common/sfc_efx/base: fix MAE match spec class comparison API

The helper exits once it encounters a field which hasn't its
capability status reported by the FW. Handle the corner case
when the two mask-value pairs match for the field, which, in
the absence of capability information, is sufficient to deem
the class unaffected by the field. Explain this in a comment.

Fixes: bb71f7e0a35a ("common/sfc_efx/base: add match specs class comparison API")
Cc: stable@dpdk.org
Reviewed-by: Andy Moreton <amoreton@xilinx.com>
Reviewed-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
Signed-off-by: Ivan Malov <ivan.malov@oktetlabs.ru>

diff --git a/drivers/common/sfc_efx/base/efx.h b/drivers/common/sfc_efx/base/efx.h
index 3b40e28..ccf9c7a 100644 (file)
--- a/drivers/common/sfc_efx/base/efx.h
+++ b/drivers/common/sfc_efx/base/efx.h
@@ -4283,6 +4283,11 @@ efx_mae_action_set_specs_equal(
  * Conduct a comparison to check whether two match specifications
  * of equal rule type (action / outer) and priority would map to
  * the very same rule class from the firmware's standpoint.
+ *
+ * For match specification fields that are not supported by firmware,
+ * the rule class only matches if the mask/value pairs for that field
+ * are equal. Clients should use efx_mae_match_spec_is_valid() before
+ * calling this API to detect usage of unsupported fields.
  */
 LIBEFX_API
 extern __checkReturn                   efx_rc_t

diff --git a/drivers/common/sfc_efx/base/efx_mae.c b/drivers/common/sfc_efx/base/efx_mae.c
index 7fd4221..eb91753 100644 (file)
--- a/drivers/common/sfc_efx/base/efx_mae.c
+++ b/drivers/common/sfc_efx/base/efx_mae.c
@@ -1426,18 +1426,32 @@ efx_mae_match_specs_class_cmp(
             ++field_id) {
                const efx_mae_mv_desc_t *descp = &desc_setp[field_id];
                efx_mae_field_cap_id_t field_cap_id = descp->emmd_field_cap_id;
-
-               if (descp->emmd_mask_size == 0)
+               const uint8_t *lmaskp = mvpl + descp->emmd_mask_offset;
+               const uint8_t *rmaskp = mvpr + descp->emmd_mask_offset;
+               size_t mask_size = descp->emmd_mask_size;
+               const uint8_t *lvalp = mvpl + descp->emmd_value_offset;
+               const uint8_t *rvalp = mvpr + descp->emmd_value_offset;
+               size_t value_size = descp->emmd_value_size;
+
+               if (mask_size == 0)
                        continue; /* Skip array gap */
 
-               if ((unsigned int)field_cap_id >= field_ncaps)
-                       break;
+               if ((unsigned int)field_cap_id >= field_ncaps) {
+                       /*
+                        * The FW has not reported capability status for this
+                        * field. It's unknown whether any difference between
+                        * the two masks / values affects the class. The only
+                        * case when the class must be the same is when these
+                        * mask-value pairs match. Otherwise, report mismatch.
+                        */
+                       if ((memcmp(lmaskp, rmaskp, mask_size) == 0) &&
+                           (memcmp(lvalp, rvalp, value_size) == 0))
+                               continue;
+                       else
+                               break;
+               }
 
                if (field_caps[field_cap_id].emfc_mask_affects_class) {
-                       const uint8_t *lmaskp = mvpl + descp->emmd_mask_offset;
-                       const uint8_t *rmaskp = mvpr + descp->emmd_mask_offset;
-                       size_t mask_size = descp->emmd_mask_size;
-
                        if (memcmp(lmaskp, rmaskp, mask_size) != 0) {
                                have_same_class = B_FALSE;
                                break;
@@ -1445,10 +1459,6 @@ efx_mae_match_specs_class_cmp(
                }
 
                if (field_caps[field_cap_id].emfc_match_affects_class) {
-                       const uint8_t *lvalp = mvpl + descp->emmd_value_offset;
-                       const uint8_t *rvalp = mvpr + descp->emmd_value_offset;
-                       size_t value_size = descp->emmd_value_size;
-
                        if (memcmp(lvalp, rvalp, value_size) != 0) {
                                have_same_class = B_FALSE;
                                break;