linux-stable.git/drivers/net/ethernet/microchip/vcap/vcap_api_debugfs.c, branch linux-rolling-stable

net: microchip: vcap: fix races on the shared Super VCAP block

2026-07-24T14:20:42+00:00

[ Upstream commit d7a8d500d7e42837bd8dce40cb52c97c6e8706a9 ]

The VCAP instances on a chip are not independent, yet they are locked
independently. On sparx5 and lan969x the IS0 and IS2 instances are
backed by the same Super VCAP hardware block and share its cache and
command registers: every access drives the shared VCAP_SUPER_CTRL
register and moves data through the shared cache registers.

Accessing one instance therefore races with accessing another. The
per-instance admin->lock cannot prevent this, as each instance takes a
different lock.

The locking issue is mostly disguised by the fact that the core usage of
the vcap api runs under rtnl. However, the full rule dump in debugfs
decodes rules straight from hardware (a READ command followed by a cache
read) and runs outside rtnl, so it races a concurrent tc-flower rule
write to another Super VCAP instance.

Besides corrupting the dump, the read repopulates the shared cache
between the writers cache fill and its write command, so the writer
commits the wrong data and corrupts the hardware entry.

Introduce vcap_lock() and vcap_unlock() helpers and route every rule
lock site in the VCAP API and its debugfs code through them. Replace the
per-instance admin->lock with a single mutex in struct vcap_control that
serializes access to all instances. The helpers reach it through a new
admin->vctrl back-pointer, and the clients initialise and destroy the
control lock instead of a per-instance one.

No path holds more than one instance lock, so collapsing them onto a
single mutex cannot self-deadlock.

Fixes: 71c9de995260 ("net: microchip: sparx5: Add VCAP locking to protect rules")
Signed-off-by: Jens Emil Schulz Østergaard
Link: https://patch.msgid.link/20260630-microchip_fix_vcap_locking-v1-1-f60a4596734d@microchip.com
Signed-off-by: Paolo Abeni
Signed-off-by: Sasha Levin

net: microchip: sparx5: clean up error checking in vcap_show_admin()

2023-10-03T14:13:32+00:00

The vcap_decode_rule() never returns NULL.  There is no need to check
for that.  This code assumes that if it did return NULL we should
end abruptly and return success.  It is confusing.  Fix the check to
just be if (IS_ERR()) instead of if (IS_ERR_OR_NULL()).

Reported-by: kernel test robot 
Closes: https://lore.kernel.org/r/202309070831.hTvj9ekP-lkp@intel.com/
Signed-off-by: Dan Carpenter 
Reviewed-by: Simon Horman 
Reviewed-by: Daniel Machon 
Link: https://lore.kernel.org/r/b88eba86-9488-4749-a896-7c7050132e7b@moroto.mountain
Signed-off-by: Jakub Kicinski

net: microchip: sparx5: Add ingress information to VCAP instance

2023-01-30T07:36:22+00:00

This allows the check of the goto action to be specific to the ingress and
egress VCAP instances.

The debugfs support is also updated to show this information.

Signed-off-by: Steen Hegelund 
Signed-off-by: David S. Miller

net: microchip: sparx5: Add ES2 VCAP keyset configuration for Sparx5

2023-01-30T07:36:22+00:00

This adds the ES2 VCAP port keyset configuration for Sparx5 and also
updates the debugFS support to show the keyset configuration and the egress
port mask.

Signed-off-by: Steen Hegelund 
Signed-off-by: David S. Miller

net: microchip: sparx5: Add VCAP admin locking in debugFS

2023-01-18T14:31:43+00:00

This ensures that the admin lock is taken before the debugFS functions
starts iterating the VCAP rules.
It also adds a separate function to decode a rule, which expects the lock
to have been taken before it is called.

Signed-off-by: Steen Hegelund 
Signed-off-by: David S. Miller

net: microchip: vcap api: Enable/Disable rules via chains in VCAP HW

2023-01-16T13:45:17+00:00

This supports that individual rules are enabled and disabled via chain
information.
This is done by keeping disabled rules in the VCAP list (cached) until they
are enabled, and only at this time are the rules written to the VCAP HW.

Signed-off-by: Horatiu Vultur 
Signed-off-by: Steen Hegelund 
Signed-off-by: David S. Miller

net: microchip: vcap api: Add a storage state to a VCAP rule

2023-01-16T13:45:17+00:00

This allows a VCAP rule to be in one of 3 states:

- permanently stored in the VCAP HW (for rules that must always be present)
- enabled (stored in HW) when the corresponding lookup has been enabled
- disabled (stored in SW) when the lookup is disabled

This way important VCAP rules can be added even before the user enables the
VCAP lookups using a TC matchall filter.

Signed-off-by: Horatiu Vultur 
Signed-off-by: Steen Hegelund 
Signed-off-by: David S. Miller

net: microchip: vcap: Fix initialization of value and mask

2022-12-19T12:23:39+00:00

Fix the following smatch warning:

smatch warnings:
drivers/net/ethernet/microchip/vcap/vcap_api_debugfs.c:103 vcap_debugfs_show_rule_keyfield() error: uninitialized symbol 'value'.
drivers/net/ethernet/microchip/vcap/vcap_api_debugfs.c:106 vcap_debugfs_show_rule_keyfield() error: uninitialized symbol 'mask'.

In case the vcap field was VCAP_FIELD_U128 and the key was different
than IP6_S/DIP then the value and mask were not initialized, therefore
initialize them.

Fixes: 610c32b2ce66 ("net: microchip: vcap: Add vcap_get_rule")
Reported-by: kernel test robot 
Reported-by: Dan Carpenter 
Reviewed-by: Saeed Mahameed 
Signed-off-by: Horatiu Vultur 
Reviewed-by: Michal Swiatkowski 
Signed-off-by: David S. Miller

net: microchip: vcap: Add vcap_get_rule

2022-12-06T12:26:43+00:00

Add function vcap_get_rule which returns a rule based on the internal
rule id.
The entire functionality of reading and decoding the rule from the VCAP
was inside vcap_api_debugfs file. So move the entire implementation in
vcap_api as this is used also by vcap_get_rule.

Signed-off-by: Horatiu Vultur 
Signed-off-by: Paolo Abeni

net: microchip: sparx5: Fix error handling in vcap_show_admin()

2022-12-01T11:12:23+00:00

If vcap_dup_rule() fails that leads to an error pointer dereference
side the call to vcap_free_rule().  Also it only returns an error if the
very last call to vcap_read_rule() fails and it returns success for
other errors.

I've changed it to just stop printing after the first error and return
an error code.

Fixes: 3a7921560d2f ("net: microchip: sparx5: Add VCAP rule debugFS support for the VCAP API")
Signed-off-by: Dan Carpenter 
Reviewed-by: Steen Hegelund 
Link: https://lore.kernel.org/r/Y4XUUx9kzurBN+BV@kili
Signed-off-by: Paolo Abeni