RDMA: Manual changes for sysfs_emit and neatening

Make changes to use sysfs_emit in the RDMA code as cocci scripts can not
be written to handle _all_ the possible variants of various sprintf family
uses in sysfs show functions.

While there, make the code more legible and update its style to be more
like the typical kernel styles.

Miscellanea:

o Use intermediate pointers for dereferences
o Add and use string lookup functions
o return early when any intermediate call fails so normal return is
  at the bottom of the function
o mlx4/mcg.c:sysfs_show_group: use scnprintf to format intermediate strings

Link: https://lore.kernel.org/r/f5c9e4c9d8dafca1b7b70bd597ee7f8f219c31c8.1602122880.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

3 files changed, 67 insertions, 61 deletions

diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index 2ac932834f98..f0864f40ea1a 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -2024,6 +2024,7 @@ static ssize_t hca_type_show(struct device *device,
 {
 	struct mlx4_ib_dev *dev =
 		rdma_device_to_drv_device(device, struct mlx4_ib_dev, ib_dev);
+
 	return sysfs_emit(buf, "MT%d\n", dev->dev->persist->pdev->device);
 }
 static DEVICE_ATTR_RO(hca_type);
@@ -2033,6 +2034,7 @@ static ssize_t hw_rev_show(struct device *device,
 {
 	struct mlx4_ib_dev *dev =
 		rdma_device_to_drv_device(device, struct mlx4_ib_dev, ib_dev);
+
 	return sysfs_emit(buf, "%x\n", dev->dev->rev_id);
 }
 static DEVICE_ATTR_RO(hw_rev);
diff --git a/drivers/infiniband/hw/mlx4/mcg.c b/drivers/infiniband/hw/mlx4/mcg.c
index 5e4ec9786081..33f525b744f2 100644
--- a/drivers/infiniband/hw/mlx4/mcg.c
+++ b/drivers/infiniband/hw/mlx4/mcg.c
@@ -988,53 +988,63 @@ int mlx4_ib_mcg_multiplex_handler(struct ib_device *ibdev, int port,
 }
 
 static ssize_t sysfs_show_group(struct device *dev,
-		struct device_attribute *attr, char *buf)
+				struct device_attribute *attr, char *buf)
 {
 	struct mcast_group *group =
 		container_of(attr, struct mcast_group, dentry);
 	struct mcast_req *req = NULL;
-	char pending_str[40];
 	char state_str[40];
-	ssize_t len = 0;
-	int f;
+	char pending_str[40];
+	int len;
+	int i;
+	u32 hoplimit;
 
 	if (group->state == MCAST_IDLE)
-		sprintf(state_str, "%s", get_state_string(group->state));
+		scnprintf(state_str, sizeof(state_str), "%s",
+			  get_state_string(group->state));
 	else
-		sprintf(state_str, "%s(TID=0x%llx)",
-				get_state_string(group->state),
-				be64_to_cpu(group->last_req_tid));
+		scnprintf(state_str, sizeof(state_str), "%s(TID=0x%llx)",
+			  get_state_string(group->state),
+			  be64_to_cpu(group->last_req_tid));
+
 	if (list_empty(&group->pending_list)) {
-		sprintf(pending_str, "No");
+		scnprintf(pending_str, sizeof(pending_str), "No");
 	} else {
-		req = list_first_entry(&group->pending_list, struct mcast_req, group_list);
-		sprintf(pending_str, "Yes(TID=0x%llx)",
-				be64_to_cpu(req->sa_mad.mad_hdr.tid));
+		req = list_first_entry(&group->pending_list, struct mcast_req,
+				       group_list);
+		scnprintf(pending_str, sizeof(pending_str), "Yes(TID=0x%llx)",
+			  be64_to_cpu(req->sa_mad.mad_hdr.tid));
 	}
-	len += sprintf(buf + len, "%1d [%02d,%02d,%02d] %4d %4s %5s     ",
-			group->rec.scope_join_state & 0xf,
-			group->members[2], group->members[1], group->members[0],
-			atomic_read(&group->refcount),
-			pending_str,
-			state_str);
-	for (f = 0; f < MAX_VFS; ++f)
-		if (group->func[f].state == MCAST_MEMBER)
-			len += sprintf(buf + len, "%d[%1x] ",
-					f, group->func[f].join_state);
-
-	len += sprintf(buf + len, "\t\t(%4hx %4x %2x %2x %2x %2x %2x "
-		"%4x %4x %2x %2x)\n",
-		be16_to_cpu(group->rec.pkey),
-		be32_to_cpu(group->rec.qkey),
-		(group->rec.mtusel_mtu & 0xc0) >> 6,
-		group->rec.mtusel_mtu & 0x3f,
-		group->rec.tclass,
-		(group->rec.ratesel_rate & 0xc0) >> 6,
-		group->rec.ratesel_rate & 0x3f,
-		(be32_to_cpu(group->rec.sl_flowlabel_hoplimit) & 0xf0000000) >> 28,
-		(be32_to_cpu(group->rec.sl_flowlabel_hoplimit) & 0x0fffff00) >> 8,
-		be32_to_cpu(group->rec.sl_flowlabel_hoplimit) & 0x000000ff,
-		group->rec.proxy_join);
+
+	len = sysfs_emit(buf, "%1d [%02d,%02d,%02d] %4d %4s %5s     ",
+			 group->rec.scope_join_state & 0xf,
+			 group->members[2],
+			 group->members[1],
+			 group->members[0],
+			 atomic_read(&group->refcount),
+			 pending_str,
+			 state_str);
+
+	for (i = 0; i < MAX_VFS; i++) {
+		if (group->func[i].state == MCAST_MEMBER)
+			len += sysfs_emit_at(buf, len, "%d[%1x] ", i,
+					     group->func[i].join_state);
+	}
+
+	hoplimit = be32_to_cpu(group->rec.sl_flowlabel_hoplimit);
+	len += sysfs_emit_at(buf, len,
+			     "\t\t(%4hx %4x %2x %2x %2x %2x %2x %4x %4x %2x %2x)\n",
+			     be16_to_cpu(group->rec.pkey),
+			     be32_to_cpu(group->rec.qkey),
+			     (group->rec.mtusel_mtu & 0xc0) >> 6,
+			     (group->rec.mtusel_mtu & 0x3f),
+			     group->rec.tclass,
+			     (group->rec.ratesel_rate & 0xc0) >> 6,
+			     (group->rec.ratesel_rate & 0x3f),
+			     (hoplimit & 0xf0000000) >> 28,
+			     (hoplimit & 0x0fffff00) >> 8,
+			     (hoplimit & 0x000000ff),
+			     group->rec.proxy_join);
 
