mlxsw: spectrum_acl: Allow to interrupt/continue rehash work

Currently, migration of vregions with many entries may take long time
during which insertions and removals of the rules are blocked
due to wait to acquire vregion->lock.

To overcome this, allow to interrupt and continue rehash work according
to the set credits - number of rules to migrate.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c
index 9dc83815644e9fd400fb4704048c8ac391833657..cfd05af3f0f6cc9ad8ca1603fbe8ffc2baf56d7f 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c
@@ -27,6 +27,7 @@ size_t mlxsw_sp_acl_tcam_priv_size(struct mlxsw_sp *mlxsw_sp)
 
 #define MLXSW_SP_ACL_TCAM_VREGION_REHASH_INTRVL_DFLT 5000 /* ms */
 #define MLXSW_SP_ACL_TCAM_VREGION_REHASH_INTRVL_MIN 3000 /* ms */
+#define MLXSW_SP_ACL_TCAM_VREGION_REHASH_CREDITS 100 /* number of entries */
 
 int mlxsw_sp_acl_tcam_init(struct mlxsw_sp *mlxsw_sp,
                           struct mlxsw_sp_acl_tcam *tcam)
@@ -732,16 +733,26 @@ mlxsw_sp_acl_tcam_vregion_rehash_work_schedule(struct mlxsw_sp_acl_tcam_vregion
 
 static int
 mlxsw_sp_acl_tcam_vregion_rehash(struct mlxsw_sp *mlxsw_sp,
-                                struct mlxsw_sp_acl_tcam_vregion *vregion);
+                                struct mlxsw_sp_acl_tcam_vregion *vregion,
+                                int *credits);
 
 static void mlxsw_sp_acl_tcam_vregion_rehash_work(struct work_struct *work)
 {
        struct mlxsw_sp_acl_tcam_vregion *vregion =
                container_of(work, struct mlxsw_sp_acl_tcam_vregion,
                             rehash.dw.work);
+       int credits = MLXSW_SP_ACL_TCAM_VREGION_REHASH_CREDITS;
+       int err;
 
-       mlxsw_sp_acl_tcam_vregion_rehash(vregion->mlxsw_sp, vregion);
-       mlxsw_sp_acl_tcam_vregion_rehash_work_schedule(vregion);
+       err = mlxsw_sp_acl_tcam_vregion_rehash(vregion->mlxsw_sp,
+                                              vregion, &credits);
+       if (credits < 0)
+               /* Rehash gone out of credits so it was interrupted.
+                * Schedule the work as soon as possible to continue.
+                */
+               mlxsw_core_schedule_dw(&vregion->rehash.dw, 0);
+       else
+               mlxsw_sp_acl_tcam_vregion_rehash_work_schedule(vregion);
 }
 
 static struct mlxsw_sp_acl_tcam_vregion *
@@ -1176,7 +1187,8 @@ mlxsw_sp_acl_tcam_ventry_activity_get(struct mlxsw_sp *mlxsw_sp,
 static int
 mlxsw_sp_acl_tcam_ventry_migrate(struct mlxsw_sp *mlxsw_sp,
                                 struct mlxsw_sp_acl_tcam_ventry *ventry,
-                                struct mlxsw_sp_acl_tcam_chunk *chunk)
+                                struct mlxsw_sp_acl_tcam_chunk *chunk,
+                                int *credits)
 {
        struct mlxsw_sp_acl_tcam_entry *new_entry;
 
@@ -1184,6 +1196,9 @@ mlxsw_sp_acl_tcam_ventry_migrate(struct mlxsw_sp *mlxsw_sp,
        if (ventry->entry->chunk == chunk)
                return 0;
 
+       if (--(*credits) < 0)
+               return 0;
+
        new_entry = mlxsw_sp_acl_tcam_entry_create(mlxsw_sp, ventry, chunk);
        if (IS_ERR(new_entry))
                return PTR_ERR(new_entry);
@@ -1223,7 +1238,8 @@ static int
 mlxsw_sp_acl_tcam_vchunk_migrate_one(struct mlxsw_sp *mlxsw_sp,
                                     struct mlxsw_sp_acl_tcam_vchunk *vchunk,
                                     struct mlxsw_sp_acl_tcam_region *region,
-                                    struct mlxsw_sp_acl_tcam_rehash_ctx *ctx)
+                                    struct mlxsw_sp_acl_tcam_rehash_ctx *ctx,
+                                    int *credits)
 {
        struct mlxsw_sp_acl_tcam_ventry *ventry;
        int err;
@@ -1240,7 +1256,7 @@ mlxsw_sp_acl_tcam_vchunk_migrate_one(struct mlxsw_sp *mlxsw_sp,
 
        list_for_each_entry(ventry, &vchunk->ventry_list, list) {
                err = mlxsw_sp_acl_tcam_ventry_migrate(mlxsw_sp, ventry,
-                                                      vchunk->chunk);
+                                                      vchunk->chunk, credits);
                if (err) {
                        if (ctx->this_is_rollback)
                                return err;
@@ -1250,6 +1266,11 @@ mlxsw_sp_acl_tcam_vchunk_migrate_one(struct mlxsw_sp *mlxsw_sp,
                         */
                        swap(vchunk->chunk, vchunk->chunk2);
                        return err;
+               } else if (*credits < 0) {
+                       /* We are out of credits, the rest of the ventries
+                        * will be migrated later.
+                        */
+                       return 0;
                }
        }
 
