[PATCH 06/12] ipwireless: Remove endian-dependent bitfields

[David Sterba]

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

Signed-off-by: David Sterba <dsterba@xxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
---

 drivers/char/pcmcia/ipwireless/hardware.c |   51 ++++++++++++++++++++++-------
 1 files changed, 38 insertions(+), 13 deletions(-)

diff --git a/drivers/char/pcmcia/ipwireless/hardware.c b/drivers/char/pcmcia/ipwireless/hardware.c
index 7428734..08423ba 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);
 

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