net/mlx4_core: Initialize all mailbox buffers to zero before use

To guarantee that all unused fields in all FW commands for both inboxes
and outboxes are zeroed out, initialize the mailbox buffer to all zeroes.

This is especially important for SRIOV comm-channel virtual commands
(such as QUERY_FUNC_CAP), where if new fields are added to support new
features, the driver can depend on older kernels passing zeroes in these
fields.

In addition to zeroing out the mailbox buffer at allocation time, all
(now unnecessary) calls to memset by the callers of
mlx4_alloc_cmd_mailbox() are removed.

Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index 7567437..6a0a0d2 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -526,7 +526,6 @@
 	if (IS_ERR(mailbox))
 		return 0;
 
-	memset(mailbox->buf, 0, 256);
 	memcpy(mailbox->buf, props->node_desc, 64);
 	mlx4_cmd(to_mdev(ibdev)->dev, mailbox->dma, 1, 0,
 		 MLX4_CMD_SET_NODE, MLX4_CMD_TIME_CLASS_A, MLX4_CMD_NATIVE);
@@ -547,8 +546,6 @@
 	if (IS_ERR(mailbox))
 		return PTR_ERR(mailbox);
 
-	memset(mailbox->buf, 0, 256);
-
 	if (dev->dev->flags & MLX4_FLAG_OLD_PORT_CMDS) {
 		*(u8 *) mailbox->buf	     = !!reset_qkey_viols << 6;
 		((__be32 *) mailbox->buf)[2] = cpu_to_be32(cap_mask);
@@ -879,8 +876,6 @@
 	struct mlx4_ib_dev *mdev = to_mdev(qp->device);
 	struct mlx4_cmd_mailbox *mailbox;
 	struct mlx4_net_trans_rule_hw_ctrl *ctrl;
-	size_t rule_size = sizeof(struct mlx4_net_trans_rule_hw_ctrl) +
-			   (sizeof(struct _rule_hw) * flow_attr->num_of_specs);
 
 	static const u16 __mlx4_domain[] = {
 		[IB_FLOW_DOMAIN_USER] = MLX4_DOMAIN_UVERBS,
@@ -905,7 +900,6 @@
 	mailbox = mlx4_alloc_cmd_mailbox(mdev->dev);
 	if (IS_ERR(mailbox))
 		return PTR_ERR(mailbox);
-	memset(mailbox->buf, 0, rule_size);
 	ctrl = mailbox->buf;
 
 	ctrl->prio = cpu_to_be16(__mlx4_domain[domain] |
diff --git a/drivers/net/ethernet/mellanox/mlx4/cmd.c b/drivers/net/ethernet/mellanox/mlx4/cmd.c
index 65d41b7..7207dcd 100644
--- a/drivers/net/ethernet/mellanox/mlx4/cmd.c
+++ b/drivers/net/ethernet/mellanox/mlx4/cmd.c
@@ -2199,6 +2199,8 @@
 		return ERR_PTR(-ENOMEM);
 	}
 
+	memset(mailbox->buf, 0, MLX4_MAILBOX_SIZE);
+
 	return mailbox;
 }
 EXPORT_SYMBOL_GPL(mlx4_alloc_cmd_mailbox);
diff --git a/drivers/net/ethernet/mellanox/mlx4/cq.c b/drivers/net/ethernet/mellanox/mlx4/cq.c
index 004e423..22fcbe7 100644
--- a/drivers/net/ethernet/mellanox/mlx4/cq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/cq.c
@@ -128,8 +128,6 @@
 		return PTR_ERR(mailbox);
 
 	cq_context = mailbox->buf;
-	memset(cq_context, 0, sizeof *cq_context);
-
 	cq_context->cq_max_count = cpu_to_be16(count);
 	cq_context->cq_period    = cpu_to_be16(period);
 
@@ -153,8 +151,6 @@
 		return PTR_ERR(mailbox);
 
 	cq_context = mailbox->buf;
-	memset(cq_context, 0, sizeof *cq_context);
-
 	cq_context->logsize_usrpage = cpu_to_be32(ilog2(entries) << 24);
 	cq_context->log_page_size   = mtt->page_shift - 12;
 	mtt_addr = mlx4_mtt_addr(dev, mtt);
@@ -274,8 +270,6 @@
 	}
 
 	cq_context = mailbox->buf;
-	memset(cq_context, 0, sizeof *cq_context);
-
 	cq_context->flags	    = cpu_to_be32(!!collapsed << 18);
 	if (timestamp_en)
 		cq_context->flags  |= cpu_to_be32(1 << 19);
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_port.c b/drivers/net/ethernet/mellanox/mlx4/en_port.c
index 3317914..5f8535e 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_port.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_port.c
@@ -56,7 +56,6 @@
 		return PTR_ERR(mailbox);
 
