Re: [PATCH V3 2/9] powerpc/pci_dn: cache vf_index in pci_dn

From: Gavin Shan <gwshan@linux.vnet.ibm.com>
To: Wei Yang <weiyang@linux.vnet.ibm.com>
Cc: Gavin Shan <gwshan@linux.vnet.ibm.com>,
	bhelgaas@google.com, linuxppc-dev@lists.ozlabs.org,
	linux-pci@vger.kernel.org
Subject: Re: [PATCH V3 2/9] powerpc/pci_dn: cache vf_index in pci_dn
Date: Tue, 12 May 2015 16:15:58 +1000	[thread overview]
Message-ID: <20150512061558.GA18734@gwshan> (raw)
In-Reply-To: <20150511055412.GA1632@richard>

On Mon, May 11, 2015 at 01:54:12PM +0800, Wei Yang wrote:
>On Mon, May 11, 2015 at 12:21:04PM +1000, Gavin Shan wrote:
>>On Mon, May 04, 2015 at 03:07:31PM +0800, Wei Yang wrote:
>>>This patch caches the index of a VF in its PF in pci_dn.
>>>
>>
>>At least you can mention the purpose of vf_index to make the commit log
>>complete. The following message looks better?
>>
>>The patch caches the VF index in pci_dn, which can be used to calculate
>>VF's bus, device and function number. Those information helps to locate
>>the VF's PCI device instance when doing hotplug during EEH recovery if
>>necessary.
>>
>
>Thanks, looks better. I added it in the log.
>
>>>Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
>>>---
>>> arch/powerpc/include/asm/pci-bridge.h |    1 +
>>> arch/powerpc/kernel/pci_dn.c          |    5 +++--
>>> 2 files changed, 4 insertions(+), 2 deletions(-)
>>>
>>>diff --git a/arch/powerpc/include/asm/pci-bridge.h b/arch/powerpc/include/asm/pci-bridge.h
>>>index 1811c44..9582aa2 100644
>>>--- a/arch/powerpc/include/asm/pci-bridge.h
>>>+++ b/arch/powerpc/include/asm/pci-bridge.h
>>>@@ -199,6 +199,7 @@ struct pci_dn {
>>> #ifdef CONFIG_PCI_IOV
>>> 	u16     vfs_expanded;		/* number of VFs IOV BAR expanded */
>>> 	u16     num_vfs;		/* number of VFs enabled*/
>>>+	int     vf_index;		/* Index to PF for VF dev */
>>                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>
>>					/* VF index in the PF */
>
>Ok, changed in the code.
>
>>
>>And I believe it can be "unsigned int", or u16. We should have
>>non-negative vf_index, no?
>
>Take a look in the virtfn_add(), the index in drivers/pci/iov.c is int. So I
>copy that.
>
>>
>>> 	int     offset;			/* PE# for the first VF PE */
>>> #define M64_PER_IOV 4
>>> 	int     m64_per_iov;
>>>diff --git a/arch/powerpc/kernel/pci_dn.c b/arch/powerpc/kernel/pci_dn.c
>>>index b3b4df9..bf0fb873 100644
>>>--- a/arch/powerpc/kernel/pci_dn.c
>>>+++ b/arch/powerpc/kernel/pci_dn.c
>>>@@ -138,7 +138,7 @@ struct pci_dn *pci_get_pdn(struct pci_dev *pdev)
>>>
>>> #ifdef CONFIG_PCI_IOV
>>> static struct pci_dn *add_one_dev_pci_data(struct pci_dn *parent,
>>>-					   struct pci_dev *pdev,
>>>+					   struct pci_dev *pdev, int vf_index,
>>
>>					   struct pci_dev *pdev,
>>					   int vf_index;
>
>Some reason for this comment?
>
>That does not exceed 80 characters.
>

No, it doesn't exceed 80 characters as you said. You take one of the following
formats, not the one you're using:

add_one_dev_pci_data(foo1, foo2,          add_one_dev_pci_data(foo1,
                     foo3, foo4,                               foo2,
                     foo5, foo6);                                :
                                                               foo6);

>>> 					   int busno, int devfn)
>>> {
>>> 	struct pci_dn *pdn;
>>>@@ -157,6 +157,7 @@ static struct pci_dn *add_one_dev_pci_data(struct pci_dn *parent,
>>> 	pdn->parent = parent;
>>> 	pdn->busno = busno;
>>> 	pdn->devfn = devfn;
>>>+	pdn->vf_index = vf_index;
>>> #ifdef CONFIG_PPC_POWERNV
>>> 	pdn->pe_number = IODA_INVALID_PE;
>>> #endif
>>>@@ -196,7 +197,7 @@ struct pci_dn *add_dev_pci_data(struct pci_dev *pdev)
>>> 		return NULL;
>>>
>>> 	for (i = 0; i < pci_sriov_get_totalvfs(pdev); i++) {
>>>-		pdn = add_one_dev_pci_data(parent, NULL,
>>>+		pdn = add_one_dev_pci_data(parent, NULL, i,
>>> 					   pci_iov_virtfn_bus(pdev, i),
>>> 					   pci_iov_virtfn_devfn(pdev, i));
>>> 		if (!pdn) {

Thanks,
Gavin