Commit a93b6a2b authored by Gustavo A. R. Silva's avatar Gustavo A. R. Silva Committed by David S. Miller
Browse files

qed/qed_ll2: Replace one-element array with flexible-array member 

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
f5823fe6 ("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: default avatarkernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/5f707198.PA1UCZ8MYozYZYAR%25lkp@intel.com/


Signed-off-by: default avatarGustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b4c5f83a

drivers/net/ethernet/qlogic/qed/qed_ll2.c

+8 −10
Original line number Diff line number Diff line
@@ -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;

drivers/net/ethernet/qlogic/qed/qed_ll2.h

+4 −4
Original line number Diff line number Diff line
@@ -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 {

CRA Git | Maintained and supported by SUSTech CRA and CCSE