The functions mbi_compose_m{b, s}i_msg may be called from non-preemptible
context. However, on RT, iommu_dma_map_msi_msg() requires to be called
from a preemptible context.
A recent patch split iommu_dma_map_msi_msg in two new functions:
one that should be called in preemptible context, the other does
not have any requirement.
The GICv3 MSI driver is reworked to avoid executing preemptible code in
non-preemptible context. This can be achieved by preparing the MSI
mapping when allocating the MSI interrupt.
Signed-off-by: Julien Grall <julien.grall@arm.com>
[maz: only call iommu_dma_prepare_msi once, fix commit log accordingly]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
The mbi_lock mutex is left uninitialized, so let's use DEFINE_MUTEX
to initialize it statically.
Fixes: 505287525c ("irqchip/gic-v3: Add support for Message Based Interrupts as an MSI controller")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
You would hope that if you have a GICv3 in your system, you'd use the ITS,
as it provides a large interrupt ID space and device isolation. Sadly,
some SoC integrations are less than perfect, and the ITS is not usesable on
those.
The only solution for these systems is to use the MBI interface, and
rely on a very small number of possible vectors.
This patch thus adds minimal support for PCI/MSI on top of the GICv3
MBI driver. Please don't use it if you can avoid it.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lkml.kernel.org/r/20180508121438.11301-9-marc.zyngier@arm.com
GICv3 offers the possibility to signal SPIs using a pair of doorbells
(SETPI, CLRSPI) under the name of Message Based Interrupts (MBI).
They can be used as either traditional (edge) MSIs, or the more exotic
level-triggered flavour.
Let's implement support for platform MSI, which is the original intent
for this feature.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Rob Herring <robh@kernel.org>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lkml.kernel.org/r/20180508121438.11301-8-marc.zyngier@arm.com
