Re: [RFC PATCH net-next 2/4] net: dsa: remove the "dsa_to_port in a loop" antipattern from the core
From: Florian Fainelli <f.fainelli@gmail.com>
Date: 2021-08-10 09:37:14
On 8/9/2021 12:03 PM, Vladimir Oltean wrote:
Ever since Vivien's conversion of the ds->ports array into a dst->ports
list, and the introduction of dsa_to_port, iterations through the ports
of a switch became quadratic whenever dsa_to_port was needed.
dsa_to_port can either be called directly, or indirectly through the
dsa_is_{user,cpu,dsa,unused}_port helpers.
Introduce a basic switch port iterator macro, dsa_switch_for_each_port,
that works with the iterator variable being a struct dsa_port *dp
directly, and not an int i. It is an expensive variable to go from i to
dp, but cheap to go from dp to i.
This macro iterates through the entire ds->dst->ports list and filters
by the ports belonging just to the switch provided as argument.
While at it, provide some more flavors of that macro which filter for
specific types of ports: at the moment just user ports and CPU ports.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> -- Florian