i2c-dev: Split i2cdev_ioctl
Split the handling of the I2C_RDWR and I2C_SMBUS ioctls to their own
functions. This limits the stack usage, saves one level of indentation
and makes the code more readable.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index 393e679..d34c14c 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -200,16 +200,176 @@
return device_for_each_child(&adapter->dev, &addr, i2cdev_check);
}
+static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client,
+ unsigned long arg)
+{
+ struct i2c_rdwr_ioctl_data rdwr_arg;
+ struct i2c_msg *rdwr_pa;
+ u8 __user **data_ptrs;
+ int i, res;
+
+ if (copy_from_user(&rdwr_arg,
+ (struct i2c_rdwr_ioctl_data __user *)arg,
+ sizeof(rdwr_arg)))
+ return -EFAULT;
+
+ /* Put an arbitrary limit on the number of messages that can
+ * be sent at once */
+ if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS)
+ return -EINVAL;
+
+ rdwr_pa = (struct i2c_msg *)
+ kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg),
+ GFP_KERNEL);
+ if (!rdwr_pa)
+ return -ENOMEM;
+
+ if (copy_from_user(rdwr_pa, rdwr_arg.msgs,
+ rdwr_arg.nmsgs * sizeof(struct i2c_msg))) {
+ kfree(rdwr_pa);
+ return -EFAULT;
+ }
+
+ data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL);
+ if (data_ptrs == NULL) {
+ kfree(rdwr_pa);
+ return -ENOMEM;
+ }
+
+ res = 0;
+ for (i = 0; i < rdwr_arg.nmsgs; i++) {
+ /* Limit the size of the message to a sane amount;
+ * and don't let length change either. */
+ if ((rdwr_pa[i].len > 8192) ||
+ (rdwr_pa[i].flags & I2C_M_RECV_LEN)) {
+ res = -EINVAL;
+ break;
+ }
+ data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
+ rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL);
+ if (rdwr_pa[i].buf == NULL) {
+ res = -ENOMEM;
+ break;
+ }
+ if (copy_from_user(rdwr_pa[i].buf, data_ptrs[i],
+ rdwr_pa[i].len)) {
+ ++i; /* Needs to be kfreed too */
+ res = -EFAULT;
+ break;
+ }
+ }
+ if (res < 0) {
+ int j;
+ for (j = 0; j < i; ++j)
+ kfree(rdwr_pa[j].buf);
+ kfree(data_ptrs);
+ kfree(rdwr_pa);
+ return res;
+ }
+
+ res = i2c_transfer(client->adapter, rdwr_pa, rdwr_arg.nmsgs);
+ while (i-- > 0) {
+ if (res >= 0 && (rdwr_pa[i].flags & I2C_M_RD)) {
+ if (copy_to_user(data_ptrs[i], rdwr_pa[i].buf,
+ rdwr_pa[i].len))
+ res = -EFAULT;
+ }
+ kfree(rdwr_pa[i].buf);
+ }
+ kfree(data_ptrs);
+ kfree(rdwr_pa);
+ return res;
+}
+
+static noinline int i2cdev_ioctl_smbus(struct i2c_client *client,
+ unsigned long arg)
+{
+ struct i2c_smbus_ioctl_data data_arg;
+ union i2c_smbus_data temp;
+ int datasize, res;
+
+ if (copy_from_user(&data_arg,
+ (struct i2c_smbus_ioctl_data __user *) arg,
+ sizeof(struct i2c_smbus_ioctl_data)))
+ return -EFAULT;
+ if ((data_arg.size != I2C_SMBUS_BYTE) &&
+ (data_arg.size != I2C_SMBUS_QUICK) &&
+ (data_arg.size != I2C_SMBUS_BYTE_DATA) &&
+ (data_arg.size != I2C_SMBUS_WORD_DATA) &&
+ (data_arg.size != I2C_SMBUS_PROC_CALL) &&
+ (data_arg.size != I2C_SMBUS_BLOCK_DATA) &&
+ (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) &&
+ (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
+ (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
+ dev_dbg(&client->adapter->dev,
+ "size out of range (%x) in ioctl I2C_SMBUS.\n",
+ data_arg.size);
+ return -EINVAL;
+ }
+ /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
+ so the check is valid if size==I2C_SMBUS_QUICK too. */
+ if ((data_arg.read_write != I2C_SMBUS_READ) &&
+ (data_arg.read_write != I2C_SMBUS_WRITE)) {
+ dev_dbg(&client->adapter->dev,
+ "read_write out of range (%x) in ioctl I2C_SMBUS.\n",
+ data_arg.read_write);
+ return -EINVAL;
+ }
+
