[Skiboot] [PATCH 3/4] ipmi: Implement Read Event and SEL parsing

[Joel Stanley]

The read event mechanism is used when the BMC has an asynchronous message
for the host. It sets a flag that we read with Get Message Flags, and then
we read the message using Read Event. This event message contains a SEL
message. There are two OEM SEL messages we expect from the AMI BMC:

 - graceful power operations. This is when the BMC wants the host to
   power down or reboot.

 - PNOR Locking. When the BMC wants to access the PNOR, it requests
   that the host not touch it.

This patch implements the parsing.

Signed-off-by: Joel Stanley <joel at jms.id.au>
---
 core/ipmi.c        |  3 ++-
 hw/ipmi/ipmi-sel.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 include/ipmi.h     |  3 +++
 3 files changed, 83 insertions(+), 1 deletion(-)

diff --git a/core/ipmi.c b/core/ipmi.c
index 35bfead..b5ada0e 100644
--- a/core/ipmi.c
+++ b/core/ipmi.c
@@ -108,7 +108,8 @@ static void ipmi_read_event_complete(struct ipmi_msg *msg)
 	prlog(PR_DEBUG, "IPMI read event %02x complete: %d bytes. cc: %02x\n",
 	      msg->cmd, msg->resp_size, msg->cc);
 
-	/* TODO: Handle power control & PNOR handshake events */
+	/* Handle power control & PNOR handshake events */
+	ipmi_parse_sel(msg);
 
 	ipmi_free_msg(msg);
 }
diff --git a/hw/ipmi/ipmi-sel.c b/hw/ipmi/ipmi-sel.c
index d6f7f47..3d4fbf7 100644
--- a/hw/ipmi/ipmi-sel.c
+++ b/hw/ipmi/ipmi-sel.c
@@ -22,6 +22,30 @@
 #include <errorlog.h>
 #include <pel.h>
 
+/* OEM SEL fields */
+#define SEL_OEM_ID_0		0x55
+#define SEL_OEM_ID_1		0x55
+#define SEL_RECORD_TYPE_OEM	0xC0
+#define SEL_RECORD_TYPE_EVENT	0x02
+
+#define SEL_NETFN_IBM		0x3a
+
+/* OEM SEL Commands */
+#define CMD_AMI_POWER		0x04
+#define CMD_AMI_PNOR_ACCESS	0x07
+
+struct oem_sel {
+	/* SEL header */
+	uint8_t id[2];
+	uint8_t type;
+	uint8_t manuf_id[3];
+	uint8_t timestamp[4];
+	/* OEM SEL data (6 bytes) follows */
+	uint8_t netfun;
+	uint8_t cmd;
+	uint8_t data[4];
+};
+
 /* As far as I can tell the size of PEL record is unbounded (due to
  * the possible presence of the user defined section). We chose this
  * size because it's what FSP uses, but we could probably reduce
@@ -148,3 +172,57 @@ int ipmi_elog_commit(struct errorlog *elog_buf)
 
 	return 0;
 }
+
+static void dump_sel(struct oem_sel *sel)
+{
+	const int level = PR_DEBUG;
+
+	prlog(level, "\tid %02x%02x\n", sel->id[0], sel->id[1]);
+	prlog(level, "\ttype %02x\n", sel->type);
+	prlog(level, "\tmanuf %02x %02x %02x\n",
+	      sel->manuf_id[0], sel->manuf_id[1], sel->manuf_id[2]);
+	prlog(level, "\ttime %02x %02x %02x %02x\n",
+	      sel->timestamp[0], sel->timestamp[1],
+	      sel->timestamp[2], sel->timestamp[3]);
+	prlog(level, "\tnetfun %02x\n", sel->netfun);
+	prlog(level, "\tcmd %02x\n", sel->cmd);
+	prlog(level, "\tdata %02x %02x %02x %02x\n", sel->data[0],
+	      sel->data[1], sel->data[2], sel->data[3]);
+}
+
+void ipmi_parse_sel(struct ipmi_msg *msg)
+{
+	struct oem_sel sel;
+
+	prlog(PR_INFO, "SEL received (size: %d)\n", msg->resp_size);
+	assert(msg->resp_size <= 16);
+
+	memcpy(&sel, msg->data, msg->resp_size);
+
+	dump_sel(&sel);
+
+	/* We do not process system event records */
+	if (sel.type == SEL_RECORD_TYPE_EVENT) {
+		prlog(PR_INFO, "IPMI: dropping System Event Record SEL\n");
+		return;
+	}
+
+	/* Only accept OEM SEL messages */
+	if (sel.id[0] != SEL_OEM_ID_0 ||
+	    sel.id[1] != SEL_OEM_ID_1 ||
+	    sel.type != SEL_RECORD_TYPE_OEM) {
+		prlog(PR_WARNING, "IPMI: unknown SEL %02x%02x (type %02x)\n",
+		      sel.id[0], sel.id[1], sel.type);
+		return;
+	}
+
+	switch (sel.cmd) {
+	case CMD_AMI_POWER:
+		break;
+	case CMD_AMI_PNOR_ACCESS:
+		break;
+	default:
+		printf("IPMI: unknown OEM SEL command %02x received\n",
+		       sel.cmd);
+	}
+}
diff --git a/include/ipmi.h b/include/ipmi.h
index b22db1b..5cfa6c7 100644
--- a/include/ipmi.h
+++ b/include/ipmi.h
@@ -212,4 +212,7 @@ void ipmi_fru_init(uint8_t fru_dev_id);
 struct errorlog;
 int ipmi_elog_commit(struct errorlog *elog_buf);
 
+/* Callback to parse an OEM SEL message */
+void ipmi_parse_sel(struct ipmi_msg *msg);
+
 #endif
-- 
2.1.4