numam-dpdk/drivers/net/mlx4/mlx4_utils.c
Adrien Mazarguil f1c9ac9f23 net/mlx4: add iovec-like allocation wrappers
These wrappers implement the ability to allocate room for several disparate
objects as a single contiguous allocation while complying with their
respective alignment constraints.

This is usually more efficient than allocating and freeing them
individually if they are not expected to be reallocated with rte_realloc().

A typical use case is when several objects that cannot be dissociated must
be allocated together, as shown in the following example:

 struct b {
    ...
    struct d *d;
 }

 struct a {
     ...
     struct b *b;
     struct c *c;
 }

 struct mlx4_malloc_vec vec[] = {
     { .size = sizeof(struct a), .addr = &ptr_a, },
     { .size = sizeof(struct b), .addr = &ptr_b, },
     { .size = sizeof(struct c), .addr = &ptr_c, },
     { .size = sizeof(struct d), .addr = &ptr_d, },
 };

 if (!mlx4_mallocv(NULL, vec, RTE_DIM(vec)))
     goto error;

 struct a *a = ptr_a;

 a->b = ptr_b;
 a->c = ptr_c;
 a->b->d = ptr_d;
 ...
 rte_free(a);

Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
2017-10-13 01:18:48 +01:00

218 lines
6.2 KiB
C

/*-
* BSD LICENSE
*
* Copyright 2017 6WIND S.A.
* Copyright 2017 Mellanox
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of 6WIND S.A. nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* @file
* Utility functions used by the mlx4 driver.
*/
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <stddef.h>
#include <stdint.h>
#include <rte_errno.h>
#include <rte_malloc.h>
#include <rte_memory.h>
#include "mlx4_utils.h"
/**
* Make a file descriptor non-blocking.
*
* @param fd
* File descriptor to alter.
*
* @return
* 0 on success, negative errno value otherwise and rte_errno is set.
*/
int
mlx4_fd_set_non_blocking(int fd)
{
int ret = fcntl(fd, F_GETFL);
if (ret != -1 && !fcntl(fd, F_SETFL, ret | O_NONBLOCK))
return 0;
assert(errno);
rte_errno = errno;
return -rte_errno;
}
/**
* Internal helper to allocate memory once for several disparate objects.
*
* The most restrictive alignment constraint for standard objects is assumed
* to be sizeof(double) and is used as a default value.
*
* C11 code would include stdalign.h and use alignof(max_align_t) however
* we'll stick with C99 for the time being.
*/
static inline size_t
mlx4_mallocv_inline(const char *type, const struct mlx4_malloc_vec *vec,
unsigned int cnt, int zero, int socket)
{
unsigned int i;
size_t size;
size_t least;
uint8_t *data = NULL;
int fill = !vec[0].addr;
fill:
size = 0;
least = 0;
for (i = 0; i < cnt; ++i) {
size_t align = (uintptr_t)vec[i].align;
if (!align) {
align = sizeof(double);
} else if (!rte_is_power_of_2(align)) {
rte_errno = EINVAL;
goto error;
}
if (least < align)
least = align;
align = RTE_ALIGN_CEIL(size, align);
size = align + vec[i].size;
if (fill && vec[i].addr)
*vec[i].addr = data + align;
}
if (fill)
return size;
if (!zero)
data = rte_malloc_socket(type, size, least, socket);
else
data = rte_zmalloc_socket(type, size, least, socket);
if (data) {
fill = 1;
goto fill;
}
rte_errno = ENOMEM;
error:
for (i = 0; i != cnt; ++i)
if (vec[i].addr)
*vec[i].addr = NULL;
return 0;
}
/**
* Allocate memory once for several disparate objects.
*
* This function adds iovec-like semantics (e.g. readv()) to rte_malloc().
* Memory is allocated once for several contiguous objects of nonuniform
* sizes and alignment constraints.
*
* Each entry of @p vec describes the size, alignment constraint and
* provides a buffer address where the resulting object pointer must be
* stored.
*
* The buffer of the first entry is guaranteed to point to the beginning of
* the allocated region and is safe to use with rte_free().
*
* NULL buffers are silently ignored.
*
* Providing a NULL buffer in the first entry prevents this function from
* allocating any memory but has otherwise no effect on its behavior. In
* this case, the contents of remaining non-NULL buffers are updated with
* addresses relative to zero (i.e. offsets that would have been used during
* the allocation).
*
* @param[in] type
* A string identifying the type of allocated objects (useful for debug
* purposes, such as identifying the cause of a memory leak). Can be NULL.
* @param[in, out] vec
* Description of objects to allocate memory for.
* @param cnt
* Number of entries in @p vec.
*
* @return
* Size in bytes of the allocated region including any padding. In case of
* error, rte_errno is set, 0 is returned and NULL is stored in the
* non-NULL buffers pointed by @p vec.
*
* @see struct mlx4_malloc_vec
* @see rte_malloc()
*/
size_t
mlx4_mallocv(const char *type, const struct mlx4_malloc_vec *vec,
unsigned int cnt)
{
return mlx4_mallocv_inline(type, vec, cnt, 0, SOCKET_ID_ANY);
}
/**
* Combines the semantics of mlx4_mallocv() with those of rte_zmalloc().
*
* @see mlx4_mallocv()
* @see rte_zmalloc()
*/
size_t
mlx4_zmallocv(const char *type, const struct mlx4_malloc_vec *vec,
unsigned int cnt)
{
return mlx4_mallocv_inline(type, vec, cnt, 1, SOCKET_ID_ANY);
}
/**
* Socket-aware version of mlx4_mallocv().
*
* This function takes one additional parameter.
*
* @param socket
* NUMA socket to allocate memory on. If SOCKET_ID_ANY is used, this
* function will behave the same as mlx4_mallocv().
*
* @see mlx4_mallocv()
* @see rte_malloc_socket()
*/
size_t
mlx4_mallocv_socket(const char *type, const struct mlx4_malloc_vec *vec,
unsigned int cnt, int socket)
{
return mlx4_mallocv_inline(type, vec, cnt, 0, socket);
}
/**
* Combines the semantics of mlx4_mallocv_socket() with those of
* mlx4_zmalloc_socket().
*
* @see mlx4_mallocv_socket()
* @see rte_zmalloc_socket()
*/
size_t
mlx4_zmallocv_socket(const char *type, const struct mlx4_malloc_vec *vec,
unsigned int cnt, int socket)
{
return mlx4_mallocv_inline(type, vec, cnt, 1, socket);
}