+ /* Note that command values are always valid! */
+
+ if ((data_arg.size == I2C_SMBUS_QUICK) ||
+ ((data_arg.size == I2C_SMBUS_BYTE) &&
+ (data_arg.read_write == I2C_SMBUS_WRITE)))
+ /* These are special: we do not use data */
+ return i2c_smbus_xfer(client->adapter, client->addr,
+ client->flags, data_arg.read_write,
+ data_arg.command, data_arg.size, NULL);
+
+ if (data_arg.data == NULL) {
+ dev_dbg(&client->adapter->dev,
+ "data is NULL pointer in ioctl I2C_SMBUS.\n");
+ return -EINVAL;
+ }
+
+ if ((data_arg.size == I2C_SMBUS_BYTE_DATA) ||
+ (data_arg.size == I2C_SMBUS_BYTE))
+ datasize = sizeof(data_arg.data->byte);
+ else if ((data_arg.size == I2C_SMBUS_WORD_DATA) ||
+ (data_arg.size == I2C_SMBUS_PROC_CALL))
+ datasize = sizeof(data_arg.data->word);
+ else /* size == smbus block, i2c block, or block proc. call */
+ datasize = sizeof(data_arg.data->block);
+
+ if ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
+ (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
+ (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) ||
+ (data_arg.read_write == I2C_SMBUS_WRITE)) {
+ if (copy_from_user(&temp, data_arg.data, datasize))
+ return -EFAULT;
+ }
+ if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
+ /* Convert old I2C block commands to the new
+ convention. This preserves binary compatibility. */
+ data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA;
+ if (data_arg.read_write == I2C_SMBUS_READ)
+ temp.block[0] = I2C_SMBUS_BLOCK_MAX;
+ }
+ res = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ data_arg.read_write, data_arg.command, data_arg.size, &temp);
+ if (!res && ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
+ (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
+ (data_arg.read_write == I2C_SMBUS_READ))) {
+ if (copy_to_user(data_arg.data, &temp, datasize))
+ return -EFAULT;
+ }
+ return res;
+}
+
static int i2cdev_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
struct i2c_client *client = (struct i2c_client *)file->private_data;
- struct i2c_rdwr_ioctl_data rdwr_arg;
- struct i2c_smbus_ioctl_data data_arg;
- union i2c_smbus_data temp;
- struct i2c_msg *rdwr_pa;
- u8 __user **data_ptrs;
- int i,datasize,res;
unsigned long funcs;
dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n",
@@ -253,164 +413,11 @@
return put_user(funcs, (unsigned long __user *)arg);
case I2C_RDWR:
- if (copy_from_user(&rdwr_arg,
- (struct i2c_rdwr_ioctl_data __user *)arg,
- sizeof(rdwr_arg)))
- return -EFAULT;
-
- /* Put an arbitrary limit on the number of messages that can
- * be sent at once */
- if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS)
- return -EINVAL;
-
- rdwr_pa = (struct i2c_msg *)
- kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg),
- GFP_KERNEL);
-
- if (rdwr_pa == NULL) return -ENOMEM;
-
- if (copy_from_user(rdwr_pa, rdwr_arg.msgs,
- rdwr_arg.nmsgs * sizeof(struct i2c_msg))) {
- kfree(rdwr_pa);
- return -EFAULT;
- }
-
- data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL);
- if (data_ptrs == NULL) {
- kfree(rdwr_pa);
- return -ENOMEM;
- }
-
- res = 0;
- for( i=0; i<rdwr_arg.nmsgs; i++ ) {
- /* Limit the size of the message to a sane amount;
- * and don't let length change either. */
- if ((rdwr_pa[i].len > 8192) ||
- (rdwr_pa[i].flags & I2C_M_RECV_LEN)) {
- res = -EINVAL;
- break;
- }
- data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
- rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL);
- if(rdwr_pa[i].buf == NULL) {
- res = -ENOMEM;
- break;
- }
- if(copy_from_user(rdwr_pa[i].buf,
- data_ptrs[i],
- rdwr_pa[i].len)) {
- ++i; /* Needs to be kfreed too */
