genirq/msi: Provide constants for PCI/IMS support

Provide the necessary constants for PCI/IMS support:

  - A new bus token for MSI irqdomain identification
  - A MSI feature flag for the MSI irqdomains to signal support
  - A secondary domain id

The latter expands the device internal domain pointer storage array from 1
to 2 entries. That extra pointer is mostly unused today, but the
alternative solutions would not be free either and would introduce more
complexity all over the place. Trade the 8bytes for simplicity.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232326.846169830@linutronix.de

diff --git a/include/linux/irqdomain_defs.h b/include/linux/irqdomain_defs.h
index 0b2d8a8..c29921f 100644 (file)
--- a/include/linux/irqdomain_defs.h
+++ b/include/linux/irqdomain_defs.h
@@ -25,6 +25,7 @@ enum irq_domain_bus_token {
        DOMAIN_BUS_PCI_DEVICE_MSIX,
        DOMAIN_BUS_DMAR,
        DOMAIN_BUS_AMDVI,
+       DOMAIN_BUS_PCI_DEVICE_IMS,
 };
 
 #endif /* _LINUX_IRQDOMAIN_DEFS_H */

diff --git a/include/linux/msi.h b/include/linux/msi.h
index 3cb1586..a112b91 100644 (file)
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -559,6 +559,8 @@ enum {
        MSI_FLAG_MSIX_CONTIGUOUS        = (1 << 19),
        /* PCI/MSI-X vectors can be dynamically allocated/freed post MSI-X enable */
        MSI_FLAG_PCI_MSIX_ALLOC_DYN     = (1 << 20),
+       /* Support for PCI/IMS */
+       MSI_FLAG_PCI_IMS                = (1 << 21),
 };
 
 /**

diff --git a/include/linux/msi_api.h b/include/linux/msi_api.h
index 5ae72d1..391087a 100644 (file)
--- a/include/linux/msi_api.h
+++ b/include/linux/msi_api.h
@@ -15,6 +15,7 @@ struct device;
  */
 enum msi_domain_ids {
        MSI_DEFAULT_DOMAIN,
+       MSI_SECONDARY_DOMAIN,
        MSI_MAX_DEVICE_IRQDOMAINS,
 };