Re: [PATCH 3/5] PCI: Set PCI_BUS_FLAGS_MSI_REMAP if MSI controller supports IRQ remapping
From: Bjorn Helgaas <helgaas@kernel.org>
Date: 2016-05-24 21:04:41
Also in:
kvm, linux-iommu, linux-pci, lkml
On Wed, Apr 27, 2016 at 08:43:28PM +0800, Yongji Xie wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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;
quoted hunk ↗ jump to hunk
#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN /** * pci_msi_domain_write_msg - Helper to write MSI message to PCI config spacediff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 6d7ab9b..25cf1b1 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c@@ -696,6 +696,9 @@ static void pci_set_bus_msi_domain(struct pci_bus *bus) if (!d) d = pci_host_bridge_msi_domain(b); + if (d && b == bus) + pci_bus_check_msi_remapping(bus, d); + dev_set_msi_domain(&bus->dev, d); }diff --git a/include/linux/msi.h b/include/linux/msi.h index 03eda72..b4c649e 100644 --- a/include/linux/msi.h +++ b/include/linux/msi.h@@ -15,6 +15,8 @@ extern int pci_msi_ignore_mask; struct irq_data; struct msi_desc; struct pci_dev; +struct pci_bus; +struct irq_domain; struct platform_msi_priv_data; void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg); void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg);@@ -155,6 +157,9 @@ void arch_restore_msi_irqs(struct pci_dev *dev); void default_teardown_msi_irqs(struct pci_dev *dev); void default_restore_msi_irqs(struct pci_dev *dev); +void pci_bus_check_msi_remapping(struct pci_bus *bus, + struct irq_domain *domain); + struct msi_controller { struct module *owner; struct device *dev;@@ -173,7 +178,6 @@ struct msi_controller { #include <linux/irqhandler.h> #include <asm/msi.h> -struct irq_domain; struct irq_domain_ops; struct irq_chip; struct device_node;-- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html