ipmi: Add a function to (re)initialise a message without allocation

Currently the only functions we have for initialising ipmi messages
with the correct values also allocate memory for the message. In some
cases we want to reuse previously allocated messages to avoid
continually freeing/allocating memory.

This patch introduces a function which (re)initialises a previously
allocated message and converts existing instances of this behaviour
over to the new function.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

5 files changed, 48 insertions, 26 deletions

diff --git a/core/ipmi.c b/core/ipmi.c
index 76b9a33..5caf057 100644
--- a/core/ipmi.c
+++ b/core/ipmi.c
@@ -30,6 +30,22 @@ void ipmi_free_msg(struct ipmi_msg *msg)
 	msg->backend->free_msg(msg);
 }
 
+void ipmi_init_msg(struct ipmi_msg *msg, int interface,
+		   uint32_t code, void (*complete)(struct ipmi_msg *),
+		   void *user_data, size_t req_size, size_t resp_size)
+{
+	/* We don't actually support multiple interfaces at the moment. */
+	assert(interface == IPMI_DEFAULT_INTERFACE);
+
+	msg->backend = ipmi_backend;
+	msg->cmd = IPMI_CMD(code);
+	msg->netfn = IPMI_NETFN(code) << 2;
+	msg->req_size = req_size;
+	msg->resp_size = resp_size;
+	msg->complete = complete;
+	msg->user_data = user_data;
+}
+
 struct ipmi_msg *ipmi_mkmsg_simple(uint32_t code, void *req_data, size_t req_size)
 {
 	return ipmi_mkmsg(IPMI_DEFAULT_INTERFACE, code, ipmi_free_msg, NULL,
@@ -43,20 +59,12 @@ struct ipmi_msg *ipmi_mkmsg(int interface, uint32_t code,
 {
 	struct ipmi_msg *msg;
 
-	/* We don't actually support multiple interfaces at the moment. */
-	assert(interface == IPMI_DEFAULT_INTERFACE);
-
 	msg = ipmi_backend->alloc_msg(req_size, resp_size);
 	if (!msg)
 		return NULL;
 
-	msg->backend = ipmi_backend;
-	msg->cmd = IPMI_CMD(code);
-	msg->netfn = IPMI_NETFN(code) << 2;
-	msg->req_size = req_size;
-	msg->resp_size = resp_size;
-	msg->complete = complete;
-	msg->user_data = user_data;
+	ipmi_init_msg(msg, interface, code, complete, user_data, req_size,
+		      resp_size);
 
 	/* Commands are free to over ride this if they want to handle errors */
 	msg->error = ipmi_free_msg;
diff --git a/hw/ipmi/ipmi-fru.c b/hw/ipmi/ipmi-fru.c
index 8728e33..be3ca90 100644
--- a/hw/ipmi/ipmi-fru.c
+++ b/hw/ipmi/ipmi-fru.c
@@ -183,10 +183,9 @@ static void fru_write_complete(struct ipmi_msg *msg)
 		goto out;
 
 	offset = msg->data[WRITE_INDEX];
-	msg->req_size = MIN(msg->data[REMAINING] + 3, IPMI_MAX_REQ_SIZE);
-	msg->cmd = IPMI_CMD(IPMI_WRITE_FRU);
-	msg->netfn = IPMI_NETFN(IPMI_WRITE_FRU) << 2;
-	msg->resp_size = 2;
+	ipmi_init_msg(msg, IPMI_DEFAULT_INTERFACE, IPMI_WRITE_FRU,
+		      fru_write_complete, NULL,
+		      MIN(msg->data[REMAINING] + 3, IPMI_MAX_REQ_SIZE), 2);
 
 	memmove(&msg->data[3], &msg->data[offset + 3], msg->req_size - 3);
 
diff --git a/hw/ipmi/ipmi-sel.c b/hw/ipmi/ipmi-sel.c
index 3f9462a..5832228 100644
--- a/hw/ipmi/ipmi-sel.c
+++ b/hw/ipmi/ipmi-sel.c
@@ -69,6 +69,7 @@ static void ipmi_elog_poll(struct ipmi_msg *msg)
 	static unsigned int reservation_id = 0;
 	static unsigned int record_id = 0;
 	struct errorlog *elog_buf = (struct errorlog *) msg->user_data;
+	size_t req_size;
 
 	if (msg->cmd == IPMI_CMD(IPMI_RESERVE_SEL)) {
 		reservation_id = msg->data[0];
@@ -103,9 +104,17 @@ static void ipmi_elog_poll(struct ipmi_msg *msg)
 		return;
 	}
 
