github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-27 08:33:17 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

ice: reduce size of queue context fields

Browse Source 
The ice_rlan_ctx and ice_tlan_ctx structures have some fields which are
intentionally sized larger than necessary relative to the packed sizes the
data must fit into. This was done because the original ice_set_ctx()
function and its helpers did not correctly handle packing when the packed
bits straddled a byte. This is no longer the case with the use of the
<linux/packing.h> implementation.

Save some bytes in these structures by sizing the variables to the number
of bytes the actual bitpacked fields fit into.

There are a couple of gaps left in the structure, which is a result of the
fields being in the order they appear in the packed bit layout, but where
alignment forces some extra gaps. We could fix this, saving ~8 bytes from
each structure. However, these structures are not used heavily, and the
resulting savings is minimal:

$ bloat-o-meter ice-before-reorder.ko ice-after-reorder.ko
add/remove: 0/0 grow/shrink: 1/1 up/down: 26/-70 (-44)
Function                                     old     new   delta
ice_vsi_cfg_txq                             1873    1899     +26
ice_setup_rx_ctx.constprop                  1529    1459     -70
Total: Before=1459555, After=1459511, chg -0.00%

Thus, the fields are left in the same order as the packed bit layout,
despite the gaps this causes.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20241210-packing-pack-fields-and-ice-implementation-v10-8-ee56a47479ac@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jacob Keller 2024-12-10 12:27:17 -08:00 committed by Jakub Kicinski
parent dc4305be46
commit f72588a426
1 changed files with 10 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
drivers/net/ethernet/intel/ice/ice_lan_tx_rx.h
View File

@ -375,23 +375,17 @@ enum ice_rx_flex_desc_status_error_1_bits {
#define ICE_TX_DRBELL_Q_CTX_SIZE_DWORDS 5
#define GLTCLAN_CQ_CNTX(i, CQ) (GLTCLAN_CQ_CNTX0(CQ) + ((i) * 0x0800))
/* RLAN Rx queue context data
*
* The sizes of the variables may be larger than needed due to crossing byte
* boundaries. If we do not have the width of the variable set to the correct
* size then we could end up shifting bits off the top of the variable when the
* variable is at the top of a byte and crosses over into the next byte.
*/
/* RLAN Rx queue context data */
struct ice_rlan_ctx {
u16 head;
u16 cpuid; /* bigger than needed, see above for reason */
u8 cpuid;
#define ICE_RLAN_BASE_S 7
u64 base;
u16 qlen;
#define ICE_RLAN_CTX_DBUF_S 7
u16 dbuf; /* bigger than needed, see above for reason */
u8 dbuf;
#define ICE_RLAN_CTX_HBUF_S 6
u16 hbuf; /* bigger than needed, see above for reason */
u8 hbuf;
u8 dtype;
u8 dsize;
u8 crcstrip;
@ -399,12 +393,12 @@ struct ice_rlan_ctx {
u8 hsplit_0;
u8 hsplit_1;
u8 showiv;
u32 rxmax; /* bigger than needed, see above for reason */
u16 rxmax;
u8 tphrdesc_ena;
u8 tphwdesc_ena;
u8 tphdata_ena;
u8 tphhead_ena;
u16 lrxqthresh; /* bigger than needed, see above for reason */
u8 lrxqthresh;
u8 prefena; /* NOTE: normally must be set to 1 at init */
};
@ -535,18 +529,12 @@ enum ice_tx_ctx_desc_eipt_offload {
#define ICE_LAN_TXQ_MAX_QGRPS 127
#define ICE_LAN_TXQ_MAX_QDIS 1023
/* Tx queue context data
*
* The sizes of the variables may be larger than needed due to crossing byte
* boundaries. If we do not have the width of the variable set to the correct
* size then we could end up shifting bits off the top of the variable when the
* variable is at the top of a byte and crosses over into the next byte.
*/
/* Tx queue context data */
struct ice_tlan_ctx {
#define ICE_TLAN_CTX_BASE_S 7
u64 base; /* base is defined in 128-byte units */
u8 port_num;
u16 cgd_num; /* bigger than needed, see above for reason */
u8 cgd_num;
u8 pf_num;
u16 vmvf_num;
u8 vmvf_type;
@ -557,7 +545,7 @@ struct ice_tlan_ctx {
u8 tsyn_ena;
u8 internal_usage_flag;
u8 alt_vlan;
u16 cpuid; /* bigger than needed, see above for reason */
u8 cpuid;
u8 wb_mode;
u8 tphrd_desc;
u8 tphrd;
@ -566,7 +554,7 @@ struct ice_tlan_ctx {
u16 qnum_in_func;
u8 itr_notification_mode;
u8 adjust_prof_id;
u32 qlen; /* bigger than needed, see above for reason */
u16 qlen;
u8 quanta_prof_idx;
u8 tso_ena;
u16 tso_qnum;