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>

1 files changed, 23 insertions, 33 deletions

diff --git a/drivers/infiniband/hw/usnic/usnic_ib_sysfs.c b/drivers/infiniband/hw/usnic/usnic_ib_sysfs.c
index 0af72fca00ff..250948c382f9 100644
--- a/drivers/infiniband/hw/usnic/usnic_ib_sysfs.c
+++ b/drivers/infiniband/hw/usnic/usnic_ib_sysfs.c
@@ -57,7 +57,7 @@ static ssize_t board_id_show(struct device *device,
 	subsystem_device_id = us_ibdev->pdev->subsystem_device;
 	mutex_unlock(&us_ibdev->usdev_lock);
 
-	return sysfs_emit(buf, "%hu\n", subsystem_device_id);
+	return sysfs_emit(buf, "%u\n", subsystem_device_id);
 }
 static DEVICE_ATTR_RO(board_id);
 
@@ -69,19 +69,13 @@ config_show(struct device *device, struct device_attribute *attr, char *buf)
 {
 	struct usnic_ib_dev *us_ibdev =
 		rdma_device_to_drv_device(device, struct usnic_ib_dev, ib_dev);
-	char *ptr;
-	unsigned left;
-	unsigned n;
 	enum usnic_vnic_res_type res_type;
-
-	/* Buffer space limit is 1 page */
-	ptr = buf;
-	left = PAGE_SIZE;
+	int len;
 
 	mutex_lock(&us_ibdev->usdev_lock);
 	if (kref_read(&us_ibdev->vf_cnt) > 0) {
 		char *busname;
-
+		char *sep = "";
 		/*
 		 * bus name seems to come with annoying prefix.
 		 * Remove it if it is predictable
@@ -90,39 +84,35 @@ config_show(struct device *device, struct device_attribute *attr, char *buf)
 		if (strncmp(busname, "PCI Bus ", 8) == 0)
 			busname += 8;
 
-		n = scnprintf(ptr, left,
-			"%s: %s:%d.%d, %s, %pM, %u VFs\n Per VF:",
-			dev_name(&us_ibdev->ib_dev.dev),
-			busname,
-			PCI_SLOT(us_ibdev->pdev->devfn),
-			PCI_FUNC(us_ibdev->pdev->devfn),
-			netdev_name(us_ibdev->netdev),
-			us_ibdev->ufdev->mac,
-			kref_read(&us_ibdev->vf_cnt));
-		UPDATE_PTR_LEFT(n, ptr, left);
+		len = sysfs_emit(buf, "%s: %s:%d.%d, %s, %pM, %u VFs\n",
+				 dev_name(&us_ibdev->ib_dev.dev),
+				 busname,
+				 PCI_SLOT(us_ibdev->pdev->devfn),
+				 PCI_FUNC(us_ibdev->pdev->devfn),
+				 netdev_name(us_ibdev->netdev),
+				 us_ibdev->ufdev->mac,
+				 kref_read(&us_ibdev->vf_cnt));
 
+		len += sysfs_emit_at(buf, len, " Per VF:");
 		for (res_type = USNIC_VNIC_RES_TYPE_EOL;
-				res_type < USNIC_VNIC_RES_TYPE_MAX;
-				res_type++) {
+		     res_type < USNIC_VNIC_RES_TYPE_MAX; res_type++) {
 			if (us_ibdev->vf_res_cnt[res_type] == 0)
 				continue;
-			n = scnprintf(ptr, left, " %d %s%s",
-				us_ibdev->vf_res_cnt[res_type],
-				usnic_vnic_res_type_to_str(res_type),
-				(res_type < (USNIC_VNIC_RES_TYPE_MAX - 1)) ?
-				 "," : "");
-			UPDATE_PTR_LEFT(n, ptr, left);
+			len += sysfs_emit_at(buf, len, "%s %d %s",
+					     sep,
+					     us_ibdev->vf_res_cnt[res_type],
+					     usnic_vnic_res_type_to_str(res_type));
+			sep = ",";
 		}
-		n = scnprintf(ptr, left, "\n");
-		UPDATE_PTR_LEFT(n, ptr, left);
+		len += sysfs_emit_at(buf, len, "\n");
 	} else {
-		n = scnprintf(ptr, left, "%s: no VFs\n",
-				dev_name(&us_ibdev->ib_dev.dev));
-		UPDATE_PTR_LEFT(n, ptr, left);
+		len = sysfs_emit(buf, "%s: no VFs\n",
+				 dev_name(&us_ibdev->ib_dev.dev));
 	}
+
 	mutex_unlock(&us_ibdev->usdev_lock);
 
-	return ptr - buf;
+	return len;
 }
 static DEVICE_ATTR_RO(config);