[PATCH 0/3] powerpc: Cleanup and convert to MSI parent domain
Nam Cao
namcao at linutronix.de
Fri Jun 27 00:47:39 AEST 2025
The initial implementation of PCI/MSI interrupt domains in the hierarchical
interrupt domain model used a shortcut by providing a global PCI/MSI
domain.
This works because the PCI/MSI[X] hardware is standardized and uniform, but
it violates the basic design principle of hierarchical interrupt domains:
Each hardware block involved in the interrupt delivery chain should have a
separate interrupt domain.
For PCI/MSI[X], the interrupt controller is per PCI device and not a global
made-up entity.
Unsurprisingly, the shortcut turned out to have downsides as it does not
allow dynamic allocation of interrupt vectors after initialization and it
prevents supporting IMS on PCI. For further details, see:
https://lore.kernel.org/lkml/20221111120501.026511281@linutronix.de/
The solution is implementing per device MSI domains, this means the
entities which provide global PCI/MSI domain so far have to implement MSI
parent domain functionality instead.
This series:
- Untangle XIVE driver from Powernv and Pseries drivers
- Convert the Powernv and Pseries drivers to implement MSI parent domain
functionality
Nam Cao (3):
powerpc/xive: Untangle xive from child interrupt controller drivers
powerpc/powernv/pci: Switch to use msi_create_parent_irq_domain()
powerpc/pseries/msi: Switch to msi_create_parent_irq_domain()
arch/powerpc/include/asm/pci-bridge.h | 2 -
arch/powerpc/include/asm/xive.h | 1 -
arch/powerpc/platforms/powernv/Kconfig | 1 +
arch/powerpc/platforms/powernv/pci-ioda.c | 96 ++++++-----------
arch/powerpc/platforms/pseries/Kconfig | 1 +
arch/powerpc/platforms/pseries/msi.c | 124 ++++++++--------------
arch/powerpc/sysdev/xive/common.c | 63 ++++++-----
7 files changed, 113 insertions(+), 175 deletions(-)
--
2.39.5
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