sbus: autoconvert trivial BKL users to private mutex

All these files use the big kernel lock in a trivial
way to serialize their private file operations,
typically resulting from an earlier semi-automatic
pushdown from VFS.

None of these drivers appears to want to lock against
other code, and they all use the BKL as the top-level
lock in their file operations, meaning that there
is no lock-order inversion problem.

Consequently, we can remove the BKL completely,
replacing it with a per-file mutex in every case.
Using a scripted approach means we can avoid
typos.

file=$1
name=$2
if grep -q lock_kernel ${file} ; then
    if grep -q 'include.*linux.mutex.h' ${file} ; then
            sed -i '/include.*<linux\/smp_lock.h>/d' ${file}
    else
            sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file}
    fi
    sed -i ${file} \
        -e "/^#include.*linux.mutex.h/,$ {
                1,/^\(static\|int\|long\)/ {
                     /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);

} }"  \
    -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
    -e '/[      ]*cycle_kernel_lock();/d'
else
    sed -i -e '/include.*\<smp_lock.h\>/d' ${file}  \
                -e '/cycle_kernel_lock()/d'
fi

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 24 insertions, 23 deletions

diff --git a/drivers/sbus/char/display7seg.c b/drivers/sbus/char/display7seg.c
index 7baf1b644039..4ad4d2c91075 100644
--- a/drivers/sbus/char/display7seg.c
+++ b/drivers/sbus/char/display7seg.c
@@ -13,7 +13,7 @@
 #include <linux/miscdevice.h>
 #include <linux/ioport.h>               /* request_region */
 #include <linux/slab.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <asm/atomic.h>
@@ -26,6 +26,7 @@
 #define DRIVER_NAME     "d7s"
 #define PFX             DRIVER_NAME ": "
 
+static DEFINE_MUTEX(d7s_mutex);
 static int sol_compat = 0;              /* Solaris compatibility mode   */
 
 /* Solaris compatibility flag -
@@ -74,7 +75,6 @@ static int d7s_open(struct inode *inode, struct file *f)
 {
         if (D7S_MINOR != iminor(inode))
                 return -ENODEV;
-        cycle_kernel_lock();
         atomic_inc(&d7s_users);
         return 0;
 }
@@ -110,7 +110,7 @@ static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
         if (D7S_MINOR != iminor(file->f_path.dentry->d_inode))
                 return -ENODEV;
 
-        lock_kernel();
+        mutex_lock(&d7s_mutex);
         switch (cmd) {
         case D7SIOCWR:
                 /* assign device register values we mask-out D7S_FLIP
@@ -151,7 +151,7 @@ static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
                 writeb(regs, p->regs);
                 break;
         };
-        unlock_kernel();
+        mutex_unlock(&d7s_mutex);
 
         return error;
 }
diff --git a/drivers/sbus/char/envctrl.c b/drivers/sbus/char/envctrl.c
index c8166ecf5276..bd0bbc621351 100644
--- a/drivers/sbus/char/envctrl.c
+++ b/drivers/sbus/char/envctrl.c
@@ -27,7 +27,6 @@
 #include <linux/kmod.h>
 #include <linux/reboot.h>
 #include <linux/slab.h>
-#include <linux/smp_lock.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 
@@ -699,7 +698,6 @@ envctrl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 static int
 envctrl_open(struct inode *inode, struct file *file)
 {
-        cycle_kernel_lock();
         file->private_data = NULL;
         return 0;
 }
diff --git a/drivers/sbus/char/flash.c b/drivers/sbus/char/flash.c
index 368d66294d83..ed9494e18859 100644
--- a/drivers/sbus/char/flash.c
+++ b/drivers/sbus/char/flash.c
@@ -10,7 +10,7 @@
 #include <linux/fcntl.h>
 #include <linux/poll.h>
 #include <linux/init.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/spinlock.h>
 #include <linux/mm.h>
 #include <linux/of.h>
@@ -22,6 +22,7 @@
 #include <asm/io.h>
 #include <asm/upa.h>
 
