Messages in this thread Patch in this message | | | Date | Sun, 29 Jan 2012 18:41:39 +0530 | From | Vaidyanathan Srinivasan <> | Subject | Re: [BUGFIX][PATCH] pci: check for 4k resource_size alignment in sriov_init |
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* Yinghai Lu <yinghai@kernel.org> [2012-01-27 13:05:41]:
> On Fri, Jan 27, 2012 at 11:10 AM, Vaidyanathan Srinivasan > <svaidy@linux.vnet.ibm.com> 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. > > > > Thanks, > > Vaidy > > > > --- > > > > pci: check for 4k resource_size alignment in sriov_init > > > > pci sriov_init should check for 4k page size alignment of resource_size > > even if base page size is larger -- like 64k in powerpc. > > > > Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> > > > > diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c > > index 0321fa3..5816fa0 100644 > > --- a/drivers/pci/iov.c > > +++ b/drivers/pci/iov.c > > @@ -474,7 +474,7 @@ found: > > pos + PCI_SRIOV_BAR + i * 4); > > if (!res->flags) > > continue; > > - if (resource_size(res) & (PAGE_SIZE - 1)) { > > + if (resource_size(res) & (HW_PAGE_SIZE - 1)) { > > rc = -EIO; > > goto failed; > > } > > > > but HW_PAGE_SIZE is only defined for powerpc.
My bad, I picked the #define used in other powerpc code.
> also there is PAGE_SHIFT around in that function.
This gets defined correctly if CONFIG_PPC_64K_PAGES=y. But the actual problem is the need for a generic 4K #define for x86 and other archs.
> maybe you can just define another MARCO according to IOV spec?
This is a good idea. I could not find an IOV specific requirement. The resource size has to be a multiple of 4K so that the overall resource-size() * PCI_SRIOV_TOTAL_VF will be a multiple of 4K or more.
Let me share a patch that has a simple #define in drivers/pci/pci.h, which is needed to get SRIOV cards started on powerpc box.
--Vaidy
---
pci: check for 4k resource_size alignment in sriov_init pci sriov_init should check for 4k page size alignment of resource_size even if base page size is larger like 64k in powerpc. Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index 0321fa3..10adede 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -474,7 +474,7 @@ found: pos + PCI_SRIOV_BAR + i * 4); if (!res->flags) continue; - if (resource_size(res) & (PAGE_SIZE - 1)) { + if (resource_size(res) & (HW_PAGE_SIZE_4K - 1)) { rc = -EIO; goto failed; } diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 1009a5e..68703ab 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -6,6 +6,9 @@ #define PCI_CFG_SPACE_SIZE 256 #define PCI_CFG_SPACE_EXP_SIZE 4096 +/* Constants used in the PCI core code */ +#define HW_PAGE_SIZE_4K 0x1000 + /* Functions internal to the PCI core code */ extern int pci_uevent(struct device *dev, struct kobj_uevent_env *env); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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