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-rw-r--r--drivers/char/nvram.c130
1 files changed, 65 insertions, 65 deletions
diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c
index 42063cefa..a32cd18df 100644
--- a/drivers/char/nvram.c
+++ b/drivers/char/nvram.c
@@ -25,9 +25,12 @@
* the kernel and is not a module. Since the functions are used by some Atari
* drivers, this is the case on the Atari.
*
+ *
+ * 1.1 Cesar Barros: SMP locking fixes
+ * added changelog
*/
-#define NVRAM_VERSION "1.0"
+#define NVRAM_VERSION "1.1"
#include <linux/module.h>
#include <linux/config.h>
@@ -81,7 +84,7 @@
#endif
/* Note that *all* calls to CMOS_READ and CMOS_WRITE must be done with
- * interrupts disabled. Due to the index-port/data-port design of the RTC, we
+ * rtc_lock held. Due to the index-port/data-port design of the RTC, we
* don't want two different things trying to get to it at once. (e.g. the
* periodic 11 min sync from time.c vs. this driver.)
*/
@@ -96,11 +99,13 @@
#include <linux/nvram.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
+#include <linux/spinlock.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/system.h>
+extern spinlock_t rtc_lock;
static int nvram_open_cnt = 0; /* #times opened */
static int nvram_open_mode; /* special open modes */
@@ -163,21 +168,20 @@ unsigned char nvram_read_byte( int i )
unsigned long flags;
unsigned char c;
- save_flags(flags);
- cli();
+ spin_lock_irqsave (&rtc_lock, flags);
c = nvram_read_int( i );
- restore_flags(flags);
+ spin_unlock_irqrestore (&rtc_lock, flags);
return( c );
}
+/* This races nicely with trying to read with checksum checking (nvram_read) */
void nvram_write_byte( unsigned char c, int i )
{
unsigned long flags;
- save_flags(flags);
- cli();
+ spin_lock_irqsave (&rtc_lock, flags);
nvram_write_int( c, i );
- restore_flags(flags);
+ spin_unlock_irqrestore (&rtc_lock, flags);
}
int nvram_check_checksum( void )
@@ -185,10 +189,9 @@ int nvram_check_checksum( void )
unsigned long flags;
int rv;
- save_flags(flags);
- cli();
+ spin_lock_irqsave (&rtc_lock, flags);
rv = nvram_check_checksum_int();
- restore_flags(flags);
+ spin_unlock_irqrestore (&rtc_lock, flags);
return( rv );
}
@@ -196,10 +199,9 @@ void nvram_set_checksum( void )
{
unsigned long flags;
- save_flags(flags);
- cli();
+ spin_lock_irqsave (&rtc_lock, flags);
nvram_set_checksum_int();
- restore_flags(flags);
+ spin_unlock_irqrestore (&rtc_lock, flags);
}
#endif /* MACH == ATARI */
@@ -228,63 +230,67 @@ static long long nvram_llseek(struct file *file,loff_t offset, int origin )
static ssize_t nvram_read(struct file * file,
char * buf, size_t count, loff_t *ppos )
{
- unsigned long flags;
+ char contents [NVRAM_BYTES];
unsigned i = *ppos;
- char *tmp = buf;
-
- if (i != *ppos)
- return -EINVAL;
+ char *tmp;
- save_flags(flags);
- cli();
+ spin_lock_irq (&rtc_lock);
- if (!nvram_check_checksum_int()) {
- restore_flags(flags);
- return( -EIO );
- }
+ if (!nvram_check_checksum_int())
+ goto checksum_err;
+
+ for (tmp = contents; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp)
+ *tmp = nvram_read_int(i);
+
+ spin_unlock_irq (&rtc_lock);
+
+ copy_to_user_ret (buf, contents, tmp - contents, -EFAULT);
- for( ; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp )
- put_user( nvram_read_int(i), tmp );
*ppos = i;
- restore_flags(flags);
- return( tmp - buf );
+ return (tmp - contents);
+
+checksum_err:
+ spin_unlock_irq (&rtc_lock);
+ return -EIO;
}
static ssize_t nvram_write(struct file * file,
const char * buf, size_t count, loff_t *ppos )
{
- unsigned long flags;
+ char contents [NVRAM_BYTES];
unsigned i = *ppos;
- const char *tmp = buf;
- char c;
-
- if (i != *ppos)
- return -EINVAL;
+ char * tmp;
- save_flags(flags);
- cli();
-
- if (!nvram_check_checksum_int()) {
- restore_flags(flags);
- return( -EIO );
- }
+ /* could comebody please help me indent this better? */
+ copy_from_user_ret (contents, buf, (NVRAM_BYTES - i) < count ?
