[PATCH v2 1/8] device core: Introduce per-device MSI domain pointer
Jiang Liu
jiang.liu at linux.intel.com
Tue Jan 20 17:34:27 PST 2015
On 2015/1/21 1:17, Stuart Yoder wrote:
> 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)?
Hi Stuart,
Currently I'm trying to go the former way as below.
Regards,
Gerry
-----------------------------------------------------------------------
struct msi_desc {
struct list_head list;
unsigned int irq;
unsigned int nvec_used; /* number of
messages */
struct device * dev;
struct msi_msg msg; /* Last set MSI
message */
#ifdef CONFIG_PCI_MSI
union {
struct { /* For PCI
MSI/MSI-X */
u32 masked; /* mask bits */
struct {
__u8 is_msix : 1;
__u8 multiple: 3; /* log2 num of
messages allocated */
__u8 multi_cap : 3; /* log2 num of
messages supported */
__u8 maskbit : 1; /* mask-pending
bit supported ? */
__u8 is_64 : 1; /* Address size:
0=32bit 1=64bit */
__u16 entry_nr; /* specific
enabled entry */
unsigned default_irq; /* default
pre-assigned irq */
} msi_attrib;
union {
u8 mask_pos;
void __iomem *mask_base;
};
};
};
#endif /* CONFIG_PCI_MSI */
};
>
> Thanks,
> Stuart
>
> On Sun, Jan 18, 2015 at 8:10 PM, Jiang Liu <jiang.liu at linux.intel.com> wrote:
>>
>>
>> On 2015/1/16 4:35, Stuart Yoder wrote:
>>> On Thu, Jan 8, 2015 at 11:06 AM, Marc Zyngier <marc.zyngier at arm.com> wrote:
>>>> 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 <marc.zyngier at arm.com>
>>>> ---
>>>> 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
>>
>>>
>>> Thanks,
>>> Stuart Yoder
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>>> the body of a message to majordomo at vger.kernel.org
>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>> Please read the FAQ at http://www.tux.org/lkml/
>>>
More information about the linux-arm-kernel
mailing list