Because all of the descriptor data structures are marked as __packed, GCC
assumes the worst case wrt. alignment and generates unaligned load/store
instructions on MIPS for access to all fields.
Since descriptors always have to be 4-byte-aligned, we can just mark the
data structures with __aligned(4), which allows GCC to generate much more
efficient code.
Verified through disassembly and OProfile comparisons.
Signed-off-by: Felix Fietkau <nbd@xxxxxxxxxxx>
---
drivers/net/wireless/ath/ath9k/ar9003_mac.h | 6 +++---
drivers/net/wireless/ath/ath9k/mac.h | 4 ++--
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/net/wireless/ath/ath9k/ar9003_mac.h b/drivers/net/wireless/ath/ath9k/ar9003_mac.h
index 9f2cea7..45cc7e8 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_mac.h
+++ b/drivers/net/wireless/ath/ath9k/ar9003_mac.h
@@ -65,7 +65,7 @@ struct ar9003_rxs {
u32 status9;
u32 status10;
u32 status11;
-} __packed;
+} __packed __aligned(4);
/* Transmit Control Descriptor */
struct ar9003_txc {
@@ -93,7 +93,7 @@ struct ar9003_txc {
u32 ctl21; /* DMA control 21 */
u32 ctl22; /* DMA control 22 */
u32 pad[9]; /* pad to cache line (128 bytes/32 dwords) */
-} __packed;
+} __packed __aligned(4);
struct ar9003_txs {
u32 ds_info;
@@ -105,7 +105,7 @@ struct ar9003_txs {
u32 status6;
u32 status7;
u32 status8;
-} __packed;
+} __packed __aligned(4);
void ar9003_hw_attach_mac_ops(struct ath_hw *hw);
void ath9k_hw_set_rx_bufsize(struct ath_hw *ah, u16 buf_size);
diff --git a/drivers/net/wireless/ath/ath9k/mac.h b/drivers/net/wireless/ath/ath9k/mac.h
index fdc2507..22907e2 100644
--- a/drivers/net/wireless/ath/ath9k/mac.h
+++ b/drivers/net/wireless/ath/ath9k/mac.h
@@ -237,7 +237,7 @@ struct ath_desc {
u32 ds_ctl1;
u32 ds_hw[20];
void *ds_vdata;
-} __packed;
+} __packed __aligned(4);
#define ATH9K_TXDESC_CLRDMASK 0x0001
#define ATH9K_TXDESC_NOACK 0x0002
@@ -307,7 +307,7 @@ struct ar5416_desc {
u32 status8;
} rx;
} u;
-} __packed;
+} __packed __aligned(4);
#define AR5416DESC(_ds) ((struct ar5416_desc *)(_ds))
#define AR5416DESC_CONST(_ds) ((const struct ar5416_desc *)(_ds))
--
1.7.2.2
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
