ipwireless: Remove endian-dependent bitfields

ipwireless: Remove endian-dependent bitfields

Remove endian-dependent bitfields and use bitmasks to transform
packet header bitfields from/to machine order.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 38 insertions, 13 deletions

diff --git a/drivers/char/pcmcia/ipwireless/hardware.c b/drivers/char/pcmcia/ipwireless/hardware.c
index 7428734d08a1..08423ba5b9dd 100644
--- a/drivers/char/pcmcia/ipwireless/hardware.c
+++ b/drivers/char/pcmcia/ipwireless/hardware.c
@@ -132,29 +132,17 @@ enum {
 #define NL_FOLLOWING_PACKET_HEADER_SIZE    1
 
 struct nl_first_packet_header {
-#if defined(__BIG_ENDIAN_BITFIELD)
-        unsigned char packet_rank:2;
-        unsigned char address:3;
-        unsigned char protocol:3;
-#else
         unsigned char protocol:3;
         unsigned char address:3;
         unsigned char packet_rank:2;
-#endif
         unsigned char length_lsb;
         unsigned char length_msb;
 };
 
 struct nl_packet_header {
-#if defined(__BIG_ENDIAN_BITFIELD)
-        unsigned char packet_rank:2;
-        unsigned char address:3;
-        unsigned char protocol:3;
-#else
         unsigned char protocol:3;
         unsigned char address:3;
         unsigned char packet_rank:2;
-#endif
 };
 
 /* Value of 'packet_rank' above */
@@ -382,7 +370,37 @@ static void dump_data_bytes(const char *type, const unsigned char *data,
                         length < DUMP_MAX_BYTES ? length : DUMP_MAX_BYTES);
 }
 
-static int do_send_fragment(struct ipw_hardware *hw, const unsigned char *data,
+static void swap_packet_bitfield_to_le(unsigned char *data)
+{
+#ifdef __BIG_ENDIAN_BITFIELD
+        unsigned char tmp = *data, ret = 0;
+
+        /*
+         * transform bits from aa.bbb.ccc to ccc.bbb.aa
+         */
+        ret |= tmp & 0xc0 >> 6;
+        ret |= tmp & 0x38 >> 1;
+        ret |= tmp & 0x07 << 5;
+        *data = ret & 0xff;
+#endif
+}
+
+static void swap_packet_bitfield_from_le(unsigned char *data)
+{
+#ifdef __BIG_ENDIAN_BITFIELD
+        unsigned char tmp = *data, ret = 0;
+
+        /*
+         * transform bits from ccc.bbb.aa to aa.bbb.ccc
+         */
+        ret |= tmp & 0xe0 >> 5;
+        ret |= tmp & 0x1c << 1;
+        ret |= tmp & 0x03 << 6;
+        *data = ret & 0xff;
+#endif
+}
+
+static int do_send_fragment(struct ipw_hardware *hw, unsigned char *data,
                             unsigned length)
 {
         unsigned i;
@@ -402,6 +420,7 @@ static int do_send_fragment(struct ipw_hardware *hw, const unsigned char *data,
         spin_lock_irqsave(&hw->lock, flags);
 
         hw->tx_ready = 0;
+        swap_packet_bitfield_to_le(data);
 
         if (hw->hw_version == HW_VERSION_1) {
                 outw((unsigned short) length, hw->base_port + IODWR);
@@ -458,6 +477,10 @@ static int do_send_packet(struct ipw_hardware *hw, struct ipw_tx_packet *packet)
         if (data_left < fragment_data_len)
                 fragment_data_len = data_left;
 
+        /*
+         * hdr_first is now in machine bitfield order, which will be swapped
+         * to le just before it goes to hw
+         */
         pkt.hdr_first.protocol = packet->protocol;
         pkt.hdr_first.address = packet->dest_addr;
         pkt.hdr_first.packet_rank = 0;
@@ -883,6 +906,8 @@ static void do_receive_packet(struct ipw_hardware *hw)
 
         acknowledge_data_read(hw);
 
+        swap_packet_bitfield_from_le(pkt);
+
         if (ipwireless_debug)
                 dump_data_bytes("recv", pkt, len);