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, 17 insertions, 12 deletions

diff --git a/drivers/infiniband/hw/mthca/mthca_provider.c b/drivers/infiniband/hw/mthca/mthca_provider.c
index 12179a41456d..1a3dd07f993b 100644
--- a/drivers/infiniband/hw/mthca/mthca_provider.c
+++ b/drivers/infiniband/hw/mthca/mthca_provider.c
@@ -965,25 +965,30 @@ static ssize_t hw_rev_show(struct device *device,
 }
 static DEVICE_ATTR_RO(hw_rev);
 
-static ssize_t hca_type_show(struct device *device,
-			     struct device_attribute *attr, char *buf)
+static const char *hca_type_string(int hca_type)
 {
-	struct mthca_dev *dev =
-		rdma_device_to_drv_device(device, struct mthca_dev, ib_dev);
-
-	switch (dev->pdev->device) {
+	switch (hca_type) {
 	case PCI_DEVICE_ID_MELLANOX_TAVOR:
-		return sysfs_emit(buf, "MT23108\n");
+		return "MT23108";
 	case PCI_DEVICE_ID_MELLANOX_ARBEL_COMPAT:
-		return sysfs_emit(buf, "MT25208 (MT23108 compat mode)\n");
+		return "MT25208 (MT23108 compat mode)";
 	case PCI_DEVICE_ID_MELLANOX_ARBEL:
-		return sysfs_emit(buf, "MT25208\n");
+		return "MT25208";
 	case PCI_DEVICE_ID_MELLANOX_SINAI:
 	case PCI_DEVICE_ID_MELLANOX_SINAI_OLD:
-		return sysfs_emit(buf, "MT25204\n");
-	default:
-		return sysfs_emit(buf, "unknown\n");
+		return "MT25204";
 	}
+
+	return "unknown";
+}
+
+static ssize_t hca_type_show(struct device *device,
+			     struct device_attribute *attr, char *buf)
+{
+	struct mthca_dev *dev =
+		rdma_device_to_drv_device(device, struct mthca_dev, ib_dev);
+
+	return sysfs_emit(buf, "%s\n", hca_type_string(dev->pdev->device));
 }
 static DEVICE_ATTR_RO(hca_type);