[PATCH v2 net-next 13/15] net: dsa: sja1105: implement a common frame memory partitioning function

From: Vladimir Oltean
Date: Mon May 11 2020 - 09:54:10 EST


From: Vladimir Oltean <vladimir.oltean@xxxxxxx>

There are 2 different features that require some reserved frame memory
space: VLAN retagging and virtual links. Create a central function that
modifies the static config and ensures frame memory is never
overcommitted.

Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
---
Changes in v2:
None.

drivers/net/dsa/sja1105/sja1105.h | 2 +
drivers/net/dsa/sja1105/sja1105_main.c | 37 +++++++++++++++++++
.../net/dsa/sja1105/sja1105_static_config.h | 1 +
drivers/net/dsa/sja1105/sja1105_vl.c | 20 +---------
4 files changed, 42 insertions(+), 18 deletions(-)

diff --git a/drivers/net/dsa/sja1105/sja1105.h b/drivers/net/dsa/sja1105/sja1105.h
index 1ecdfd6be4c2..198d2a7d7f95 100644
--- a/drivers/net/dsa/sja1105/sja1105.h
+++ b/drivers/net/dsa/sja1105/sja1105.h
@@ -244,6 +244,8 @@ enum sja1105_reset_reason {
int sja1105_static_config_reload(struct sja1105_private *priv,
enum sja1105_reset_reason reason);

+void sja1105_frame_memory_partitioning(struct sja1105_private *priv);
+
/* From sja1105_spi.c */
int sja1105_xfer_buf(const struct sja1105_private *priv,
sja1105_spi_rw_mode_t rw, u64 reg_addr,
diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c
index 99139fcdc715..99b453d0d205 100644
--- a/drivers/net/dsa/sja1105/sja1105_main.c
+++ b/drivers/net/dsa/sja1105/sja1105_main.c
@@ -432,6 +432,41 @@ static int sja1105_init_l2_forwarding_params(struct sja1105_private *priv)
return 0;
}

+void sja1105_frame_memory_partitioning(struct sja1105_private *priv)
+{
+ struct sja1105_l2_forwarding_params_entry *l2_fwd_params;
+ struct sja1105_vl_forwarding_params_entry *vl_fwd_params;
+ struct sja1105_table *table;
+ int max_mem;
+
+ /* VLAN retagging is implemented using a loopback port that consumes
+ * frame buffers. That leaves less for us.
+ */
+ if (priv->vlan_state == SJA1105_VLAN_BEST_EFFORT)
+ max_mem = SJA1105_MAX_FRAME_MEMORY_RETAGGING;
+ else
+ max_mem = SJA1105_MAX_FRAME_MEMORY;
+
+ table = &priv->static_config.tables[BLK_IDX_L2_FORWARDING_PARAMS];
+ l2_fwd_params = table->entries;
+ l2_fwd_params->part_spc[0] = max_mem;
+
+ /* If we have any critical-traffic virtual links, we need to reserve
+ * some frame buffer memory for them. At the moment, hardcode the value
+ * at 100 blocks of 128 bytes of memory each. This leaves 829 blocks
+ * remaining for best-effort traffic. TODO: figure out a more flexible
+ * way to perform the frame buffer partitioning.
+ */
+ if (!priv->static_config.tables[BLK_IDX_VL_FORWARDING].entry_count)
+ return;
+
+ table = &priv->static_config.tables[BLK_IDX_VL_FORWARDING_PARAMS];
+ vl_fwd_params = table->entries;
+
+ l2_fwd_params->part_spc[0] -= SJA1105_VL_FRAME_MEMORY;
+ vl_fwd_params->partspc[0] = SJA1105_VL_FRAME_MEMORY;
+}
+
static int sja1105_init_general_params(struct sja1105_private *priv)
{
struct sja1105_general_params_entry default_general_params = {
@@ -2213,6 +2248,8 @@ static int sja1105_vlan_filtering(struct dsa_switch *ds, int port, bool enabled)
l2_lookup_params = table->entries;
l2_lookup_params->shared_learn = want_tagging;

