECAM
> +       depends on ACPI
> +
>  source "drivers/pci/Kconfig"
>  source "drivers/pci/pcie/Kconfig"
>  source "drivers/pci/hotplug/Kconfig"
> diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
> index 4095379..d1629dc 100644
> --- a/arch/arm64/kernel/pci.c
> +++ b/arch/arm64/kernel/pci.c
> @@ -11,12 +11,15 @@
>   */
> 
>  #include <linux/acpi.h>
> +#include <linux/ecam.h>
>  #include <linux/init.h>
>  #include <linux/io.h>
>  #include <linux/kernel.h>
>  #include <linux/mm.h>
> +#include <linux/of_address.h>
>  #include <linux/of_pci.h>
>  #include <linux/of_platform.h>
> +#include <linux/pci-acpi.h>
>  #include <linux/slab.h>
> 
>  #include <asm/pci-bridge.h>
> @@ -43,31 +46,251 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
>   */
>  int pcibios_add_device(struct pci_dev *dev)
>  {
> -       dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
> +       if (acpi_disabled)
> +               dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
> 
>         return 0;
>  }
> 
> +#ifdef CONFIG_ACPI
> +int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
> +{
> +       struct pci_controller *sd = bridge->bus->sysdata;
> +
> +       ACPI_COMPANION_SET(&bridge->dev, sd->companion);
> +       return 0;
> +}
> +
> +void pcibios_add_bus(struct pci_bus *bus)
> +{
> +       acpi_pci_add_bus(bus);
> +}
> +
> +void pcibios_remove_bus(struct pci_bus *bus)
> +{
> +       acpi_pci_remove_bus(bus);
> +}
> +
> +int pcibios_enable_irq(struct pci_dev *dev)
> +{
> +       if (!pci_dev_msi_enabled(dev))
> +               acpi_pci_irq_enable(dev);
> +       return 0;
> +}
> +
> +int pcibios_disable_irq(struct pci_dev *dev)
> +{
> +       if (!pci_dev_msi_enabled(dev))
> +               acpi_pci_irq_disable(dev);
> +       return 0;
> +}
> +
> +int pcibios_enable_device(struct pci_dev *dev, int bars)
> +{
> +       int err;
> +
> +       err = pci_enable_resources(dev, bars);
> +       if (err < 0)
> +               return err;
> +
> +       return pcibios_enable_irq(dev);
> +}
> +
> +static int __init pcibios_assign_resources(void)
> +{
> +       struct pci_bus *root_bus;
> +
> +       if (acpi_disabled)
> +               return 0;
> +
> +       list_for_each_entry(root_bus, &pci_root_buses, node) {
> +               pcibios_resource_survey_bus(root_bus);
> +               pci_assign_unassigned_root_bus_resources(root_bus);
> +       }
> +       return 0;
> +}

I'm starting to sound like a stuck record (and getting bored of it
myself!), but none of this looks arch-specific. Can it be moved into the
core?

Will