 	filter = mailbox->buf;
-	memset(filter, 0, sizeof(*filter));
 	for (i = VLAN_FLTR_SIZE - 1; i >= 0; i--) {
 		entry = 0;
 		for (j = 0; j < 32; j++)
@@ -81,7 +80,6 @@
 	mailbox = mlx4_alloc_cmd_mailbox(mdev->dev);
 	if (IS_ERR(mailbox))
 		return PTR_ERR(mailbox);
-	memset(mailbox->buf, 0, sizeof(*qport_context));
 	err = mlx4_cmd_box(mdev->dev, 0, mailbox->dma, port, 0,
 			   MLX4_CMD_QUERY_PORT, MLX4_CMD_TIME_CLASS_B,
 			   MLX4_CMD_WRAPPED);
@@ -127,7 +125,6 @@
 	mailbox = mlx4_alloc_cmd_mailbox(mdev->dev);
 	if (IS_ERR(mailbox))
 		return PTR_ERR(mailbox);
-	memset(mailbox->buf, 0, sizeof(*mlx4_en_stats));
 	err = mlx4_cmd_box(mdev->dev, 0, mailbox->dma, in_mod, 0,
 			   MLX4_CMD_DUMP_ETH_STATS, MLX4_CMD_TIME_CLASS_B,
 			   MLX4_CMD_WRAPPED);
diff --git a/drivers/net/ethernet/mellanox/mlx4/eq.c b/drivers/net/ethernet/mellanox/mlx4/eq.c
index 0416c5b..c9cdb2a 100644
--- a/drivers/net/ethernet/mellanox/mlx4/eq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/eq.c
@@ -936,7 +936,6 @@
 	if (err)
 		goto err_out_free_mtt;
 
-	memset(eq_context, 0, sizeof *eq_context);
 	eq_context->flags	  = cpu_to_be32(MLX4_EQ_STATUS_OK   |
 						MLX4_EQ_STATE_ARMED);
 	eq_context->log_eq_size	  = ilog2(eq->nent);
diff --git a/drivers/net/ethernet/mellanox/mlx4/fw.c b/drivers/net/ethernet/mellanox/mlx4/fw.c
index c3e70bc..fda2667 100644
--- a/drivers/net/ethernet/mellanox/mlx4/fw.c
+++ b/drivers/net/ethernet/mellanox/mlx4/fw.c
@@ -159,8 +159,6 @@
 		return PTR_ERR(mailbox);
 	inbox = mailbox->buf;
 
-	memset(inbox, 0, MOD_STAT_CFG_IN_SIZE);
-
 	MLX4_PUT(inbox, cfg->log_pg_sz, MOD_STAT_CFG_PG_SZ_OFFSET);
 	MLX4_PUT(inbox, cfg->log_pg_sz_m, MOD_STAT_CFG_PG_SZ_M_OFFSET);
 
@@ -967,7 +965,6 @@
 	mailbox = mlx4_alloc_cmd_mailbox(dev);
 	if (IS_ERR(mailbox))
 		return PTR_ERR(mailbox);
-	memset(mailbox->buf, 0, MLX4_MAILBOX_SIZE);
 	pages = mailbox->buf;
 
 	for (mlx4_icm_first(icm, &iter);
@@ -1316,8 +1313,6 @@
 		return PTR_ERR(mailbox);
 	inbox = mailbox->buf;
 
-	memset(inbox, 0, INIT_HCA_IN_SIZE);
-
 	*((u8 *) mailbox->buf + INIT_HCA_VERSION_OFFSET) = INIT_HCA_VERSION;
 
 	*((u8 *) mailbox->buf + INIT_HCA_CACHELINE_SZ_OFFSET) =
@@ -1616,8 +1611,6 @@
 			return PTR_ERR(mailbox);
 		inbox = mailbox->buf;
 
-		memset(inbox, 0, INIT_PORT_IN_SIZE);
-
 		flags = 0;
 		flags |= (dev->caps.vl_cap[port] & 0xf) << INIT_PORT_VL_SHIFT;
 		flags |= (dev->caps.port_width_cap[port] & 0xf) << INIT_PORT_PORT_WIDTH_SHIFT;
diff --git a/drivers/net/ethernet/mellanox/mlx4/mcg.c b/drivers/net/ethernet/mellanox/mlx4/mcg.c
index 70f0213..acf9d5f 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mcg.c
+++ b/drivers/net/ethernet/mellanox/mlx4/mcg.c
@@ -506,7 +506,6 @@
 		goto out_list;
 	}
 	mgm = mailbox->buf;
-	memset(mgm, 0, sizeof *mgm);
 	members_count = 0;
 	list_for_each_entry(dqp, &s_steer->promisc_qps[steer], list)
 		mgm->qp[members_count++] = cpu_to_be32(dqp->qpn & MGM_QPN_MASK);
@@ -857,7 +856,6 @@
 	if (IS_ERR(mailbox))
 		return PTR_ERR(mailbox);
 
