015d239a - uacce: add uacce driver

Tue, 11 Feb 2020 07:54:23 +0000

uacce: add uacce driverUacce (Unified/User-space-access-intended Accelerator Framework) targets toprovide Shared Virtual Addressing (SVA) between accelerators and processes.So accelerator can access any data structure of the main cpu.This differs from the data sharing between cpu and io device, which shareonly data content rather than address.Since unified address, hardware and user space of process can share thesame virtual address in the communication.Uacce create a chrdev for every registration, the queue is allocated tothe process when the chrdev is opened. Then the process can access thehardware resource by interact with the queue file. By mmap the queuefile space to user space, the process can directly put requests to thehardware without syscall to the kernel space.The IOMMU core only tracks mm<->device bonds at the moment, because itonly needs to handle IOTLB invalidation and PASID table entries. Howeveruacce needs a finer granularity since multiple queues from the samedevice can be bound to an mm. When the mm exits, all bound queues mustbe stopped so that the IOMMU can safely clear the PASID table entry andreallocate the PASID.An intermediate struct uacce_mm links uacce devices and queues.Note that an mm may be bound to multiple devices but an uacce_mmstructure only ever belongs to a single device, because we don't needanything more complex (if multiple devices are bound to one mm, thenwe'll create one uacce_mm for each bond). uacce_device --+-- uacce_mm --+-- uacce_queue | '-- uacce_queue | '-- uacce_mm --+-- uacce_queue +-- uacce_queue '-- uacce_queueReviewed-by: Greg Kroah-Hartman Reviewed-by: Jonathan Cameron Signed-off-by: Kenneth Lee Signed-off-by: Zaibo Xu Signed-off-by: Zhou Wang Signed-off-by: Jean-Philippe Brucker Signed-off-by: Zhangfei Gao Signed-off-by: Herbert Xu List of files: /linux-6.15/drivers/misc/uacce/Makefile

Changes in Makefile

015d239a - uacce: add uacce driver