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2025-07-08irqchip/gic-v3: Rename GICv3 ITS MSI parentLorenzo Pieralisi
The GICv5 ITS will reuse some GICv3 ITS MSI parent functions therefore it makes sense to keep the code functionality in a compilation unit shared by the two drivers. Rename the GICv3 ITS MSI parent file and update the related Kconfig/Makefile entries to pave the way for code sharing. Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org> Reviewed-by: Marc Zyngier <maz@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250703-gicv5-host-v7-26-12e71f1b3528@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-27Merge tag 'irq-msi-2025-05-25' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull MSI updates from Thomas Gleixner: "Updates for the MSI subsystem (core code and PCI): - Switch the MSI descriptor locking to lock guards - Replace a broken and naive implementation of PCI/MSI-X control word updates in the PCI/TPH driver with a properly serialized variant in the PCI/MSI core code. - Remove the MSI descriptor abuse in the SCCI/UFS/QCOM driver by replacing the direct access to the MSI descriptors with the proper API function calls. People will never understand that APIs exist for a reason... - Provide core infrastructre for the upcoming PCI endpoint library extensions. Currently limited to ARM GICv3+, but in theory extensible to other architectures. - Provide a MSI domain::teardown() callback, which allows drivers to undo the effects of the prepare() callback. - Move the MSI domain::prepare() callback invocation to domain creation time to avoid redundant (and in case of ARM/GIC-V3-ITS confusing) invocations on every allocation. In combination with the new teardown callback this removes some ugly hacks in the GIC-V3-ITS driver, which pretended to work around the short comings of the core code so far. With this update the code is correct by design and implementation. - Make the irqchip MSI library globally available, provide a MSI parent domain creation helper and convert a bunch of (PCI/)MSI drivers over to the modern MSI parent mechanism. This is the first step to get rid of at least one incarnation of the three PCI/MSI management schemes. - The usual small cleanups and improvements" * tag 'irq-msi-2025-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits) PCI/MSI: Use bool for MSI enable state tracking PCI: tegra: Convert to MSI parent infrastructure PCI: xgene: Convert to MSI parent infrastructure PCI: apple: Convert to MSI parent infrastructure irqchip/msi-lib: Honour the MSI_FLAG_NO_AFFINITY flag irqchip/mvebu: Convert to msi_create_parent_irq_domain() helper irqchip/gic: Convert to msi_create_parent_irq_domain() helper genirq/msi: Add helper for creating MSI-parent irq domains irqchip: Make irq-msi-lib.h globally available irqchip/gic-v3-its: Use allocation size from the prepare call genirq/msi: Engage the .msi_teardown() callback on domain removal genirq/msi: Move prepare() call to per-device allocation irqchip/gic-v3-its: Implement .msi_teardown() callback genirq/msi: Add .msi_teardown() callback as the reverse of .msi_prepare() irqchip/gic-v3-its: Add support for device tree msi-map and msi-mask dt-bindings: PCI: pci-ep: Add support for iommu-map and msi-map irqchip/gic-v3-its: Set IRQ_DOMAIN_FLAG_MSI_IMMUTABLE for ITS irqdomain: Add IRQ_DOMAIN_FLAG_MSI_IMMUTABLE and irq_domain_is_msi_immutable() platform-msi: Add msi_remove_device_irq_domain() in platform_device_msi_free_irqs_all() genirq/msi: Rename msi_[un]lock_descs() ...
2025-05-16irqchip: Make irq-msi-lib.h globally availableMarc Zyngier
Move irq-msi-lib.h into include/linux/irqchip, making it available to compilation units outside of drivers/irqchip. This requires some churn in drivers to fetch it from the new location, generated using this script: git grep -l -w \"irq-msi-lib.h\" | \ xargs sed -i -e 's:"irq-msi-lib.h":\<linux/irqchip/irq-msi-lib.h\>:' Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250513172819.2216709-2-maz@kernel.org
2025-05-14irqchip: Drop MSI_CHIP_FLAG_SET_ACK from unsuspecting MSI driversMarc Zyngier
Commit 1c000dcaad2be ("irqchip/irq-msi-lib: Optionally set default irq_eoi()/irq_ack()") added blanket MSI_CHIP_FLAG_SET_ACK flags, irrespective of whether the underlying irqchip required it or not. Drop it from a number of drivers that do not require it. Fixes: 1c000dcaad2be ("irqchip/irq-msi-lib: Optionally set default irq_eoi()/irq_ack()") Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250513172819.2216709-6-maz@kernel.org
2025-05-14irqchip/gic-v3-its: Use allocation size from the prepare callMarc Zyngier
Now that .msi_prepare() gets called at the right time and not with semi-random parameters, remove the ugly hack that tried to fix up the number of allocated vectors. It is now correct by construction. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250513163144.2215824-6-maz@kernel.org
2025-05-14irqchip/gic-v3-its: Implement .msi_teardown() callbackMarc Zyngier
The ITS driver currently nukes the structure representing an endpoint device translating via an ITS on freeing the last LPI allocated for it. That's an unfortunate state of affair, as it is pretty common for a driver to allocate a single MSI, do something clever, teardown this MSI, and reallocate a whole bunch of them. The NVME driver does exactly that, amongst others. What happens in that case is that the core code is accidentaly issuing another .msi_prepare() call, even if it shouldn't. This luckily cancels the above behaviour and hides the problem. In order to fix the core code, start by implementing the new .msi_teardown() callback. Nothing calls it yet, so a side effect is that the its_dev structure will not be freed and that the DID will stay mapped. Not a big deal, and this will be solved in following patches. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250513163144.2215824-3-maz@kernel.org
2025-05-07irqchip/gic-v3-its: Add support for device tree msi-map and msi-maskFrank Li
Some platform devices create child devices dynamically and require the parent device's msi-map to map device IDs to actual sideband information. A typical use case is using ITS as a PCIe Endpoint Controller(EPC)'s doorbell function, where PCI hosts send TLP memory writes to the EP controller. The EP controller converts these writes to AXI transactions and appends platform-specific sideband information. EPC's DTS will provide such information by msi-map and msi-mask. A simplified dts as pcie-ep@10000000 { ... msi-map = <0 &its 0xc 8>; ^^^ 0xc is implement defined sideband information, which append to AXI write transaction. ^ 0 is function index. msi-mask = <0x7> } Check msi-map if msi-parent missed to keep compatility with existing systems. Signed-off-by: Frank Li <Frank.Li@nxp.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250414-ep-msi-v18-5-f69b49917464@nxp.com
2025-02-20irqchip/irq-msi-lib: Optionally set default irq_eoi()/irq_ack()Thomas Gleixner
msi_lib_init_dev_msi_info() sets the default irq_eoi()/irq_ack() callbacks unconditionally. This is correct for all existing users, but prevents the IMSIC driver to be moved to the MSI library implementation. Introduce chip_flags in struct msi_parent_ops, which instruct the library to selectively set the callbacks depending on the flags, and update all current users to set them. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250217085657.789309-3-apatel@ventanamicro.com
2024-07-18irqchip/gic-v3-its: Correctly fish out the DID for platform MSIMarc Zyngier
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
2024-07-18irqchip/gic-v3-its: Correctly honor the RID remappingMarc Zyngier
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
2024-07-18irqchip/gic-v3-its: Switch platform MSI to MSI parentThomas Gleixner
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
2024-07-18irqchip/gic-v3-its: Provide MSI parent for PCI/MSI[-X]Thomas Gleixner
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
2024-07-18irqchip/gic-v3-its: Provide MSI parent infrastructureThomas Gleixner
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