[Skiboot] [PATCH V10 10/21] core/pldm: PLDM for Platform Monitoring and Control Specification

Christophe Lombard clombard at linux.ibm.com
Tue Aug 29 19:23:27 AEST 2023


This specification defines the functions and data structures used for
discovering, describing, initializing, and accessing sensors and effecters
within the management controllers and management devices of a platform
management subsystem using PLDM messaging.

A PDR (Platform Descriptor Record) is a set of data that is used to
provide semantic information about sensors, effecters, monitored or
controller entities, and functions and services within a PLDM
implementation.
PDRs are mostly used to support PLDM monitoring and control and platform
events.

The PDRs for a PLDM subsystem are collected into a single, central PDR
Repository. A central repository provides a single place from which PDR
information can be retrieved.

The GetPDR command is used to retrieve individual PDRs from a PDR
Repository. The record is identified by the PDR recordHandle value that is
passed in the request.

The patch dump all the PDRs within a PDR Repository.

Reviewed-by: Abhishek Singh Tomar <abhishek at linux.ibm.com>
Signed-off-by: Christophe Lombard <clombard at linux.ibm.com>
---
 core/pldm/Makefile.inc             |   1 +
 core/pldm/pldm-base-requests.c     |  76 +++++++
 core/pldm/pldm-mctp.c              |   8 +-
 core/pldm/pldm-platform-requests.c | 309 +++++++++++++++++++++++++++++
 core/pldm/pldm.h                   |   9 +
 5 files changed, 402 insertions(+), 1 deletion(-)
 create mode 100644 core/pldm/pldm-base-requests.c
 create mode 100644 core/pldm/pldm-platform-requests.c

diff --git a/core/pldm/Makefile.inc b/core/pldm/Makefile.inc
index f2328a4bf..933b0c616 100644
--- a/core/pldm/Makefile.inc
+++ b/core/pldm/Makefile.inc
@@ -8,6 +8,7 @@ CPPFLAGS += -I$(SRC)/pldm/include/
 CPPFLAGS += -I$(SRC)/pldm/include/libpldm/oem/ibm/
 
 PLDM_OBJS = pldm-mctp.o pldm-responder.o pldm-requester.o
+PLDM_OBJS += pldm-base-requests.o pldm-platform-requests.o
 
 PLDM = $(PLDM_DIR)/built-in.a
 $(PLDM): $(PLDM_OBJS:%=$(PLDM_DIR)/%)
diff --git a/core/pldm/pldm-base-requests.c b/core/pldm/pldm-base-requests.c
new file mode 100644
index 000000000..d8984277f
--- /dev/null
+++ b/core/pldm/pldm-base-requests.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+// Copyright 2022 IBM Corp.
+
+#define pr_fmt(fmt) "PLDM: " fmt
+
+#include <cpu.h>
+#include <opal.h>
+#include <stdio.h>
+#include <string.h>
+#include <inttypes.h>
+#include <libpldm/base.h>
+#include "pldm.h"
+
+static uint8_t bmc_tid = -1;
+
+uint8_t pldm_base_get_bmc_tid(void)
+{
+	return bmc_tid;
+}
+
+/*
+ * Create a PLDM request message for GetTID.
+ */
+int pldm_base_get_tid_req(void)
+{
+	size_t data_size = PLDM_MSG_SIZE(0); /* the command doesn't have a message payload */
+	size_t response_len, payload_len;
+	struct pldm_tx_data *tx = NULL;
+	void *response_msg;
+	int rc;
+
+	struct pldm_get_tid_resp response;
+
+	/* Encode the get tid request */
+	tx = zalloc(sizeof(struct pldm_tx_data) + data_size);
+	if (!tx)
+		return OPAL_NO_MEM;
+	tx->data_size = data_size;
+
+	rc = encode_get_tid_req(DEFAULT_INSTANCE_ID,
+				(struct pldm_msg *)tx->data);
+	if (rc != PLDM_SUCCESS) {
+		prlog(PR_ERR, "Encode GetTID Error, rc: %d\n", rc);
+		free(tx);
+		return OPAL_PARAMETER;
+	}
+
+	/* Send and get the response message bytes */
+	rc = pldm_requester_queue_and_wait(tx, &response_msg, &response_len);
+	if (rc) {
+		prlog(PR_ERR, "Communication Error, req: GetTID, rc: %d\n", rc);
+		free(tx);
+		return rc;
+	}
+
+	/* Decode the message */
+	payload_len = response_len - sizeof(struct pldm_msg_hdr);
+
+	rc = decode_get_tid_resp(response_msg, payload_len,
+				 &response.completion_code,
+				 &response.tid);
+	if ((rc != PLDM_SUCCESS) || (response.completion_code != PLDM_SUCCESS)) {
+		prlog(PR_ERR, "Decode GetTID Error, rc: %d, cc: %d\n",
+			      rc, response.completion_code);
+		free(tx);
+		free(response_msg);
+		return OPAL_PARAMETER;
+	}
+
+	prlog(PR_INFO, "BMC's TID is %d\n", response.tid);
+	bmc_tid = response.tid;
+	free(tx);
+	free(response_msg);
+
+	return OPAL_SUCCESS;
+}
diff --git a/core/pldm/pldm-mctp.c b/core/pldm/pldm-mctp.c
index 569fe2553..a07d95035 100644
--- a/core/pldm/pldm-mctp.c
+++ b/core/pldm/pldm-mctp.c
@@ -74,18 +74,22 @@ out:
 
