Vladimir Oltean
e7072750bb
The driver uses the DPAA_TC_TXQ_NUM and DPAA_ETH_TXQ_NUM macros for TX
queue handling, and they depend on CONFIG_NR_CPUS.
In generic .config files, these can go to very large (8096 CPUs) values
for the systems that DPAA1 is integrated in (1-24 CPUs). We allocate a
lot of resources that will never be used. Those are:
- system memory
- QMan FQIDs as managed by qman_alloc_fqid_range(). This is especially
painful since currently, when booting with CONFIG_NR_CPUS=8096, a
LS1046A-RDB system will only manage to probe 3 of its 6 interfaces.
The rest will run out of FQD ("/reserved-memory/qman-fqd" in the
device tree) and fail at the qman_create_fq() stage of the probing
process.
- netdev queues as alloc_etherdev_mq() argument. The high queue indices
are simply hidden from the network stack after the call to
netif_set_real_num_tx_queues().
With just a tiny bit more effort, we can replace the NR_CPUS
compile-time constant with the num_possible_cpus() run-time constant,
and dynamically allocate the egress_fqs[] and conf_fqs[] arrays.
Even on a system with a high CONFIG_NR_CPUS, num_possible_cpus() will
remain equal to the number of available cores on the SoC.
The replacement is as follows:
- DPAA_TC_TXQ_NUM -> dpaa_num_txqs_per_tc()
- DPAA_ETH_TXQ_NUM -> dpaa_max_num_txqs()
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Madalin Bucur <madalin.bucur@oss.nxp.com>
Link: https://patch.msgid.link/20240713225336.1746343-3-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@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 reStructuredText 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.