Re: [PATCH 1/8] powerpc/64: Adjust order in pcibios_init()

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 20/03/2019 13:58, Sam Bobroff wrote:
> The pcibios_init() function for 64 bit PowerPC currently calls
> pci_bus_add_devices() before pcibios_resource_survey(), which seems
> incorrect because it adds devices and attempts to bind their drivers
> before allocating their resources (although no problems seem to be
> apparent).
> 
> So move the call to pci_bus_add_devices() to after
> pcibios_resource_survey(), while extracting call to the
> pcibios_fixup() hook so that it remains in the same location.
> 
> This will also allow the ppc_md.pcibios_bus_add_device() hooks to
> perform actions that depend on PCI resources, both during rescanning
> (where this is already the case) and at boot time, to support future
> work.
> 
> Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>


Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>



> ---
>  arch/powerpc/kernel/pci-common.c |  4 ----
>  arch/powerpc/kernel/pci_32.c     |  4 ++++
>  arch/powerpc/kernel/pci_64.c     | 12 +++++++++---
>  3 files changed, 13 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
> index ff4b7539cbdf..3146eb73e3b3 100644
> --- a/arch/powerpc/kernel/pci-common.c
> +++ b/arch/powerpc/kernel/pci-common.c
> @@ -1383,10 +1383,6 @@ void __init pcibios_resource_survey(void)
>  		pr_debug("PCI: Assigning unassigned resources...\n");
>  		pci_assign_unassigned_resources();
>  	}
> -
> -	/* Call machine dependent fixup */
> -	if (ppc_md.pcibios_fixup)
> -		ppc_md.pcibios_fixup();
>  }
>  
>  /* This is used by the PCI hotplug driver to allocate resource
> diff --git a/arch/powerpc/kernel/pci_32.c b/arch/powerpc/kernel/pci_32.c
> index d3f04f2d8249..40aaa1a6e193 100644
> --- a/arch/powerpc/kernel/pci_32.c
> +++ b/arch/powerpc/kernel/pci_32.c
> @@ -259,6 +259,10 @@ static int __init pcibios_init(void)
>  	/* Call common code to handle resource allocation */
>  	pcibios_resource_survey();
>  
> +	/* Call machine dependent fixup */
> +	if (ppc_md.pcibios_fixup)
> +		ppc_md.pcibios_fixup();
> +
>  	/* Call machine dependent post-init code */
>  	if (ppc_md.pcibios_after_init)
>  		ppc_md.pcibios_after_init();
> diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c
> index 9d8c10d55407..6f16f30031d7 100644
> --- a/arch/powerpc/kernel/pci_64.c
> +++ b/arch/powerpc/kernel/pci_64.c
> @@ -58,14 +58,20 @@ static int __init pcibios_init(void)
>  	pci_add_flags(PCI_ENABLE_PROC_DOMAINS | PCI_COMPAT_DOMAIN_0);
>  
>  	/* Scan all of the recorded PCI controllers.  */
> -	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
> +	list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
>  		pcibios_scan_phb(hose);
> -		pci_bus_add_devices(hose->bus);
> -	}
>  
>  	/* Call common code to handle resource allocation */
>  	pcibios_resource_survey();
>  
> +	/* Add devices. */
> +	list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
> +		pci_bus_add_devices(hose->bus);
> +
> +	/* Call machine dependent fixup */
> +	if (ppc_md.pcibios_fixup)
> +		ppc_md.pcibios_fixup();
> +
>  	printk(KERN_DEBUG "PCI: Probing PCI hardware done\n");
>  
>  	return 0;
> 

-- 
Alexey