@@ -1260,7 +1281,8 @@ mlxsw_sp_acl_tcam_vchunk_migrate_one(struct mlxsw_sp *mlxsw_sp,
 static int
 mlxsw_sp_acl_tcam_vchunk_migrate_all(struct mlxsw_sp *mlxsw_sp,
                                     struct mlxsw_sp_acl_tcam_vregion *vregion,
-                                    struct mlxsw_sp_acl_tcam_rehash_ctx *ctx)
+                                    struct mlxsw_sp_acl_tcam_rehash_ctx *ctx,
+                                    int *credits)
 {
        struct mlxsw_sp_acl_tcam_vchunk *vchunk;
        int err;
@@ -1268,8 +1290,8 @@ mlxsw_sp_acl_tcam_vchunk_migrate_all(struct mlxsw_sp *mlxsw_sp,
        list_for_each_entry(vchunk, &vregion->vchunk_list, list) {
                err = mlxsw_sp_acl_tcam_vchunk_migrate_one(mlxsw_sp, vchunk,
                                                           vregion->region,
-                                                          ctx);
-               if (err)
+                                                          ctx, credits);
+               if (err || *credits < 0)
                        return err;
        }
        return 0;
@@ -1278,13 +1300,15 @@ mlxsw_sp_acl_tcam_vchunk_migrate_all(struct mlxsw_sp *mlxsw_sp,
 static int
 mlxsw_sp_acl_tcam_vregion_migrate(struct mlxsw_sp *mlxsw_sp,
                                  struct mlxsw_sp_acl_tcam_vregion *vregion,
-                                 struct mlxsw_sp_acl_tcam_rehash_ctx *ctx)
+                                 struct mlxsw_sp_acl_tcam_rehash_ctx *ctx,
+                                 int *credits)
 {
        int err, err2;
 
        trace_mlxsw_sp_acl_tcam_vregion_migrate(mlxsw_sp, vregion);
        mutex_lock(&vregion->lock);
-       err = mlxsw_sp_acl_tcam_vchunk_migrate_all(mlxsw_sp, vregion, ctx);
+       err = mlxsw_sp_acl_tcam_vchunk_migrate_all(mlxsw_sp, vregion,
+                                                  ctx, credits);
        if (err) {
                /* In case migration was not successful, we need to swap
                 * so the original region pointer is assigned again
@@ -1292,7 +1316,8 @@ mlxsw_sp_acl_tcam_vregion_migrate(struct mlxsw_sp *mlxsw_sp,
                 */
                swap(vregion->region, vregion->region2);
                ctx->this_is_rollback = true;
-               err2 = mlxsw_sp_acl_tcam_vchunk_migrate_all(mlxsw_sp, vregion, ctx);
+               err2 = mlxsw_sp_acl_tcam_vchunk_migrate_all(mlxsw_sp, vregion,
+                                                           ctx, credits);
                if (err2)
                        vregion->failed_rollback = true;
        }
@@ -1301,6 +1326,12 @@ mlxsw_sp_acl_tcam_vregion_migrate(struct mlxsw_sp *mlxsw_sp,
        return err;
 }
 
+static bool
+mlxsw_sp_acl_tcam_vregion_rehash_in_progress(const struct mlxsw_sp_acl_tcam_rehash_ctx *ctx)
+{
+       return ctx->hints_priv;
+}
+
 static int
 mlxsw_sp_acl_tcam_vregion_rehash_start(struct mlxsw_sp *mlxsw_sp,
                                       struct mlxsw_sp_acl_tcam_vregion *vregion,
@@ -1372,19 +1403,28 @@ mlxsw_sp_acl_tcam_vregion_rehash_end(struct mlxsw_sp *mlxsw_sp,
 
 static int
 mlxsw_sp_acl_tcam_vregion_rehash(struct mlxsw_sp *mlxsw_sp,
-                                struct mlxsw_sp_acl_tcam_vregion *vregion)
+                                struct mlxsw_sp_acl_tcam_vregion *vregion,
+                                int *credits)
 {
        struct mlxsw_sp_acl_tcam_rehash_ctx *ctx = &vregion->rehash.ctx;
        int err;
 
-       err = mlxsw_sp_acl_tcam_vregion_rehash_start(mlxsw_sp, vregion, ctx);
-       if (err) {
-               if (err != -EAGAIN)
-                       dev_err(mlxsw_sp->bus_info->dev, "Failed get rehash hints\n");
-               return err;
+       /* Check if the previous rehash work was interrupted
+        * which means we have to continue it now.
+        * If not, start a new rehash.
+        */
+       if (!mlxsw_sp_acl_tcam_vregion_rehash_in_progress(ctx)) {
+               err = mlxsw_sp_acl_tcam_vregion_rehash_start(mlxsw_sp,
+                                                            vregion, ctx);
+               if (err) {
+                       if (err != -EAGAIN)
+                               dev_err(mlxsw_sp->bus_info->dev, "Failed get rehash hints\n");
+                       return err;
+               }
        }
 
-       err = mlxsw_sp_acl_tcam_vregion_migrate(mlxsw_sp, vregion, ctx);
+       err = mlxsw_sp_acl_tcam_vregion_migrate(mlxsw_sp, vregion,
+                                               ctx, credits);
        if (err) {
                dev_err(mlxsw_sp->bus_info->dev, "Failed to migrate vregion\n");
                if (vregion->failed_rollback) {
@@ -1394,7 +1434,9 @@ mlxsw_sp_acl_tcam_vregion_rehash(struct mlxsw_sp *mlxsw_sp,
                }
        }
 
-       mlxsw_sp_acl_tcam_vregion_rehash_end(mlxsw_sp, vregion, ctx);
+       if (*credits >= 0)
+               mlxsw_sp_acl_tcam_vregion_rehash_end(mlxsw_sp, vregion, ctx);
+
        return err;
 }