The driver code qede_free_fp_array() depend on kfree() can be called
with a NULL pointer. This stems from the qede_alloc_fp_array()
function which either (kz)alloc memory for fp->txq or fp->rxq.
This also simplifies error handling code in case of memory allocation
failures, but xdp_rxq_info_unreg need to know the difference.
Introduce xdp_rxq_info_is_reg() to handle if a memory allocation fails
and detect this is the failure path by seeing that xdp_rxq_info was
not registred yet, which first happens after successful alloaction in
qede_init_fp().
Driver hook points for xdp_rxq_info:
* reg : qede_init_fp
* unreg: qede_free_fp_array
Tested on actual hardware with samples/bpf program.
V2: Driver have no proper error path for failed XDP RX-queue info reg, as
qede_init_fp() is a void function.
Cc: everest-linux-l2@cavium.com
Cc: Ariel Elior <Ariel.Elior@cavium.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch only introduce the core data structures and API functions.
All XDP enabled drivers must use the API before this info can used.
There is a need for XDP to know more about the RX-queue a given XDP
frames have arrived on. For both the XDP bpf-prog and kernel side.
Instead of extending xdp_buff each time new info is needed, the patch
creates a separate read-mostly struct xdp_rxq_info, that contains this
info. We stress this data/cache-line is for read-only info. This is
NOT for dynamic per packet info, use the data_meta for such use-cases.
The performance advantage is this info can be setup at RX-ring init
time, instead of updating N-members in xdp_buff. A possible (driver
level) micro optimization is that xdp_buff->rxq assignment could be
done once per XDP/NAPI loop. The extra pointer deref only happens for
program needing access to this info (thus, no slowdown to existing
use-cases).
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
