linux/kernel/irq
Thomas Gleixner 3d393b2174 genirq/msi: Provide msi_domain_alloc_irq_at()
For supporting post MSI-X enable allocations and for the upcoming PCI/IMS
support a separate interface is required which allows not only the
allocation of a specific index, but also the allocation of any, i.e. the
next free index. The latter is especially required for IMS because IMS
completely does away with index to functionality mappings which are
often found in MSI/MSI-X implementation.

But even with MSI-X there are devices where only the first few indices have
a fixed functionality and the rest is freely assignable by software,
e.g. to queues.

msi_domain_alloc_irq_at() is also different from the range based interfaces
as it always enforces that the MSI descriptor is allocated by the core code
and not preallocated by the caller like the PCI/MSI[-X] enable code path
does.

msi_domain_alloc_irq_at() can be invoked with the index argument set to
MSI_ANY_INDEX which makes the core code pick the next free index. The irq
domain can provide a prepare_desc() operation callback in it's
msi_domain_ops to do domain specific post allocation initialization before
the actual Linux interrupt and the associated interrupt descriptor and
hierarchy alloccations are conducted.

The function also takes an optional @icookie argument which is of type
union msi_instance_cookie. This cookie is not used by the core code and is
stored in the allocated msi_desc::data::icookie. The meaning of the cookie
is completely implementation defined. In case of IMS this might be a PASID
or a pointer to a device queue, but for the MSI core it's opaque and not
used in any way.

The function returns a struct msi_map which on success contains the
allocated index number and the Linux interrupt number so the caller can
spare the index to Linux interrupt number lookup.

On failure map::index contains the error code and map::virq is 0.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232326.501359457@linutronix.de
2022-12-05 22:22:34 +01:00
..
affinity.c irqchip updates for 5.19: 2022-05-20 18:48:54 +02:00
autoprobe.c genirq: Delay deactivation in free_irq() 2019-07-03 10:12:28 +02:00
chip.c genirq/irqdomain: Rename irq_domain::dev to irq_domain:: Pm_dev 2022-12-05 19:20:58 +01:00
cpuhotplug.c sched/isolation: Use single feature type while referring to housekeeping cpumask 2022-02-16 15:57:55 +01:00
debug.h Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk 2018-02-01 13:36:15 -08:00
debugfs.c genirq: Return a const cpumask from irq_data_get_affinity_mask 2022-07-07 09:38:04 +01:00
devres.c genirq/devres: Use struct_size() in devm_kzalloc() 2019-04-16 21:54:03 +02:00
dummychip.c irq: Fix typos in comments 2021-03-22 04:23:14 +01:00
generic-chip.c genirq/generic_chip: Export irq_unmap_generic_chip 2022-07-20 12:05:55 +01:00
handle.c irq: remove unused flags argument from __handle_irq_event_percpu() 2022-01-07 00:25:25 +01:00
internals.h genirq/irqdesc: Don't try to remove non-existing sysfs files 2022-11-30 14:52:11 +01:00
ipi.c genirq: Return a const cpumask from irq_data_get_affinity_mask 2022-07-07 09:38:04 +01:00
irq_sim.c genirq/irq_sim: Make the irq_work always run in hard irq context 2022-05-14 17:48:27 +02:00
irqdesc.c genirq/irqdesc: Don't try to remove non-existing sysfs files 2022-11-30 14:52:11 +01:00
irqdomain.c irqdomain: Use hwirq_max instead of revmap_size for NOMAP domains 2022-07-19 14:51:56 +01:00
Kconfig genirq: Get rid of GENERIC_MSI_IRQ_DOMAIN 2022-11-17 15:15:20 +01:00
Makefile genirq/timings: Add selftest for circular array 2019-06-12 10:47:04 +02:00
manage.c genirq: Remove unused argument force of irq_set_affinity_deactivated() 2022-11-17 14:00:55 +01:00
matrix.c genirq/matrix: Remove redundant assignment to variable 'end' 2022-04-25 15:02:57 +02:00
migration.c genirq: Fix typos and misspellings in comments 2021-03-16 15:08:29 +01:00
msi.c genirq/msi: Provide msi_domain_alloc_irq_at() 2022-12-05 22:22:34 +01:00
pm.c genirq/PM: Unexport {suspend,resume}_device_irqs() 2022-06-13 12:27:37 +02:00
proc.c proc: remove PDE_DATA() completely 2022-01-22 08:33:37 +02:00
resend.c genirq: Fix typos and misspellings in comments 2021-03-16 15:08:29 +01:00
settings.h genirq: Add a IRQF_NO_DEBUG flag 2021-05-17 20:01:35 +02:00
spurious.c genirq: Disable irqfixup/poll on PREEMPT_RT. 2021-09-19 23:01:15 +02:00
timings.c Updates to the interrupt core and driver subsystems: 2021-08-30 14:38:37 -07:00