ipmi: Add an opal interface to the ipmi stack

This patch adds two opal calls (opal_ipmi_send and opal_ipmi_recv)
to allow an operating system to send and receive arbitrary ipmi
messages to the BMC.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

3 files changed, 175 insertions, 9 deletions

diff --git a/hw/bt.c b/hw/bt.c
index 561ed14..1fe25dc 100644
--- a/hw/bt.c
+++ b/hw/bt.c
@@ -58,7 +58,9 @@
 /*
  * How long (in TB ticks) before a message is timed out.
  */
-#define BT_MSG_TIMEOUT (secs_to_tb(1))
+#define BT_MSG_TIMEOUT (secs_to_tb(3))
+
+#define BT_QUEUE_DEBUG 0
 
 enum bt_states {
 	BT_STATE_IDLE = 0,
@@ -76,7 +78,6 @@ struct bt_msg {
 	struct list_node link;
 	unsigned long tb;
 	uint8_t seq;
-	uint8_t lun;
 	struct ipmi_msg ipmi_msg;
 };
 
@@ -132,7 +133,6 @@ static int bt_add_ipmi_msg(struct ipmi_msg *ipmi_msg)
 {
 	struct bt_msg *bt_msg = container_of(ipmi_msg, struct bt_msg, ipmi_msg);
 
-	bt_msg->lun = 0;
 	lock(&bt.lock);
 	bt_msg->tb = mftb();
 	bt_msg->seq = ipmi_seq++;
@@ -197,7 +197,7 @@ static bool bt_try_send_msg(void)
 	bt_outb(ipmi_msg->req_size + BT_MIN_REQ_LEN, BT_HOST2BMC);
 
 	/* Byte 2 - NetFn/LUN */
-	bt_outb((ipmi_msg->netfn << 2) | (bt_msg->lun & 0x3), BT_HOST2BMC);
+	bt_outb(ipmi_msg->netfn, BT_HOST2BMC);
 
 	/* Byte 3 - Seq */
 	bt_outb(bt_msg->seq, BT_HOST2BMC);
@@ -290,16 +290,13 @@ static bool bt_get_resp(void)
 	}
 	ipmi_msg->resp_size = resp_len;
 
-	bt_msg->lun = netfn & 0x3;
-	netfn = netfn >> 2;
-
 	/* Byte 6:N - Data */
 	for (i = 0; i < resp_len; i++)
 		ipmi_msg->data[i] = bt_inb(BT_HOST2BMC);
 	bt_set_h_busy(false);
 
 	if (cc != IPMI_CC_NO_ERROR)
-		prerror("BT: Host error 0x%02x receiving BT/IPMI response\n", cc);
+		prerror("BT: Host error 0x%02x receiving BT/IPMI response for msg 0x%02x\n", cc, seq);
 
 	/* Make sure the other side is idle before we move to the idle state */
 	bt_set_state(BT_STATE_B_BUSY);
@@ -310,6 +307,10 @@ static bool bt_get_resp(void)
 	/*
 	 * Call the IPMI layer to finish processing the message.
 	 */
+#if BT_QUEUE_DEBUG
+	prlog(PR_DEBUG, "cmd 0x%02x done\n", seq);
+#endif
+
 	ipmi_cmd_done(cmd, netfn, cc, ipmi_msg);
 
 	/* Immediately send the next message */
@@ -337,6 +338,25 @@ static void bt_poll(void *data __unused)
 	bool ret = true;
 
 	do {
+
+#if BT_QUEUE_DEBUG
+		struct bt_msg *msg;
+		static bool printed = false;
+		lock(&bt.lock);
+		if (!list_empty(&bt.msgq)) {
+			printed = false;
+			prlog(PR_DEBUG, "-------- BT Msg Queue --------\n");
+			list_for_each(&bt.msgq, msg, link) {
+				prlog(PR_DEBUG, "Seq: 0x%02x Cmd: 0x%02x\n", msg->seq, msg->ipmi_msg.cmd);
+			}
+			prlog(PR_DEBUG, "-----------------------------\n");
+		} else if (!printed) {
+			printed = true;
+			prlog(PR_DEBUG, "----- BT Msg Queue Empty -----\n");
+		}
+		unlock(&bt.lock);
+#endif
+
 		bt_expire_old_msg();
 
 		switch(bt.state) {
diff --git a/hw/ipmi/Makefile.inc b/hw/ipmi/Makefile.inc
index c939f6c..b27ef93 100644
--- a/hw/ipmi/Makefile.inc
+++ b/hw/ipmi/Makefile.inc
@@ -1,5 +1,5 @@
 SUBDIRS += hw/ipmi
 