-	msg->cmd = IPMI_CMD(IPMI_PARTIAL_ADD_ESEL);
-	msg->netfn = IPMI_NETFN(IPMI_PARTIAL_ADD_ESEL) << 2;
-	msg->resp_size = 2;
+	if ((pel_size - index) < (IPMI_MAX_REQ_SIZE - ESEL_HDR_SIZE)) {
+		/* Last data to send */
+		msg->data[6] = 1;
+		req_size = pel_size - index + ESEL_HDR_SIZE;
+	} else {
+		msg->data[6] = 0;
+		req_size = IPMI_MAX_REQ_SIZE;
+	}
+
+	ipmi_init_msg(msg, IPMI_DEFAULT_INTERFACE, IPMI_PARTIAL_ADD_ESEL,
+		      ipmi_elog_poll, elog_buf, req_size, 2);
 
 	msg->data[0] = reservation_id & 0xff;
 	msg->data[1] = (reservation_id >> 8) & 0xff;
@@ -114,15 +123,6 @@ static void ipmi_elog_poll(struct ipmi_msg *msg)
 	msg->data[4] = index & 0xff;
 	msg->data[5] = (index >> 8) & 0xff;
 
-	if ((pel_size - index) < (IPMI_MAX_REQ_SIZE - ESEL_HDR_SIZE)) {
-		/* Last data to send */
-		msg->data[6] = 1;
-		msg->req_size = pel_size - index + ESEL_HDR_SIZE;
-	} else {
-		msg->data[6] = 0;
-		msg->req_size = IPMI_MAX_REQ_SIZE;
-	}
-
 	memcpy(&msg->data[ESEL_HDR_SIZE], &pel_buf[index], msg->req_size - ESEL_HDR_SIZE);
 	index += msg->req_size - ESEL_HDR_SIZE;
 
diff --git a/hw/ipmi/test/run-fru.c b/hw/ipmi/test/run-fru.c
index f147a28..0c70e2d 100644
--- a/hw/ipmi/test/run-fru.c
+++ b/hw/ipmi/test/run-fru.c
@@ -27,6 +27,14 @@ void ipmi_free_msg(struct ipmi_msg __unused *msg)
 {
 }
 
+void ipmi_init_msg(struct ipmi_msg __unused *msg, int __unused interface,
+		   uint32_t __unused code,
+		   void __unused (*complete)(struct ipmi_msg *),
+		   void __unused *user_data, size_t __unused req_size,
+		   size_t __unused resp_size)
+{
+}
+
 struct ipmi_msg *ipmi_mkmsg(int __unused interface, uint32_t __unused code,
 			    void __unused (*complete)(struct ipmi_msg *),
 			    void __unused *user_data, void __unused *req_data, size_t __unused req_size,
diff --git a/include/ipmi.h b/include/ipmi.h
index 50de293..bbeae5a 100644
--- a/include/ipmi.h
+++ b/include/ipmi.h
@@ -163,6 +163,13 @@ struct ipmi_msg *ipmi_mkmsg(int interface, uint32_t code,
 			    void *user_data, void *req_data, size_t req_size,
 			    size_t resp_size);
 
+/* Initialise a previously allocated message with the required
+fields. The caller must ensure the message is large enough to hold the
+request and response data. */
+void ipmi_init_msg(struct ipmi_msg *msg, int interface,
+		   uint32_t code, void (*complete)(struct ipmi_msg *),
+		   void *user_data, size_t req_size, size_t resp_size);
+
 /* Add an ipmi message to the queue */
 int ipmi_queue_msg(struct ipmi_msg *msg);