starfive-tech/linux.git/include/linux/msi.h, branch visionfive_v1_5.13

PCI/MSI: Protect msi_desc::masked for multi-MSI

2021-08-18T07:07:06+00:00

commit 77e89afc25f30abd56e76a809ee2884d7c1b63ce upstream. Multi-MSI uses a single MSI descriptor and there is a single mask register when the device supports per vector masking. To avoid reading back the mask register the value is cached in the MSI descriptor and updates are done by clearing and setting bits in the cache and writing it to the device. But nothing protects msi_desc::masked and the mask register from being modified concurrently on two different CPUs for two different Linux interrupts which belong to the same multi-MSI descriptor. Add a lock to struct device and protect any operation on the mask and the mask register with it. This makes the update of msi_desc::masked unconditional, but there is no place which requires a modification of the hardware register without updating the masked cache. msi_mask_irq() is now an empty wrapper which will be cleaned up in follow up changes. The problem goes way back to the initial support of multi-MSI, but picking the commit which introduced the mask cache is a valid cut off point (2.6.30). Fixes: f2440d9acbe8 ("PCI MSI: Refactor interrupt masking code") Signed-off-by: Thomas Gleixner Tested-by: Marc Zyngier Reviewed-by: Marc Zyngier Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210729222542.726833414@linutronix.de Signed-off-by: Greg Kroah-Hartman

PCI/MSI: Kill default_teardown_msi_irqs()

2021-04-20T13:11:22+00:00

It doesn't have any caller left. Link: https://lore.kernel.org/r/20210330151145.997953-10-maz@kernel.org Signed-off-by: Marc Zyngier Signed-off-by: Lorenzo Pieralisi Acked-by: Bjorn Helgaas

PCI/MSI: Kill msi_controller structure

2021-04-20T13:11:22+00:00

msi_controller had a good, long life as the abstraction for a driver providing MSIs to PCI devices. But it has been replaced in all drivers by the more expressive generic MSI framework. Farewell, struct msi_controller. Link: https://lore.kernel.org/r/20210330151145.997953-9-maz@kernel.org Signed-off-by: Marc Zyngier Signed-off-by: Lorenzo Pieralisi Acked-by: Bjorn Helgaas

genirq/msi: Activate Multi-MSI early when MSI_FLAG_ACTIVATE_EARLY is set

2021-01-30T00:22:31+00:00

When MSI_FLAG_ACTIVATE_EARLY is set (which is the case for PCI), __msi_domain_alloc_irqs() performs the activation of the interrupt (which in the case of PCI results in the endpoint being programmed) as soon as the interrupt is allocated. But it appears that this is only done for the first vector, introducing an inconsistent behaviour for PCI Multi-MSI. Fix it by iterating over the number of vectors allocated to each MSI descriptor. This is easily achieved by introducing a new "for_each_msi_vector" iterator, together with a tiny bit of refactoring. Fixes: f3b0946d629c ("genirq/msi: Make sure PCI MSIs are activated early") Reported-by: Shameer Kolothum Signed-off-by: Marc Zyngier Signed-off-by: Thomas Gleixner Tested-by: Shameer Kolothum Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210123122759.1781359-1-maz@kernel.org

genirq/msi: Allow shadow declarations of msi_msg:: $member

2020-10-28T19:26:25+00:00

Architectures like x86 have their MSI messages in various bits of the data, address_lo and address_hi field. Composing or decomposing these messages with bitmasks and shifts is possible, but unreadable gunk. Allow architectures to provide an architecture specific representation for each member of msi_msg. Provide empty defaults for each and stick them into an union. Signed-off-by: Thomas Gleixner Signed-off-by: David Woodhouse Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20201024213535.443185-12-dwmw2@infradead.org

PCI/MSI: Make arch_.*_msi_irq[s] fallbacks selectable

2020-09-16T14:52:37+00:00

The arch_.*_msi_irq[s] fallbacks are compiled in whether an architecture requires them or not. Architectures which are fully utilizing hierarchical irq domains should never call into that code. It's not only architectures which depend on that by implementing one or more of the weak functions, there is also a bunch of drivers which relies on the weak functions which invoke msi_controller::setup_irq[s] and msi_controller::teardown_irq. Make the architectures and drivers which rely on them select them in Kconfig and if not selected replace them by stub functions which emit a warning and fail the PCI/MSI interrupt allocation. Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20200826112333.992429909@linutronix.de

irqdomain/msi: Allow to override msi_domain_alloc/free_irqs()

2020-09-16T14:52:37+00:00

To support MSI irq domains which do not fit at all into the regular MSI irqdomain scheme, like the XEN MSI interrupt management for PV/HVM/DOM0, it's necessary to allow to override the alloc/free implementation. This is a preperatory step to switch X86 away from arch_*_msi_irqs() and store the irq domain pointer right in struct device. No functional change for existing MSI irq domain users. Aside of the evil XEN wrapper this is also useful for special MSI domains which need to do extra alloc/free work before/after calling the generic core function. Work like allocating/freeing MSI descriptors, MSI storage space etc. Signed-off-by: Thomas Gleixner Reviewed-by: Marc Zyngier Link: https://lore.kernel.org/r/20200826112333.526797548@linutronix.de

PCI/MSI: Provide pci_dev_has_special_msi_domain() helper

2020-09-16T14:52:36+00:00

Provide a helper function to check whether a PCI device is handled by a non-standard PCI/MSI domain. This will be used to exclude such devices which hang of a special bus, e.g. VMD, to be excluded from the irq domain override in irq remapping. Signed-off-by: Thomas Gleixner Acked-by: Bjorn Helgaas Link: https://lore.kernel.org/r/20200826112333.139387358@linutronix.de

x86/msi: Use generic MSI domain ops

2020-09-16T14:52:35+00:00

pci_msi_get_hwirq() and pci_msi_set_desc are not longer special. Enable the generic MSI domain ops in the core and PCI MSI code unconditionally and get rid of the x86 specific implementations in the X86 MSI code and in the hyperv PCI driver. Signed-off-by: Thomas Gleixner Reviewed-by: Marc Zyngier Link: https://lore.kernel.org/r/20200826112332.564274859@linutronix.de

PCI/MSI: Rework pci_msi_domain_calc_hwirq()

2020-09-16T14:52:34+00:00

Retrieve the PCI device from the msi descriptor instead of doing so at the call sites. Signed-off-by: Thomas Gleixner Acked-by: Bjorn Helgaas Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/20200826112332.352583299@linutronix.de