+static DEFINE_MUTEX(flash_mutex);
 static DEFINE_SPINLOCK(flash_lock);
 static struct {
         unsigned long read_base;        /* Physical read address */
@@ -80,7 +81,7 @@ flash_mmap(struct file *file, struct vm_area_struct *vma)
 static long long
 flash_llseek(struct file *file, long long offset, int origin)
 {
-        lock_kernel();
+        mutex_lock(&flash_mutex);
         switch (origin) {
                 case 0:
                         file->f_pos = offset;
@@ -94,10 +95,10 @@ flash_llseek(struct file *file, long long offset, int origin)
                         file->f_pos = flash.read_size;
                         break;
                 default:
-                        unlock_kernel();
+                        mutex_unlock(&flash_mutex);
                         return -EINVAL;
         }
-        unlock_kernel();
+        mutex_unlock(&flash_mutex);
         return file->f_pos;
 }
 
@@ -125,13 +126,13 @@ flash_read(struct file * file, char __user * buf,
 static int
 flash_open(struct inode *inode, struct file *file)
 {
-        lock_kernel();
+        mutex_lock(&flash_mutex);
         if (test_and_set_bit(0, (void *)&flash.busy) != 0) {
-                unlock_kernel();
+                mutex_unlock(&flash_mutex);
                 return -EBUSY;
         }
 
-        unlock_kernel();
+        mutex_unlock(&flash_mutex);
         return 0;
 }
 
diff --git a/drivers/sbus/char/openprom.c b/drivers/sbus/char/openprom.c
index aacbe14e2e7a..8d6e508222b8 100644
--- a/drivers/sbus/char/openprom.c
+++ b/drivers/sbus/char/openprom.c
@@ -33,7 +33,7 @@
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/string.h>
 #include <linux/miscdevice.h>
 #include <linux/init.h>
@@ -61,6 +61,7 @@ typedef struct openprom_private_data
 } DATA;
 
 /* ID of the PROM node containing all of the EEPROM options. */
+static DEFINE_MUTEX(openprom_mutex);
 static struct device_node *options_node;
 
 /*
@@ -316,7 +317,7 @@ static long openprom_sunos_ioctl(struct file * file,
         if (bufsize < 0)
                 return bufsize;
 
-        lock_kernel();
+        mutex_lock(&openprom_mutex);
 
         switch (cmd) {
         case OPROMGETOPT:
@@ -367,7 +368,7 @@ static long openprom_sunos_ioctl(struct file * file,
         }
 
         kfree(opp);
-        unlock_kernel();
+        mutex_unlock(&openprom_mutex);
 
         return error;
 }
@@ -558,7 +559,7 @@ static int openprom_bsd_ioctl(struct file * file,
         void __user *argp = (void __user *)arg;
         int err;
 
-        lock_kernel();
+        mutex_lock(&openprom_mutex);
         switch (cmd) {
         case OPIOCGET:
                 err = opiocget(argp, data);
@@ -589,7 +590,7 @@ static int openprom_bsd_ioctl(struct file * file,
                 err = -EINVAL;
                 break;
         };
-        unlock_kernel();
+        mutex_unlock(&openprom_mutex);
 
         return err;
 }
@@ -697,11 +698,11 @@ static int openprom_open(struct inode * inode, struct file * file)
         if (!data)
                 return -ENOMEM;
 
-        lock_kernel();
+        mutex_lock(&openprom_mutex);
         data->current_node = of_find_node_by_path("/");
         data->lastnode = data->current_node;
         file->private_data = (void *) data;
-        unlock_kernel();
+        mutex_unlock(&openprom_mutex);
 
         return 0;
 }
diff --git a/drivers/sbus/char/uctrl.c b/drivers/sbus/char/uctrl.c
index 5f253665a1da..079da4cb45a5 100644
--- a/drivers/sbus/char/uctrl.c
+++ b/drivers/sbus/char/uctrl.c
@@ -9,7 +9,7 @@
 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/slab.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/ioport.h>
 #include <linux/init.h>
 #include <linux/miscdevice.h>
@@ -72,6 +72,7 @@ struct ts102_regs {
 #define UCTRL_STAT_RXNE_STA        0x04    /* receive FIFO not empty status */
 #define UCTRL_STAT_RXO_STA         0x08    /* receive FIFO overflow status */
 
+static DEFINE_MUTEX(uctrl_mutex);
 static const char *uctrl_extstatus[16] = {
         "main power available",
         "internal battery attached",
@@ -210,10 +211,10 @@ uctrl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 static int
 uctrl_open(struct inode *inode, struct file *file)
 {
-        lock_kernel();
+        mutex_lock(&uctrl_mutex);
         uctrl_get_event_status(global_driver);
         uctrl_get_external_status(global_driver);
-        unlock_kernel();
+        mutex_unlock(&uctrl_mutex);
         return 0;
 }