iwlwifi: use rmb/wmb to protect indirect mmio operation

This patch protects iwlwifi indirect mmio operations with rmb() and
wmb(). It makes sure CPU reordering won't affect our indirect mmio
access.

Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-3945-io.h b/drivers/net/wireless/iwlwifi/iwl-3945-io.h
index 994f8bab0dab..d381b82a7598 100644
--- a/drivers/net/wireless/iwlwifi/iwl-3945-io.h
+++ b/drivers/net/wireless/iwlwifi/iwl-3945-io.h
@@ -298,6 +298,7 @@ static inline int __iwl3945_poll_direct_bit(const char *f, u32 l,
 static inline u32 _iwl3945_read_prph(struct iwl3945_priv *priv, u32 reg)
 {
         _iwl3945_write_direct32(priv, HBUS_TARG_PRPH_RADDR, reg | (3 << 24));
+        rmb();
         return _iwl3945_read_direct32(priv, HBUS_TARG_PRPH_RDAT);
 }
 #ifdef CONFIG_IWL3945_DEBUG
@@ -319,6 +320,7 @@ static inline void _iwl3945_write_prph(struct iwl3945_priv *priv,
 {
         _iwl3945_write_direct32(priv, HBUS_TARG_PRPH_WADDR,
                               ((addr & 0x0000FFFF) | (3 << 24)));
+        wmb();
         _iwl3945_write_direct32(priv, HBUS_TARG_PRPH_WDAT, val);
 }
 #ifdef CONFIG_IWL3945_DEBUG
@@ -380,12 +382,14 @@ static inline void iwl3945_clear_bits_prph(struct iwl3945_priv
 static inline u32 iwl3945_read_targ_mem(struct iwl3945_priv *priv, u32 addr)
 {
         iwl3945_write_direct32(priv, HBUS_TARG_MEM_RADDR, addr);
+        rmb();
         return iwl3945_read_direct32(priv, HBUS_TARG_MEM_RDAT);
 }
 
 static inline void iwl3945_write_targ_mem(struct iwl3945_priv *priv, u32 addr, u32 val)
 {
         iwl3945_write_direct32(priv, HBUS_TARG_MEM_WADDR, addr);
+        wmb();
         iwl3945_write_direct32(priv, HBUS_TARG_MEM_WDAT, val);
 }
 
@@ -393,6 +397,7 @@ static inline void iwl3945_write_targ_mem_buf(struct iwl3945_priv *priv, u32 add
                                           u32 len, u32 *values)
 {
         iwl3945_write_direct32(priv, HBUS_TARG_MEM_WADDR, addr);
+        wmb();
         for (; 0 < len; len -= sizeof(u32), values++)
                 iwl3945_write_direct32(priv, HBUS_TARG_MEM_WDAT, *values);
 }