diff options
Diffstat (limited to 'drivers/net/dsa/sja1105/sja1105_dynamic_config.c')
-rw-r--r-- | drivers/net/dsa/sja1105/sja1105_dynamic_config.c | 156 |
1 files changed, 153 insertions, 3 deletions
diff --git a/drivers/net/dsa/sja1105/sja1105_dynamic_config.c b/drivers/net/dsa/sja1105/sja1105_dynamic_config.c index 352bb6e89297..6bfb1696a6f2 100644 --- a/drivers/net/dsa/sja1105/sja1105_dynamic_config.c +++ b/drivers/net/dsa/sja1105/sja1105_dynamic_config.c @@ -3,6 +3,98 @@ */ #include "sja1105.h" +/* In the dynamic configuration interface, the switch exposes a register-like + * view of some of the static configuration tables. + * Many times the field organization of the dynamic tables is abbreviated (not + * all fields are dynamically reconfigurable) and different from the static + * ones, but the key reason for having it is that we can spare a switch reset + * for settings that can be changed dynamically. + * + * This file creates a per-switch-family abstraction called + * struct sja1105_dynamic_table_ops and two operations that work with it: + * - sja1105_dynamic_config_write + * - sja1105_dynamic_config_read + * + * Compared to the struct sja1105_table_ops from sja1105_static_config.c, + * the dynamic accessors work with a compound buffer: + * + * packed_buf + * + * | + * V + * +-----------------------------------------+------------------+ + * | ENTRY BUFFER | COMMAND BUFFER | + * +-----------------------------------------+------------------+ + * + * <----------------------- packed_size ------------------------> + * + * The ENTRY BUFFER may or may not have the same layout, or size, as its static + * configuration table entry counterpart. When it does, the same packing + * function is reused (bar exceptional cases - see + * sja1105pqrs_dyn_l2_lookup_entry_packing). + * + * The reason for the COMMAND BUFFER being at the end is to be able to send + * a dynamic write command through a single SPI burst. By the time the switch + * reacts to the command, the ENTRY BUFFER is already populated with the data + * sent by the core. + * + * The COMMAND BUFFER is always SJA1105_SIZE_DYN_CMD bytes (one 32-bit word) in + * size. + * + * Sometimes the ENTRY BUFFER does not really exist (when the number of fields + * that can be reconfigured is small), then the switch repurposes some of the + * unused 32 bits of the COMMAND BUFFER to hold ENTRY data. + * + * The key members of struct sja1105_dynamic_table_ops are: + * - .entry_packing: A function that deals with packing an ENTRY structure + * into an SPI buffer, or retrieving an ENTRY structure + * from one. + * The @packed_buf pointer it's given does always point to + * the ENTRY portion of the buffer. + * - .cmd_packing: A function that deals with packing/unpacking the COMMAND + * structure to/from the SPI buffer. + * It is given the same @packed_buf pointer as .entry_packing, + * so most of the time, the @packed_buf points *behind* the + * COMMAND offset inside the buffer. + * To access the COMMAND portion of the buffer, the function + * knows its correct offset. + * Giving both functions the same pointer is handy because in + * extreme cases (see sja1105pqrs_dyn_l2_lookup_entry_packing) + * the .entry_packing is able to jump to the COMMAND portion, + * or vice-versa (sja1105pqrs_l2_lookup_cmd_packing). + * - .access: A bitmap of: + * OP_READ: Set if the hardware manual marks the ENTRY portion of the + * dynamic configuration table buffer as R (readable) after + * an SPI read command (the switch will populate the buffer). + * OP_WRITE: Set if the manual marks the ENTRY portion of the dynamic + * table buffer as W (writable) after an SPI write command + * (the switch will read the fields provided in the buffer). + * OP_DEL: Set if the manual says the VALIDENT bit is supported in the + * COMMAND portion of this dynamic config buffer (i.e. the + * specified entry can be invalidated through a SPI write + * command). + * OP_SEARCH: Set if the manual says that the index of an entry can + * be retrieved in the COMMAND portion of the buffer based + * on its ENTRY portion, as a result of a SPI write command. + * Only the TCAM-based FDB table on SJA1105 P/Q/R/S supports + * this. + * - .max_entry_count: The number of entries, counting from zero, that can be + * reconfigured through the dynamic interface. If a static + * table can be reconfigured at all dynamically, this + * number always matches the maximum number of supported + * static entries. + * - .packed_size: The length in bytes of the compound ENTRY + COMMAND BUFFER. + * Note that sometimes the compound buffer may contain holes in + * it (see sja1105_vlan_lookup_cmd_packing). The @packed_buf is + * contiguous however, so @packed_size includes any unused + * bytes. + * - .addr: The base SPI address at which the buffer must be written to the + * switch's memory. When looking at the hardware manual, this must + * always match the lowest documented address for the ENTRY, and not + * that of the COMMAND, since the other 32-bit words will follow along + * at the correct addresses. + */ + #define