612ad43330
The upcoming mechanism to allocate MSI-X vectors after enabling MSI-X needs to share some of the MSI-X descriptor setup. The regular descriptor setup on enable has the following code flow: 1) Allocate descriptor 2) Setup descriptor with PCI specific data 3) Insert descriptor 4) Allocate interrupts which in turn scans the inserted descriptors This cannot be easily changed because the PCI/MSI code needs to handle the legacy architecture specific allocation model and the irq domain model where quite some domains have the assumption that the above flow is how it works. Ideally the code flow should look like this: 1) Invoke allocation at the MSI core 2) MSI core allocates descriptor 3) MSI core calls back into the irq domain which fills in the domain specific parts This could be done for underlying parent MSI domains which support post-enable allocation/free but that would create significantly different code pathes for MSI/MSI-X enable. Though for dynamic allocation which wants to share the allocation code with the upcoming PCI/IMS support it's the right thing to do. Split the MSI-X descriptor setup into the preallocation part which just sets the index and fills in the horrible hack of virtual IRQs and the real PCI specific MSI-X setup part which solely depends on the index in the descriptor. This allows to provide a common dynamic allocation interface at the MSI core level for both PCI/MSI-X and PCI/IMS. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221124232326.616292598@linutronix.de |
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api.c | ||
irqdomain.c | ||
legacy.c | ||
Makefile | ||
msi.c | ||
msi.h | ||
pcidev_msi.c |