SAI proposal for SyncE

Signed-off-by: rpmarvell <rperumal@marvell.com>

Author: rpmarvell

doc/SyncE/SAI-Proposal-SyncE.md

@@ -0,0 +1,311 @@
+# [SAI] Synchronous Ethernet
+-------------------------------------------------------------------------------
+ Title       | Synchronous Ethernet
+-------------|-----------------------------------------------------------------
+ Authors     | Rajesh Perumal, Ravindranath C K (Marvell)
+ Status      | In review
+ Type        | Standards track
+ Created     | 2025-02-20
+ SAI-Version | 1.16
+-------------------------------------------------------------------------------
+
+## 1.0  Introduction
+
+The aim of the Synchronous Ethernet(SyncE) is to transfer timing(frequency) over the Ethernet physical layer across a network.
+SyncE synchronizes the system clock(which drives the tx frequency) at the Switch device. The switch NPU can have one or more
+SyncE clocks. The SyncE clocks recover the frequency from any port of the switch and inputs it to the system clock.
+                                SyncE relies on Ethernet port, System clock, the recovered clock signal from SyncE clock and
+the quality of recovered clock signal. As the Ethernet port programming can be done through an already available SAI_OBJECT_TYPE_PORT object,
+the SyncE clock programming and the SSM for SyncE is focused in this proposal.
+
+## 2.0  Behavior
+
+### SyncE clock object
+
+![SyncE Clocks](SyncE_hardware_diagram.png)
+SyncE clock and an Ethernet port needs to be associated to setup the the clock source for the associated SyncE clock object.
+The recovered clock signal will be fed to the System clock. System clock drives the Ethernet Tx(frequency) with the help of 
+these SyncE clock sources. SyncE clock has the following attributes : clock-status, clock-hardware-id and clock-src-port.
+
+
+```mermaid
+classDiagram
+    class SYNCE_CLOCK {
+        - src_port
+        - clock_hardware_id
+        - clock_valid
+        - clock_force_valid
+    }
+
+    class PORT {
+        - ...
+    }
+
+    class SWITCH {
+        - port_list
+        - synce_clock_list [proposed]
+    }
+
+
+    %% Relationships
+    SWITCH --> SYNCE_CLOCK : SYNCE_CLOCK_LIST
+    SWITCH --> PORT : PORT_LIST
+    PORT <-- SYNCE_CLOCK : SRC_PORT
+
+style PORT fill:#bbf,stroke:#f66,stroke-width:2px,color:green;
+style SWITCH fill:#bbf,stroke:#f66,stroke-width:2px,color:green;
+
+```
+
+### SSM over ESMC for SyncE
+SyncE relies on quality of recovered clock which needs to be communicated through synchronization status message(SSM) over the
+Ethernet synchronization messaging channel(ESMC). To trap the SSM PDUs, new Hostif trap is added.
+
+## 3.0 SAI Enhancement
+
+### 1. New object type for SyncE clock
+
+```c
+      SAI_OBJECT_TYPE_SYNCE_CLOCK                    = 114,
+```
+
+
+```c
+/**
+ * @brief Enum defining SyncE attributes.
+ */
+typedef enum _sai_synce_clock_attr_t
+{
+    /**
+     * @brief Start of attributes
+     */
+    SAI_SYNCE_CLOCK_ATTR_START = 0x00000000,
+    /**
+     * @brief Synchronous ethernet(SyncE) clock source port
+     *
+     * Sets the Port to be the source for SyncE
+     *
+     * @type sai_object_id_t
+     * @objects SAI_OBJECT_TYPE_PORT
+     * @allownull true
+     * @flags CREATE_AND_SET
+     * @default SAI_NULL_OBJECT_ID
+     */
+    SAI_SYNCE_CLOCK_ATTR_SRC_PORT = SAI_SYNCE_CLOCK_ATTR_START,
+
+    /**
+     * @brief Synchronous ethernet (SyncE) clock status
+     *
+     * Gets recovered clock signal with respect to hardware
+     * (valid only after attaching the clock to a clock source port)
+     *
+     * @type bool
+     * @flags READ_ONLY
+     */
+    SAI_SYNCE_CLOCK_ATTR_CLOCK_VALID,
+
+    /**
+     * @brief Hardware clock-id
+     *
+     * Returns the hardware clock-id associated
+     *
+     * @type sai_uint32_t
+     * @flags READ_ONLY
+     */
+    SAI_SYNCE_CLOCK_ATTR_CLOCK_HARDWARE_ID,
+
+    /**
+     * @brief Synchronous ethernet (SyncE) clock status
+     *
+     * Force set the recovered clock signal state (for debugging)
+     *
+     * @type sai_synce_recovered_clock_state_t
+     * @flags CREATE_AND_SET
+     * @default SAI_SYNCE_CLOCK_FORCE_VALID_DISABLE
+     */
+    SAI_SYNCE_CLOCK_ATTR_DEBUG_FORCE_CLOCK_VALID,
+
+    /**
+     * @brief End of attributes
+     */
+    SAI_SYNCE_CLOCK_ATTR_END,
+    /** Custom range base value */
+    SAI_SYNCE_CLOCK_ATTR_CUSTOM_RANGE_START = 0x10000000,
+
+    /** End of custom range base */
+    SAI_SYNCE_CLOCK_ATTR_CUSTOM_RANGE_END
+
+} sai_synce_clock_attr_t;
+
+/**
+ * @brief Attribute data for #SAI_SYNCE_CLOCK_ATTR_DEBUG_FORCE_CLOCK_VALID
+ */
+typedef enum _sai_synce_recovered_clock_state_t
+{
+    /** Valid signal set as per device fault status */
+    SAI_SYNCE_CLOCK_FORCE_VALID_DISABLE,
+
+    /** Valid signal forced to valid */
+    SAI_SYNCE_CLOCK_FORCE_ENABLE_VALID,
+
+    /** Valid signal forced to invalid */
+    SAI_SYNCE_CLOCK_FORCE_ENABLE_INVALID,
+
+} sai_synce_recovered_clock_state_t;
