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, 21 deletions

diff --git a/drivers/infiniband/hw/hfi1/sysfs.c b/drivers/infiniband/hw/hfi1/sysfs.c
index e2a88f3cea7f..9a695e1571c0 100644
--- a/drivers/infiniband/hw/hfi1/sysfs.c
+++ b/drivers/infiniband/hw/hfi1/sysfs.c
@@ -510,13 +510,11 @@ static ssize_t board_id_show(struct device *device,
 	struct hfi1_ibdev *dev =
 		rdma_device_to_drv_device(device, struct hfi1_ibdev, rdi.ibdev);
 	struct hfi1_devdata *dd = dd_from_dev(dev);
-	int ret;
 
 	if (!dd->boardname)
-		ret = -EINVAL;
-	else
-		ret = sysfs_emit(buf, "%s\n", dd->boardname);
-	return ret;
+		return -EINVAL;
+
+	return sysfs_emit(buf, "%s\n", dd->boardname);
 }
 static DEVICE_ATTR_RO(board_id);
 
@@ -570,6 +568,7 @@ static ssize_t serial_show(struct device *device,
 		rdma_device_to_drv_device(device, struct hfi1_ibdev, rdi.ibdev);
 	struct hfi1_devdata *dd = dd_from_dev(dev);
 
+	/* dd->serial is already newline terminated in chip.c */
 	return sysfs_emit(buf, "%s", dd->serial);
 }
 static DEVICE_ATTR_RO(serial);
@@ -598,9 +597,8 @@ static DEVICE_ATTR_WO(chip_reset);
  * Convert the reported temperature from an integer (reported in
  * units of 0.25C) to a floating point number.
  */
-#define temp2str(temp, buf, size, idx)					\
-	scnprintf((buf) + (idx), (size) - (idx), "%u.%02u ",		\
-			      ((temp) >> 2), ((temp) & 0x3) * 25)
+#define temp_d(t) ((t) >> 2)
+#define temp_f(t) (((t)&0x3) * 25u)
 
 /*
  * Dump tempsense values, in decimal, to ease shell-scripts.
@@ -615,19 +613,17 @@ static ssize_t tempsense_show(struct device *device,
 	int ret;
 
 	ret = hfi1_tempsense_rd(dd, &temp);
-	if (!ret) {
-		int idx = 0;
-
-		idx += temp2str(temp.curr, buf, PAGE_SIZE, idx);
-		idx += temp2str(temp.lo_lim, buf, PAGE_SIZE, idx);
-		idx += temp2str(temp.hi_lim, buf, PAGE_SIZE, idx);
-		idx += temp2str(temp.crit_lim, buf, PAGE_SIZE, idx);
-		idx += scnprintf(buf + idx, PAGE_SIZE - idx,
-				"%u %u %u\n", temp.triggers & 0x1,
-				temp.triggers & 0x2, temp.triggers & 0x4);
-		ret = idx;
-	}
-	return ret;
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%u.%02u %u.%02u %u.%02u %u.%02u %u %u %u\n",
+			  temp_d(temp.curr), temp_f(temp.curr),
+			  temp_d(temp.lo_lim), temp_f(temp.lo_lim),
+			  temp_d(temp.hi_lim), temp_f(temp.hi_lim),
+			  temp_d(temp.crit_lim), temp_f(temp.crit_lim),
+			  temp.triggers & 0x1,
+			  temp.triggers & 0x2,
+			  temp.triggers & 0x4);
 }
 static DEVICE_ATTR_RO(tempsense);