Subject: Re: [PATCH v8 29/45] powerpc/pci: Export pci_traverse_device_nodes()

From: Alexey Kardashevskiy <[email-masked]>
Date: Wed, 20 Apr 2016 13:39:39 +1000

On 04/20/2016 11:27 AM, Gavin Shan wrote:
> On Tue, Apr 19, 2016 at 03:51:03PM +1000, Alexey Kardashevskiy wrote:
>> On 02/17/2016 02:44 PM, Gavin Shan wrote:
>>> This renames traverse_pci_devices() to pci_traverse_device_nodes().
>>> The function traverses all subordinate device nodes of the specified
>>> one. Also, below cleanup applied to the function. No logical changes
>>> introduced.
>>>
>>>     * Rename "pre" to "fn".
>>>     * Avoid assignment in if condition reported from checkpatch.pl.
>>>
>>> Signed-off-by: Gavin Shan <[email-masked]>
>>> ---
>>>   arch/powerpc/include/asm/ppc-pci.h   |  6 +++---
>>>   arch/powerpc/kernel/pci_dn.c         | 15 ++++++++++-----
>>>   arch/powerpc/platforms/pseries/msi.c |  4 ++--
>>>   3 files changed, 15 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/arch/powerpc/include/asm/ppc-pci.h b/arch/powerpc/include/asm/ppc-pci.h
>>> index ca0c5bf..8753e4e 100644
>>> --- a/arch/powerpc/include/asm/ppc-pci.h
>>> +++ b/arch/powerpc/include/asm/ppc-pci.h
>>> @@ -33,9 +33,9 @@ extern struct pci_dev *isa_bridge_pcidev;	/* may be NULL if no ISA bus */
>>>   struct device_node;
>>>   struct pci_dn;
>>>
>>> -typedef void *(*traverse_func)(struct device_node *me, void *data);
>>
>>
>>
>> Why removing this typedef? Typedef's are good.
>>
>> Anyway,
>>
>
> Could you please provide more details why it's good? I removed it
> because it was used for only once.

I have some thoughts but never mind, nobody seems to care about this and 
typedefs are considered bad by the CodingStyle.

>
>
>>
>> Reviewed-by: Alexey Kardashevskiy <[email-masked]>
>>
>>
>>
>>
>>> -void *traverse_pci_devices(struct device_node *start, traverse_func pre,
>>> -		void *data);
>>> +void *pci_traverse_device_nodes(struct device_node *start,
>>> +				void *(*fn)(struct device_node *, void *),
>>> +				void *data);
>>>   void *traverse_pci_dn(struct pci_dn *root,
>>>   		      void *(*fn)(struct pci_dn *, void *),
>>>   		      void *data);
>>> diff --git a/arch/powerpc/kernel/pci_dn.c b/arch/powerpc/kernel/pci_dn.c
>>> index ce10281..ecdccce 100644
>>> --- a/arch/powerpc/kernel/pci_dn.c
>>> +++ b/arch/powerpc/kernel/pci_dn.c
>>> @@ -372,8 +372,9 @@ EXPORT_SYMBOL_GPL(pci_remove_device_node_info);
>>>    * one of these nodes we also assume its siblings are non-pci for
>>>    * performance.
>>>    */
>>> -void *traverse_pci_devices(struct device_node *start, traverse_func pre,
>>> -		void *data)
>>> +void *pci_traverse_device_nodes(struct device_node *start,
>>> +				void *(*fn)(struct device_node *, void *),
>>> +				void *data)
>>>   {
>>>   	struct device_node *dn, *nextdn;
>>>   	void *ret;
>>> @@ -388,8 +389,11 @@ void *traverse_pci_devices(struct device_node *start, traverse_func pre,
>>>   		if (classp)
>>>   			class = of_read_number(classp, 1);
>>>
>>> -		if (pre && ((ret = pre(dn, data)) != NULL))
>>> -			return ret;
>>> +		if (fn) {
>>> +			ret = fn(dn, data);
>>> +			if (ret)
>>> +				return ret;
>>> +		}
>>>
>>>   		/* If we are a PCI bridge, go down */
>>>   		if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
>>> @@ -411,6 +415,7 @@ void *traverse_pci_devices(struct device_node *start, traverse_func pre,
>>>   	}
>>>   	return NULL;
>>>   }
>>> +EXPORT_SYMBOL_GPL(pci_traverse_device_nodes);
>>>
>>>   static struct pci_dn *pci_dn_next_one(struct pci_dn *root,
>>>   				      struct pci_dn *pdn)
>>> @@ -487,7 +492,7 @@ void pci_devs_phb_init_dynamic(struct pci_controller *phb)
>>>   	}
>>>
>>>   	/* Update dn->phb ptrs for new phb and children devices */
>>> -	traverse_pci_devices(dn, add_pdn, phb);
>>> +	pci_traverse_device_nodes(dn, add_pdn, phb);
>>>   }
>>>
>>>   /**
>>> diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c
>>> index 272e9ec..543a638 100644
>>> --- a/arch/powerpc/platforms/pseries/msi.c
>>> +++ b/arch/powerpc/platforms/pseries/msi.c
>>> @@ -305,7 +305,7 @@ static int msi_quota_for_device(struct pci_dev *dev, int request)
>>>   	memset(&counts, 0, sizeof(struct msi_counts));
>>>
>>>   	/* Work out how many devices we have below this PE */
>>> -	traverse_pci_devices(pe_dn, count_non_bridge_devices, &counts);
>>> +	pci_traverse_device_nodes(pe_dn, count_non_bridge_devices, &counts);
>>>
>>>   	if (counts.num_devices == 0) {
>>>   		pr_err("rtas_msi: found 0 devices under PE for %s\n",
>>> @@ -320,7 +320,7 @@ static int msi_quota_for_device(struct pci_dev *dev, int request)
>>>   	/* else, we have some more calculating to do */
>>>   	counts.requestor = pci_device_to_OF_node(dev);
>>>   	counts.request = request;
>>> -	traverse_pci_devices(pe_dn, count_spare_msis, &counts);
>>> +	pci_traverse_device_nodes(pe_dn, count_spare_msis, &counts);
>>>
>>>   	/* If the quota isn't an integer multiple of the total, we can
>>>   	 * use the remainder as spare MSIs for anyone that wants them. */
>>>
>>
>>
>> --
>> Alexey
>>
>

-- 
Alexey