Commit Graph

6 Commits

Author SHA1 Message Date
Oded Gabbay
d9c3aa8038 habanalabs: rename functions to improve code readability
This patch renames four functions in the ASIC-specific functions section,
so it will be easier to differentiate them from the generic kernel
functions with the same name.

This will help in future code reviews, to make sure we don't use the
kernel functions directly.

Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
2019-05-01 11:47:04 +03:00
Oded Gabbay
3f5398cfbf habanalabs: improve IOCTLs behavior when disabled or reset
This patch makes some improvement in how IOCTLs behave when the device is
disabled or under reset.

The new code checks, at the start of every IOCTL, if the device is
disabled or in reset. If so, it prints an appropriate kernel message and
returns -EBUSY to user-space.

In addition, the code modifies the location of where the
hard_reset_pending flag is being set or cleared:

1. It is now cleared immediately after the reset *tear-down* flow is
   finished but before the re-initialization flow begins.

2. It is being set in the remove function of the device, to make the
   behavior the same with the hard-reset flow

There are two exceptions to the disable or in reset check:

1. The HL_INFO_DEVICE_STATUS opcode in the INFO IOCTL. This opcode allows
   the user to inquire about the status of the device, whether it is
   operational, in reset or malfunction (disabled). If the driver will
   block this IOCTL, the user won't be able to retrieve the status in
   case of malfunction or in reset.

2. The WAIT_FOR_CS IOCTL. This IOCTL allows the user to inquire about the
   status of a CS. We want to allow the user to continue to do so, even if
   we started a soft-reset process because it will allow the user to get
   the correct error code for each CS he submitted.

Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
2019-04-06 15:41:35 +03:00
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