linux-stable/drivers/infiniband/hw/mthca/mthca_memfree.h
Gustavo A. R. Silva 5b361328ca RDMA: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Link: https://lore.kernel.org/r/20200213010425.GA13068@embeddedor.com
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> # added a few more
2020-02-20 13:33:51 -04:00

179 lines
5.6 KiB
C

/*
* Copyright (c) 2004, 2005 Topspin Communications. All rights reserved.
* Copyright (c) 2005 Cisco Systems. All rights reserved.
* Copyright (c) 2005 Mellanox Technologies. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* 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.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef MTHCA_MEMFREE_H
#define MTHCA_MEMFREE_H
#include <linux/list.h>
#include <linux/mutex.h>
#define MTHCA_ICM_CHUNK_LEN \
((256 - sizeof (struct list_head) - 2 * sizeof (int)) / \
(sizeof (struct scatterlist)))
enum {
MTHCA_ICM_PAGE_SHIFT = 12,
MTHCA_ICM_PAGE_SIZE = 1 << MTHCA_ICM_PAGE_SHIFT,
MTHCA_DB_REC_PER_PAGE = MTHCA_ICM_PAGE_SIZE / 8
};
struct mthca_icm_chunk {
struct list_head list;
int npages;
int nsg;
struct scatterlist mem[MTHCA_ICM_CHUNK_LEN];
};
struct mthca_icm {
struct list_head chunk_list;
int refcount;
};
struct mthca_icm_table {
u64 virt;
int num_icm;
int num_obj;
int obj_size;
int lowmem;
int coherent;
struct mutex mutex;
struct mthca_icm *icm[];
};
struct mthca_icm_iter {
struct mthca_icm *icm;
struct mthca_icm_chunk *chunk;
int page_idx;
};
struct mthca_dev;
struct mthca_icm *mthca_alloc_icm(struct mthca_dev *dev, int npages,
gfp_t gfp_mask, int coherent);
void mthca_free_icm(struct mthca_dev *dev, struct mthca_icm *icm, int coherent);
struct mthca_icm_table *mthca_alloc_icm_table(struct mthca_dev *dev,
u64 virt, int obj_size,
int nobj, int reserved,
int use_lowmem, int use_coherent);
void mthca_free_icm_table(struct mthca_dev *dev, struct mthca_icm_table *table);
int mthca_table_get(struct mthca_dev *dev, struct mthca_icm_table *table, int obj);
void mthca_table_put(struct mthca_dev *dev, struct mthca_icm_table *table, int obj);
void *mthca_table_find(struct mthca_icm_table *table, int obj, dma_addr_t *dma_handle);
int mthca_table_get_range(struct mthca_dev *dev, struct mthca_icm_table *table,
int start, int end);
void mthca_table_put_range(struct mthca_dev *dev, struct mthca_icm_table *table,
int start, int end);
static inline void mthca_icm_first(struct mthca_icm *icm,
struct mthca_icm_iter *iter)
{
iter->icm = icm;
iter->chunk = list_empty(&icm->chunk_list) ?
NULL : list_entry(icm->chunk_list.next,
struct mthca_icm_chunk, list);
iter->page_idx = 0;
}
static inline int mthca_icm_last(struct mthca_icm_iter *iter)
{
return !iter->chunk;
}
static inline void mthca_icm_next(struct mthca_icm_iter *iter)
{
if (++iter->page_idx >= iter->chunk->nsg) {
if (iter->chunk->list.next == &iter->icm->chunk_list) {
iter->chunk = NULL;
return;
}
iter->chunk = list_entry(iter->chunk->list.next,
struct mthca_icm_chunk, list);
iter->page_idx = 0;
}
}
static inline dma_addr_t mthca_icm_addr(struct mthca_icm_iter *iter)
{
return sg_dma_address(&iter->chunk->mem[iter->page_idx]);
}
static inline unsigned long mthca_icm_size(struct mthca_icm_iter *iter)
{
return sg_dma_len(&iter->chunk->mem[iter->page_idx]);
}
struct mthca_db_page {
DECLARE_BITMAP(used, MTHCA_DB_REC_PER_PAGE);
__be64 *db_rec;
dma_addr_t mapping;
};
struct mthca_db_table {
int npages;
int max_group1;
int min_group2;
struct mthca_db_page *page;
struct mutex mutex;
};
enum mthca_db_type {
MTHCA_DB_TYPE_INVALID = 0x0,
MTHCA_DB_TYPE_CQ_SET_CI = 0x1,
MTHCA_DB_TYPE_CQ_ARM = 0x2,
MTHCA_DB_TYPE_SQ = 0x3,
MTHCA_DB_TYPE_RQ = 0x4,
MTHCA_DB_TYPE_SRQ = 0x5,
MTHCA_DB_TYPE_GROUP_SEP = 0x7
};
struct mthca_user_db_table;
struct mthca_uar;
int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
struct mthca_user_db_table *db_tab, int index, u64 uaddr);
void mthca_unmap_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
struct mthca_user_db_table *db_tab, int index);
struct mthca_user_db_table *mthca_init_user_db_tab(struct mthca_dev *dev);
void mthca_cleanup_user_db_tab(struct mthca_dev *dev, struct mthca_uar *uar,
struct mthca_user_db_table *db_tab);
int mthca_init_db_tab(struct mthca_dev *dev);
void mthca_cleanup_db_tab(struct mthca_dev *dev);
int mthca_alloc_db(struct mthca_dev *dev, enum mthca_db_type type,
u32 qn, __be32 **db);
void mthca_free_db(struct mthca_dev *dev, int type, int db_index);
#endif /* MTHCA_MEMFREE_H */