[MTD] Unabuse file-f_mode for OTP purpose

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 27 insertions, 21 deletions

diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 6ea2d8058a4a..548b89204aa2 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -1,5 +1,5 @@
 /*
- * $Id: mtdchar.c,v 1.67 2005/02/08 17:45:51 nico Exp $
+ * $Id: mtdchar.c,v 1.68 2005/02/08 19:12:50 nico Exp $
  *
  * Character-device access to raw MTD devices.
  *
@@ -59,15 +59,25 @@ static inline void mtdchar_devfs_exit(void)
 #define mtdchar_devfs_exit() do { } while(0)
 #endif
 
+/*
+ * We use file->private_data to store a pointer to the MTDdevice.
+ * Since alighment is at least 32 bits, we have 2 bits free for OTP
+ * modes as well.
+ */
+
+#define TO_MTD(file) (struct mtd_info *)((long)((file)->private_data) & ~3L)
 
-/* Well... let's abuse the unused bits in file->f_mode for those */
-#define MTD_MODE_OTP_FACT       0x1000
-#define MTD_MODE_OTP_USER       0x2000
-#define MTD_MODE_MASK           0xf000
+#define MTD_MODE_OTP_FACT       1
+#define MTD_MODE_OTP_USER       2
+#define MTD_MODE(file)          ((long)((file)->private_data) & 3)
+
+#define SET_MTD_MODE(file, mode) \
+        do { long __p = (long)((file)->private_data); \
+             (file)->private_data = (void *)((__p & ~3L) | mode); } while (0)
 
 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
 {
-        struct mtd_info *mtd = file->private_data;
+        struct mtd_info *mtd = TO_MTD(file);
 
         switch (orig) {
         case 0:
@@ -111,10 +121,6 @@ static int mtd_open(struct inode *inode, struct file *file)
         if ((file->f_mode & 2) && (minor & 1))
                 return -EACCES;
 
-        /* make sure the locally abused bits are initialy clear */
-        if (file->f_mode & MTD_MODE_MASK)
-                return -EWOULDBLOCK;
-
         mtd = get_mtd_device(NULL, devnum);
         
         if (!mtd)
@@ -144,7 +150,7 @@ static int mtd_close(struct inode *inode, struct file *file)
 
         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
 
-        mtd = file->private_data;
+        mtd = TO_MTD(file);
         
         if (mtd->sync)
                 mtd->sync(mtd);
@@ -161,7 +167,7 @@ static int mtd_close(struct inode *inode, struct file *file)
 
 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 {
-        struct mtd_info *mtd = file->private_data;
+        struct mtd_info *mtd = TO_MTD(file);
         size_t retlen=0;
         size_t total_retlen=0;
         int ret=0;
@@ -188,7 +194,7 @@ static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t
                 if (!kbuf)
                         return -ENOMEM;
                 
-                switch (file->f_mode & MTD_MODE_MASK) {
+                switch (MTD_MODE(file)) {
                 case MTD_MODE_OTP_FACT:
                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
                         break;
@@ -231,7 +237,7 @@ static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t
 
 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 {
-        struct mtd_info *mtd = file->private_data;
+        struct mtd_info *mtd = TO_MTD(file);
         char *kbuf;
         size_t retlen;
         size_t total_retlen=0;
@@ -266,7 +272,7 @@ static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count
                         return -EFAULT;
                 }
                 
-                switch (file->f_mode & MTD_MODE_MASK) {
+                switch (MTD_MODE(file)) {
                 case MTD_MODE_OTP_FACT:
                         ret = -EROFS;
                         break;
@@ -310,7 +316,7 @@ static void mtdchar_erase_callback (struct erase_info *instr)
 static int mtd_ioctl(struct inode *inode, struct file *file,
                      u_int cmd, u_long arg)
 {
-        struct mtd_info *mtd = file->private_data;
+        struct mtd_info *mtd = TO_MTD(file);
         void __user *argp = (void __user *)arg;
         int ret = 0;
         u_long size;
@@ -558,19 +564,19 @@ static int mtd_ioctl(struct inode *inode, struct file *file,
                 int mode;
                 if (copy_from_user(&mode, argp, sizeof(int)))
                         return -EFAULT;
-                file->f_mode &= ~MTD_MODE_MASK;
+                SET_MTD_MODE(file, 0);
                 switch (mode) {
                 case MTD_OTP_FACTORY:
                         if (!mtd->read_fact_prot_reg)
                                 ret = -EOPNOTSUPP;
                         else
-                                file->f_mode |= MTD_MODE_OTP_FACT;
+                                SET_MTD_MODE(file, MTD_MODE_OTP_FACT);
                         break;
                 case MTD_OTP_USER:
                         if (!mtd->read_fact_prot_reg)
                                 ret = -EOPNOTSUPP;
                         else
-                                file->f_mode |= MTD_MODE_OTP_USER;
+                                SET_MTD_MODE(file, MTD_MODE_OTP_USER);
                         break;
                 default:
                         ret = -EINVAL;
@@ -587,7 +593,7 @@ static int mtd_ioctl(struct inode *inode, struct file *file,
                 if (!buf)
                         return -ENOMEM;
                 ret = -EOPNOTSUPP;
-                switch (file->f_mode & MTD_MODE_MASK) {
+                switch (MTD_MODE(file)) {
                 case MTD_MODE_OTP_FACT:
                         if (mtd->get_fact_prot_info)
                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
@@ -614,7 +620,7 @@ static int mtd_ioctl(struct inode *inode, struct file *file,
         {
                 struct otp_info info;
 
-                if ((file->f_mode & MTD_MODE_MASK) != MTD_MODE_OTP_USER)
+                if (MTD_MODE(file) != MTD_MODE_OTP_USER)
                         return -EINVAL;
                 if (copy_from_user(&info, argp, sizeof(info)))
                         return -EFAULT;