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
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
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
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
