Re: [PATCH net-next 1/4] net: hns3: refine the tcam key convert handle

Can you please explain why do you need special define for boolean AND?
we use '&', just define a bitwise AND, not define boolean AND.

On Tue, Sep 28, 2022 at 10:28:02AM +0800, Leon Romanovsky wrote:

On Tue, Sep 27, 2022 at 07:12:02PM +0800, Guangbin Huang wrote:

quoted

From: Jian Shen <shenjian15@huawei.com>

The expression '(k ^ ~v)' is exaclty '(k & v)', and '(k & v) & k' is 
exaclty 'k & v'. So simplify the expression for tcam key convert.

It also add necessary brackets for them.

Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Guangbin Huang <redacted>
---
 .../net/ethernet/hisilicon/hns3/hns3pf/hclge_main.h   | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.h 

b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.h
index 495b639b0dc2..59bfacc687c9 100644

--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.h
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.h

@@ -827,15 +827,10 @@ struct hclge_vf_vlan_cfg {
  * Then for input key(k) and mask(v), we can calculate the value by
  * the formulae:
  *	x = (~k) & v
- *	y = (k ^ ~v) & k
+ *	y = k & v
  */
-#define calc_x(x, k, v) (x = ~(k) & (v)) -#define calc_y(y, k, v) \
-	do { \
-		const typeof(k) _k_ = (k); \
-		const typeof(v) _v_ = (v); \
-		(y) = (_k_ ^ ~_v_) & (_k_); \
-	} while (0)
+#define calc_x(x, k, v) ((x) = ~(k) & (v)) #define calc_y(y, k, v) 
+((y) = (k) & (v))

Can you please explain why do you need special define for boolean AND?

Thanks

we use '&', just define a bitwise AND, not define boolean AND.

quoted

 
 #define HCLGE_MAC_STATS_FIELD_OFF(f) (offsetof(struct 
hclge_mac_stats, f))  #define HCLGE_STATS_READ(p, offset) (*(u64 
*)((u8 *)(p) + (offset)))
--
2.33.0

-----邮件原件-----
发件人: Leon Romanovsky [off-list ref] 
发送时间: 2022年9月28日 18:29
收件人: huangguangbin (A) [off-list ref]
抄送: davem@davemloft.net; kuba@kernel.org; edumazet@google.com; pabeni@redhat.com; netdev@vger.kernel.org; linux-kernel@vger.kernel.org; shenjian (K) [off-list ref]; Lanhao (Lan) [off-list ref]
主题: Re: [PATCH net-next 1/4] net: hns3: refine the tcam key convert handle

On Tue, Sep 27, 2022 at 07:12:02PM +0800, Guangbin Huang wrote:

quoted hunk

From: Jian Shen <shenjian15@huawei.com>

The expression '(k ^ ~v)' is exaclty '(k & v)', and '(k & v) & k' is 
exaclty 'k & v'. So simplify the expression for tcam key convert.

It also add necessary brackets for them.

Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Guangbin Huang <redacted>
---
 .../net/ethernet/hisilicon/hns3/hns3pf/hclge_main.h   | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.h 

b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.h
index 495b639b0dc2..59bfacc687c9 100644

--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.h
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.h

@@ -827,15 +827,10 @@ struct hclge_vf_vlan_cfg {
  * Then for input key(k) and mask(v), we can calculate the value by
  * the formulae:
  *	x = (~k) & v
- *	y = (k ^ ~v) & k
+ *	y = k & v
  */
-#define calc_x(x, k, v) (x = ~(k) & (v)) -#define calc_y(y, k, v) \
-	do { \
-		const typeof(k) _k_ = (k); \
-		const typeof(v) _v_ = (v); \
-		(y) = (_k_ ^ ~_v_) & (_k_); \
-	} while (0)
+#define calc_x(x, k, v) ((x) = ~(k) & (v)) #define calc_y(y, k, v) 
+((y) = (k) & (v))

Can you please explain why do you need special define for boolean AND?

Thanks

 
 #define HCLGE_MAC_STATS_FIELD_OFF(f) (offsetof(struct 
hclge_mac_stats, f))  #define HCLGE_STATS_READ(p, offset) (*(u64 
*)((u8 *)(p) + (offset)))
--
2.33.0