+ (NVRAM_BYTES - i) : count,
+ -EFAULT);
+
+ spin_lock_irq (&rtc_lock);
+
+ if (!nvram_check_checksum_int())
+ goto checksum_err;
+
+ for (tmp = contents; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp)
+ nvram_write_int (*tmp, i);
- for( ; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp ) {
- get_user( c, tmp );
- nvram_write_int( c, i );
- }
nvram_set_checksum_int();
+
+ spin_unlock_irq (&rtc_lock);
+
*ppos = i;
- restore_flags(flags);
- return( tmp - buf );
+ return (tmp - contents);
+
+checksum_err:
+ spin_unlock_irq (&rtc_lock);
+ return -EIO;
}
static int nvram_ioctl( struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg )
{
- unsigned long flags;
int i;
switch( cmd ) {
@@ -293,14 +299,13 @@ static int nvram_ioctl( struct inode *inode, struct file *file,
if (!capable(CAP_SYS_ADMIN))
return( -EACCES );
- save_flags(flags);
- cli();
+ spin_lock_irq (&rtc_lock);
for( i = 0; i < NVRAM_BYTES; ++i )
nvram_write_int( 0, i );
nvram_set_checksum_int();
- restore_flags(flags);
+ spin_unlock_irq (&rtc_lock);
return( 0 );
case NVRAM_SETCKS: /* just set checksum, contents unchanged
@@ -309,10 +314,9 @@ static int nvram_ioctl( struct inode *inode, struct file *file,
if (!capable(CAP_SYS_ADMIN))
return( -EACCES );
- save_flags(flags);
- cli();
+ spin_lock_irq (&rtc_lock);
nvram_set_checksum_int();
- restore_flags(flags);
+ spin_unlock_irq (&rtc_lock);
return( 0 );
default:
@@ -355,16 +359,14 @@ static int nvram_read_proc( char *buffer, char **start, off_t offset,
static int nvram_read_proc( char *buffer, char **start, off_t offset,
int size, int *eof, void *data )
{
- unsigned long flags;
unsigned char contents[NVRAM_BYTES];
int i, len = 0;
off_t begin = 0;
-
- save_flags(flags);
- cli();
+
+ spin_lock_irq (&rtc_lock);
for( i = 0; i < NVRAM_BYTES; ++i )
contents[i] = nvram_read_int( i );
- restore_flags(flags);
+ spin_unlock_irq (&rtc_lock);
*eof = mach_proc_infos( contents, buffer, &len, &begin, offset, size );
@@ -475,15 +477,13 @@ static char *gfx_types[] = {
static int pc_proc_infos( unsigned char *nvram, char *buffer, int *len,
off_t *begin, off_t offset, int size )
{
- unsigned long flags;
int checksum;
int type;
- save_flags(flags);
- cli();
+ spin_lock_irq (&rtc_lock);
checksum = nvram_check_checksum_int();
- restore_flags(flags);
-
+ spin_unlock_irq (&rtc_lock);
+
PRINT_PROC( "Checksum status: %svalid\n", checksum ? "" : "not " );
PRINT_PROC( "# floppies : %d\n",
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-20 05:29:16 +0000