Re: [RFC v2 5/7] PCI/ACPI: Consolidate common PCI host bridge code into ACPI core

Hanjun Guo
2015-05-13T09:29:22Z

Hi Jiang,

On 2015年05月05日 10:46, Jiang Liu wrote:
> Introduce common interface acpi_pci_root_create() and related data
> structures to create PCI root bus for ACPI PCI host bridges. It will
> be used to kill duplicated arch specific code for IA64 and x86. It may
> also help ARM64 in future.
>
[...]
> diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
> index a965efa52152..a292ee33d74b 100644
> --- a/include/linux/pci-acpi.h
> +++ b/include/linux/pci-acpi.h
> @@ -52,6 +52,30 @@ static inline acpi_handle acpi_pci_get_bridge_handle(struct pci_bus *pbus)
> return ACPI_HANDLE(dev);
> }
>
> +struct acpi_pci_root;
> +struct acpi_pci_root_ops;
> +
> +struct acpi_pci_root_info_common {
> + struct pci_controller controller;

There is another problem that this patch will lead to
compile error on ARM64 since ARM64 has basic ACPI support
in 4.1.

struct pci_controller controller is not available
on ARM64, that's the reason why compile errors happens on ARM64.

How about move struct pci_controller to this head file?

because all the related file you changed in this patch set
are only compiled when CONFI_ACPI=y, so for x86,

struct pci_controller {
#ifdef CONFIG_ACPI
struct acpi_device *companion; /* ACPI companion device */
#endif
#ifdef CONFIG_X86_64
void *iommu; /* IOMMU private data */
#endif
int segment; /* PCI domain */
int node; /* NUMA node */
};

I'm sure #ifdef CONFIG_ACPI .. #endif can be removed
with no harm, and for *iommu, we can remove the #ifdef CONFIG_X86_64
with introducing little more memory on x86_32, after
that, the struct pci_controller is almost the same as ia64:

struct pci_controller {
struct acpi_device *companion;
void *iommu;
int segment;
int node; /* nearest node with memory or
NUMA_NO_NODE for global allocation */

void *platform_data;
};

except void *platform_data;

On ARM64, the structure is almost the same, so how about
introduce

struct pci_controller {
struct acpi_device *companion; /* ACPI companion device */
void *iommu; /* IOMMU private data */
int segment; /* PCI domain */
int node; /* NUMA node */
#ifdef CONFIG_IA64
void *platform_data;
#endif
};

in this file, then can be used for all architectures?

Thanks
Hanjun