On 2016/5/25 5:04, Bjorn Helgaas wrote:
On Wed, Apr 27, 2016 at 08:43:28PM +0800, Yongji Xie wrote:
On ARM HW the capability of IRQ remapping is abstracted on
MSI controller side. MSI_FLAG_IRQ_REMAPPING is used to advertise
this [1].
To have a universal flag to test this capability for different
archs on PCI side, we set PCI_BUS_FLAGS_MSI_REMAP for PCI buses
when MSI_FLAG_IRQ_REMAPPING is set.
[1] http://www.spinics.net/lists/kvm/msg130256.html
Signed-off-by: Yongji Xie <xyjxie@xxxxxxxxxxxxxxxxxx>
---
drivers/pci/msi.c | 12 ++++++++++++
drivers/pci/probe.c | 3 +++
include/linux/msi.h | 6 +++++-
3 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index a080f44..1661cdf 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1134,6 +1134,18 @@ void *msi_desc_to_pci_sysdata(struct msi_desc *desc)
}
EXPORT_SYMBOL_GPL(msi_desc_to_pci_sysdata);
+void pci_bus_check_msi_remapping(struct pci_bus *bus,
+ struct irq_domain *domain)
+{
+#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
+ struct msi_domain_info *info;
+
+ info = msi_get_domain_info(domain);
+ if (info->flags & MSI_FLAG_IRQ_REMAPPING)
+ bus->bus_flags |= PCI_BUS_FLAGS_MSI_REMAP;
+#endif
+}
Functions named "check_foo" are a pet peeve of mine because the name
doesn't tell us anything about what the function *does*. In this
case, we know it checks something about MSI remapping, but we don't
know whether we're checking whether it's enabled, disabled, or some
other property.
I'd prefer something like:
int pci_bus_msi_isolated(struct pci_bus *bus, struct irq_domain *domain)
{
struct msi_domain_info *info;
if (!domain)
return 0;
info = msi_get_domain_info(domain);
if (info->flags & MSI_FLAG_IRQ_REMAPPING)
return 1;
return 0;
}
void pci_set_bus_msi_domain(struct pci_bus *bus)
{
...
if (b == bus && pci_bus_msi_isolated(bus, d))
bus->bus_flags |= PCI_BUS_FLAGS_MSI_REMAP;
Yes. This looks more reasonable. Thank you!
Regards,
Yongji
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