[Skiboot] [PATCH 14/19] core/pldm: PLDM for BIOS Control and Configuration Specification

Christophe Lombard clombard at linux.vnet.ibm.com
Sat Feb 26 01:28:43 AEDT 2022


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.

Signed-off-by: Christophe Lombard <clombard at linux.vnet.ibm.com>
---
 core/pldm/Makefile.inc         |   3 +-
 core/pldm/pldm-bios-requests.c | 210 +++++++++++++++++++++++++++++++++
 core/pldm/pldm-common.c        |   5 +
 core/pldm/pldm.h               |   2 +
 4 files changed, 219 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 72f71cba..fcd97a0a 100644
--- a/core/pldm/Makefile.inc
+++ b/core/pldm/Makefile.inc
@@ -8,9 +8,10 @@ CPPFLAGS += -I$(SRC)/pldm/libpldm/
 CPPFLAGS += -I$(SRC)/pldm/ibm/libpldm/
 
 CFLAGS_$(PLDM_DIR)/pldm-platform-requests.o = -Wno-strict-prototypes
+CFLAGS_$(PLDM_DIR)/pldm-bios-requests.o = -Wno-strict-prototypes
 
 PLDM_OBJS = pldm-common.o pldm-responder.o pldm-requester.o
-PLDM_OBJS += pldm-platform-requests.o
+PLDM_OBJS += pldm-platform-requests.o 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 00000000..cb1d3f34
--- /dev/null
+++ b/core/pldm/pldm-bios-requests.c
@@ -0,0 +1,210 @@
+// 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 <pldm/libpldm/bios.h>
+#include <pldm/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)
+{
+	char request_msg[PKT_SIZE(struct pldm_get_bios_table_req)];
+	size_t response_len, payload_len, bios_table_offset;
+	uint8_t completion_code, transfer_flag;
+	uint32_t next_transfer_handle;
+	void *response_msg;
+	int rc;
+
+	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 - GetBIOSTableReq, table type: %d\n",
+			__func__, table_type);
+
+	/* Encode the bios table request */
+	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 *)request_msg);
+	if (rc != PLDM_SUCCESS) {
+		prlog(PR_ERR, "Encode GetBIOSTableReq Error, type: %d (rc: %d)\n",
+			      table_type, rc);
+		return OPAL_PARAMETER;
+	}
+
+	/* Send and get the response message bytes */
+	rc = pldm_do_request(BMC_EID, request_msg, sizeof(request_msg),
+			     &response_msg, &response_len);
+	if (rc) {
+		prlog(PR_ERR, "PLDM: Communication Error (rc: %d)\n", rc);
+		return OPAL_PARAMETER;
+	}
+
+	/* 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);
+		return OPAL_PARAMETER;
+	}
+
+	/* 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 -
+		       sizeof(next_transfer_handle) -
+		       sizeof(transfer_flag) -
+		       sizeof(completion_code);
+	*bios_table = malloc(*bios_length);
+	memcpy(*bios_table,
+	       ((struct pldm_msg *)response_msg)->payload + bios_table_offset,
+	       *bios_length);
+
+	free(response_msg);
+
+	return OPAL_SUCCESS;
+}
+
+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-common.c b/core/pldm/pldm-common.c
index ea6cb2c3..98628afe 100644
--- a/core/pldm/pldm-common.c
+++ b/core/pldm/pldm-common.c
@@ -126,6 +126,11 @@ int pldm_mctp_init(void)
 
 	/* Get PDRs data */
 	rc = pldm_platform_init();
+	if (rc)
+		goto out;
+
+	/* Get Bios data */
+	rc = pldm_bios_init();
 
 out:
 	prlog(PR_NOTICE, "%s - done (rc: %d)\n", __func__, rc);
diff --git a/core/pldm/pldm.h b/core/pldm/pldm.h
index 8cbdd225..7f275e06 100644
--- a/core/pldm/pldm.h
+++ b/core/pldm/pldm.h
@@ -50,6 +50,8 @@ int pldm_rx_handle_request(struct pldm_rx_data *rx);
 int pldm_mctp_responder_init(void);
 
 /* Requester support */
+int pldm_bios_init(void);
+
 void pldm_platform_exit(void);
 int pldm_platform_init(void);
 
-- 
2.35.1



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