2023-11-18 15:54:40

by Yury Norov

Subject: [PATCH 19/34] sfc: switch to using atomic find_bit() API where appropriate

SFC code traverses rps_slot_map and rxq_retry_mask bit by bit. We can do
it better by using dedicated atomic find_bit() functions, because they
skip already clear bits.

Signed-off-by: Yury Norov <[email protected]>
---
drivers/net/ethernet/sfc/rx_common.c | 4 +---
drivers/net/ethernet/sfc/siena/rx_common.c | 4 +---
drivers/net/ethernet/sfc/siena/siena_sriov.c | 14 ++++++--------
3 files changed, 8 insertions(+), 14 deletions(-)

diff --git a/drivers/net/ethernet/sfc/rx_common.c b/drivers/net/ethernet/sfc/rx_common.c
index d2f35ee15eff..0112968b3fe7 100644
--- a/drivers/net/ethernet/sfc/rx_common.c
+++ b/drivers/net/ethernet/sfc/rx_common.c
@@ -950,9 +950,7 @@ int efx_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
int rc;

/* find a free slot */
- for (slot_idx = 0; slot_idx < EFX_RPS_MAX_IN_FLIGHT; slot_idx++)
- if (!test_and_set_bit(slot_idx, &efx->rps_slot_map))
- break;
+ slot_idx = find_and_set_bit(&efx->rps_slot_map, EFX_RPS_MAX_IN_FLIGHT);
if (slot_idx >= EFX_RPS_MAX_IN_FLIGHT)
return -EBUSY;

diff --git a/drivers/net/ethernet/sfc/siena/rx_common.c b/drivers/net/ethernet/sfc/siena/rx_common.c
index 4579f43484c3..160b16aa7486 100644
--- a/drivers/net/ethernet/sfc/siena/rx_common.c
+++ b/drivers/net/ethernet/sfc/siena/rx_common.c
@@ -958,9 +958,7 @@ int efx_siena_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
int rc;

/* find a free slot */
- for (slot_idx = 0; slot_idx < EFX_RPS_MAX_IN_FLIGHT; slot_idx++)
- if (!test_and_set_bit(slot_idx, &efx->rps_slot_map))
- break;
+ slot_idx = find_and_set_bit(&efx->rps_slot_map, EFX_RPS_MAX_IN_FLIGHT);
if (slot_idx >= EFX_RPS_MAX_IN_FLIGHT)
return -EBUSY;

diff --git a/drivers/net/ethernet/sfc/siena/siena_sriov.c b/drivers/net/ethernet/sfc/siena/siena_sriov.c
index 8353c15dc233..554b799288b8 100644
--- a/drivers/net/ethernet/sfc/siena/siena_sriov.c
+++ b/drivers/net/ethernet/sfc/siena/siena_sriov.c
@@ -722,14 +722,12 @@ static int efx_vfdi_fini_all_queues(struct siena_vf *vf)
efx_vfdi_flush_wake(vf),
timeout);
rxqs_count = 0;
- for (index = 0; index < count; ++index) {
- if (test_and_clear_bit(index, vf->rxq_retry_mask)) {
- atomic_dec(&vf->rxq_retry_count);
- MCDI_SET_ARRAY_DWORD(
- inbuf, FLUSH_RX_QUEUES_IN_QID_OFST,
- rxqs_count, vf_offset + index);
- rxqs_count++;
- }
+ for_each_test_and_clear_bit(index, vf->rxq_retry_mask, count) {
+ atomic_dec(&vf->rxq_retry_count);
+ MCDI_SET_ARRAY_DWORD(
+ inbuf, FLUSH_RX_QUEUES_IN_QID_OFST,
+ rxqs_count, vf_offset + index);
+ rxqs_count++;
}
}

--
2.39.2

2023-11-21 19:48:23

by Edward Cree

Subject: Re: [PATCH 19/34] sfc: switch to using atomic find_bit() API where appropriate

On 18/11/2023 15:50, Yury Norov wrote:
> SFC code traverses rps_slot_map and rxq_retry_mask bit by bit. We can do
> it better by using dedicated atomic find_bit() functions, because they
> skip already clear bits.
>
> Signed-off-by: Yury Norov <[email protected]>

Reviewed-by: Edward Cree <[email protected]>