- res = -EFAULT;
- break;
- }
- }
- if (res < 0) {
- int j;
- for (j = 0; j < i; ++j)
- kfree(rdwr_pa[j].buf);
- kfree(data_ptrs);
- kfree(rdwr_pa);
- return res;
- }
-
- res = i2c_transfer(client->adapter,
- rdwr_pa,
- rdwr_arg.nmsgs);
- while(i-- > 0) {
- if( res>=0 && (rdwr_pa[i].flags & I2C_M_RD)) {
- if(copy_to_user(
- data_ptrs[i],
- rdwr_pa[i].buf,
- rdwr_pa[i].len)) {
- res = -EFAULT;
- }
- }
- kfree(rdwr_pa[i].buf);
- }
- kfree(data_ptrs);
- kfree(rdwr_pa);
- return res;
+ return i2cdev_ioctl_rdrw(client, arg);
case I2C_SMBUS:
- if (copy_from_user(&data_arg,
- (struct i2c_smbus_ioctl_data __user *) arg,
- sizeof(struct i2c_smbus_ioctl_data)))
- return -EFAULT;
- if ((data_arg.size != I2C_SMBUS_BYTE) &&
- (data_arg.size != I2C_SMBUS_QUICK) &&
- (data_arg.size != I2C_SMBUS_BYTE_DATA) &&
- (data_arg.size != I2C_SMBUS_WORD_DATA) &&
- (data_arg.size != I2C_SMBUS_PROC_CALL) &&
- (data_arg.size != I2C_SMBUS_BLOCK_DATA) &&
- (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) &&
- (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
- (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
- dev_dbg(&client->adapter->dev,
- "size out of range (%x) in ioctl I2C_SMBUS.\n",
- data_arg.size);
- return -EINVAL;
- }
- /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
- so the check is valid if size==I2C_SMBUS_QUICK too. */
- if ((data_arg.read_write != I2C_SMBUS_READ) &&
- (data_arg.read_write != I2C_SMBUS_WRITE)) {
- dev_dbg(&client->adapter->dev,
- "read_write out of range (%x) in ioctl I2C_SMBUS.\n",
- data_arg.read_write);
- return -EINVAL;
- }
+ return i2cdev_ioctl_smbus(client, arg);
- /* Note that command values are always valid! */
-
- if ((data_arg.size == I2C_SMBUS_QUICK) ||
- ((data_arg.size == I2C_SMBUS_BYTE) &&
- (data_arg.read_write == I2C_SMBUS_WRITE)))
- /* These are special: we do not use data */
- return i2c_smbus_xfer(client->adapter, client->addr,
- client->flags,
- data_arg.read_write,
- data_arg.command,
- data_arg.size, NULL);
-
- if (data_arg.data == NULL) {
- dev_dbg(&client->adapter->dev,
- "data is NULL pointer in ioctl I2C_SMBUS.\n");
- return -EINVAL;
- }
-
- if ((data_arg.size == I2C_SMBUS_BYTE_DATA) ||
- (data_arg.size == I2C_SMBUS_BYTE))
- datasize = sizeof(data_arg.data->byte);
- else if ((data_arg.size == I2C_SMBUS_WORD_DATA) ||
- (data_arg.size == I2C_SMBUS_PROC_CALL))
- datasize = sizeof(data_arg.data->word);
- else /* size == smbus block, i2c block, or block proc. call */
- datasize = sizeof(data_arg.data->block);
-
- if ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
- (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
- (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) ||
- (data_arg.read_write == I2C_SMBUS_WRITE)) {
- if (copy_from_user(&temp, data_arg.data, datasize))
- return -EFAULT;
- }
- if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
- /* Convert old I2C block commands to the new
- convention. This preserves binary compatibility. */
- data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA;
- if (data_arg.read_write == I2C_SMBUS_READ)
- temp.block[0] = I2C_SMBUS_BLOCK_MAX;
- }
- res = i2c_smbus_xfer(client->adapter,client->addr,client->flags,
- data_arg.read_write,
- data_arg.command,data_arg.size,&temp);
- if (! res && ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
- (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
- (data_arg.read_write == I2C_SMBUS_READ))) {
- if (copy_to_user(data_arg.data, &temp, datasize))
- return -EFAULT;
- }
- return res;
case I2C_RETRIES:
client->adapter->retries = arg;
break;