 int pldm_mctp_init(void)
 {
-	int nbr_elt = 3, rc = OPAL_SUCCESS;
+	int nbr_elt = 5, rc = OPAL_SUCCESS;
 
 	int (*pldm_config[])(void) = {
 		ast_mctp_init,		/* MCTP Binding */
 		pldm_responder_init,	/* Register mandatory commands we'll respond to */
 		pldm_requester_init,	/* Requester implementation */
+		pldm_base_get_tid_req,	/* Get BMC tid */
+		pldm_platform_init,	/* Get PDRs data */
 	};
 
 	const char *pldm_config_error[] = {
 		"Failed to bind MCTP",
 		"Failed to register mandatory commands",
 		"Failed to configure requister",
+		"Failed to retrieve BMC Tid",
+		"Failed to retrieve Data Records",
 	};
 
 	prlog(PR_NOTICE, "%s - Getting PLDM data\n", __func__);
@@ -105,5 +109,7 @@ out:
 
 void pldm_mctp_exit(void)
 {
+	pldm_platform_exit();
+
 	ast_mctp_exit();
 }
diff --git a/core/pldm/pldm-platform-requests.c b/core/pldm/pldm-platform-requests.c
new file mode 100644
index 000000000..6c0191823
--- /dev/null
+++ b/core/pldm/pldm-platform-requests.c
@@ -0,0 +1,309 @@
+// SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+// Copyright 2022 IBM Corp.
+
+#define pr_fmt(fmt) "PLDM: " fmt
+
+#include <cpu.h>
+#include <opal.h>
+#include <stdio.h>
+#include <string.h>
+#include <timebase.h>
+#include <inttypes.h>
+#include <libpldm/entity.h>
+#include <libpldm/pdr.h>
+#include <libpldm/state_set.h>
+#include <libpldm/platform.h>
+#include "pldm.h"
+
+#define NO_MORE_PDR_HANDLES 0
+
+static pldm_pdr *pdrs_repo;
+static bool pdr_ready;
+
+struct pldm_pdrs {
+	struct pldm_tx_data *tx;
+	uint32_t record_hndl;
+	bool done;
+	int rc;
+};
+
+struct pldm_pdrs *pdrs;
+
+static void pdr_init_complete(bool success)
+{
+	/* Read not successful, error out and free the buffer */
+	if (!success) {
+		pdr_ready = false;
+
+		if (pdrs_repo)
+			pldm_pdr_destroy(pdrs_repo);
+		return;
+	}
+
+	/* Mark ready */
+	pdr_ready = true;
+}
+
+struct get_pdr_response {
+	uint8_t completion_code;
+	uint32_t next_record_hndl;
+	uint32_t next_data_transfer_hndl;
+	uint8_t transfer_flag;
+	uint16_t resp_cnt;
+	uint8_t *record_data;
+	size_t record_data_length;
+	uint8_t transfer_crc;
+};
+
+static int encode_and_queue_get_pdr_req(struct pldm_pdrs *pdrs);
+
+static void get_pdr_req_complete(struct pldm_rx_data *rx,
+				 void *data)
+{
+	struct pldm_pdrs *pdrs = (struct pldm_pdrs *)data;
+	uint32_t record_hndl = pdrs->record_hndl;
+	struct get_pdr_response response;
+	size_t payload_len;
+	int rc, i;
+
+	prlog(PR_DEBUG, "%s - record_hndl: %d\n", __func__, record_hndl);
+
+	if (rx == NULL) {
+		pdrs->rc = OPAL_PARAMETER;
+		pdrs->done = true;
+	}
+
+	/* Decode the message twice; the first time, the payload buffer
+	 * will be null so that the decoder will simply tell us how big
+	 * the buffer should be. Then we create a suitable payload
+	 * buffer and call the decoder again, this time with the real
+	 * buffer so that it can fill it with data from the message.
+	 *
+	 * transfer_crc is not used in case of PLDM_START_AND_END.
+	 */
+	payload_len = rx->msg_len - sizeof(struct pldm_msg_hdr);
+	response.record_data_length = 0;
+	response.record_data = NULL;
+
+	for (i = 0; i < 2; i++) {
+		rc = decode_get_pdr_resp(
+				rx->msg, payload_len,
+				&response.completion_code,
+				&response.next_record_hndl,