-IPMI_OBJS  = ipmi-rtc.o ipmi-power.o
+IPMI_OBJS  = ipmi-rtc.o ipmi-power.o ipmi-opal.o
 IPMI = hw/ipmi/built-in.o
 $(IPMI): $(IPMI_OBJS:%=hw/ipmi/%)
diff --git a/hw/ipmi/ipmi-opal.c b/hw/ipmi/ipmi-opal.c
new file mode 100644
index 0000000..4a90468
--- /dev/null
+++ b/hw/ipmi/ipmi-opal.c
@@ -0,0 +1,146 @@
+/* Copyright 2013-2014 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * 	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <ipmi.h>
+#include <lock.h>
+#include <opal.h>
+#include <device.h>
+#include <ccan/list/list.h>
+
+enum {
+	OPAL_IPMI_MSG_FORMAT_VERSION_1 = 1,
+};
+
+struct opal_ipmi_msg {
+	uint8_t version;
+	uint8_t netfn;
+	uint8_t cmd;
+	uint8_t data[];
+};
+
+static struct lock msgq_lock = LOCK_UNLOCKED;
+static struct list_head msgq = LIST_HEAD_INIT(msgq);
+
+static void opal_send_complete(struct ipmi_msg *msg)
+{
+	lock(&msgq_lock);
+	list_add_tail(&msgq, &msg->link);
+	opal_update_pending_evt(ipmi_backend->opal_event_ipmi_recv,
+				ipmi_backend->opal_event_ipmi_recv);
+	unlock(&msgq_lock);
+}
+
+static int64_t opal_ipmi_send(uint64_t interface,
+			      struct opal_ipmi_msg *opal_ipmi_msg, uint64_t msg_len)
+{
+	struct ipmi_msg *msg;
+
+	if (opal_ipmi_msg->version != OPAL_IPMI_MSG_FORMAT_VERSION_1) {
+		prerror("OPAL IPMI: Incorrect version\n");
+		return OPAL_UNSUPPORTED;
+	}
+
+	msg_len -= sizeof(struct opal_ipmi_msg);
+	if (msg_len > IPMI_MAX_REQ_SIZE) {
+		prerror("OPAL IPMI: Invalid request length\n");
+		return OPAL_PARAMETER;
+	}
+
+	prlog(PR_DEBUG, "opal_ipmi_send(cmd: 0x%02x netfn: 0x%02x len: 0x%02llx)\n",
+	       opal_ipmi_msg->cmd, opal_ipmi_msg->netfn >> 2, msg_len);
+
+	msg = ipmi_mkmsg(interface,
+			 IPMI_CODE(opal_ipmi_msg->netfn >> 2, opal_ipmi_msg->cmd),
+			 opal_send_complete, NULL, opal_ipmi_msg->data,
+			 msg_len, IPMI_MAX_RESP_SIZE);
+	if (!msg)
+		return OPAL_RESOURCE;
+
+	msg->complete = opal_send_complete;
+	msg->error = opal_send_complete;
+	return ipmi_queue_msg(msg);
+}
+
+static int64_t opal_ipmi_recv(uint64_t interface,
+			      struct opal_ipmi_msg *opal_ipmi_msg, uint64_t *msg_len)
+{
+	struct ipmi_msg *msg;
+	int64_t rc;
+
+	lock(&msgq_lock);
+	msg = list_top(&msgq, struct ipmi_msg, link);
+
+	if (!msg) {
+		rc = OPAL_EMPTY;
+		goto out_unlock;
+	}
+
+	if (opal_ipmi_msg->version != OPAL_IPMI_MSG_FORMAT_VERSION_1) {
+		prerror("OPAL IPMI: Incorrect version\n");
+		rc = OPAL_UNSUPPORTED;
+		goto out_unlock;
+	}
+
+	if (interface != IPMI_DEFAULT_INTERFACE) {
+		prerror("IPMI: Invalid interface 0x%llx in opal_ipmi_recv\n", interface);
+		rc = OPAL_EMPTY;
+		goto out_unlock;
+	}
+
+	if (*msg_len - sizeof(struct opal_ipmi_msg) < msg->resp_size + 1) {
+		rc = OPAL_RESOURCE;
+		goto out_unlock;
+	}
+
+	list_del(&msg->link);
+	if (list_empty(&msgq))
+		opal_update_pending_evt(ipmi_backend->opal_event_ipmi_recv, 0);
+	unlock(&msgq_lock);
+
+	opal_ipmi_msg->cmd = msg->cmd;
+	opal_ipmi_msg->netfn = msg->netfn;
+	opal_ipmi_msg->data[0] = msg->cc;
+	memcpy(&opal_ipmi_msg->data[1], msg->data, msg->resp_size);
+
+	prlog(PR_DEBUG, "opal_ipmi_recv(cmd: 0x%02x netfn: 0x%02x resp_size: 0x%02x)\n",
+	      msg->cmd, msg->netfn >> 2, msg->resp_size);
+
+	/* Add one as the completion code is returned in the message data */
+	*msg_len = msg->resp_size + sizeof(struct opal_ipmi_msg) + 1;
+	ipmi_free_msg(msg);
+
+	return OPAL_SUCCESS;
+
+out_unlock:
+	unlock(&msgq_lock);
+	return rc;
+}
+
+void ipmi_opal_init(void)
+{
+	struct dt_node *opal_ipmi;
+
+	opal_ipmi = dt_new(opal_node, "ipmi");
+	dt_add_property_strings(opal_ipmi, "compatible", "ibm,opal-ipmi");
+	dt_add_property_cells(opal_ipmi, "ibm,ipmi-interface-id",
+			      IPMI_DEFAULT_INTERFACE);
+	dt_add_property_cells(opal_ipmi, "interrupts",
+			      ilog2(ipmi_backend->opal_event_ipmi_recv));
+
+	opal_register(OPAL_IPMI_SEND, opal_ipmi_send, 3);
+	opal_register(OPAL_IPMI_RECV, opal_ipmi_recv, 3);
+}