linux-dev - Linux kernel development work

Age	Commit message (Collapse)	Author	Files	Lines
2020-03-06	uacce: unmap remaining mmapping from user space	Zhangfei Gao	1	-0/+2
	When uacce parent device module is removed, user app may still keep the mmaped area, which can be accessed unsafely. When rmmod, Parent device driver will call uacce_remove, which unmap all remaining mapping from user space for safety. VM_FAULT_SIGBUS is also reported to user space accordingly. Suggested-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-02-22	uacce: add uacce driver	Kenneth Lee	1	-0/+161
	Uacce (Unified/User-space-access-intended Accelerator Framework) targets to provide 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 share only data content rather than address. Since unified address, hardware and user space of process can share the same virtual address in the communication. Uacce create a chrdev for every registration, the queue is allocated to the process when the chrdev is opened. Then the process can access the hardware resource by interact with the queue file. By mmap the queue file space to user space, the process can directly put requests to the hardware without syscall to the kernel space. The IOMMU core only tracks mm<->device bonds at the moment, because it only needs to handle IOTLB invalidation and PASID table entries. However uacce needs a finer granularity since multiple queues from the same device can be bound to an mm. When the mm exits, all bound queues must be stopped so that the IOMMU can safely clear the PASID table entry and reallocate 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_mm structure only ever belongs to a single device, because we don't need anything more complex (if multiple devices are bound to one mm, then we'll create one uacce_mm for each bond). uacce_device --+-- uacce_mm --+-- uacce_queue \| '-- uacce_queue \| '-- uacce_mm --+-- uacce_queue +-- uacce_queue '-- uacce_queue Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Kenneth Lee <liguozhu@hisilicon.com> Signed-off-by: Zaibo Xu <xuzaibo@huawei.com> Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>