On Wed, 1 Feb 2012 18:32:06 +0530 Vaidyanathan Srinivasan wrote: > * Ram Pai [2012-02-01 14:21:45]: > > > On Tue, Jan 31, 2012 at 11:14:02PM +0530, Vaidyanathan Srinivasan wrote: > > > * Ram Pai [2012-01-30 11:18:45]: > > > > > > > On Sat, Jan 28, 2012 at 12:40:32AM +0530, Vaidyanathan Srinivasan wrote: > > > > > Hi Ram and Jesse, > > > > > > > > > > I found a trivial issue with page size alignment check on IBM POWER > > > > > box with 64k base page size. In sriov_init(), changing the check from > > > > > PAGE_SIZE (arch and config dependent) to HW_PAGE_SIZE (always 4k) was > > > > > required to use one of the sriov adapter as PF since the > > > > > resource_size() comes up as 0x8000 and PAGE_SIZE would be 0x10000 for > > > > > pseries boxes. > > > > > > > > > > I think resource_size() could be less than SystemPageSize, but I would > > > > > like your comments/ack/nack on any consequences of checking for only > > > > > 4k alignment here in a system with larger base page size. > > > > > > > > As per the SRIOV specs, the resource has to be System page size aligned. > > > > > > > > PFs are required to support 4-KB, 8-KB, 64-KB, 256-KB, 1-MB, and 4-MB > > > > page sizes. In your case if your adapter's PF is not supporting 64K page size > > > > then I think it is not conforming to the PCI SRIOV spec. > > > > > > Hi Ram, > > > > > > Thanks for the pointer. I did some more experiments and found that > > > the card does support 64k page size, but the PCI_SRIOV_SYS_PGSIZE was > > > set to default 4k when we do the query and check resource_size(). > > > > > > You were correct, the resource_size() has to come up with 64k on 64k > > > PAGE_SIZE system. We should not change that check. I was able to > > > get a working solution by setting PCI_SRIOV_SYS_PGSIZE to 64k before > > > we do the query. > > > > > > This was the case in the original code before you moved these to > > > sriov_enable(). If it is ok to leave the SYS_PGSIZE setting in > > > sriov_init(), then I have the following fix that works for me. > > > > > > Please review and let me know your comments. > > > > > > Thanks, > > > Vaidy > > > --- > > > > > > pci: set pci sriov page size before reading sriov bar > > > > > > For an SRIOV device, PCI_SRIOV_SYS_PGSIZE should be set before > > > the PCI_SRIOV_BAR is queried. The sys pagesize defaults to 4k, > > > so this change is required on powerpc box with 64k base page size. > > > > > > This is a regression caused due to moving SRIOV init to sriov_enable(). > > > > > > | commit afd24ece5c76af87f6fc477f2747b83a764f161c > > > | Author: Ram Pai > > > > > > | PCI: delay configuration of SRIOV capability > > > | The SRIOV capability, namely page size and total_vfs of a device are > > > | configured during enumeration phase of the device. This can potentially > > > | interfere with the PCI operations of the platform, if the IOV capability > > > | of the device is not enabled. > > > > > > Signed-off-by: Vaidyanathan Srinivasan > > > > > > diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c > > > index 0321fa3..0dab5ec 100644 > > > --- a/drivers/pci/iov.c > > > +++ b/drivers/pci/iov.c > > > @@ -347,8 +347,6 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn) > > > return rc; > > > } > > > > > > - pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz); > > > - > > > iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE; > > > pci_cfg_access_lock(dev); > > > pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl); > > > @@ -466,6 +464,7 @@ found: > > > return -EIO; > > > > > > pgsz &= ~(pgsz - 1); > > > + pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz); > > > > > > nres = 0; > > > for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) { > > > > > > ACK. I think it is better to revert afd24ece5c76af87f6fc477f2747b83a764f161c. > > Hi Ram, > > Thanks for the ack. But afd24ece5c76af87f6fc477f2747b83a764f161c has > one more change of moving > pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, total) to sriov_enable(). > > This change is required so that we set the PCI_SRIOV_NUM_VF only > during sriov_enable. > > So we should not revert the entire commit, we can just add this change. So which is it Ram, the ack or the revert? :) Having the right page size early seems like the right solution... -- Jesse Barnes, Intel Open Source Technology Center