From: Manish Honap <[email protected]> vfio-pci-core must stay free of any CXL header dependency, so CXL Type-2 handling lives in a separate vfio-cxl module that plugs in a set of callbacks. Add the registration interface: vfio-cxl registers a single struct vfio_cxl_ops at module_init, and vfio-pci-core stores it under a mutex.
The owner field lets a later patch pin vfio-cxl for the lifetime of each bound CXL device. No caller yet; the detection path is added next. Signed-off-by: Manish Honap <[email protected]> --- drivers/vfio/pci/vfio_pci_core.c | 27 +++++++++++++++++++++++++++ include/linux/vfio_pci_core.h | 10 ++++++++++ 2 files changed, 37 insertions(+) diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c index 3f11a9624b9c..88e68d43af9a 100644 --- a/drivers/vfio/pci/vfio_pci_core.c +++ b/drivers/vfio/pci/vfio_pci_core.c @@ -2670,6 +2670,33 @@ static void vfio_pci_dev_set_try_reset(struct vfio_device_set *dev_set) } } +static const struct vfio_cxl_ops *vfio_pci_cxl_ops; +static DEFINE_MUTEX(vfio_pci_cxl_ops_lock); + +int vfio_pci_core_register_cxl_ops(const struct vfio_cxl_ops *ops) +{ + int ret = 0; + + mutex_lock(&vfio_pci_cxl_ops_lock); + if (vfio_pci_cxl_ops) + ret = -EBUSY; + else + vfio_pci_cxl_ops = ops; + mutex_unlock(&vfio_pci_cxl_ops_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(vfio_pci_core_register_cxl_ops); + +void vfio_pci_core_unregister_cxl_ops(const struct vfio_cxl_ops *ops) +{ + mutex_lock(&vfio_pci_cxl_ops_lock); + if (vfio_pci_cxl_ops == ops) + vfio_pci_cxl_ops = NULL; + mutex_unlock(&vfio_pci_cxl_ops_lock); +} +EXPORT_SYMBOL_GPL(vfio_pci_core_unregister_cxl_ops); + static void vfio_pci_core_cleanup(void) { vfio_pci_uninit_perm_bits(); diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h index 9a1674c152aa..14753972e714 100644 --- a/include/linux/vfio_pci_core.h +++ b/include/linux/vfio_pci_core.h @@ -66,6 +66,16 @@ struct vfio_pci_device_ops { size_t nr_ranges); }; +struct vfio_cxl_ops { + int (*init_device)(struct vfio_pci_core_device *vdev); + void (*release_device)(struct vfio_pci_core_device *vdev); + /* Pinned per bound CXL device so vfio-cxl cannot unload under usage */ + struct module *owner; +}; + +int vfio_pci_core_register_cxl_ops(const struct vfio_cxl_ops *ops); +void vfio_pci_core_unregister_cxl_ops(const struct vfio_cxl_ops *ops); + #if IS_ENABLED(CONFIG_VFIO_PCI_DMABUF) int vfio_pci_core_fill_phys_vec(struct phys_vec *phys_vec, struct vfio_region_dma_range *dma_ranges, -- 2.25.1
