--- zzzz-none-000/linux-3.10.107/drivers/pci/proc.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/pci/proc.c	2021-02-04 17:41:59.000000000 +0000
@@ -17,34 +17,14 @@
 
 static int proc_initialized;	/* = 0 */
 
-static loff_t
-proc_bus_pci_lseek(struct file *file, loff_t off, int whence)
+static loff_t proc_bus_pci_lseek(struct file *file, loff_t off, int whence)
 {
-	loff_t new = -1;
-	struct inode *inode = file_inode(file);
-
-	mutex_lock(&inode->i_mutex);
-	switch (whence) {
-	case 0:
-		new = off;
-		break;
-	case 1:
-		new = file->f_pos + off;
-		break;
-	case 2:
-		new = inode->i_size + off;
-		break;
-	}
-	if (new < 0 || new > inode->i_size)
-		new = -EINVAL;
-	else
-		file->f_pos = new;
-	mutex_unlock(&inode->i_mutex);
-	return new;
+	struct pci_dev *dev = PDE_DATA(file_inode(file));
+	return fixed_size_llseek(file, off, whence, dev->cfg_size);
 }
 
-static ssize_t
-proc_bus_pci_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
+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));
 	unsigned int pos = *ppos;
@@ -127,8 +107,8 @@
 	return nbytes;
 }
 
-static ssize_t
-proc_bus_pci_write(struct file *file, const char __user *buf, size_t nbytes, loff_t *ppos)
+static ssize_t proc_bus_pci_write(struct file *file, const char __user *buf,
+				  size_t nbytes, loff_t *ppos)
 {
 	struct inode *ino = file_inode(file);
 	struct pci_dev *dev = PDE_DATA(ino);
@@ -241,7 +221,7 @@
 	default:
 		ret = -EINVAL;
 		break;
-	};
+	}
 
 	return ret;
 }
@@ -432,7 +412,7 @@
 	return 0;
 }
 
-int pci_proc_detach_bus(struct pci_bus* bus)
+int pci_proc_detach_bus(struct pci_bus *bus)
 {
 	proc_remove(bus->procdir);
 	return 0;
@@ -442,6 +422,7 @@
 {
 	return seq_open(file, &proc_bus_pci_devices_op);
 }
+
 static const struct file_operations proc_bus_pci_dev_operations = {
 	.owner		= THIS_MODULE,
 	.open		= proc_bus_pci_dev_open,
@@ -462,6 +443,4 @@
 
 	return 0;
 }
-
 device_initcall(pci_proc_init);
-