Subject: Re: [PATCH V2 5/6] powerpc/powernv: boundary the total vf bar size instead of the individual one

From: Gavin Shan <[email-masked]>
Date: Fri, 7 Aug 2015 11:23:54 +1000

On Thu, Aug 06, 2015 at 10:03:04PM +0800, Wei Yang wrote:
>On Thu, Aug 06, 2015 at 03:28:51PM +1000, Gavin Shan wrote:
>>On Wed, Aug 05, 2015 at 09:25:02AM +0800, Wei Yang wrote:
>>>Each VF could have 6 BARs at most. When the total BAR size exceeds the
>>>gate, after expanding it will also exhaust the M64 Window.
>>>
>>>This patch limits the boundary by checking the total VF BAR size instead of
>>>the individual BAR.
>>>
>>>Signed-off-by: Wei Yang <[email-masked]>
>>
>>Ok. I didn't look at this when giving comments to last patch. It turns
>>you have the change in this patch. Please merge it with the previous
>>patch.
>>
>
>Hmm... I prefer to have them in two patches. One focus on the calculation of
>gate and the other focus on checking the total VF BAR size. This would help
>record the change.
>

It's fine to me as well. I'll take close look on your next revision since
you have to refresh the whole series. Is that fine to you?

>>>---
>>> arch/powerpc/platforms/powernv/pci-ioda.c |   13 +++++++------
>>> 1 file changed, 7 insertions(+), 6 deletions(-)
>>>
>>>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>>>index 31dcedc..4042303 100644
>>>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>>>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>>>@@ -2702,7 +2702,7 @@ static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev)
>>> 	struct pnv_phb *phb;
>>> 	struct resource *res;
>>> 	int i;
>>>-	resource_size_t size, gate;
>>>+	resource_size_t size, gate, total_vf_bar_sz;
>>> 	struct pci_dn *pdn;
>>> 	int mul, total_vfs;
>>>
>>>@@ -2729,6 +2729,7 @@ static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev)
>>> 	 * Window and limit the system flexibility.
>>> 	 */
>>> 	gate = phb->ioda.m64_segsize >> 1;
>>>+	total_vf_bar_sz = 0;
>>>
>>> 	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
>>> 		res = &pdev->resource[i + PCI_IOV_RESOURCES];
>>>@@ -2741,13 +2742,13 @@ static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev)
>>> 			return;
>>> 		}
>>>
>>>-		size = pci_iov_resource_size(pdev, i + PCI_IOV_RESOURCES);
>>>+		total_vf_bar_sz += pci_iov_resource_size(pdev,
>>>+				i + PCI_IOV_RESOURCES);
>>>
>>> 		/* bigger than or equal to gate */
>>>-		if (size >= gate) {
>>>-			dev_info(&pdev->dev, "PowerNV: VF BAR%d: %pR IOV size "
>>>-				"is bigger than %lld, roundup power2\n",
>>>-				 i, res, gate);
>>>+		if (total_vf_bar_sz >= gate) {
>>>+			dev_info(&pdev->dev, "PowerNV: VF BAR Total IOV size "
>>>+				"is bigger than %lld, roundup power2\n", gate);
>>> 			mul = roundup_pow_of_two(total_vfs);
>>> 			pdn->m64_single_mode = true;
>>> 			break;
>>>-- 
>>>1.7.9.5
>>>
>
>-- 
>Richard Yang
>Help you, Help me