target/linux/generic/backport-6.1/703-10-v5.16-net-dsa-introduce-helpers-for-iterating-through-port.patch

   1 From 82b318983c515f29b8b3a0dad9f6a5fe8a68a7f4 Mon Sep 17 00:00:00 2001
   2 From: Vladimir Oltean <vladimir.oltean@nxp.com>
   3 Date: Wed, 20 Oct 2021 20:49:49 +0300
   4 Subject: [PATCH] net: dsa: introduce helpers for iterating through ports using
   5  dp
   6
   7 Since the DSA conversion from the ds->ports array into the dst->ports
   8 list, the DSA API has encouraged driver writers, as well as the core
   9 itself, to write inefficient code.
  10
  11 Currently, code that wants to filter by a specific type of port when
  12 iterating, like {!unused, user, cpu, dsa}, uses the dsa_is_*_port helper.
  13 Under the hood, this uses dsa_to_port which iterates again through
  14 dst->ports. But the driver iterates through the port list already, so
  15 the complexity is quadratic for the typical case of a single-switch
  16 tree.
  17
  18 This patch introduces some iteration helpers where the iterator is
  19 already a struct dsa_port *dp, so that the other variant of the
  20 filtering functions, dsa_port_is_{unused,user,cpu_dsa}, can be used
  21 directly on the iterator. This eliminates the second lookup.
  22
  23 These functions can be used both by the core and by drivers.
  24
  25 Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
  26 Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
  27 Signed-off-by: David S. Miller <davem@davemloft.net>
  28 ---
  29  include/net/dsa.h | 28 ++++++++++++++++++++++++++++
  30  1 file changed, 28 insertions(+)
  31
  32 --- a/include/net/dsa.h
  33 +++ b/include/net/dsa.h
  34 @@ -476,6 +476,34 @@ static inline bool dsa_is_user_port(stru
  35         return dsa_to_port(ds, p)->type == DSA_PORT_TYPE_USER;
  36  }
  37
  38 +#define dsa_tree_for_each_user_port(_dp, _dst) \
  39 +       list_for_each_entry((_dp), &(_dst)->ports, list) \
  40 +               if (dsa_port_is_user((_dp)))
  41 +
  42 +#define dsa_switch_for_each_port(_dp, _ds) \
  43 +       list_for_each_entry((_dp), &(_ds)->dst->ports, list) \
  44 +               if ((_dp)->ds == (_ds))
  45 +
  46 +#define dsa_switch_for_each_port_safe(_dp, _next, _ds) \
  47 +       list_for_each_entry_safe((_dp), (_next), &(_ds)->dst->ports, list) \
  48 +               if ((_dp)->ds == (_ds))
  49 +
  50 +#define dsa_switch_for_each_port_continue_reverse(_dp, _ds) \
  51 +       list_for_each_entry_continue_reverse((_dp), &(_ds)->dst->ports, list) \
  52 +               if ((_dp)->ds == (_ds))
  53 +
  54 +#define dsa_switch_for_each_available_port(_dp, _ds) \
  55 +       dsa_switch_for_each_port((_dp), (_ds)) \
  56 +               if (!dsa_port_is_unused((_dp)))
  57 +
  58 +#define dsa_switch_for_each_user_port(_dp, _ds) \
  59 +       dsa_switch_for_each_port((_dp), (_ds)) \
  60 +               if (dsa_port_is_user((_dp)))
  61 +
  62 +#define dsa_switch_for_each_cpu_port(_dp, _ds) \
  63 +       dsa_switch_for_each_port((_dp), (_ds)) \
  64 +               if (dsa_port_is_cpu((_dp)))
  65 +
  66  static inline u32 dsa_user_ports(struct dsa_switch *ds)
  67  {
  68         u32 mask = 0;