Similarly to PCI where msi-map/msi-mask are used to compute the full RID
(aka DID in ITS speak), use the msi-parent as the discovery mechanism,
since there is no way a device can generally express its ID.
However, since switching to a per-device MSI domain model, the domain
passed to its_pmsi_prepare() is the wrong one, and points to the device's
instead of the ITS'. Bad.
Use the parent domain instead, which is the ITS domain.
Fixes: 80b63cc1cc146 ("irqchip/gic-v3-its: Switch platform MSI to MSI parent")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240718075804.2245733-1-maz@kernel.org
Since 6adb35ff43a16 ("irqchip/gic-v3-its: Provide MSI parent for
PCI/MSI[-X]"), the primary domain a PCI device allocates its interrupts
from is the one that is directly attached to the device itself.
By virtue of being a PCI device, it has no OF node.
This domain is (through more layer than it is worth describing)
passed to its_pci_msi_prepare(), which tries to compute the
full RID that is presented to the ITS by the device. This is ultimately
done by calling pci_msi_domain_get_msi_rid(), passing both the
domain and the PCI device as arguments.
The baked-in assumption is that either the domain that is passed
to pci_msi_domain_get_msi_rid() describes an interrupt controller
with either an OF node or an entry in an ACPI IORT table.
In this case, it is *neither*. This domain is does not represent
anything firmware-based, but just an allocation unit for the device.
As a result, it fails to provide the full RID (which requires inspecting
the msi-map/msi-mask properties in the DT), and stick to the BDF, which
isn't very useful.
Tragedy follows with a litany of devices that randomly die as they fail to
see any MSI (because the RID is wrong) or fail to get an allocation
(because they try to steal LPIs from their neighbour's pool).
This will happen on any system where a single ITS is shared by multiple
root ports and end-points with overlapping BDF numbers, and has the
topology described in the device-tree. Simpler DT topologies will luckily
work, and so will ACPI-based systems.
Solve it by pointing pci_msi_domain_get_msi_rid() at the *parent* domain,
which is the ITS, resulting in a correct mapping and a restored happiness
in my personal zoo.
Fixes: 6adb35ff43a16 ("irqchip/gic-v3-its: Provide MSI parent for PCI/MSI[-X]")
Reported-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20240717195937.2240400-1-maz@kernel.org
Similar to the previous conversion of the PCI/MSI support lift the
prepare() callback from the existing platform MSI code and enable
platform MSI and the related device domain bus tokens in select
and the child domain initialization code.
All platform MSI users are automatically using the new per device MSI model
now.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Shivamurthy Shastri <shivamurthy.shastri@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240623142235.271734124@linutronix.de
The its_pci_msi_prepare() function from the ITS-PCI/MSI code provides the
'global' PCI/MSI domains. Move this function to the ITS-MSI parent code and
amend the function to use the domain hardware size, which is the MSI[X]
vector count, for allocating the ITS slots for the PCI device.
Enable PCI matching in msi_parent_ops and provide the necessary update to
the ITS specific child domain initialization function so that the prepare
callback gets invoked on allocations.
The latter might be optimized to do the allocation right at the point where
the child domain is initialized, but keep it simple for now.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Shivamurthy Shastri <shivamurthy.shastri@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240623142235.024567623@linutronix.de
To support per device MSI domains the ITS must provide MSI parent domain
functionality.
Provide the basic skeleton for this:
- msi_parent_ops
- child domain init callback
- the MSI parent flag set in irqdomain::flags
This does not make ITS a functional parent domain as there is no bit set in
the bus_select_mask yet, but it provides the base to implement PCI and
platform MSI support gradually on top.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Shivamurthy Shastri <shivamurthy.shastri@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240623142234.903076277@linutronix.de
