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From:   Alexey Kardashevskiy <aik@ozlabs.ru>
To:     linuxppc-dev@lists.ozlabs.org
Cc:     =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= <clg@kaod.org>,
        "Oliver O'Halloran" <oohall@gmail.com>,
        Marc Zyngier <maz@kernel.org>,
        Michael Ellerman <mpe@ellerman.id.au>, Qian Cai <cai@lca.pw>,
        Rob Herring <robh@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-kernel@vger.kernel.org,
        Frederic Barrat <fbarrat@linux.ibm.com>,
        =?UTF-8?q?Michal=20Such=C3=A1nek?= <msuchanek@suse.de>,
        Alexey Kardashevskiy <aik@ozlabs.ru>
Subject: [RFC PATCH kernel 0/2] irq: Add reference counting to IRQ mappings
Date:   Tue, 27 Oct 2020 20:06:53 +1100
Message-Id: <20201027090655.14118-1-aik@ozlabs.ru>
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This is an attempt to fix a bug with PCI hot unplug with
a bunch of PCIe bridges and devices sharing INTx.

This did not hit us before as even if we did not
call irq_domain_ops::unmap, the platform (PowerVM) would not
produce an error but with POWER9's XIVE interrupt controller
there is an error if unmap is not called at all (2/2 fixes that)
or an error if we unmapped an interrupt which is still in use
by another device (1/2 fixes that).

One way of fixing that is doing reference counting in
the POWERPC code but since there is a kobj in irq_desc
already, I thought I'll give it a try first.


This is based on sha1
4525c8781ec0 Linus Torvalds "scsi: qla2xxx: remove incorrect sparse #ifdef".

Please comment. Thanks.


Alexey Kardashevskiy (1):
  irq: Add reference counting to IRQ mappings

Oliver O'Halloran (1):
  powerpc/pci: Remove LSI mappings on device teardown

 arch/powerpc/kernel/pci-common.c | 21 +++++++++++++++++++
 kernel/irq/irqdesc.c             | 35 +++++++++++++++++++++-----------
 kernel/irq/irqdomain.c           | 27 ++++++++++++------------
 3 files changed, 57 insertions(+), 26 deletions(-)

-- 
2.17.1