+				&response.next_data_transfer_hndl,
+				&response.transfer_flag,
+				&response.resp_cnt,
+				response.record_data,
+				response.record_data_length,
+				&response.transfer_crc);
+
+		if (rc != PLDM_SUCCESS || response.completion_code != PLDM_SUCCESS) {
+			/* Message decoding failed */
+			prlog(PR_ERR, "Decode GetPDRResp Error (rc: %d, cc: %d)\n",
+				      rc, response.completion_code);
+
+			/* BMC is not ready, try again. This behavior can be
+			 * encountered when the BMC reboots and the host is
+			 * still operational.
+			 * The host receives a GET VERSION request indicating
+			 * that we must rehcrage the pdrs.
+			 */
+			if (response.completion_code == PLDM_ERROR_NOT_READY) {
+				time_wait_ms(500);
+				encode_and_queue_get_pdr_req(pdrs);
+				return;
+			}
+
+			pdrs->rc = OPAL_PARAMETER;
+			pdrs->done = true;
+			return;
+		}
+
+		if (response.record_data == NULL) {
+			response.record_data_length = response.resp_cnt;
+			response.record_data = zalloc(response.resp_cnt);
+			if (!response.record_data) {
+				prlog(PR_ERR, "failed to allocate record data (size: 0x%lx)\n", response.record_data_length);
+				pdrs->rc = OPAL_NO_MEM;
+				pdrs->done = true;
+				return;
+			}
+		}
+	}
+
+	/* we do not support multipart transfer */
+	if (response.transfer_flag != PLDM_START_AND_END)
+		prlog(PR_ERR, "Transfert GetPDRResp not complete, transfer_flag: %d\n",
+			      response.transfer_flag);
+
+	prlog(PR_DEBUG, "%s - record_hndl: %d, next_record_hndl: %d, resp_cnt: %d\n",
+			__func__, record_hndl,
+			response.next_record_hndl,
+			response.resp_cnt);
+
+	/* Add a PDR record to a PDR repository.
+	 * Use HOST_TID as terminus handle
+	 */
+	pldm_pdr_add(pdrs_repo,
+		     response.record_data,
+		     response.resp_cnt,
+		     record_hndl,
+		     false,
+		     HOST_TID);
+
+	free(response.record_data);
+
+	if (response.next_record_hndl != NO_MORE_PDR_HANDLES) {
+		pdrs->record_hndl = response.next_record_hndl;
+		encode_and_queue_get_pdr_req(pdrs);
+	} else {
+		/* We have to indicate the end of the initialization when we
+		 * reload the pdrs in background
+		 */
+		pdr_init_complete(true);
+		pdrs->done = true;
+		pdrs->rc = OPAL_SUCCESS;
+		prlog(PR_DEBUG, "%s - done\n", __func__);
+	}
+}
+
+/*
+ * Send/receive a PLDM GetPDR stateEffecter request message
+ * Get platform descriptor records.
+ *
+ * pldmtool platform GetPDR -t stateEffecter
+ * ...
+ * {
+ * "nextRecordHandle": 138,
+ * "responseCount": 30,
+ * "recordHandle": 137,
+ * "PDRHeaderVersion": 1,
+ * "PDRType": "State Effecter PDR",
+ * "recordChangeNumber": 0,
+ * "dataLength": 20,
+ * "PLDMTerminusHandle": 1,
+ * "effecterID": 43,
+ * "entityType": "[Physical] System chassis (main enclosure)",
+ * ...
+ * "Off-Soft Graceful(9)"
+ * }
+ * ...
+ */
+static int encode_and_queue_get_pdr_req(struct pldm_pdrs *pdrs)
+{
+	uint32_t record_hndl = pdrs->record_hndl;
+	int rc;
+
+	struct pldm_get_pdr_req pdr_req = {
+		.record_handle = record_hndl, /* record change number (0 for first request) */
+		.data_transfer_handle = 0, /* (0 if transfer op is FIRSTPART) */
+		.transfer_op_flag = PLDM_GET_FIRSTPART, /* transfer op flag */
+		.request_count = SHRT_MAX, /* Don't limit the size of the PDR */
