linux.git/kernel/irq/msi.c, branch v6.11

genirq/msi: Move msi_device_data to core

2024-07-18T18:31:21+00:00

Now that the platform MSI hack is gone, nothing needs to know about struct
msi_device_data outside of the core code.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Anna-Maria Behnsen 
Signed-off-by: Shivamurthy Shastri 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20240623142236.003295177@linutronix.de

genirq/msi: Remove platform MSI leftovers

2024-07-18T18:31:21+00:00

No more users!

Signed-off-by: Thomas Gleixner 
Signed-off-by: Anna-Maria Behnsen 
Signed-off-by: Shivamurthy Shastri 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Greg Kroah-Hartman 
Link: https://lore.kernel.org/r/20240623142235.943295676@linutronix.de

genirq/msi: Add MSI allocation helper and export MSI functions

2024-04-23T20:27:52+00:00

MSI functions for allocation and free can be directly used by
the device drivers without any wrapper provided by bus drivers.
So export these MSI functions.

Also, add a wrapper API to allocate MSIs providing only the
number of interrupts rather than range for simpler driver usage.

Signed-off-by: Nipun Gupta 
Reviewed-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20240423111021.1686144-1-nipun.gupta@amd.com
Signed-off-by: Alex Williamson

genirq/msi: Provide MSI_FLAG_PARENT_PM_DEV

2024-02-15T16:55:41+00:00

Some platform-MSI implementations require that power management is
redirected to the underlying interrupt chip device. To make this work
with per device MSI domains provide a new feature flag and let the
core code handle the setup of dev->pm_dev when set during device MSI
domain creation.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Anup Patel 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20240127161753.114685-14-apatel@ventanamicro.com

genirq/msi: Provide allocation/free functions for "wired" MSI interrupts

2024-02-15T16:55:41+00:00

To support wire to MSI bridges proper in the MSI core infrastructure it is
required to have separate allocation/free interfaces which can be invoked
from the regular irqdomain allocaton/free functions.

The mechanism for allocation is:
  - Allocate the next free MSI descriptor index in the domain
  - Store the hardware interrupt number and the trigger type
    which was extracted by the irqdomain core from the firmware spec
    in the MSI descriptor device cookie so it can be retrieved by
    the underlying interrupt domain and interrupt chip
  - Use the regular MSI allocation mechanism for the newly allocated
    index which returns a fully initialized Linux interrupt on succes

This works because:
  - the domains have a fixed size
  - each hardware interrupt is only allocated once
  - the underlying domain does not care about the MSI index it only cares
    about the hardware interrupt number and the trigger type

The free function looks up the MSI index in the MSI descriptor of the
provided Linux interrupt number and uses the regular index based free
functions of the MSI core.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Anup Patel 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20240127161753.114685-12-apatel@ventanamicro.com

genirq/msi: Optionally use dev->fwnode for device domain

2024-02-15T16:55:41+00:00

To support wire to MSI domains via the MSI infrastructure it is required to
use the firmware node of the device which implements this for creating the
MSI domain. Otherwise the existing firmware match mechanisms to find the
correct irqdomain for a wired interrupt which is connected to a wire to MSI
bridge would fail.

This cannot be used for the general case because not all devices provide
firmware nodes and all regular per device MSI domains are directly
associated to the device and have not be searched for.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Anup Patel 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20240127161753.114685-11-apatel@ventanamicro.com

genirq/msi: Split msi_domain_alloc_irq_at()

2024-02-15T16:55:40+00:00

In preparation for providing a special allocation function for wired
interrupts which are connected to a wire to MSI bridge, split the inner
workings of msi_domain_alloc_irq_at() out into a helper function so the
code can be shared.

No functional change.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Anup Patel 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20240127161753.114685-9-apatel@ventanamicro.com

genirq/msi: Provide optional translation op

2024-02-15T16:55:40+00:00

irq_create_fwspec_mapping() requires translation of the firmware spec to a
hardware interrupt number and the trigger type information.

Wired interrupts which are connected to a wire to MSI bridge, like MBIGEN
are allocated that way. So far MBIGEN provides a regular irqdomain which
then hooks backwards into the MSI infrastructure. That's an unholy mess and
will be replaced with per device MSI domains which are regular MSI domains.

Interrupts on MSI domains are not supported by irq_create_fwspec_mapping(),
but for making the wire to MSI bridges sane it makes sense to provide a
special allocation/free interface in the MSI infrastructure. That avoids
the backdoors into the core MSI allocation code and just shares all the
regular MSI infrastructure.

Provide an optional translation callback in msi_domain_ops which can be
utilized by these wire to MSI bridges. No other MSI domain should provide a
translation callback. The default translation callback of the MSI
irqdomains will warn when it is invoked on a non-prepared MSI domain.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Anup Patel 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20240127161753.114685-8-apatel@ventanamicro.com

x86/apic/msi: Fix misconfigured non-maskable MSI quirk

2023-10-26T11:53:06+00:00

commit ef8dd01538ea ("genirq/msi: Make interrupt allocation less
convoluted"), reworked the code so that the x86 specific quirk for affinity
setting of non-maskable PCI/MSI interrupts is not longer activated if
necessary.

This could be solved by restoring the original logic in the core MSI code,
but after a deeper analysis it turned out that the quirk flag is not
required at all.

The quirk is only required when the PCI/MSI device cannot mask the MSI
interrupts, which in turn also prevents reservation mode from being enabled
for the affected interrupt.

This allows ot remove the NOMASK quirk bit completely as msi_set_affinity()
can instead check whether reservation mode is enabled for the interrupt,
which gives exactly the same answer.

Even in the momentary non-existing case that the reservation mode would be
not set for a maskable MSI interrupt this would not cause any harm as it
just would cause msi_set_affinity() to go needlessly through the
functionaly equivalent slow path, which works perfectly fine with maskable
interrupts as well.

Rework msi_set_affinity() to query the reservation mode and remove all
NOMASK quirk logic from the core code.

[ tglx: Massaged changelog ]

Fixes: ef8dd01538ea ("genirq/msi: Make interrupt allocation less convoluted")
Suggested-by: Thomas Gleixner 
Signed-off-by: Koichiro Den 
Signed-off-by: Thomas Gleixner 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231026032036.2462428-1-den@valinux.co.jp

x86/pci/xen: populate MSI sysfs entries

2023-05-24T16:08:49+00:00

Commit bf5e758f02fc ("genirq/msi: Simplify sysfs handling") reworked the
creation of sysfs entries for MSI IRQs. The creation used to be in
msi_domain_alloc_irqs_descs_locked after calling ops->domain_alloc_irqs.
Then it moved into __msi_domain_alloc_irqs which is an implementation of
domain_alloc_irqs. However, Xen comes with the only other implementation
of domain_alloc_irqs and hence doesn't run the sysfs population code
anymore.

Commit 6c796996ee70 ("x86/pci/xen: Fixup fallout from the PCI/MSI
overhaul") set the flag MSI_FLAG_DEV_SYSFS for the xen msi_domain_info
but that doesn't actually have an effect because Xen uses it's own
domain_alloc_irqs implementation.

Fix this by making use of the fallback functions for sysfs population.

Fixes: bf5e758f02fc ("genirq/msi: Simplify sysfs handling")
Signed-off-by: Maximilian Heyne 
Reviewed-by: Juergen Gross 
Link: https://lore.kernel.org/r/20230503131656.15928-1-mheyne@amazon.de
Signed-off-by: Juergen Gross