[patch V1A 09/20] genirq/msi: Make msi_get_virq() device domain aware

Thomas Gleixner
2022-11-13T10:37:19Z

From: Ahmed S. Darwish <darwi@linutronix.de>

In preparation of the upcoming per device multi MSI domain support, change
the interface to support lookups based on domain id and zero based index
within the domain.

Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
V1A: Fix the locking leak and a operator precedence issue (Dan, kernel robot)

This was reported earlier and I missed to fold the fix before
posting. :(
---
include/linux/msi_api.h | 14 +++++++++++++-
kernel/irq/msi.c | 27 +++++++++++++++++++++------
2 files changed, 34 insertions(+), 7 deletions(-)

--- a/include/linux/msi_api.h
+++ b/include/linux/msi_api.h
@@ -18,6 +18,18 @@ enum msi_domain_ids {
MSI_MAX_DEVICE_IRQDOMAINS,
};

-unsigned int msi_get_virq(struct device *dev, unsigned int index);
+unsigned int msi_domain_get_virq(struct device *dev, unsigned int domid, unsigned int index);
+
+/**
+ * msi_get_virq - Lookup the Linux interrupt number for a MSI index on the default interrupt domain
+ * @dev: Device for which the lookup happens
+ * @index: The MSI index to lookup
+ *
+ * Return: The Linux interrupt number on success (> 0), 0 if not found
+ */
+static inline unsigned int msi_get_virq(struct device *dev, unsigned int index)
+{
+ return msi_domain_get_virq(dev, MSI_DEFAULT_DOMAIN, index);
+}

#endif
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -351,25 +351,38 @@ struct msi_desc *msi_next_desc(struct de
EXPORT_SYMBOL_GPL(msi_next_desc);

/**
- * msi_get_virq - Return Linux interrupt number of a MSI interrupt
+ * msi_domain_get_virq - Lookup the Linux interrupt number for a MSI index on a interrupt domain
* @dev: Device to operate on
+ * @domid: Domain ID of the interrupt domain associated to the device
* @index: MSI interrupt index to look for (0-based)
*
* Return: The Linux interrupt number on success (> 0), 0 if not found
*/
-unsigned int msi_get_virq(struct device *dev, unsigned int index)
+unsigned int msi_domain_get_virq(struct device *dev, unsigned int domid, unsigned int index)
{
struct msi_desc *desc;
unsigned int ret = 0;
- bool pcimsi;
+ bool pcimsi = false;
+ int base;

if (!dev->msi.data)
return 0;

- pcimsi = dev_is_pci(dev) ? to_pci_dev(dev)->msi_enabled : false;
+ if (WARN_ON_ONCE(index >= MSI_MAX_INDEX))
+ return 0;
+
+ /* This check is only valid for the PCI default MSI domain */
+ if (dev_is_pci(dev) && domid == MSI_DEFAULT_DOMAIN)
+ pcimsi = to_pci_dev(dev)->msi_enabled;

msi_lock_descs(dev);
- desc = xa_load(&dev->msi.data->__store, pcimsi ? 0 : index);
+
+ base = msi_get_domain_base_index(dev, domid);
+ if (base < 0)
+ goto unlock;
+
+ base += pcimsi ? 0 : index;
+ desc = xa_load(&dev->msi.data->__store, base);
if (desc && desc->irq) {
/*
* PCI-MSI has only one descriptor for multiple interrupts.
@@ -383,10 +396,12 @@ unsigned int msi_get_virq(struct device
ret = desc->irq;
}
}
+
+unlock:
msi_unlock_descs(dev);
return ret;
}
-EXPORT_SYMBOL_GPL(msi_get_virq);
+EXPORT_SYMBOL_GPL(msi_domain_get_virq);

#ifdef CONFIG_SYSFS
static struct attribute *msi_dev_attrs[] = {