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path: root/drivers/irqchip/irq-msi-lib.c
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2025-09-09irqchip/msi-lib: Honor the MSI_FLAG_PCI_MSI_MASK_PARENT flagMarc Zyngier
For systems that implement interrupt masking at the interrupt controller level, the MSI library offers MSI_FLAG_PCI_MSI_MASK_PARENT. It indicates that it isn't enough to only unmask the interrupt at the PCI device level, but that the interrupt controller must also be involved. However, the way this is currently done is less than optimal, as the masking/unmasking is done on both sides, always. It would be far cheaper to unmask both at the start of times, and then only deal with the interrupt controller mask, which is cheaper than a round-trip to the PCI endpoint. Now that the PCI/MSI layer implements irq_startup() and irq_shutdown() callbacks, which [un]mask at the PCI level and honor the request to [un]mask the parent, this can be trivially done. Overwrite the irq_mask/unmask() callbacks of the device domain interrupt chip with irq_[un]mask_parent() when the parent domain asks for it. [ tglx: Adopted to the PCI/MSI changes ] Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Marc Zyngier <maz@kernel.org> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/all/20250903135433.380783272@linutronix.de
2025-08-05irqchip/msi-lib: Fix fwnode refcount in msi_lib_irq_domain_select()Lorenzo Pieralisi
Commit 8b65db1e93a2 ("irqchip/msi-lib: Add IRQ_DOMAIN_FLAG_FWNODE_PARENT handling") added logic in msi_lib_irq_domain_select() to match the domain fwnode against the fwnode parent of the fwspec.fwnode. The fwnode_get_parent() caller must call fwnode_handle_put() on the returned pointer value, lest fwnode refcounting for the parent ends up being out of kilter. Fix this by relying on the fwnode_handle clean-up handlers and by incrementing the fwnode refcount regardless of whether parent matching is used or not (the domain selection code already holds a reference before calling msi_lib_irq_domain_select() but to make the exit path more uniform if IRQ_DOMAIN_FLAG_FWNODE_PARENT is not set fwnode_handle_get() is called again on fwspec.fwnode so that the clean-up code is the same for the two matching patterns). Fixes: 8b65db1e93a2 ("irqchip/msi-lib: Add IRQ_DOMAIN_FLAG_FWNODE_PARENT handling") Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250804145553.795065-1-lpieralisi@kernel.org
2025-07-08irqchip/msi-lib: Add IRQ_DOMAIN_FLAG_FWNODE_PARENT handlingLorenzo Pieralisi
In some irqchip implementations the fwnode representing the IRQdomain and the MSI controller fwnode do not match; in particular the IRQdomain fwnode is the MSI controller fwnode parent. To support selecting such IRQ domains, add a flag in core IRQ domain code that explicitly tells the MSI lib to use the parent fwnode while carrying out IRQ domain selection. Update the msi-lib select callback with the resulting logic. 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-v7-27-12e71f1b3528@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-16irqchip/msi-lib: Honour the MSI_FLAG_NO_AFFINITY flagMarc Zyngier
Bad MSI implementations multiplex MSIs onto a single downstream interrupt, meaning they have no concept of individual affinity. The old MSI code did a reasonable job at this by honouring the MSI_FLAG_NO_AFFINITY, but the new shiny device MSI code doesn't. Teach it about the sad reality of existing hardware. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250513172819.2216709-7-maz@kernel.org
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
2025-02-20irqchip/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
2024-08-23irqchip/irq-msi-lib: Check for NULL ops in msi_lib_irq_domain_select()Maxime Chevallier
The irq_domain passed to msi_lib_irq_domain_select() may not have msi_parent_ops set. There is a NULL pointer check for it, but unfortunately there is a dereference of the parent ops pointer before that. Move the NULL pointer test before the first use of that pointer. This was found on a MacchiatoBin (Marvell Armada 8K SoC), which uses the irq-mvebu-sei driver. Fixes: 72e257c6f058 ("irqchip: Provide irq-msi-lib") Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20240823100733.1900666-1-maxime.chevallier@bootlin.com Closes: https://lore.kernel.org/all/20240821165034.1af97bad@fedora-3.home/
2024-07-18irqchip/imx-mu-msi: Switch to MSI parentThomas Gleixner
All platform MSI users and the PCI/MSI code handle per device MSI domains when the irqdomain associated to the device provides MSI parent functionality. Remove the "global" platform domain related code and provide the MSI parent functionality by filling in msi_parent_ops. 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/20240623142235.574932935@linutronix.de
2024-07-18irqchip/irq-msi-lib: Prepare for DOMAIN_BUS_WIRED_TO_MSIThomas Gleixner
Add the new bus token to the accepted list of child domain tokens. 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/20240623142235.207343466@linutronix.de
2024-07-18irqchip/irq-msi-lib: Prepare for DEVICE MSI to replace platform MSIThomas Gleixner
Add the prerequisites for DEVICE MSI into the shared select() and child domain init function. These domains are really trivial and just provide a custom irq chip callback to write the MSI message. 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/20240623142235.085171290@linutronix.de
2024-07-18irqchip/irq-msi-lib: Prepare for PCI MSI/MSIXThomas Gleixner
Add the bus tokens for DOMAIN_BUS_PCI_DEVICE_MSI and DOMAIN_BUS_PCI_DEVICE_MSIX to the common child init function. Provide the match mask which can be used by parent domain implementation so the bitmask based child bus token match works. 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/20240623142234.964056815@linutronix.de
2024-07-18irqchip: Provide irq-msi-libThomas Gleixner
All irqdomains which provide MSI parent domain functionality for per device MSI domains need to provide a select() callback for the irqdomain and a function to initialize the child domain. Most of these functions would just be copy&paste with minimal modifications, so provide a library function which implements the required functionality and is customizable via parent_domain::msi_parent_ops. The check for the supported bus tokens in msi_lib_init_dev_msi_info() is expanded step by step within the next patches. 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/20240623142234.840975799@linutronix.de