[PATCH net-next 2/4] i40e: use generic unrolled_count() macro

Alexander Lobakin
2025-02-06T18:30:35Z

i40e, as well as ice, has a custom loop unrolling macro for unrolling
Tx descriptors filling on XSk xmit.
Replace i40e defs with generic unrolled_count(), which is also more
convenient as it allows passing defines as its argument, not hardcoded
values, while the loop declaration will still be a usual for-loop.

Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
---
drivers/net/ethernet/intel/i40e/i40e_xsk.h | 10 +---------
drivers/net/ethernet/intel/i40e/i40e_xsk.c | 4 +++-
2 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.h b/drivers/net/ethernet/intel/i40e/i40e_xsk.h
index ef156fad52f2..dd16351a7af8 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.h
@@ -6,7 +6,7 @@

#include <linux/types.h>

-/* This value should match the pragma in the loop_unrolled_for
+/* This value should match the pragma in the unrolled_count()
* macro. Why 4? It is strictly empirical. It seems to be a good
* compromise between the advantage of having simultaneous outstanding
* reads to the DMA array that can hide each others latency and the
@@ -14,14 +14,6 @@
*/
#define PKTS_PER_BATCH 4

-#ifdef __clang__
-#define loop_unrolled_for _Pragma("clang loop unroll_count(4)") for
-#elif __GNUC__ >= 8
-#define loop_unrolled_for _Pragma("GCC unroll 4") for
-#else
-#define loop_unrolled_for for
-#endif
-
struct i40e_ring;
struct i40e_vsi;
struct net_device;
diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index e28f1905a4a0..9f47388eaba5 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -2,6 +2,7 @@
/* Copyright(c) 2018 Intel Corporation. */

#include <linux/bpf_trace.h>
+#include <linux/unroll.h>
#include <net/xdp_sock_drv.h>
#include "i40e_txrx_common.h"
#include "i40e_xsk.h"
@@ -529,7 +530,8 @@ static void i40e_xmit_pkt_batch(struct i40e_ring *xdp_ring, struct xdp_desc *des
dma_addr_t dma;
u32 i;

- loop_unrolled_for(i = 0; i < PKTS_PER_BATCH; i++) {
+ unrolled_count(PKTS_PER_BATCH)
+ for (i = 0; i < PKTS_PER_BATCH; i++) {
u32 cmd = I40E_TX_DESC_CMD_ICRC | xsk_is_eop_desc(&desc[i]);

dma = xsk_buff_raw_get_dma(xdp_ring->xsk_pool, desc[i].addr);
--
2.48.1