+ sja1105_frame_memory_partitioning(priv);
+
rc = sja1105_static_config_reload(priv, SJA1105_VLAN_FILTERING);
if (rc)
dev_err(ds->dev, "Failed to change VLAN Ethertype\n");
diff --git a/drivers/net/dsa/sja1105/sja1105_static_config.h b/drivers/net/dsa/sja1105/sja1105_static_config.h
index d96044d86b11..5946847bb5b9 100644
--- a/drivers/net/dsa/sja1105/sja1105_static_config.h
+++ b/drivers/net/dsa/sja1105/sja1105_static_config.h
@@ -108,6 +108,7 @@ enum sja1105_blk_idx {

#define SJA1105_MAX_FRAME_MEMORY 929
#define SJA1105_MAX_FRAME_MEMORY_RETAGGING 910
+#define SJA1105_VL_FRAME_MEMORY 100

#define SJA1105E_DEVICE_ID 0x9C00000Cull
#define SJA1105T_DEVICE_ID 0x9E00030Eull
diff --git a/drivers/net/dsa/sja1105/sja1105_vl.c b/drivers/net/dsa/sja1105/sja1105_vl.c
index 312401995b54..f37611885376 100644
--- a/drivers/net/dsa/sja1105/sja1105_vl.c
+++ b/drivers/net/dsa/sja1105/sja1105_vl.c
@@ -5,7 +5,6 @@
#include <linux/dsa/8021q.h>
#include "sja1105.h"

-#define SJA1105_VL_FRAME_MEMORY 100
#define SJA1105_SIZE_VL_STATUS 8

/* The switch flow classification core implements TTEthernet, which 'thinks' in
@@ -141,8 +140,6 @@ static bool sja1105_vl_key_lower(struct sja1105_vl_lookup_entry *a,
static int sja1105_init_virtual_links(struct sja1105_private *priv,
struct netlink_ext_ack *extack)
{
- struct sja1105_l2_forwarding_params_entry *l2_fwd_params;
- struct sja1105_vl_forwarding_params_entry *vl_fwd_params;
struct sja1105_vl_policing_entry *vl_policing;
struct sja1105_vl_forwarding_entry *vl_fwd;
struct sja1105_vl_lookup_entry *vl_lookup;
@@ -153,10 +150,6 @@ static int sja1105_init_virtual_links(struct sja1105_private *priv,
int max_sharindx = 0;
int i, j, k;

- table = &priv->static_config.tables[BLK_IDX_L2_FORWARDING_PARAMS];
- l2_fwd_params = table->entries;
- l2_fwd_params->part_spc[0] = SJA1105_MAX_FRAME_MEMORY;
-
/* Figure out the dimensioning of the problem */
list_for_each_entry(rule, &priv->flow_block.rules, list) {
if (rule->type != SJA1105_RULE_VL)
@@ -308,17 +301,6 @@ static int sja1105_init_virtual_links(struct sja1105_private *priv,
if (!table->entries)
return -ENOMEM;
table->entry_count = 1;
- vl_fwd_params = table->entries;
-
- /* Reserve some frame buffer memory for the critical-traffic virtual
- * links (this needs to be done). At the moment, hardcode the value
- * at 100 blocks of 128 bytes of memory each. This leaves 829 blocks
- * remaining for best-effort traffic. TODO: figure out a more flexible
- * way to perform the frame buffer partitioning.
- */
- l2_fwd_params->part_spc[0] = SJA1105_MAX_FRAME_MEMORY -
- SJA1105_VL_FRAME_MEMORY;
- vl_fwd_params->partspc[0] = SJA1105_VL_FRAME_MEMORY;

for (i = 0; i < num_virtual_links; i++) {
unsigned long cookie = vl_lookup[i].flow_cookie;
@@ -342,6 +324,8 @@ static int sja1105_init_virtual_links(struct sja1105_private *priv,
}
}

+ sja1105_frame_memory_partitioning(priv);
+
return 0;
}

--
2.17.1