[PATCH v2 6/6] PCI: Align proc_bus_pci_read() with pci_read_config()

proc_bus_pci_read() and pci_read_config() implement essentially the
same functionality. To improve consistency across the PCI subsystem,
align the implementation in procfs with the sysfs counterpart.

Specifically:
  - Rename the variable 'pos' to 'off' and replace 'cnt' with 'count'.
  - Remove the redundant bounds check `if (nbytes >= size)`.
  - Use the same transfer loop conditions as pci_read_config().

No functional change intended.

Suggested-by: Bjorn Helgaas <[email protected]>
Signed-off-by: Ziming Du <[email protected]>
---
 drivers/pci/proc.c | 58 +++++++++++++++++++++++-----------------------
 1 file changed, 29 insertions(+), 29 deletions(-)

diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c
index 71d1f34e13a7d..13ac92da4624b 100644
--- a/drivers/pci/proc.c
+++ b/drivers/pci/proc.c
@@ -30,8 +30,9 @@ static ssize_t proc_bus_pci_read(struct file *file, char __user *buf,
 				 size_t nbytes, loff_t *ppos)
 {
 	struct pci_dev *dev = pde_data(file_inode(file));
-	loff_t pos = *ppos;
-	unsigned int cnt, size;
+	loff_t off = *ppos;
+	unsigned int count = nbytes;
+	unsigned int size;
 
 	/*
 	 * Normal users can read only the standardized portion of the
@@ -46,66 +47,65 @@ static ssize_t proc_bus_pci_read(struct file *file, char __user *buf,
 	else
 		size = 64;
 
-	if (pos >= size)
+	if (off >= size)
 		return 0;
-	if (nbytes >= size)
-		nbytes = size;
-	if (pos + nbytes > size)
-		nbytes = size - pos;
-	cnt = nbytes;
+	if (off + count > size) {
+		count = size - off;
+		nbytes = count;
+	}
 
-	if (!access_ok(buf, cnt))
+	if (!access_ok(buf, count))
 		return -EINVAL;
 
 	pci_config_pm_runtime_get(dev);
 
-	if ((pos & 1) && cnt) {
+	if ((off & 1) && count) {
 		unsigned char val;
-		pci_user_read_config_byte(dev, pos, &val);
+		pci_user_read_config_byte(dev, off, &val);
 		__put_user(val, buf);
 		buf++;
-		pos++;
-		cnt--;
+		off++;
+		count--;
 	}
 
-	if ((pos & 3) && cnt > 2) {
+	if ((off & 3) && count > 2) {
 		unsigned short val;
-		pci_user_read_config_word(dev, pos, &val);
+		pci_user_read_config_word(dev, off, &val);
 		__put_user(cpu_to_le16(val), (__le16 __user *) buf);
 		buf += 2;
-		pos += 2;
-		cnt -= 2;
+		off += 2;
+		count -= 2;
 	}
 
-	while (cnt >= 4) {
+	while (count > 3) {
 		unsigned int val;
-		pci_user_read_config_dword(dev, pos, &val);
+		pci_user_read_config_dword(dev, off, &val);
 		__put_user(cpu_to_le32(val), (__le32 __user *) buf);
 		buf += 4;
-		pos += 4;
-		cnt -= 4;
+		off += 4;
+		count -= 4;
 		cond_resched();
 	}
 
-	if (cnt >= 2) {
+	if (count >= 2) {
 		unsigned short val;
-		pci_user_read_config_word(dev, pos, &val);
+		pci_user_read_config_word(dev, off, &val);
 		__put_user(cpu_to_le16(val), (__le16 __user *) buf);
 		buf += 2;
-		pos += 2;
-		cnt -= 2;
+		off += 2;
+		count -= 2;
 	}
 
-	if (cnt) {
+	if (count > 0) {
 		unsigned char val;
-		pci_user_read_config_byte(dev, pos, &val);
+		pci_user_read_config_byte(dev, off, &val);
 		__put_user(val, buf);
-		pos++;
+		off++;
 	}
 
 	pci_config_pm_runtime_put(dev);
 
-	*ppos = pos;
+	*ppos = off;
 	return nbytes;
 }
 
-- 
2.43.0