4 Commits

Author SHA1 Message Date
Oded Gabbay
9e28c17641 habanalabs: fix memory leak with CBs with unaligned size
This patch fix a bug when a command buffer with unaligned size (with
regard to PAGE_SIZE) was used. The accounting for the unmap operation
wasn't done correctly and could result in a memory leak.

Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-28 13:06:09 +01:00
Oded Gabbay
c216477363 habanalabs: add debugfs support
This patch adds debugfs support to the driver. It allows the user-space to
display information that is contained in the internal structures of the
driver, such as:
- active command submissions
- active user virtual memory mappings
- number of allocated command buffers

It also enables the user to perform reads and writes through Goya's PCI
bars.

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 09:46:46 +01:00
Oded Gabbay
f8c8c7d5f1 habanalabs: add device reset support
This patch adds support for doing various on-the-fly reset of Goya.

The driver supports two types of resets:
1. soft-reset
2. hard-reset

Soft-reset is done when the device detects a timeout of a command
submission that was given to the device. The soft-reset process only resets
the engines that are relevant for the submission of compute jobs, i.e. the
DMA channels, the TPCs and the MME. The purpose is to bring the device as
fast as possible to a working state.

Hard-reset is done in several cases:
1. After soft-reset is done but the device is not responding
2. When fatal errors occur inside the device, e.g. ECC error
3. When the driver is removed

Hard-reset performs a reset of the entire chip except for the PCI
controller and the PLLs. It is a much longer process then soft-reset but it
helps to recover the device without the need to reboot the Host.

After hard-reset, the driver will restore the max power attribute and in
case of manual power management, the frequencies that were set.

This patch also adds two entries to the sysfs, which allows the root user
to initiate a soft or hard reset.

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 09:46:45 +01:00
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