From: Nam Cao <namcao@linutronix.de>
To: Madhavan Srinivasan <maddy@linux.ibm.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Nicholas Piggin <npiggin@gmail.com>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
Thomas Gleixner <tglx@linutronix.de>,
Marc Zyngier <maz@kernel.org>,
Gautam Menghani <gautam@linux.ibm.com>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Cc: Nam Cao <namcao@linutronix.de>
Subject: [PATCH v2 0/3] powerpc: Cleanup and convert to MSI parent domain
Date: Mon, 11 Aug 2025 11:28:53 +0200 [thread overview]
Message-ID: <cover.1754903590.git.namcao@linutronix.de> (raw)
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
v2: Fix up boot issue with NVMe
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 | 132 ++++++++--------------
arch/powerpc/sysdev/xive/common.c | 63 +++++------
7 files changed, 117 insertions(+), 179 deletions(-)
--
2.39.5
next reply other threads:[~2025-08-11 9:29 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-11 9:28 Nam Cao [this message]
2025-08-11 9:28 ` [PATCH v2 1/3] powerpc/xive: Untangle xive from child interrupt controller drivers Nam Cao
2025-10-07 3:24 ` Ritesh Harjani
2025-10-07 5:24 ` Nam Cao
2025-10-07 15:08 ` Nam Cao
2025-08-11 9:28 ` [PATCH v2 2/3] powerpc/powernv/pci: Switch to use msi_create_parent_irq_domain() Nam Cao
2025-08-11 9:28 ` [PATCH v2 3/3] powerpc/pseries/msi: Switch to msi_create_parent_irq_domain() Nam Cao
2025-09-03 14:07 ` [PATCH v2 0/3] powerpc: Cleanup and convert to MSI parent domain Thomas Gleixner
2025-09-06 11:48 ` Madhavan Srinivasan
2025-09-12 3:56 ` Madhavan Srinivasan
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