[Skiboot] [PATCH V4 03/21] core/pldm: PLDM over MCTP Binding

Christophe Lombard clombard at linux.vnet.ibm.com
Thu Apr 14 23:43:46 AEST 2022


Enable the mctp binding over LPC bus interface and new wrappers to send
and receive PLDM messages over the mctp library.

PLDM is supported as a message type over MCTP. PLDM over MCTP binding
defines the format of PLDM over MCTP messages.

An MCTP Endpoint is the terminus for MCTP communication. A physical device
that supports MCTP may provide one or more MCTP Endpoints. Endpoints are
addressed using a logical address called the Endpoint ID, or EID. EIDs in
MCTP are analogous to IP Addresses in Internet Protocol networking.

The BMC EID default is 8.

First byte of the PLDM over MCTP Message Fields identifies the MCTP
message as carrying a PLDM message:
Message Type (7 bits)  PLDM = 0x01 (000_0001b).

Signed-off-by: Christophe Lombard <clombard at linux.vnet.ibm.com>
---
 core/Makefile.inc       |   6 +-
 core/pldm/Makefile.inc  |  13 +++++
 core/pldm/pldm-common.c | 118 ++++++++++++++++++++++++++++++++++++++++
 core/pldm/pldm.h        |  42 ++++++++++++++
 include/pldm.h          |  18 ++++++
 5 files changed, 196 insertions(+), 1 deletion(-)
 create mode 100644 core/pldm/Makefile.inc
 create mode 100644 core/pldm/pldm-common.c
 create mode 100644 core/pldm/pldm.h
 create mode 100644 include/pldm.h

diff --git a/core/Makefile.inc b/core/Makefile.inc
index f80019b6..263a0e50 100644
--- a/core/Makefile.inc
+++ b/core/Makefile.inc
@@ -22,8 +22,12 @@ endif
 
 CORE=core/built-in.a
 
+ifeq ($(CONFIG_PLDM),1)
+include $(SRC)/core/pldm/Makefile.inc
+endif
+
 CFLAGS_SKIP_core/relocate.o = -pg -fstack-protector-all
 CFLAGS_SKIP_core/relocate.o += -fstack-protector -fstack-protector-strong
 CFLAGS_SKIP_core/relocate.o += -fprofile-arcs -ftest-coverage
 
