linux/drivers/misc/habanalabs
Oded Gabbay be5d926b5c habanalabs: add command buffer module
This patch adds the command buffer (CB) module, which allows the user to
create and destroy CBs and to map them to the user's process
address-space.

A command buffer is a memory blocks that reside in DMA-able address-space
and is physically contiguous so it can be accessed by the device without
MMU translation. The command buffer memory is allocated using the
coherent DMA API.

When creating a new CB, the IOCTL returns a handle of it, and the
user-space process needs to use that handle to mmap the buffer to get a VA
in the user's address-space.

Before destroying (freeing) a CB, the user must unmap the CB's VA using the
CB handle.

Each CB has a reference counter, which tracks its usage in command
submissions and also its mmaps (only a single mmap is allowed).

The driver maintains a pool of pre-allocated CBs in order to reduce
latency during command submissions. In case the pool is empty, the driver
will go to the slow-path of allocating a new CB, i.e. calling
dma_alloc_coherent.

Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-18 09:46:44 +01:00
..
goya habanalabs: add command buffer module 2019-02-18 09:46:44 +01:00
include/goya habanalabs: add basic Goya support 2019-02-18 09:46:44 +01:00
asid.c habanalabs: add context and ASID modules 2019-02-18 09:46:44 +01:00
command_buffer.c habanalabs: add command buffer module 2019-02-18 09:46:44 +01:00
context.c habanalabs: add context and ASID modules 2019-02-18 09:46:44 +01:00
device.c habanalabs: add command buffer module 2019-02-18 09:46:44 +01:00
habanalabs_drv.c habanalabs: add command buffer module 2019-02-18 09:46:44 +01:00
habanalabs_ioctl.c habanalabs: add command buffer module 2019-02-18 09:46:44 +01:00
habanalabs.h habanalabs: add command buffer module 2019-02-18 09:46:44 +01:00
Kconfig
Makefile habanalabs: add command buffer module 2019-02-18 09:46:44 +01:00