+		.record_change_number = 0 /* record change number (0 for first request) */
+	};
+
+	prlog(PR_DEBUG, "%s - record_hndl: %d\n", __func__, record_hndl);
+
+	/* Encode the get_PDR request */
+	rc = encode_get_pdr_req(DEFAULT_INSTANCE_ID,
+				pdr_req.record_handle,
+				pdr_req.data_transfer_handle,
+				pdr_req.transfer_op_flag,
+				pdr_req.request_count,
+				pdr_req.record_change_number,
+				(struct pldm_msg *)pdrs->tx->data,
+				PLDM_GET_PDR_REQ_BYTES);
+	if (rc != PLDM_SUCCESS) {
+		prlog(PR_ERR, "Encode GetPDRReq Error, rc: %d\n", rc);
+		pdrs->done = true;
+		pdrs->rc = OPAL_PARAMETER;
+		return OPAL_PARAMETER;
+	}
+
+	/* Queue the first getpdr request */
+	rc = pldm_requester_queue(pdrs->tx, get_pdr_req_complete, pdrs);
+	if (rc) {
+		prlog(PR_ERR, "Communication Error, req: GetPDRReq, rc: %d\n", rc);
+		pdrs->done = true;
+		pdrs->rc = OPAL_PARAMETER;
+	}
+
+	return rc;
+}
+
+static int pldm_platform_load_pdrs(void)
+{
+	/* destroy current repo and mark repo not ready */
+	pdr_init_complete(false);
+
+	/* make a new PDR repository */
+	pdrs_repo = pldm_pdr_init();
+
+	/* collect all PDrs into a PDR Repository */
+	pdrs->record_hndl = 0;
+	pdrs->done = false;
+	return encode_and_queue_get_pdr_req(pdrs);
+}
+
+static int pdrs_init(void)
+{
+	int rc;
+
+	rc = pldm_platform_load_pdrs();
+	if (rc)
+		return rc;
+
+	/* wait for the end of pdrs received */
+	for (;;) {
+		if (pdrs->done)
+			break;
+
+		time_wait_ms(5);
+	}
+	return pdrs->rc;
+}
+
+int pldm_platform_init(void)
+{
+	size_t data_size = PLDM_MSG_SIZE(struct pldm_get_pdr_req);
+	int rc;
+
+	pdrs = zalloc(sizeof(struct pldm_pdrs));
+	if (!pdrs) {
+		prlog(PR_ERR, "failed to allocate pdrs\n");
+		return OPAL_NO_MEM;
+	}
+
+	pdrs->tx = zalloc(sizeof(struct pldm_tx_data) + data_size);
+	if (!pdrs->tx)
+		return OPAL_NO_MEM;
+	pdrs->tx->data_size = data_size;
+
+	/* retrieve all PDRs */
+	rc = pdrs_init();
+	if (rc)
+		goto err;
+
+	pdr_init_complete(true);
+	prlog(PR_DEBUG, "%s - done\n", __func__);
+
+	return OPAL_SUCCESS;
+
+err:
+	prlog(PR_ERR, "%s - failed to initialize pdrs, rc: %d\n", __func__, rc);
+	pdr_init_complete(false);
+	free(pdrs->tx);
+	free(pdrs);
+	return rc;
+}
+
+void pldm_platform_exit(void)
+{
+	if (pdr_ready)
+		pldm_pdr_destroy(pdrs_repo);
+
+	if (pdrs) {
+		free(pdrs->tx);
+		free(pdrs);
+	}
+}
diff --git a/core/pldm/pldm.h b/core/pldm/pldm.h
index 7c7da9f8e..fd7959770 100644
--- a/core/pldm/pldm.h
+++ b/core/pldm/pldm.h
@@ -11,6 +11,9 @@
 
 #define PLDM_MSG_SIZE(x) (sizeof(struct pldm_msg_hdr) + sizeof(x))
 
+/* For all of the encode functions just pass in a default ID (0x00) */
+#define DEFAULT_INSTANCE_ID 0
+
 struct pldm_tx_data {
 	/* Contains an message header and payload of an MCTP packet.
 	 * Size of data[]
@@ -48,6 +51,12 @@ int pldm_responder_handle_request(struct pldm_rx_data *rx);
 int pldm_responder_init(void);
 
 /* Requester support */
+uint8_t pldm_base_get_bmc_tid(void);
+int pldm_base_get_tid_req(void);
+
+int pldm_platform_init(void);
+void pldm_platform_exit(void);
+
 int pldm_requester_handle_response(struct pldm_rx_data *rx);
 int pldm_requester_queue(struct pldm_tx_data *tx,
 			 void (*complete)(struct pldm_rx_data *rx, void *data),
-- 
2.41.0



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