dpif-netdev-private-extract.h

/*
 * Copyright (c) 2021 Intel.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef MFEX_AVX512_EXTRACT
#define MFEX_AVX512_EXTRACT 1

#include <sys/types.h>

/* Forward declarations. */
struct dp_packet;
struct miniflow;
struct dp_netdev_pmd_thread;
struct dp_packet_batch;
struct netdev_flow_key;

/* Function pointer prototype to be implemented in the optimized miniflow
 * extract code.
 * returns the hitmask of the processed packets on success.
 * returns zero on failure.
 */
typedef uint32_t (*miniflow_extract_func)(struct dp_packet_batch *batch,
                                          struct netdev_flow_key *keys,
                                          uint32_t keys_size,
                                          odp_port_t in_port,
                                          struct dp_netdev_pmd_thread
                                          *pmd_handle);


/* The function pointer miniflow_extract_func depends on batch size. */
BUILD_ASSERT_DECL(NETDEV_MAX_BURST == 32);

/* Probe function is used to detect if this CPU has the ISA required
 * to run the optimized miniflow implementation.
 * returns one on successful probe.
 * returns negative errno on failure.
 */
typedef int (*miniflow_extract_probe)(void);

/* Structure representing the attributes of an optimized implementation. */
struct dpif_miniflow_extract_impl {
    /* When it is true, this impl has passed the probe() checks. */
    bool available;

    /* Probe function is used to detect if this CPU has the ISA required
     * to run the optimized miniflow implementation. It is optional and
     * if it is not used, then it must be null.
     */
    miniflow_extract_probe probe;

    /* Optional function to call to extract miniflows for a burst of packets.
     * If it is not used must be set to NULL;
     */
    miniflow_extract_func extract_func;

    /* Name of the optimized implementation. */
    char *name;
};


/* Enum to hold implementation indexes. The list is traversed
 * linearly as from the ISA perspective, the VBMI version
 * should always come before the generic AVX512-F version.
 */
enum dpif_miniflow_extract_impl_idx {
    MFEX_IMPL_SCALAR,
    MFEX_IMPL_MAX
};

extern struct ovs_mutex dp_netdev_mutex;

/* This function returns all available implementations to the caller. The
 * quantity of implementations is returned by the int return value.
 */
void
dp_mfex_impl_get(struct ds *reply, struct dp_netdev_pmd_thread **pmd_list,
                 size_t pmd_list_size) OVS_REQUIRES(dp_netdev_mutex);

/* This function checks all available MFEX implementations, and selects the
 * returns the function pointer to the one requested by "name".
 */
int
dp_mfex_impl_get_by_name(const char *name, miniflow_extract_func *out_func);

/* Returns the default MFEX which is first ./configure selected, but can be
 * overridden at runtime. */
miniflow_extract_func dp_mfex_impl_get_default(void);

/* Overrides the default MFEX with the user set MFEX. */
int dp_mfex_impl_set_default_by_name(const char *name);


/* Initializes the available miniflow extract implementations by probing for
 * the CPU ISA requirements. As the runtime available CPU ISA does not change
 * and the required ISA of the implementation also does not change, it is safe
 * to cache the probe() results, and not call probe() at runtime.
 */
void
dpif_miniflow_extract_init(void);

#endif /* MFEX_AVX512_EXTRACT */