[Skiboot] [PATCH V10 14/21] core/pldm: PLDM for BIOS Control and Configuration Specification

Christophe Lombard clombard at linux.ibm.com
Tue Aug 29 19:23:31 AEST 2023


This specification defines the data structures and messages for
communicating BIOS settings, BIOS attributes, boot configurations, and
boot order settings.

Use the GetBIOSTable command to get STRING, Attribute and Attribute values
tables from the BIOS.

The content of these tables is useful to read/write the lid files located
on the BMC.

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-bios-requests.c | 222 +++++++++++++++++++++++++++++++++
 core/pldm/pldm-mctp.c          |   4 +-
 core/pldm/pldm.h               |   2 +
 4 files changed, 228 insertions(+), 1 deletion(-)
 create mode 100644 core/pldm/pldm-bios-requests.c

diff --git a/core/pldm/Makefile.inc b/core/pldm/Makefile.inc
index 933b0c616..e4135ac97 100644
--- a/core/pldm/Makefile.inc
+++ b/core/pldm/Makefile.inc
@@ -9,6 +9,7 @@ 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_OBJS += pldm-bios-requests.o
 
 PLDM = $(PLDM_DIR)/built-in.a
 $(PLDM): $(PLDM_OBJS:%=$(PLDM_DIR)/%)
diff --git a/core/pldm/pldm-bios-requests.c b/core/pldm/pldm-bios-requests.c
new file mode 100644
index 000000000..0fa198a27
--- /dev/null
+++ b/core/pldm/pldm-bios-requests.c
@@ -0,0 +1,222 @@
+// SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+// Copyright 2022 IBM Corp.
+
+#define pr_fmt(fmt) "PLDM: " fmt
+
+#include <opal.h>
+#include <stdio.h>
+#include <string.h>
+#include <inttypes.h>
+#include <libpldm/bios.h>
+#include <libpldm/bios_table.h>
+#include "pldm.h"
+
+/*
+ * PLDM_BIOS_STRING_TABLE = 0
+ * pldmtool bios GetBIOSTable -t 0
+ * pldmtool: Tx: 08 01 80 03 01 00 00 00 00 01 00
+ *    ...
+ *    "60": "hb_lid_ids",
+ *    ...
+ */
+static void *bios_string_table;
+static size_t bios_string_length;
+
+/*
+ * PLDM_BIOS_ATTR_TABLE = 1
+ * pldmtool bios GetBIOSTable -t 1
+ * pldmtool: Tx: 08 01 80 03 01 00 00 00 00 01 01
+ *
+ * {
+ *   "AttributeHandle": 8,
+ *   "AttributeNameHandle": "60(hb_lid_ids)",
+ *   "AttributeType": "BIOSString",
+ *   "StringType": "0x01",
+ *   "MinimumStringLength": 0,
+ *   "MaximumStringLength": 1024,
+ *   "DefaultStringLength": 0,
+ *   "DefaultString": ""
+ * },
+ */
+static void *bios_attr_table;
+static size_t bios_attr_length;
+
+/*
+ * PLDM_BIOS_ATTR_VAL_TABLE = 2
+ * pldmtool bios GetBIOSTable -t 2
+ * pldmtool: Tx: 08 01 80 03 01 00 00 00 00 01 02
+ *
+ * {
+ *   "AttributeHandle": 8,
+ *   "AttributeType": "BIOSString",
+ *   "CurrentStringLength": 616,
+ *   "CurrentString": "ATTR_PERM=81e00663,ATTR_TMP=81e00664, ...
+ *                   NVRAM=81e0066b,...,pnor.toc=NA"
+ * }, ...
+ */
+static void *bios_val_table;
+static size_t bios_val_length;
+
+static bool bios_ready;
+
+static void bios_init_complete(bool success)
+{
+	/* Read not successful, error out and free the buffer */
+	if (!success) {
+		bios_ready = false;
+
+		if (bios_string_table != NULL) {
+			free(bios_string_table);
+			bios_string_length = 0;
+		}
+		if (bios_attr_table != NULL) {
+			free(bios_attr_table);
+			bios_attr_length = 0;
+		}
+		if (bios_val_table != NULL) {
+			free(bios_val_table);
+			bios_val_length = 0;
+		}
+		return;
+	}
+
+	/* Mark ready */
+	bios_ready = true;
+}
+
+/*
+ * Send/receive a PLDM GetBIOSTable request message
+ */
+static int get_bios_table_req(enum pldm_bios_table_types table_type,
+			      void **bios_table, size_t *bios_length)
+{
+	size_t data_size = PLDM_MSG_SIZE(struct pldm_get_bios_table_req);
+	size_t response_len, payload_len, bios_table_offset;
+	uint8_t completion_code, transfer_flag;
+	struct pldm_tx_data *tx = NULL;
+	uint32_t next_transfer_handle;
+	int rc = OPAL_SUCCESS;
+	void *response_msg;
+
+	struct pldm_get_bios_table_req bios_table_req = {
+		.transfer_handle = 0, /* (0 if transfer op is FIRSTPART) */
+		.transfer_op_flag = PLDM_GET_FIRSTPART,
+		.table_type = table_type
+	};
+
+	prlog(PR_DEBUG, "%s - table type: %d\n", __func__, table_type);
+
+	/* Encode the bios table request */
+	tx = zalloc(sizeof(struct pldm_tx_data) + data_size);
+	if (!tx)
+		return OPAL_NO_MEM;
+	tx->data_size = data_size;
+
+	rc = encode_get_bios_table_req(
+				DEFAULT_INSTANCE_ID,
+				bios_table_req.transfer_handle,
+				bios_table_req.transfer_op_flag,
+				bios_table_req.table_type,
+				(struct pldm_msg *)tx->data);
+	if (rc != PLDM_SUCCESS) {
+		prlog(PR_ERR, "Encode GetBIOSTableReq Error, type: %d, rc: %d\n",
+			      table_type, 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: GetBIOSTableReq, rc: %d\n", rc);
+		free(tx);
+		return rc;
+	}
+
+	/* Decode the message */
+	payload_len = response_len - sizeof(struct pldm_msg_hdr);
+	rc = decode_get_bios_table_resp(
+				response_msg,
+				payload_len,
+				&completion_code,
+				&next_transfer_handle,
+				&transfer_flag,
+				&bios_table_offset);
+	if (rc != PLDM_SUCCESS || completion_code != PLDM_SUCCESS) {
+		prlog(PR_ERR, "Decode GetBIOSTableResp Error, rc: %d, cc: %d\n",
+			      rc, completion_code);
+		rc = OPAL_PARAMETER;
+		goto out;
+	}
+
+	/* we do not support multipart transfer */
+	if ((next_transfer_handle != PLDM_GET_NEXTPART) ||
+	    (transfer_flag != PLDM_START_AND_END)) {
+		prlog(PR_ERR, "Transfert GetBIOSTable not complete "
+			      "transfer_hndl: %d, transfer_flag: %d\n",
+			      next_transfer_handle,
+			      transfer_flag);
+	}
+
+	*bios_length = payload_len - bios_table_offset;
+	*bios_table = zalloc(*bios_length);
+	if (!bios_table) {
+		prlog(PR_ERR, "failed to allocate bios table (size: 0x%lx)\n",
+			      *bios_length);
+		rc = OPAL_NO_MEM;
+		goto out;
+	}
+
+	memcpy(*bios_table,
+	       ((struct pldm_msg *)response_msg)->payload + bios_table_offset,
+	       *bios_length);
+
+out:
+	free(tx);
+	free(response_msg);
+	return rc;
+}
+
+int pldm_bios_init(void)
+{
+	int rc;
+
+	/* BIOS String Table is a BIOS table that contains all the BIOS
+	 * strings including attribute names, and pre-configured strings
+	 * used in representing the values of the attributes.
+	 * Each string in the BIOS String Table has an associated unique
+	 * handle.
+	 */
+	rc = get_bios_table_req(PLDM_BIOS_STRING_TABLE,
+				&bios_string_table, &bios_string_length);
+	if (rc)
+		goto err;
+
+	/* BIOS Attribute Table is a BIOS table that contains attribute
+	 * name handles, attribute types, type-specific metadata,
+	 * type-specific possible values (if any), and default values.
+	 */
+	rc = get_bios_table_req(PLDM_BIOS_ATTR_TABLE,
+				&bios_attr_table, &bios_attr_length);
+	if (rc)
+		goto err;
+
+	/* BIOS Attribute Value Table is a BIOS table that contains all
+	 * the current values of the BIOS attributes and settings.
+	 * Each entry in this table contains the attribute handle, the
+	 * attribute type, and current values.
+	 */
+	rc = get_bios_table_req(PLDM_BIOS_ATTR_VAL_TABLE,
+				&bios_val_table, &bios_val_length);
+	if (rc)
+		goto err;
+
+	bios_init_complete(true);
+	prlog(PR_DEBUG, "%s - done\n", __func__);
+
+	return OPAL_SUCCESS;
+
+err:
+	bios_init_complete(false);
+	return rc;
+}
diff --git a/core/pldm/pldm-mctp.c b/core/pldm/pldm-mctp.c
index a07d95035..6003b66c9 100644
--- a/core/pldm/pldm-mctp.c
+++ b/core/pldm/pldm-mctp.c
@@ -74,7 +74,7 @@ out:
 
