linux/net/core/xdp.c
Jesper Dangaard Brouer c0124f327e xdp/qede: setup xdp_rxq_info and intro xdp_rxq_info_is_reg
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>
2018-01-05 15:21:21 -08:00

74 lines
1.8 KiB
C

/* net/core/xdp.c
*
* Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
* Released under terms in GPL version 2. See COPYING.
*/
#include <linux/types.h>
#include <linux/mm.h>
#include <net/xdp.h>
#define REG_STATE_NEW 0x0
#define REG_STATE_REGISTERED 0x1
#define REG_STATE_UNREGISTERED 0x2
#define REG_STATE_UNUSED 0x3
void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq)
{
/* Simplify driver cleanup code paths, allow unreg "unused" */
if (xdp_rxq->reg_state == REG_STATE_UNUSED)
return;
WARN(!(xdp_rxq->reg_state == REG_STATE_REGISTERED), "Driver BUG");
xdp_rxq->reg_state = REG_STATE_UNREGISTERED;
xdp_rxq->dev = NULL;
}
EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg);
static void xdp_rxq_info_init(struct xdp_rxq_info *xdp_rxq)
{
memset(xdp_rxq, 0, sizeof(*xdp_rxq));
}
/* Returns 0 on success, negative on failure */
int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
struct net_device *dev, u32 queue_index)
{
if (xdp_rxq->reg_state == REG_STATE_UNUSED) {
WARN(1, "Driver promised not to register this");
return -EINVAL;
}
if (xdp_rxq->reg_state == REG_STATE_REGISTERED) {
WARN(1, "Missing unregister, handled but fix driver");
xdp_rxq_info_unreg(xdp_rxq);
}
if (!dev) {
WARN(1, "Missing net_device from driver");
return -ENODEV;
}
/* State either UNREGISTERED or NEW */
xdp_rxq_info_init(xdp_rxq);
xdp_rxq->dev = dev;
xdp_rxq->queue_index = queue_index;
xdp_rxq->reg_state = REG_STATE_REGISTERED;
return 0;
}
EXPORT_SYMBOL_GPL(xdp_rxq_info_reg);
void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq)
{
xdp_rxq->reg_state = REG_STATE_UNUSED;
}
EXPORT_SYMBOL_GPL(xdp_rxq_info_unused);
bool xdp_rxq_info_is_reg(struct xdp_rxq_info *xdp_rxq)
{
return (xdp_rxq->reg_state == REG_STATE_REGISTERED);
}
EXPORT_SYMBOL_GPL(xdp_rxq_info_is_reg);