net: dsa: sja1105: Plug in support for TCAM searches via the dynamic interface

Only a single dynamic configuration table of the SJA1105 P/Q/R/S
supports this operation: the FDB.

To keep the existing structure in place (sja1105_dynamic_config_read and
sja1105_dynamic_config_write) and not introduce any new function, a
convention is made for sja1105_dynamic_config_read that a negative index
argument denotes a search for the entry provided as argument.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/dsa/sja1105/sja1105_dynamic_config.c b/drivers/net/dsa/sja1105/sja1105_dynamic_config.c
index 0023b03..7e7efc2 100644 (file)
--- a/drivers/net/dsa/sja1105/sja1105_dynamic_config.c
+++ b/drivers/net/dsa/sja1105/sja1105_dynamic_config.c
@@ -36,6 +36,7 @@
        SJA1105PQRS_SIZE_MAC_CONFIG_DYN_CMD
 
 struct sja1105_dyn_cmd {
+       bool search;
        u64 valid;
        u64 rdwrset;
        u64 errors;
@@ -248,6 +249,7 @@ sja1105et_general_params_entry_packing(void *buf, void *entry_ptr,
 #define OP_READ                BIT(0)
 #define OP_WRITE       BIT(1)
 #define OP_DEL         BIT(2)
+#define OP_SEARCH      BIT(3)
 
 /* SJA1105E/T: First generation */
 struct sja1105_dynamic_table_ops sja1105et_dyn_ops[BLK_IDX_MAX_DYN] = {
@@ -367,6 +369,24 @@ struct sja1105_dynamic_table_ops sja1105pqrs_dyn_ops[BLK_IDX_MAX_DYN] = {
        [BLK_IDX_XMII_PARAMS] = {0},
 };
 
+/* Provides read access to the settings through the dynamic interface
+ * of the switch.
+ * @blk_idx    is used as key to select from the sja1105_dynamic_table_ops.
+ *             The selection is limited by the hardware in respect to which
+ *             configuration blocks can be read through the dynamic interface.
+ * @index      is used to retrieve a particular table entry. If negative,
+ *             (and if the @blk_idx supports the searching operation) a search
+ *             is performed by the @entry parameter.
+ * @entry      Type-casted to an unpacked structure that holds a table entry
+ *             of the type specified in @blk_idx.
+ *             Usually an output argument. If @index is negative, then this
+ *             argument is used as input/output: it should be pre-populated
+ *             with the element to search for. Entries which support the
+ *             search operation will have an "index" field (not the @index
+ *             argument to this function) and that is where the found index
+ *             will be returned (or left unmodified - thus negative - if not
+ *             found).
+ */
 int sja1105_dynamic_config_read(struct sja1105_private *priv,
                                enum sja1105_blk_idx blk_idx,
                                int index, void *entry)
@@ -385,6 +405,8 @@ int sja1105_dynamic_config_read(struct sja1105_private *priv,
 
        if (index >= ops->max_entry_count)
                return -ERANGE;
+       if (index < 0 && !(ops->access & OP_SEARCH))
+               return -EOPNOTSUPP;
        if (!(ops->access & OP_READ))
                return -EOPNOTSUPP;
        if (ops->packed_size > SJA1105_MAX_DYN_CMD_SIZE)
@@ -396,9 +418,19 @@ int sja1105_dynamic_config_read(struct sja1105_private *priv,
 
        cmd.valid = true; /* Trigger action on table entry */
        cmd.rdwrset = SPI_READ; /* Action is read */
-       cmd.index = index;
+       if (index < 0) {
+               /* Avoid copying a signed negative number to an u64 */
+               cmd.index = 0;
+               cmd.search = true;
+       } else {
+               cmd.index = index;
+               cmd.search = false;
+       }
        ops->cmd_packing(packed_buf, &cmd, PACK);
 
+       if (cmd.search)
+               ops->entry_packing(packed_buf, entry, PACK);
+
        /* Send SPI write operation: read config table entry */
        rc = sja1105_spi_send_packed_buf(priv, SPI_WRITE, ops->addr,
                                         packed_buf, ops->packed_size);
@@ -456,6 +488,8 @@ int sja1105_dynamic_config_write(struct sja1105_private *priv,
 
        if (index >= ops->max_entry_count)
                return -ERANGE;
+       if (index < 0)
+               return -ERANGE;
        if (!(ops->access & OP_WRITE))
                return -EOPNOTSUPP;
        if (!keep && !(ops->access & OP_DEL))

diff --git a/drivers/net/dsa/sja1105/sja1105_dynamic_config.h b/drivers/net/dsa/sja1105/sja1105_dynamic_config.h
index 49c611e..740dadf 100644 (file)
--- a/drivers/net/dsa/sja1105/sja1105_dynamic_config.h
+++ b/drivers/net/dsa/sja1105/sja1105_dynamic_config.h
@@ -7,6 +7,9 @@
 #include "sja1105.h"
 #include <linux/packing.h>
 
+/* Special index that can be used for sja1105_dynamic_config_read */
+#define SJA1105_SEARCH         -1
+
 struct sja1105_dyn_cmd;
 
 struct sja1105_dynamic_table_ops {