From a93b6a2b9f466afb4fa1d0bd23ae2f1d29914811 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Mon, 28 Sep 2020 10:16:17 -0500 Subject: [PATCH] qed/qed_ll2: Replace one-element array with flexible-array member MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. Refactor the code according to the use of a flexible-array member in struct qed_ll2_tx_packet, instead of a one-element array and use the struct_size() helper to calculate the size for the allocations. Commit f5823fe6897c ("qed: Add ll2 option to limit the number of bds per packet") was used as a reference point for these changes. Also, it's important to notice that flexible-array members should occur last in any structure, and structures containing such arrays and that are members of other structures, must also occur last in the containing structure. That's why _cur_completing_packet_ is now moved to the bottom in struct qed_ll2_tx_queue. _descq_mem_ and _cur_send_packet_ are also moved for unification. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays Tested-by: kernel test robot Link: https://lore.kernel.org/lkml/5f707198.PA1UCZ8MYozYZYAR%25lkp@intel.com/ Signed-off-by: Gustavo A. R. Silva Signed-off-by: David S. Miller --- drivers/net/ethernet/qlogic/qed/qed_ll2.c | 18 ++++++++---------- drivers/net/ethernet/qlogic/qed/qed_ll2.h | 8 ++++---- 2 files changed, 12 insertions(+), 14 deletions(-) diff --git a/drivers/net/ethernet/qlogic/qed/qed_ll2.c b/drivers/net/ethernet/qlogic/qed/qed_ll2.c index 0452b728c527..49783f365079 100644 --- a/drivers/net/ethernet/qlogic/qed/qed_ll2.c +++ b/drivers/net/ethernet/qlogic/qed/qed_ll2.c @@ -1185,7 +1185,7 @@ static int qed_ll2_acquire_connection_tx(struct qed_hwfn *p_hwfn, .elem_size = sizeof(struct core_tx_bd), }; struct qed_ll2_tx_packet *p_descq; - u32 desc_size; + size_t desc_size; u32 capacity; int rc = 0; @@ -1198,10 +1198,9 @@ static int qed_ll2_acquire_connection_tx(struct qed_hwfn *p_hwfn, goto out; capacity = qed_chain_get_capacity(&p_ll2_info->tx_queue.txq_chain); - /* First element is part of the packet, rest are flexibly added */ - desc_size = (sizeof(*p_descq) + - (p_ll2_info->input.tx_max_bds_per_packet - 1) * - sizeof(p_descq->bds_set)); + /* All bds_set elements are flexibily added. */ + desc_size = struct_size(p_descq, bds_set, + p_ll2_info->input.tx_max_bds_per_packet); p_descq = kcalloc(capacity, desc_size, GFP_KERNEL); if (!p_descq) { @@ -1524,7 +1523,7 @@ int qed_ll2_establish_connection(void *cxt, u8 connection_handle) struct qed_ptt *p_ptt; int rc = -EINVAL; u32 i, capacity; - u32 desc_size; + size_t desc_size; u8 qid; p_ptt = qed_ptt_acquire(p_hwfn); @@ -1558,10 +1557,9 @@ int qed_ll2_establish_connection(void *cxt, u8 connection_handle) INIT_LIST_HEAD(&p_tx->sending_descq); spin_lock_init(&p_tx->lock); capacity = qed_chain_get_capacity(&p_tx->txq_chain); - /* First element is part of the packet, rest are flexibly added */ - desc_size = (sizeof(*p_pkt) + - (p_ll2_conn->input.tx_max_bds_per_packet - 1) * - sizeof(p_pkt->bds_set)); + /* All bds_set elements are flexibily added. */ + desc_size = struct_size(p_pkt, bds_set, + p_ll2_conn->input.tx_max_bds_per_packet); for (i = 0; i < capacity; i++) { p_pkt = p_tx->descq_mem + desc_size * i; diff --git a/drivers/net/ethernet/qlogic/qed/qed_ll2.h b/drivers/net/ethernet/qlogic/qed/qed_ll2.h index 500d0c4f8077..df88d00053a2 100644 --- a/drivers/net/ethernet/qlogic/qed/qed_ll2.h +++ b/drivers/net/ethernet/qlogic/qed/qed_ll2.h @@ -56,7 +56,7 @@ struct qed_ll2_tx_packet { struct core_tx_bd *txq_bd; dma_addr_t tx_frag; u16 frag_len; - } bds_set[1]; + } bds_set[]; }; struct qed_ll2_rx_queue { @@ -86,9 +86,6 @@ struct qed_ll2_tx_queue { struct list_head active_descq; struct list_head free_descq; struct list_head sending_descq; - void *descq_mem; /* memory for variable sized qed_ll2_tx_packet*/ - struct qed_ll2_tx_packet *cur_send_packet; - struct qed_ll2_tx_packet cur_completing_packet; u16 cur_completing_bd_idx; void __iomem *doorbell_addr; struct core_db_data db_msg; @@ -96,6 +93,9 @@ struct qed_ll2_tx_queue { u16 cur_send_frag_num; u16 cur_completing_frag_num; bool b_completing_packet; + void *descq_mem; /* memory for variable sized qed_ll2_tx_packet*/ + struct qed_ll2_tx_packet *cur_send_packet; + struct qed_ll2_tx_packet cur_completing_packet; }; struct qed_ll2_info {