cffe00ff9c
[ Upstream commit 203b01001c4d741205b9c329acddc5193ed56fbd ]
If a request has the flag CRYPTO_TFM_REQ_MAY_BACKLOG set, the function
qat_alg_send_message_maybacklog(), enqueues it in a backlog list if
either (1) there is already at least one request in the backlog list, or
(2) the HW ring is nearly full or (3) the enqueue to the HW ring fails.
If an interrupt occurs right before the lock in qat_alg_backlog_req() is
taken and the backlog queue is being emptied, then there is no request
in the HW queues that can trigger a subsequent interrupt that can clear
the backlog queue. In addition subsequent requests are enqueued to the
backlog list and not sent to the hardware.
Fix it by holding the lock while taking the decision if the request
needs to be included in the backlog queue or not. This synchronizes the
flow with the interrupt handler that drains the backlog queue.
For performance reasons, the logic has been changed to try to enqueue
first without holding the lock.
Fixes: 386823839732 ("crypto: qat - add backlog mechanism")
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Closes: https://lore.kernel.org/all/af9581e2-58f9-cc19-428f-6f18f1f83d54@redhat.com/T/
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.