-$(CORE): $(CORE_OBJS:%=core/%)
+$(CORE): $(CORE_OBJS:%=core/%) $(PLDM)
diff --git a/core/pldm/Makefile.inc b/core/pldm/Makefile.inc
new file mode 100644
index 00000000..005c7b94
--- /dev/null
+++ b/core/pldm/Makefile.inc
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+# Copyright 2022 IBM Corp
+
+PLDM_DIR ?= core/pldm
+SUBDIRS += $(PLDM_DIR)
+
+CPPFLAGS += -I$(SRC)/pldm/libpldm/
+CPPFLAGS += -I$(SRC)/pldm/ibm/libpldm/
+
+PLDM_OBJS = pldm-common.o
+
+PLDM = $(PLDM_DIR)/built-in.a
+$(PLDM): $(PLDM_OBJS:%=$(PLDM_DIR)/%)
diff --git a/core/pldm/pldm-common.c b/core/pldm/pldm-common.c
new file mode 100644
index 00000000..5271dfbd
--- /dev/null
+++ b/core/pldm/pldm-common.c
@@ -0,0 +1,118 @@
+// 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 <ast.h>
+#include "pldm.h"
+
+/*
+ * Print content of PLDM message in hex mode.
+ * 15 bytes per line.
+ * Ex: pldm_send: 000: 08 01 00 00 02 00 01
+ */
+void printbuf(const char *name, const char *msg, int len)
+{
+	int i, j;
+	char linebuf[128];
+
+	linebuf[0] = 0;
+
+	for (i = 0; i < len; i += j) {
+		linebuf[0] = 0;
+		for (j = 0; i + j < len && j < 15; j++) {
+			char s[5];
+
+			snprintf(s, 5, "%02x ", msg[i + j]);
+			strcat(linebuf, s);
+		}
+		prlog(PR_TRACE, "%s: %03x: %s\n", name, i, linebuf);
+	}
+}
+
+/*
+ * Send PLDM message over MCTP
+ */
+int pldm_send(uint8_t dest_id, uint8_t *buf, int len)
+{
+	uint8_t *msg;
+	int rc;
+
+	/* Message TYPE: PLDM = 0x01 (000_0001b) - DSP0240 */
+	msg = malloc(len + 1);
+	msg[0] = 0x01;
+	memcpy(&msg[1], buf, len);
+
+	rc = ast_mctp_message_tx(dest_id, msg, len + 1);
+	free(msg);
+
+	return rc;
+}
+
+/*
+ * Handle messages received from MCTP
+ */
+static int pldm_handle(uint8_t eid, const uint8_t *buf, int len)
+{
+	struct pldm_rx_data rx;
+
+	if (len < sizeof(rx.msg->hdr)) {
+		prlog(PR_ERR, "%s: packet is smaller than pldm header\n", __func__);
+		return OPAL_EMPTY;
+	}
+
+	memset(&rx, 0, sizeof(rx));
+	rx.msg = (struct pldm_msg *) buf;
+	rx.source_eid = eid;
+	rx.msg_len = len;
+
+	if (unpack_pldm_header(&rx.msg->hdr, &rx.hdrinf)) {
+		prlog(PR_ERR, "%s: unable to decode header\n", __func__);
+		return OPAL_EMPTY;
+	}
+
+	return OPAL_UNSUPPORTED;
+}
+
+/*
+ * MCTP message rx callback
+ */
+static void pldm_rx_message(uint8_t eid, bool tag_owner __unused,
+			    uint8_t msg_tag __unused, void *data __unused,
+			    void *vmsg, size_t len)
+{
+	uint8_t *msg = vmsg;
+
+	prlog(PR_TRACE, "message received: msg: %p, len %zd (eid: %d)\n",
+			 msg, len, eid);
+
+	/* pldm message type */
+	if ((msg[0] & 0x7f) != 0x01) {
+		prlog(PR_ERR, "%s - not a pldm message type\n", __func__);
+		return;
+	}
+
+	pldm_handle(eid, &msg[1], len - 1);
+}
+
+int pldm_mctp_init(void)
+{
+	int rc;
+
+	/* MCTP Binding */
+	rc = ast_mctp_init(pldm_rx_message);
+	if (rc)
+		prlog(PR_ERR, "Failed to bind MCTP\n");
+
+	prlog(PR_NOTICE, "%s - done, rc: %d\n", __func__, rc);
+	return rc;
+}
+
+void pldm_mctp_exit(void)
+{
+	ast_mctp_exit();
+}
diff --git a/core/pldm/pldm.h b/core/pldm/pldm.h
new file mode 100644
index 00000000..84649cf1
--- /dev/null
+++ b/core/pldm/pldm.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ * Copyright 2022 IBM Corp.
+ */
+
+#ifndef __COREPLDM_H__
+#define __COREPLDM_H__
+
+#include <pldm/libpldm/base.h>
+#include <pldm.h>
+
+/* Common support */
+
+void printbuf(const char *name, const char *msg, int len);
+
+/*
+ * EID is the MCTP endpoint ID, which aids in routing MCTP packets.
+ * For the EIDs: the valid range is 8-254.
+ * We are saying that BMC is EID 8 and Skiboot is HOST_EID 9
+ */
+#define BMC_EID  8
+#define HOST_EID 9
+
+struct pldm_rx_data {
+	struct pldm_header_info hdrinf; /* parsed message header */
+
+	struct pldm_msg *msg;
+	int msg_len;
+	int source_eid;
+};
+
+struct pldm_type {
+	const char *name;
+	int pldm_type_id;
+	ver32_t version;
+
+	struct list_head commands;
+	struct list_node link;
+};
+
+int pldm_send(uint8_t dest_id, uint8_t *buf, int len);
+
+#endif /* __COREPLDM_H__ */
diff --git a/include/pldm.h b/include/pldm.h
new file mode 100644
index 00000000..3d01086f
--- /dev/null
+++ b/include/pldm.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ * Copyright 2022 IBM Corp.
+ */
+
+#ifndef __PLDM_H__
+#define __PLDM_H__
+
+/**
+ * PLDM over MCTP initialization
+ */
+int pldm_mctp_init(void);
+
+/**
+ * PLDM over MCTP stop
+ */
+void pldm_mctp_exit(void);
+
+#endif /* __PLDM_H__ */
-- 
2.35.1



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