[PATCH iwl-next] ice: ice_base.c: Add const modifier to params and vars

[PATCH iwl-next] ice: ice_base.c: Add const modifier to params and vars

[Jan Glaza]

Add const modifier to function parameters and variables where appropriate
in ice_base.c and corresponding declarations in ice_base.h.

The reason for starting the change is that read-only pointers should be
marked as const when possible to allow for smoother and more optimal code
generation and optimization as well as allowing the compiler to warn the
developer about potentially unwanted modifications, while not carrying
noticable negative impact.

Reviewed-by: Andrii Staikov <andrii.staikov@intel.com>
Reviewed-by: Sachin Bahadur <sachin.bahadur@intel.com>
Signed-off-by: Jan Glaza <jan.glaza@intel.com>
---
This change is done in one file to get comment feedback and, if positive,
will be rolled out across the entire ice driver code.
---
 drivers/net/ethernet/intel/ice/ice_base.c | 6 +++---
 drivers/net/ethernet/intel/ice/ice_base.h | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_base.c b/drivers/net/ethernet/intel/ice/ice_base.c
index 7fa43827a3f0..5ca323ac36ce 100644
--- a/drivers/net/ethernet/intel/ice/ice_base.c
+++ b/drivers/net/ethernet/intel/ice/ice_base.c
@@ -278,7 +278,7 @@ static u16 ice_calc_txq_handle(struct ice_vsi *vsi, struct ice_tx_ring *ring, u8
  */
 static u16 ice_eswitch_calc_txq_handle(struct ice_tx_ring *ring)
 {
-	struct ice_vsi *vsi = ring->vsi;
+	const struct ice_vsi *vsi = ring->vsi;
 	int i;
 
 	ice_for_each_txq(vsi, i) {
@@ -960,7 +960,7 @@ ice_cfg_rxq_interrupt(struct ice_vsi *vsi, u16 rxq, u16 msix_idx, u16 itr_idx)
  * @hw: pointer to the HW structure
  * @q_vector: interrupt vector to trigger the software interrupt for
  */
-void ice_trigger_sw_intr(struct ice_hw *hw, struct ice_q_vector *q_vector)
+void ice_trigger_sw_intr(struct ice_hw *hw, const struct ice_q_vector *q_vector)
 {
 	wr32(hw, GLINT_DYN_CTL(q_vector->reg_idx),
 	     (ICE_ITR_NONE << GLINT_DYN_CTL_ITR_INDX_S) |
@@ -1035,7 +1035,7 @@ ice_vsi_stop_tx_ring(struct ice_vsi *vsi, enum ice_disq_rst_src rst_src,
  * are needed for stopping Tx queue
  */
 void
-ice_fill_txq_meta(struct ice_vsi *vsi, struct ice_tx_ring *ring,
+ice_fill_txq_meta(const struct ice_vsi *vsi, struct ice_tx_ring *ring,
 		  struct ice_txq_meta *txq_meta)
 {
 	struct ice_channel *ch = ring->ch;
diff --git a/drivers/net/ethernet/intel/ice/ice_base.h b/drivers/net/ethernet/intel/ice/ice_base.h
index b67dca417acb..17321ba75602 100644
--- a/drivers/net/ethernet/intel/ice/ice_base.h
+++ b/drivers/net/ethernet/intel/ice/ice_base.h
@@ -22,12 +22,12 @@ void
 ice_cfg_txq_interrupt(struct ice_vsi *vsi, u16 txq, u16 msix_idx, u16 itr_idx);
 void
 ice_cfg_rxq_interrupt(struct ice_vsi *vsi, u16 rxq, u16 msix_idx, u16 itr_idx);
-void ice_trigger_sw_intr(struct ice_hw *hw, struct ice_q_vector *q_vector);
+void ice_trigger_sw_intr(struct ice_hw *hw, const struct ice_q_vector *q_vector);
 int
 ice_vsi_stop_tx_ring(struct ice_vsi *vsi, enum ice_disq_rst_src rst_src,
 		     u16 rel_vmvf_num, struct ice_tx_ring *ring,
 		     struct ice_txq_meta *txq_meta);
 void
-ice_fill_txq_meta(struct ice_vsi *vsi, struct ice_tx_ring *ring,
+ice_fill_txq_meta(const struct ice_vsi *vsi, struct ice_tx_ring *ring,
 		  struct ice_txq_meta *txq_meta);
 #endif /* _ICE_BASE_H_ */
-- 
2.39.3

Re: [PATCH iwl-next] ice: ice_base.c: Add const modifier to params and vars

[Simon Horman]

On Wed, Nov 29, 2023 at 02:36:11AM -0500, Jan Glaza wrote:
> Add const modifier to function parameters and variables where appropriate
> in ice_base.c and corresponding declarations in ice_base.h.
> 
> The reason for starting the change is that read-only pointers should be
> marked as const when possible to allow for smoother and more optimal code
> generation and optimization as well as allowing the compiler to warn the
> developer about potentially unwanted modifications, while not carrying
> noticable negative impact.

Hi Jan,

it's probably not worth respinning for this, but: noticeable

> 
> Reviewed-by: Andrii Staikov <andrii.staikov@intel.com>
> Reviewed-by: Sachin Bahadur <sachin.bahadur@intel.com>
> Signed-off-by: Jan Glaza <jan.glaza@intel.com>
> ---
> This change is done in one file to get comment feedback and, if positive,
> will be rolled out across the entire ice driver code.

The nit above notwithstanding, this looks good to me.

Reviewed-by: Simon Horman <horms@kernel.org>