Gerry,

So which direction did you take in your patch set--  a) common,
generic msi_desc, or b)  bus-specific msi_desc like Marc showed
(mybus_msi_desc)?

Thanks,
Stuart

On Sun, Jan 18, 2015 at 8:10 PM, Jiang Liu [off-list ref] wrote:

On 2015/1/16 4:35, Stuart Yoder wrote:

quoted

On Thu, Jan 8, 2015 at 11:06 AM, Marc Zyngier [off-list ref] wrote:

quoted

As MSI-type features are creeping into non-PCI devices, it is
starting to make sense to give our struct device some form of
support for this, by allowing a pointer to an MSI irq domain to
be set/retrieved.

Signed-off-by: Marc Zyngier <redacted>
---
 include/linux/device.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/include/linux/device.h b/include/linux/device.h
index fb50673..ec4cee5 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h

@@ -690,6 +690,7 @@ struct acpi_dev_node {
  *             along with subsystem-level and driver-level callbacks.
  * @pins:      For device pin management.
  *             See Documentation/pinctrl.txt for details.
+ * @msi_domain: The generic MSI domain this device is using.
  * @numa_node: NUMA node this device is close to.
  * @dma_mask:  Dma mask (if dma'ble device).
  * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all

@@ -750,6 +751,9 @@ struct device {
        struct dev_pm_info      power;
        struct dev_pm_domain    *pm_domain;

+#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
+       struct irq_domain       *msi_domain; /* MSI domain device uses */
+#endif

This is not a comment on this patch specifically, but a question about other
MSI specific fields that might be needed in struct device.

Currently the generic MSI domain handling has hardcoded assumptions
that devices are PCI-- see the for_each_msi_entry() iterator in msi.h:

  #define dev_to_msi_list(dev)            (&to_pci_dev((dev))->msi_list)

  #define for_each_msi_entry(desc, dev)   \
        list_for_each_entry((desc), dev_to_msi_list((dev)), list)

One approach would be to move the msi_list out of pci_dev and put
it in struct device, so all devices can have an msi_list.

The other approach would be to keep msi_list in a bus specific
device struct, and then dev_to_msi_list() would need to be
implemented as a bus specific callback of some kind.

The above hardcoded PCI assumption isn't going to work.   Wanted to
see if there is any advice in which direction to go.

Hi Stuart,
        I already have some a patch set to go that direction waiting
send out for review:)
Thanks!
Gerry

quoted

Thanks,
Stuart Yoder
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