[tip: irq/core] genirq/msi: Provide constants for PCI/IMS support

[tip-bot2 for Thomas Gleixner]

The following commit has been merged into the irq/core branch of tip:

Commit-ID:     52a50e8785c28723c15867a07c5d5ee3b2ed1c25
Gitweb:        https://git.kernel.org/tip/52a50e8785c28723c15867a07c5d5ee3b2ed1c25
Author:        Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate:    Fri, 25 Nov 2022 00:26:28 +01:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Mon, 05 Dec 2022 19:21:04 +01:00

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@xxxxxxxxxxxxx>
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Acked-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20221124232326.846169830@xxxxxxxxxxxxx

---
 include/linux/irqdomain_defs.h | 1 +
 include/linux/msi.h            | 2 ++
 include/linux/msi_api.h        | 1 +
 3 files changed, 4 insertions(+)

diff --git a/include/linux/irqdomain_defs.h b/include/linux/irqdomain_defs.h
index 0b2d8a8..c29921f 100644
--- 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
--- 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
--- 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,
 };