+
+/**
+ * @brief Create SyncE clock
+ *
+ * @param[out] synce_id SyncE clock id
+ * @param[in] switch_id The Switch id
+ * @param[in] attr_count Number of attributes
+ * @param[in] attr_list Array of attributes
+ *
+ * @return #SAI_STATUS_SUCCESS on success, failure status code on error
+ */
+typedef sai_status_t (*sai_create_synce_clock_fn)(
+        _Out_ sai_object_id_t *synce_clock_id,
+        _In_ sai_object_id_t switch_id,
+        _In_ uint32_t attr_count,
+        _In_ const sai_attribute_t *attr_list);
+
+/**
+ * @brief Remove SyncE clock
+ *
+ * @param[in] synce_id SyncE clock id
+ *
+ * @return #SAI_STATUS_SUCCESS on success, failure status code on error
+ */
+typedef sai_status_t (*sai_remove_synce_clock_fn)(
+        _In_ sai_object_id_t synce_clock_id);
+
+/**
+ * @brief Set SyncE clock Attribute
+ *
+ * @param[in] synce_id SyncE clock id
+ * @param[in] attr Attribute to set
+ *
+ * @return #SAI_STATUS_SUCCESS on success, failure status code on error
+ */
+typedef sai_status_t (*sai_set_synce_clock_attribute_fn)(
+        _In_ sai_object_id_t synce_clock_id,
+        _In_ const sai_attribute_t *attr);
+
+/**
+ * @brief Get SyncE clock attribute
+ *
+ * @param[in] synce_id SyncE clock id
+ * @param[in] attr_count Number of attributes
+ * @param[inout] attr_list Array of attributes
+ *
+ * @return #SAI_STATUS_SUCCESS on success, failure status code on error
+ */
+typedef sai_status_t (*sai_get_synce_clock_attribute_fn)(
+        _In_ sai_object_id_t synce_clock_id,
+        _In_ uint32_t attr_count,
+        _Inout_ sai_attribute_t *attr_list);
+```
+
+### 2. New hostif trap for SSM over ESMC PDUs
+
+```c
+    /**
+     * @brief ITU-T G.8264/Y.1364 Ethernet synchronization messaging channel (ESMC) protocol
+     * (Dst Mac = 01-80-C2-00-00-02 EtherType = 0x8809 Slow Protocol Subtype = 0xA)
+     * (default packet action is drop)
+     */
+    SAI_HOSTIF_TRAP_TYPE_ESMC = 0x00008003,
+```
+
+### 3. Switch attributes for SyncE clock
+```c
+    /**
+     * @brief Maximum number of SyncE clocks supported
+     *
+     * @type sai_uint32_t
+     * @flags READ_ONLY
+     */
+    SAI_SWITCH_ATTR_MAX_SYNCE_CLOCK_COUNT,
+
+    /**
+     *
+     *@brief List of SyncE clock objects on the Switch
+     *
+     *@type sai_object_list_t
+     *@flags READ_ONLY
+     *@objects SAI_OBJECT_TYPE_SYNCE_CLOCK
+     *@default internal
+     */
+    SAI_SWITCH_ATTR_SYNCE_CLOCK_LIST,
+```
+
+## 4.0 API Example
+
+The API workflow is as given below,
+1. Get the maximum number of available SyncE clocks from the switch
+2. Get the list of available SyncE clocks from the switch
+3. Update the clock source by associating an Ethernet port to the SyncE clock object
+4. Update the clock source by updating the port at SyncE clock object​
+5. Remove the clock source by setting NULL oid to SyncE clock object
+6. Get and set SyncE clock object
+
+### 1. Get the maximum SyncE-clock objects present at the switch​
+
+```c
+attr_count = 0;​
+attr_list[attr_count++].id = SAI_SWITCH_ATTR_MAX_SYNCE_CLOCK_COUNT;​
+sai_get_switch_attribute_fn(switch_id, attr_count, attr_list) ;​
+synce_clocks_count = attr_list[0].value.u32;
+```
+### 2. Get the list of SyncE-clock objects present at the switch​
+```c
+attr_count = 0;​
+attr_clock_list[attr_count].id = SAI_SWITCH_ATTR_SYNCE_CLOCK_LIST;​
+attr_clock_list[attr_count].value.objlist.count = synce_clocks_count;
+attr_clock_list[attr_count++].value.objlist.list  = malloc(synce_clocks_count * sizeof(sai_object_id_t))
+sai_get_switch_attribute_fn(switch_id, attr_count, attr_clock_list) ;​
+```
+### 3. Associate a port to the SyncE-clock object to make it a clock source​
+```c
+attr_count = 0;​
+attr_list[attr_count].id = SAI_SYNCE_CLOCK_ATTR_SRC_PORT ;​
+attr_list[attr_count++].value.oid = port_oid;​
+
+sai_object_t clock0_oid = attr_clock_list[0].value.oid;​
+
+sai_set_synce_clock_fn(clock0_oid, switch_oid, attr_count, attr_list) ;
+```
+
+### 4. Update the clock source by updating the port at SyncE clock object​
+
+```c
+synce_attr.id = SAI_SYNCE_CLOCK_ATTR_SRC_PORT;​
+synce_attr.value.oid = new_port_oid;​
+sai_set_synce_clock_fn (clock0_oid, synce_attr);
+```
+
+### 5. Remove a port from clock source by setting NULL oid to SyncE object​
+
+```c
+synce_attr.id = SAI_SYNCE_CLOCK_ATTR_SRC_PORT;​
+synce_attr.value.oid = SAI_NULL_OBJECT_ID;​
+sai_set_synce_clock_fn (synce_oid, synce_attr) ;​
+```
+
+### 6.    Getting/Setting syncE-clock attributes
+```c
+/** Get Synce-clock */​
+
+attr_count = 0;​
+
+attr_list[attr_count++].id = SAI_SYNCE_CLOCK_ATTR_CLOCK_VALID;​
+attr_list[attr_count++].id = SAI_SYNCE_CLOCK_ATTR_CLOCK_HARDWARE_ID;​
+sai_get_synce_clock_fn (synce_clock_oid, attr_count, attr_list) ;​
+
+
+/** Set Synce-clock state by force */​
+synce_clock_attr.id = SAI_SYNCE_CLOCK_ATTR_DEBUG_FORCE_CLOCK_STATE;​
+synce_clock_attr.value.u32 = SAI_SYNCE_CLOCK_FORCE_ENABLE_VALID;​
+
+sai_set_synce_clock_fn (synce_clock_oid, synce_clock_attr) ;​
+```