 int pldm_mctp_init(void)
 {
-	int nbr_elt = 5, rc = OPAL_SUCCESS;
+	int nbr_elt = 6, rc = OPAL_SUCCESS;
 
 	int (*pldm_config[])(void) = {
 		ast_mctp_init,		/* MCTP Binding */
@@ -82,6 +82,7 @@ int pldm_mctp_init(void)
 		pldm_requester_init,	/* Requester implementation */
 		pldm_base_get_tid_req,	/* Get BMC tid */
 		pldm_platform_init,	/* Get PDRs data */
+		pldm_bios_init,		/* Get Bios data */
 	};
 
 	const char *pldm_config_error[] = {
@@ -90,6 +91,7 @@ int pldm_mctp_init(void)
 		"Failed to configure requister",
 		"Failed to retrieve BMC Tid",
 		"Failed to retrieve Data Records",
+		"Failed to retrieve Bios data",
 	};
 
 	prlog(PR_NOTICE, "%s - Getting PLDM data\n", __func__);
diff --git a/core/pldm/pldm.h b/core/pldm/pldm.h
index fd7959770..3f465902d 100644
--- a/core/pldm/pldm.h
+++ b/core/pldm/pldm.h
@@ -51,6 +51,8 @@ int pldm_responder_handle_request(struct pldm_rx_data *rx);
 int pldm_responder_init(void);
 
 /* Requester support */
+int pldm_bios_init(void);
+
 uint8_t pldm_base_get_bmc_tid(void);
 int pldm_base_get_tid_req(void);
 
-- 
2.41.0



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