i2c: cpm: Fix i2c_ram structure

[ Upstream commit a2bd970 ]

the i2c_ram structure is missing the sdmatmp field mentionned in
datasheet for MPC8272 at paragraph 36.5. With this field missing, the
hardware would write past the allocated memory done through
cpm_muram_alloc for the i2c_ram structure and land in memory allocated
for the buffers descriptors corrupting the cbd_bufaddr field. Since this
field is only set during setup(), the first i2c transaction would work
and the following would send data read from an arbitrary memory
location.

Fixes: 61045db ("i2c: Add support for I2C bus on Freescale CPM1/CPM2 controllers")
Signed-off-by: Nicolas VINCENT <nicolas.vincent@vossloh.com>
Acked-by: Jochen Friedrich <jochen@scram.de>
Acked-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/i2c/busses/i2c-cpm.c

@@ -65,6 +65,9 @@ struct i2c_ram {
 	char    res1[4];	/* Reserved */
 	ushort  rpbase;		/* Relocation pointer */
 	char    res2[2];	/* Reserved */
+	/* The following elements are only for CPM2 */
+	char    res3[4];	/* Reserved */
+	uint    sdmatmp;	/* Internal */
 };
 
 #define I2COM_START	0x80