-	memset(mailbox->buf, 0, sizeof(struct mlx4_net_trans_rule_hw_ctrl));
 	trans_rule_ctrl_to_hw(rule, mailbox->buf);
 
 	size += sizeof(struct mlx4_net_trans_rule_hw_ctrl);
diff --git a/drivers/net/ethernet/mellanox/mlx4/mr.c b/drivers/net/ethernet/mellanox/mlx4/mr.c
index 63391a1..b3ee9ba 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mr.c
+++ b/drivers/net/ethernet/mellanox/mlx4/mr.c
@@ -480,9 +480,6 @@
 		goto err_table;
 	}
 	mpt_entry = mailbox->buf;
-
-	memset(mpt_entry, 0, sizeof *mpt_entry);
-
 	mpt_entry->flags = cpu_to_be32(MLX4_MPT_FLAG_MIO	 |
 				       MLX4_MPT_FLAG_REGION	 |
 				       mr->access);
@@ -695,8 +692,6 @@
 	}
 	mpt_entry = mailbox->buf;
 
-	memset(mpt_entry, 0, sizeof(*mpt_entry));
-
 	/* Note that the MLX4_MPT_FLAG_REGION bit in mpt_entry->flags is turned
 	 * off, thus creating a memory window and not a memory region.
 	 */
diff --git a/drivers/net/ethernet/mellanox/mlx4/port.c b/drivers/net/ethernet/mellanox/mlx4/port.c
index caaa154..97d342f 100644
--- a/drivers/net/ethernet/mellanox/mlx4/port.c
+++ b/drivers/net/ethernet/mellanox/mlx4/port.c
@@ -469,8 +469,6 @@
 
 	inbuf = inmailbox->buf;
 	outbuf = outmailbox->buf;
-	memset(inbuf, 0, 256);
-	memset(outbuf, 0, 256);
 	inbuf[0] = 1;
 	inbuf[1] = 1;
 	inbuf[2] = 1;
@@ -653,8 +651,6 @@
 	if (IS_ERR(mailbox))
 		return PTR_ERR(mailbox);
 
-	memset(mailbox->buf, 0, 256);
-
 	((__be32 *) mailbox->buf)[1] = dev->caps.ib_port_def_cap[port];
 
 	if (pkey_tbl_sz >= 0 && mlx4_is_master(dev)) {
@@ -692,8 +688,6 @@
 	if (IS_ERR(mailbox))
 		return PTR_ERR(mailbox);
 	context = mailbox->buf;
-	memset(context, 0, sizeof *context);
-
 	context->flags = SET_PORT_GEN_ALL_VALID;
 	context->mtu = cpu_to_be16(mtu);
 	context->pptx = (pptx * (!pfctx)) << 7;
@@ -727,8 +721,6 @@
 	if (IS_ERR(mailbox))
 		return PTR_ERR(mailbox);
 	context = mailbox->buf;
-	memset(context, 0, sizeof *context);
-
 	context->base_qpn = cpu_to_be32(base_qpn);
 	context->n_mac = dev->caps.log_num_macs;
 	context->promisc = cpu_to_be32(promisc << SET_PORT_PROMISC_SHIFT |
@@ -761,8 +753,6 @@
 	if (IS_ERR(mailbox))
 		return PTR_ERR(mailbox);
 	context = mailbox->buf;
-	memset(context, 0, sizeof *context);
-
 	for (i = 0; i < MLX4_NUM_UP; i += 2)
 		context->prio2tc[i >> 1] = prio2tc[i] << 4 | prio2tc[i + 1];
 
@@ -788,7 +778,6 @@
 	if (IS_ERR(mailbox))
 		return PTR_ERR(mailbox);
 	context = mailbox->buf;
-	memset(context, 0, sizeof *context);
 
 	for (i = 0; i < MLX4_NUM_TC; i++) {
 		struct mlx4_port_scheduler_tc_cfg_be *tc = &context->tc[i];
diff --git a/drivers/net/ethernet/mellanox/mlx4/srq.c b/drivers/net/ethernet/mellanox/mlx4/srq.c
index 9e08e35..8fdf237 100644
--- a/drivers/net/ethernet/mellanox/mlx4/srq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/srq.c
@@ -189,8 +189,6 @@
 	}
 
 	srq_context = mailbox->buf;
-	memset(srq_context, 0, sizeof *srq_context);
-
 	srq_context->state_logsize_srqn = cpu_to_be32((ilog2(srq->max) << 24) |
 						      srq->srqn);
 	srq_context->logstride          = srq->wqe_shift - 4;