 	return len;
 }
diff --git a/drivers/infiniband/hw/mlx4/sysfs.c b/drivers/infiniband/hw/mlx4/sysfs.c
index 22ae363088ed..0279b780c446 100644
--- a/drivers/infiniband/hw/mlx4/sysfs.c
+++ b/drivers/infiniband/hw/mlx4/sysfs.c
@@ -117,22 +117,24 @@ static ssize_t show_port_gid(struct device *dev,
 	struct mlx4_ib_iov_port *port = mlx4_ib_iov_dentry->ctx;
 	struct mlx4_ib_dev *mdev = port->dev;
 	union ib_gid gid;
-	ssize_t ret;
+	int ret;
+	__be16 *raw;
 
 	ret = __mlx4_ib_query_gid(&mdev->ib_dev, port->num,
 				  mlx4_ib_iov_dentry->entry_num, &gid, 1);
 	if (ret)
 		return ret;
-	ret = sysfs_emit(buf, "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
-			 be16_to_cpu(((__be16 *)gid.raw)[0]),
-			 be16_to_cpu(((__be16 *)gid.raw)[1]),
-			 be16_to_cpu(((__be16 *)gid.raw)[2]),
-			 be16_to_cpu(((__be16 *)gid.raw)[3]),
-			 be16_to_cpu(((__be16 *)gid.raw)[4]),
-			 be16_to_cpu(((__be16 *)gid.raw)[5]),
-			 be16_to_cpu(((__be16 *)gid.raw)[6]),
-			 be16_to_cpu(((__be16 *)gid.raw)[7]));
-	return ret;
+
+	raw = (__be16 *)gid.raw;
+	return sysfs_emit(buf, "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
+			  be16_to_cpu(raw[0]),
+			  be16_to_cpu(raw[1]),
+			  be16_to_cpu(raw[2]),
+			  be16_to_cpu(raw[3]),
+			  be16_to_cpu(raw[4]),
+			  be16_to_cpu(raw[5]),
+			  be16_to_cpu(raw[6]),
+			  be16_to_cpu(raw[7]));
 }
 
 static ssize_t show_phys_port_pkey(struct device *dev,
@@ -542,14 +544,10 @@ static ssize_t sysfs_show_smi_enabled(struct device *dev,
 {
 	struct mlx4_port *p =
 		container_of(attr, struct mlx4_port, smi_enabled);
-	ssize_t len = 0;
 
-	if (mlx4_vf_smi_enabled(p->dev->dev, p->slave, p->port_num))
-		len = sysfs_emit(buf, "%d\n", 1);
-	else
-		len = sysfs_emit(buf, "%d\n", 0);
-
-	return len;
+	return sysfs_emit(buf, "%d\n",
+			  !!mlx4_vf_smi_enabled(p->dev->dev, p->slave,
+						p->port_num));
 }
 
 static ssize_t sysfs_show_enable_smi_admin(struct device *dev,
@@ -558,14 +556,10 @@ static ssize_t sysfs_show_enable_smi_admin(struct device *dev,
 {
 	struct mlx4_port *p =
 		container_of(attr, struct mlx4_port, enable_smi_admin);
-	ssize_t len = 0;
-
-	if (mlx4_vf_get_enable_smi_admin(p->dev->dev, p->slave, p->port_num))
-		len = sysfs_emit(buf, "%d\n", 1);
-	else
-		len = sysfs_emit(buf, "%d\n", 0);
 
-	return len;
+	return sysfs_emit(buf, "%d\n",
+			  !!mlx4_vf_get_enable_smi_admin(p->dev->dev, p->slave,
+							 p->port_num));
 }
 
 static ssize_t sysfs_store_enable_smi_admin(struct device *dev,