SJA1105_SIZE_DYN_CMD 4 #define SJA1105ET_SIZE_MAC_CONFIG_DYN_ENTRY \ @@ -57,13 +149,11 @@ sja1105pqrs_l2_lookup_cmd_packing(void *buf, struct sja1105_dyn_cmd *cmd, { u8 *p = buf + SJA1105PQRS_SIZE_L2_LOOKUP_ENTRY; const int size = SJA1105_SIZE_DYN_CMD; - u64 lockeds = 0; u64 hostcmd; sja1105_packing(p, &cmd->valid, 31, 31, size, op); sja1105_packing(p, &cmd->rdwrset, 30, 30, size, op); sja1105_packing(p, &cmd->errors, 29, 29, size, op); - sja1105_packing(p, &lockeds, 28, 28, size, op); sja1105_packing(p, &cmd->valident, 27, 27, size, op); /* VALIDENT is supposed to indicate "keep or not", but in SJA1105 E/T, @@ -113,6 +203,64 @@ sja1105pqrs_l2_lookup_cmd_packing(void *buf, struct sja1105_dyn_cmd *cmd, SJA1105PQRS_SIZE_L2_LOOKUP_ENTRY, op); } +/* The switch is so retarded that it makes our command/entry abstraction + * crumble apart. + * + * On P/Q/R/S, the switch tries to say whether a FDB entry + * is statically programmed or dynamically learned via a flag called LOCKEDS. + * The hardware manual says about this fiels: + * + * On write will specify the format of ENTRY. + * On read the flag will be found cleared at times the VALID flag is found + * set. The flag will also be found cleared in response to a read having the + * MGMTROUTE flag set. In response to a read with the MGMTROUTE flag + * cleared, the flag be set if the most recent access operated on an entry + * that was either loaded by configuration or through dynamic reconfiguration + * (as opposed to automatically learned entries). + * + * The trouble with this flag is that it's part of the *command* to access the + * dynamic interface, and not part of the *entry* retrieved from it. + * Otherwise said, for a sja1105_dynamic_config_read, LOCKEDS is supposed to be + * an output from the switch into the command buffer, and for a + * sja1105_dynamic_config_write, the switch treats LOCKEDS as an input + * (hence we can write either static, or automatically learned entries, from + * the core). + * But the manual contradicts itself in the last phrase where it says that on + * read, LOCKEDS will be set to 1 for all FDB entries written through the + * dynamic interface (therefore, the value of LOCKEDS from the + * sja1105_dynamic_config_write is not really used for anything, it'll store a + * 1 anyway). + * This means you can't really write a FDB entry with LOCKEDS=0 (automatically + * learned) into the switch, which kind of makes sense. + * As for reading through the dynamic interface, it doesn't make too much sense + * to put LOCKEDS into the command, since the switch will inevitably have to + * ignore it (otherwise a command would be like "read the FDB entry 123, but + * only if it's dynamically learned" <- well how am I supposed to know?) and + * just use it as an output buffer for its findings. But guess what... that's + * what the entry buffer is for! + * Unfortunately, what really breaks this abstraction is the fact that it + * wasn't designed having the fact in mind that the switch can output + * entry-related data as writeback through the command buffer. + * However, whether a FDB entry is statically or dynamically learned *is* part + * of the entry and not the command data, no matter what the switch thinks. + * In order to do that, we'll need to wrap around the + * sja1105pqrs_l2_lookup_entry_packing from sja1105_static_config.c, and take + * a peek outside of the caller-supplied @buf (the entry buffer), to reach the + * command buffer. + */ +static size_t +sja1105pqrs_dyn_l2_lookup_entry_packing(void *buf, void *entry_ptr, + enum packing_op op) +{ + struct sja1105_l2_lookup_entry *entry = entry_ptr; + u8 *cmd = buf + SJA1105PQRS_SIZE_L2_LOOKUP_ENTRY; + const int size = SJA1105_SIZE_DYN_CMD; + + sja1105_packing(cmd, &entry->lockeds, 28, 28, size, op); + + return sja1105pqrs_l2_lookup_entry_packing(buf, entry_ptr, op); +} + static void sja1105et_l2_lookup_cmd_packing(void *buf, struct sja1105_dyn_cmd *cmd, enum packing_op op) @@ -378,6 +526,7 @@ struct sja1105_dynamic_table_ops sja1105et_dyn_ops[BLK_IDX_MAX_DYN] = { .addr = 0x38, }, [BLK_IDX_L2_FORWARDING_PARAMS] = {0}, + [BLK_IDX_AVB_PARAMS] = {0}, [BLK_IDX_GENERAL_PARAMS] = { .entry_packing = sja1105et_general_params_entry_packing, .cmd_packing = sja1105et_general_params_cmd_packing, @@ -392,7 +541,7 @@ struct sja1105_dynamic_table_ops sja1105et_dyn_ops[BLK_IDX_MAX_DYN] = { /* SJA1105P/Q/R/S: Second generation */ struct sja1105_dynamic_table_ops sja1105pqrs_dyn_ops[BLK_IDX_MAX_DYN] = { [BLK_IDX_L2_LOOKUP] = { - .entry_packing = sja1105pqrs_l2_lookup_entry_packing, + .entry_packing = sja1105pqrs_dyn_l2_lookup_entry_packing, .cmd_packing = sja1105pqrs_l2_lookup_cmd_packing, .access = (OP_READ | OP_WRITE | OP_DEL | OP_SEARCH), .max_entry_count = SJA1105_MAX_L2_LOOKUP_COUNT, @@ -441,6 +590,7 @@ struct sja1105_dynamic_table_ops sja1105pqrs_dyn_ops[BLK_IDX_MAX_DYN] = { .addr = 0x38, }, [BLK_IDX_L2_FORWARDING_PARAMS] = {0}, + [BLK_IDX_AVB_PARAMS] = {0}, [BLK_IDX_GENERAL_PARAMS] = { .entry_packing = sja1105et_general_params_entry_packing, .cmd_packing = sja1105et_general_params_cmd_packing, |