On 07/26/2013 03:48 PM, Bjorn Helgaas wrote:
On Thu, Jul 25, 2013 at 02:25:04PM -0400, Don Dutile wrote:
On 07/25/2013 01:19 PM, Bjorn Helgaas wrote:
On Wed, Jul 24, 2013 at 04:42:03PM -0400, Don Dutile wrote:
On 07/23/2013 06:35 PM, Bjorn Helgaas wrote:
On Thu, Jul 11, 2013 at 03:03:27PM -0600, Alex Williamson wrote:
+ * pcie_for_each_requester - Call callback @fn on each devices and DMA source
+ * from @requestee to the PCIe requester ID visible
+ * to @bridge.
Transactions from a device may appear with one of several requester IDs,
but there's not necessarily an actual pci_dev for each ID, so I think the
ditto above; have to have a pdev for each id....
This *might* be true, but I don't think we should rely on it. For
example:
00:1c.0 PCIe to PCI bridge to [bus 01]
01:01.0 PCI endpoint
The bridge will take ownership of DMA transactions from the 01:01.0
endpoint. An IOMMU on bus 00 will see a bridge-assigned requester
ID of 01:00.0 (subordinate bus number, devfn zero), but there is no
01:00.0 device.
Clarification:
I meant that each requester-id must have at least 1 PCI device associated
with it.
I don't think that's true, as in the example above. Requester ID
0x0100 has no pci_dev associated with it. What am I missing?
Maybe you mean that requester ID 0x0100 is associated with pci_dev
01:01.0 in the sense that DMAs from 01:01.0 appear with that ID?
yes.
That's true, but I can't think of a reason why we would start with
ID 0x0100 and try to look up 01:01.0 from it. And of course, if you
other than to figure out errant device behavior, or a bug in sw. ;)
*did* try to look up the device, there could be several of them.
Bjorn
What's most important for the consumers (IOMMUs) is to get all the requester-id's
related to a (p)dev for mapping & unmapping setup & teardown, resp.
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