doc/SyncE/SyncE_hardware_diagram.png

@@ -81,6 +81,7 @@
 #include "saiversion.h"
 #include "saipoe.h"
 #include "saiicmpecho.h"
+#include "saisynce.h"
 
 /**
  * @defgroup SAI SAI - Entry point specific API definitions.
@@ -151,6 +152,7 @@ typedef enum _sai_api_t
     SAI_API_POE              = 51, /**< sai_poe_api_t */
     SAI_API_ICMP_ECHO        = 52, /**< sai_icmp_echo_api_t */
     SAI_API_PREFIX_COMPRESSION = 53, /**< sai_prefix_compression_api_t */
+    SAI_API_SYNCE            = 54, /**< sai_synce_api_t */
     SAI_API_MAX,                   /**< total number of APIs */
 
     /**

inc/sai.h

@@ -516,6 +516,13 @@ typedef enum _sai_hostif_trap_type_t
      */
     SAI_HOSTIF_TRAP_TYPE_MPLS_LABEL_LOOKUP_MISS = 0x00008002,
 
+    /**
+     * @brief ITU-T G.8264/Y.1364 Ethernet synchronization messaging channel protocol
+     * (Dst MAC = 01-80-C2-00-00-02 EtherType = 0x8809 Slow Protocol sub-type = 0xA)
+     * (default packet action is drop)
+     */
+    SAI_HOSTIF_TRAP_TYPE_ESMC = 0x00008003,
+
     /** Exception traps custom range start */
     SAI_HOSTIF_TRAP_TYPE_CUSTOM_EXCEPTION_RANGE_BASE = 0x00009000,
 

inc/saihostif.h

@@ -3197,6 +3197,24 @@ typedef enum _sai_switch_attr_t
      */
     SAI_SWITCH_ATTR_SHARED_BUFFER_CELL_SIZE,
 
+    /**
+     * @brief Maximum number of synchronous ethernet clocks supported.
+     *
+     * @type sai_uint32_t
+     * @flags READ_ONLY
+     */
+    SAI_SWITCH_ATTR_MAX_SYNCE_CLOCK_COUNT,
+
+    /**
+     * @brief Gets the synchronous ethernet clock object list
+     *
+     * @type sai_object_list_t
+     * @flags READ_ONLY
+     * @objects SAI_OBJECT_TYPE_SYNCE_CLOCK
+     * @default internal
+     */
+    SAI_SWITCH_ATTR_SYNCE_CLOCK_LIST,
+
     /**
      * @brief End of attributes
      */