On 01/10/15 17:13, David Daney wrote:
> On 10/01/2015 02:24 AM, Marc Zyngier wrote:
>> Hi David,
>>
>> On 30/09/15 23:47, David Daney wrote:
>>> From: David Daney <david.daney@xxxxxxxxxx>
>>>
>>> Add pci_msi_domain_get_msi_rid() to return the MSI requester id (RID).
>>> Initially needed by gic-v3 based systems. It will be used by follow on
>>> patch to drivers/irqchip/irq-gic-v3-its-pci-msi.c
>>>
>>> Initially supports mapping the RID via OF device tree. In the future,
>>> this could be extended to use ACPI _IORT tables as well.
>>>
>>> Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
>>> ---
>>> drivers/pci/msi.c | 31 +++++++++++++++++++++++++++++++
>>> include/linux/msi.h | 1 +
>>> 2 files changed, 32 insertions(+)
>>>
>>> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
>>> index d449714..92b6dc9 100644
>>> --- a/drivers/pci/msi.c
>>> +++ b/drivers/pci/msi.c
>>> @@ -20,6 +20,7 @@
>>> #include <linux/io.h>
>>> #include <linux/slab.h>
>>> #include <linux/irqdomain.h>
>>> +#include <linux/of_irq.h>
>>>
>>> #include "pci.h"
>>>
>>> @@ -1327,4 +1328,34 @@ struct irq_domain *pci_msi_create_default_irq_domain(struct device_node *node,
>>>
>>> return domain;
>>> }
>>> +
>>> +struct get_mis_id_data {
>>> + u32 alias;
>>> +};
>>> +
>>> +static int get_msi_id_cb(struct pci_dev *pdev, u16 alias, void *data)
>>> +{
>>> + struct get_mis_id_data *s = data;
>>> +
>>> + s->alias = alias;
>>> + return 0;
>>> +}
>>
>> Why not use a naked u32, since you only have a single field in this
>> structure? Or is it that you are anticipating other fields there?
>
> In this case, I think using a pointer to u32 is a good idea. It would
> simplify the source code somewhat. Although, I think the generated
> binary would likely be the same. I don't foresee adding things to this
> structure. If it becomes necessary in the future, we can just go back
> to using a pointer to a structure.
>
>>
>>> +/**
>>> + * pci_msi_domain_get_msi_rid - Get the MSI requester id (RID)
>>> + * @domain: The interrupt domain
>>> + * @pdev: The PCI device.
>>> + *
>>> + * The RID for a device is formed from the alias, with a firmware
>>> + * supplied mapping applied
>>> + *
>>> + * Returns: The RID.
>>> + */
>>> +u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
>>> +{
>>> + struct get_mis_id_data d;
>>> +
>>> + d.alias = 0;
>>> + pci_for_each_dma_alias(pdev, get_msi_id_cb, &d);
>>> + return of_msi_map_rid(&pdev->dev, domain->of_node, d.alias);
>>
>> Should you check whether domain->of_node is NULL first? I don't think
>> of_msi_map_rid would have any problem with that, but a domain that is
>> not backed by an of_node makes me feel a bit uneasy and would tend to
>> indicate that we're not using DT.
>
> Yes, that makes sense. As you observe, I think it probably works as is,
> but it would be good to make it more clear. This is especially true
> when we add ACPI support. We will want to be clear on which of
> device-tree or ACPI we are using.
>
>
>>
>>> +}
>>> #endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */
>>> diff --git a/include/linux/msi.h b/include/linux/msi.h
>>> index ad939d0..56e3b76 100644
>>> --- a/include/linux/msi.h
>>> +++ b/include/linux/msi.h
>>> @@ -293,6 +293,7 @@ irq_hw_number_t pci_msi_domain_calc_hwirq(struct pci_dev *dev,
>>> struct msi_desc *desc);
>>> int pci_msi_domain_check_cap(struct irq_domain *domain,
>>> struct msi_domain_info *info, struct device *dev);
>>> +u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev);
>>> #endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */
>>>
>>> #endif /* LINUX_MSI_H */
>>>
>>
>> Otherwise looks good to me.
>
> I will send what I hope is the final revision of the patches later today.
Excellent. In related news, I've rebased my msi-parent stuff on top of
this series, and extended it to also deal with msi-map for matching MSI
domains.
With the two series, we should now have something vaguely coherent that
deals with both the old version of msi-parent, its new definition, and
msi-map in its whole glory. Fun times!
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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