linux/drivers/net/netdevsim/dev.c, branch v5.7

netdevsim: Ensure policer drop counter always increases

2020-05-22T23:05:42Z

In case the policer drop counter is retrieved when the jiffies value is a multiple of 64, the counter will not be incremented. This randomly breaks a selftest [1] the reads the counter twice and checks that it was incremented: ``` TEST: Trap policer [FAIL] Policer drop counter was not incremented ``` Fix by always incrementing the counter by 1. [1] tools/testing/selftests/drivers/net/netdevsim/devlink_trap.sh Fixes: ad188458d012 ("netdevsim: Add devlink-trap policer support") Signed-off-by: Ido Schimmel Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller

netdevsim: dev: Fix memory leak in nsim_dev_take_snapshot_write

2020-03-31T03:14:22Z

In case memory resources for dummy_data were allocated, release them before return. Addresses-Coverity-ID: 1491997 ("Resource leak") Fixes: 7ef19d3b1d5e ("devlink: report error once U32_MAX snapshot ids have been used") Signed-off-by: Gustavo A. R. Silva Reviewed-by: Jakub Kicinski Signed-off-by: David S. Miller

netdevsim: Add support for setting of packet trap group parameters

2020-03-31T00:54:58Z

Add a dummy callback to set trap group parameters. Return an error when the 'fail_trap_group_set' debugfs file is set in order to exercise error paths and verify that error is propagated to user space when should. Signed-off-by: Ido Schimmel Reviewed-by: Jiri Pirko Reviewed-by: Jakub Kicinski Signed-off-by: David S. Miller

devlink: Add packet trap group parameters support

2020-03-31T00:54:58Z

Packet trap groups are used to aggregate logically related packet traps. Currently, these groups allow user space to batch operations such as setting the trap action of all member traps. In order to prevent the CPU from being overwhelmed by too many trapped packets, it is desirable to bind a packet trap policer to these groups. For example, to limit all the packets that encountered an exception during routing to 10Kpps. Allow device drivers to bind default packet trap policers to packet trap groups when the latter are registered with devlink. The next patch will enable user space to change this default binding. Signed-off-by: Ido Schimmel Reviewed-by: Jiri Pirko Reviewed-by: Jakub Kicinski Signed-off-by: David S. Miller

netdevsim: Add devlink-trap policer support

2020-03-31T00:54:58Z

Register three dummy packet trap policers with devlink and implement callbacks to change their parameters and read their counters. This will be used later on in the series to test the devlink-trap policer infrastructure. v2: * Remove check about burst size being a power of 2 and instead add a debugfs knob to fail the operation * Provide max/min rate/burst size when registering policers and remove the validity checks from nsim_dev_devlink_trap_policer_set() Signed-off-by: Ido Schimmel Reviewed-by: Jiri Pirko Reviewed-by: Jakub Kicinski Signed-off-by: David S. Miller

netdevsim: support taking immediate snapshot via devlink

2020-03-27T02:39:26Z

Implement the .snapshot region operation for the dummy data region. This enables a region snapshot to be taken upon request via the new DEVLINK_CMD_REGION_SNAPSHOT command. Signed-off-by: Jacob Keller Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller

devlink: track snapshot id usage count using an xarray

2020-03-27T02:39:26Z

Each snapshot created for a devlink region must have an id. These ids are supposed to be unique per "event" that caused the snapshot to be created. Drivers call devlink_region_snapshot_id_get to obtain a new id to use for a new event trigger. The id values are tracked per devlink, so that the same id number can be used if a triggering event creates multiple snapshots on different regions. There is no mechanism for snapshot ids to ever be reused. Introduce an xarray to store the count of how many snapshots are using a given id, replacing the snapshot_id field previously used for picking the next id. The devlink_region_snapshot_id_get() function will use xa_alloc to insert an initial value of 1 value at an available slot between 0 and U32_MAX. The new __devlink_snapshot_id_increment() and __devlink_snapshot_id_decrement() functions will be used to track how many snapshots currently use an id. Drivers must now call devlink_snapshot_id_put() in order to release their reference of the snapshot id after adding region snapshots. By tracking the total number of snapshots using a given id, it is possible for the decrement() function to erase the id from the xarray when it is not in use. With this method, a snapshot id can become reused again once all snapshots that referred to it have been deleted via DEVLINK_CMD_REGION_DEL, and the driver has finished adding snapshots. This work also paves the way to introduce a mechanism for userspace to request a snapshot. Signed-off-by: Jacob Keller Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller

devlink: report error once U32_MAX snapshot ids have been used

2020-03-27T02:39:26Z

The devlink_snapshot_id_get() function returns a snapshot id. The snapshot id is a u32, so there is no way to indicate an error code. A future change is going to possibly add additional cases where this function could fail. Refactor the function to return the snapshot id in an argument, so that it can return zero or an error value. This ensures that snapshot ids cannot be confused with error values, and aids in the future refactor of snapshot id allocation management. Because there is no current way to release previously used snapshot ids, add a simple check ensuring that an error is reported in case the snapshot_id would over flow. Signed-off-by: Jacob Keller Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller

devlink: convert snapshot destructor callback to region op

2020-03-27T02:39:26Z

It does not makes sense that two snapshots for a given region would use different destructors. Simplify snapshot creation by adding a .destructor op for regions. This operation will replace the data_destructor for the snapshot creation, and makes snapshot creation easier. Noticed-by: Jakub Kicinski Signed-off-by: Jacob Keller Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller

devlink: prepare to support region operations

2020-03-27T02:39:26Z

Modify the devlink region code in preparation for adding new operations on regions. Create a devlink_region_ops structure, and move the name pointer from within the devlink_region structure into the ops structure (similar to the devlink_health_reporter_ops). This prepares the regions to enable support of additional operations in the future such as requesting snapshots, or accessing the region directly without a snapshot. In order to re-use the constant strings in the mlx4 driver their declaration must be changed to 'const char * const' to ensure the compiler realizes that both the data and the pointer cannot change. Signed-off-by: Jacob Keller Reviewed-by: Jakub Kicinski Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller