On Tue, 28 Sep 2021, Rahul Singh wrote:
> Based Linux commit 41e5c0f81d3e676d671d96a0a1fafb27abfbd9d7
>
> Import the Linux helper of_get_pci_domain_nr. This function will try to
> obtain the host bridge domain number by finding a property called
> "linux,pci-domain" of the given device node.
>
> Signed-off-by: Rahul Singh <rahul.si...@arm.com>
Reviewed-by: Stefano Stabellini <sstabell...@kernel.org>
> ---
> Change in v3:
> - Modify commit message to include upstream Linux commit-id not stable
> Linux commit-id
> - Remove return value as those are not valid for XEN
> Change in v2: Patch introduced in v2
> ---
> xen/common/device_tree.c | 12 ++++++++++++
> xen/include/xen/device_tree.h | 17 +++++++++++++++++
> 2 files changed, 29 insertions(+)
>
> diff --git a/xen/common/device_tree.c b/xen/common/device_tree.c
> index 53160d61f8..ea93da1725 100644
> --- a/xen/common/device_tree.c
> +++ b/xen/common/device_tree.c
> @@ -2183,6 +2183,18 @@ void __init dt_unflatten_host_device_tree(void)
> dt_alias_scan();
> }
>
> +int dt_get_pci_domain_nr(struct dt_device_node *node)
> +{
> + u32 domain;
> + int error;
> +
> + error = dt_property_read_u32(node, "linux,pci-domain", &domain);
> + if ( !error )
> + return -EINVAL;
> +
> + return (u16)domain;
> +}
> +
> /*
> * Local variables:
> * mode: C
> diff --git a/xen/include/xen/device_tree.h b/xen/include/xen/device_tree.h
> index 3ffe3eb3d2..2297c59ce6 100644
> --- a/xen/include/xen/device_tree.h
> +++ b/xen/include/xen/device_tree.h
> @@ -832,6 +832,23 @@ int dt_count_phandle_with_args(const struct
> dt_device_node *np,
> const char *list_name,
> const char *cells_name);
>
> +/**
> + * dt_get_pci_domain_nr - Find the host bridge domain number
> + * of the given device node.
> + * @node: Device tree node with the domain information.
> + *
> + * This function will try to obtain the host bridge domain number by finding
> + * a property called "linux,pci-domain" of the given device node.
> + *
> + * Return:
> + * * > 0 - On success, an associated domain number.
> + * * -EINVAL - The property "linux,pci-domain" does not exist.
> + *
> + * Returns the associated domain number from DT in the range [0-0xffff], or
> + * a negative value if the required property is not found.
> + */
> +int dt_get_pci_domain_nr(struct dt_device_node *node);
> +
> #ifdef CONFIG_DEVICE_TREE_DEBUG
> #define dt_dprintk(fmt, args...) \
> printk(XENLOG_DEBUG fmt, ## args)
> --
> 2.17.1
>
