RE: [PATCH V2] pci: introduce static_nr to indicate domain_nr from which IDA

[Peng Fan]

Hi,

> Subject: [PATCH V2] pci: introduce static_nr to indicate domain_nr from
> which IDA

Gentle ping..

Thanks,
Peng.

> 
> From: Peng Fan <peng.fan@xxxxxxx>
> 
> When PCI node was created using an overlay and the overlay is
> reverted/destroyed, the "linux,pci-domain" property no longer exists, so
> of_get_pci_domain_nr will return failure. Then
> of_pci_bus_release_domain_nr will actually use the dynamic IDA, even if
> the IDA was allocated in static IDA.
> 
> Introduce a static_nr field in pci_bus to indicate whether the IDA is a
> dynamic or static in order to free the correct one.
> 
> Fixes: c14f7ccc9f5d ("PCI: Assign PCI domain IDs by ida_alloc()")
> Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
> ---
> 
> V2:
>  Update commit message
>  Move static_nr:1 to stay besides others :1 fields.
> 
>  drivers/pci/pci.c   | 22 ++++++++++++++--------
>  include/linux/pci.h |  1 +
>  2 files changed, 15 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index
> 60230da957e0..5c98502bcda6 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -6881,10 +6881,10 @@ static void
> of_pci_reserve_static_domain_nr(void)
>  	}
>  }
> 
> -static int of_pci_bus_find_domain_nr(struct device *parent)
> +static int of_pci_bus_find_domain_nr(struct pci_bus *bus, struct device
> +*parent)
>  {
>  	static bool static_domains_reserved = false;
> -	int domain_nr;
> +	int domain_nr, ret;
> 
>  	/* On the first call scan device tree for static allocations. */
>  	if (!static_domains_reserved) {
> @@ -6892,6 +6892,8 @@ static int of_pci_bus_find_domain_nr(struct
> device *parent)
>  		static_domains_reserved = true;
>  	}
> 
> +	bus->static_nr = 0;
> +
>  	if (parent) {
>  		/*
>  		 * If domain is in DT, allocate it in static IDA.  This @@ -
> 6899,10 +6901,14 @@ static int of_pci_bus_find_domain_nr(struct device
> *parent)
>  		 * in DT.
>  		 */
>  		domain_nr = of_get_pci_domain_nr(parent->of_node);
> -		if (domain_nr >= 0)
> -			return ida_alloc_range(&pci_domain_nr_static_ida,
> -					       domain_nr, domain_nr,
> -					       GFP_KERNEL);
> +		if (domain_nr >= 0) {
> +			ret = ida_alloc_range(&pci_domain_nr_static_ida,
> +					      domain_nr, domain_nr,
> GFP_KERNEL);
> +			if (ret >= 0)
> +				bus->static_nr = 1;
> +
> +			return ret;
> +		}
>  	}
> 
>  	/*
> @@ -6920,7 +6926,7 @@ static void of_pci_bus_release_domain_nr(struct
> pci_bus *bus, struct device *par
>  		return;
> 
>  	/* Release domain from IDA where it was allocated. */
> -	if (of_get_pci_domain_nr(parent->of_node) == bus->domain_nr)
> +	if (bus->static_nr)
>  		ida_free(&pci_domain_nr_static_ida, bus->domain_nr);
>  	else
>  		ida_free(&pci_domain_nr_dynamic_ida, bus->domain_nr);
> @@ -6928,7 +6934,7 @@ static void of_pci_bus_release_domain_nr(struct
> pci_bus *bus, struct device *par
> 
>  int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent)  {
> -	return acpi_disabled ? of_pci_bus_find_domain_nr(parent) :
> +	return acpi_disabled ? of_pci_bus_find_domain_nr(bus, parent) :
>  			       acpi_pci_bus_find_domain_nr(bus);  }
> 
> diff --git a/include/linux/pci.h b/include/linux/pci.h index
> eeb2e6f6130f..222a1729ea7e 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -677,6 +677,7 @@ struct pci_bus {
>  	struct bin_attribute	*legacy_mem;	/* Legacy mem */
>  	unsigned int		is_added:1;
>  	unsigned int		unsafe_warn:1;	/* warned about
> RW1C config write */
> +	unsigned int		static_nr:1;
>  };
> 
>  #define to_pci_bus(n)	container_of(n, struct pci_bus, dev)
> --
> 2.37.1