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authorArnd Bergmann <arnd@arndb.de>2010-06-02 08:28:52 -0400
committerArnd Bergmann <arnd@arndb.de>2010-10-05 09:01:04 -0400
commit613655fa39ff6957754fa8ceb8559980920eb8ee (patch)
treead19600cb81207b24188683d7fc4ae88013339d1 /drivers/char/ds1302.c
parent609146fdb319cebce93be550938ab852f7bade90 (diff)
drivers: 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. These drivers do not seem to be under active maintainance from my brief investigation. Apologies to those maintainers that I have missed. 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>
Diffstat (limited to 'drivers/char/ds1302.c')
-rw-r--r--drivers/char/ds1302.c15
1 files changed, 8 insertions, 7 deletions
diff --git a/drivers/char/ds1302.c b/drivers/char/ds1302.c
index 170693c93c73..e3d72aa3cbd2 100644
--- a/drivers/char/ds1302.c
+++ b/drivers/char/ds1302.c
@@ -20,7 +20,7 @@
20#include <linux/miscdevice.h> 20#include <linux/miscdevice.h>
21#include <linux/delay.h> 21#include <linux/delay.h>
22#include <linux/bcd.h> 22#include <linux/bcd.h>
23#include <linux/smp_lock.h> 23#include <linux/mutex.h>
24#include <linux/uaccess.h> 24#include <linux/uaccess.h>
25#include <linux/io.h> 25#include <linux/io.h>
26 26
@@ -32,6 +32,7 @@
32 32
33#define RTC_MAJOR_NR 121 /* local major, change later */ 33#define RTC_MAJOR_NR 121 /* local major, change later */
34 34
35static DEFINE_MUTEX(rtc_mutex);
35static const char ds1302_name[] = "ds1302"; 36static const char ds1302_name[] = "ds1302";
36 37
37/* Send 8 bits. */ 38/* Send 8 bits. */
@@ -164,9 +165,9 @@ static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
164 struct rtc_time rtc_tm; 165 struct rtc_time rtc_tm;
165 166
166 memset(&rtc_tm, 0, sizeof (struct rtc_time)); 167 memset(&rtc_tm, 0, sizeof (struct rtc_time));
167 lock_kernel(); 168 mutex_lock(&rtc_mutex);
168 get_rtc_time(&rtc_tm); 169 get_rtc_time(&rtc_tm);
169 unlock_kernel(); 170 mutex_unlock(&rtc_mutex);
170 if (copy_to_user((struct rtc_time*)arg, &rtc_tm, sizeof(struct rtc_time))) 171 if (copy_to_user((struct rtc_time*)arg, &rtc_tm, sizeof(struct rtc_time)))
171 return -EFAULT; 172 return -EFAULT;
172 return 0; 173 return 0;
@@ -218,7 +219,7 @@ static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
218 mon = bin2bcd(mon); 219 mon = bin2bcd(mon);
219 yrs = bin2bcd(yrs); 220 yrs = bin2bcd(yrs);
220 221
221 lock_kernel(); 222 mutex_lock(&rtc_mutex);
222 local_irq_save(flags); 223 local_irq_save(flags);
223 CMOS_WRITE(yrs, RTC_YEAR); 224 CMOS_WRITE(yrs, RTC_YEAR);
224 CMOS_WRITE(mon, RTC_MONTH); 225 CMOS_WRITE(mon, RTC_MONTH);
@@ -227,7 +228,7 @@ static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
227 CMOS_WRITE(min, RTC_MINUTES); 228 CMOS_WRITE(min, RTC_MINUTES);
228 CMOS_WRITE(sec, RTC_SECONDS); 229 CMOS_WRITE(sec, RTC_SECONDS);
229 local_irq_restore(flags); 230 local_irq_restore(flags);
230 unlock_kernel(); 231 mutex_unlock(&rtc_mutex);
231 232
232 /* Notice that at this point, the RTC is updated but 233 /* Notice that at this point, the RTC is updated but
233 * the kernel is still running with the old time. 234 * the kernel is still running with the old time.
@@ -247,10 +248,10 @@ static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
247 if(copy_from_user(&tcs_val, (int*)arg, sizeof(int))) 248 if(copy_from_user(&tcs_val, (int*)arg, sizeof(int)))
248 return -EFAULT; 249 return -EFAULT;
249 250
250 lock_kernel(); 251 mutex_lock(&rtc_mutex);
251 tcs_val = RTC_TCR_PATTERN | (tcs_val & 0x0F); 252 tcs_val = RTC_TCR_PATTERN | (tcs_val & 0x0F);
252 ds1302_writereg(RTC_TRICKLECHARGER, tcs_val); 253 ds1302_writereg(RTC_TRICKLECHARGER, tcs_val);
253 unlock_kernel(); 254 mutex_unlock(&rtc_mutex);
254 return 0; 255 return 0;
255 } 256 }
256 default: 257 default: