fsp/ipmi: Add the in-band IPMI support for FSP systems

FSP implements the IPMI commands support that can be accessed over
the mailbox interface from the host. The host needs to provide and
receive the message/data bytes of the IPMI command in the TCE space
in the  KCS (Keyboard Controller Style) format.

Signed-off-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
Acked-By: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

2 files changed, 356 insertions, 1 deletions

diff --git a/hw/fsp/Makefile.inc b/hw/fsp/Makefile.inc
index 2fe4f0dd..71690954 100644
--- a/hw/fsp/Makefile.inc
+++ b/hw/fsp/Makefile.inc
@@ -4,7 +4,7 @@ FSP_OBJS  = fsp.o fsp-console.o fsp-rtc.o fsp-nvram.o fsp-sysparam.o
 FSP_OBJS += fsp-surveillance.o fsp-codeupdate.o fsp-sensor.o
 FSP_OBJS += fsp-diag.o fsp-leds.o fsp-mem-err.o fsp-op-panel.o
 FSP_OBJS += fsp-elog-read.o fsp-elog-write.o fsp-epow.o fsp-dpo.o
-FSP_OBJS += fsp-dump.o fsp-mdst-table.o fsp-chiptod.o
+FSP_OBJS += fsp-dump.o fsp-mdst-table.o fsp-chiptod.o fsp-ipmi.o
 FSP_OBJS += fsp-attn.o
 FSP = hw/fsp/built-in.o
 $(FSP): $(FSP_OBJS:%=hw/fsp/%)
diff --git a/hw/fsp/fsp-ipmi.c b/hw/fsp/fsp-ipmi.c
new file mode 100644
index 00000000..e5cd6e26
--- /dev/null
+++ b/hw/fsp/fsp-ipmi.c
@@ -0,0 +1,355 @@
+/* Copyright 2014-2015 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 <errorlog.h>
+#include <fsp.h>
+#include <ipmi.h>
+#include <lock.h>
+#include <opal-api.h>
+
+/*
+ * Under the hood, FSP IPMI component implements the KCS (Keyboard Controller
+ * Style) interface
+ *
+ * KCS interface request message format
+ *
+ *    BYTE 1	 BYTE 2	       BYTE 3:N
+ *  -------------------------------------
+ * | NetFn/LUN |    Cmd    |    Data     |
+ *  -------------------------------------
+ *
+ * KCS interface response message format
+ *
+ *    BYTE 1	 BYTE 2		BYTE 3	  BYTE 4:N
+ *  ------------------------------------------------
+ * | NetFn/LUN |    Cmd    |  CompCode  |   Data    |
+ *  ------------------------------------------------
+
+ */
+
+#define FSP_IPMI_REQ_MIN_LEN	2 /* NetFn + Cmd */
+#define FSP_IPMI_RESP_MIN_LEN	3 /* NetFn + Cmd + Completion code */
+
+DEFINE_LOG_ENTRY(OPAL_RC_IPMI_REQ, OPAL_PLATFORM_ERR_EVT, OPAL_IPMI,
+		 OPAL_PLATFORM_FIRMWARE, OPAL_PREDICTIVE_ERR_GENERAL,
+		 OPAL_NA, NULL);
+DEFINE_LOG_ENTRY(OPAL_RC_IPMI_RESP, OPAL_PLATFORM_ERR_EVT, OPAL_IPMI,
+		 OPAL_PLATFORM_FIRMWARE, OPAL_PREDICTIVE_ERR_GENERAL,
+		 OPAL_NA, NULL);
+
+struct fsp_ipmi_msg {
+	struct list_node	link;
+	struct ipmi_msg		ipmi_msg;
+};
+
+static struct fsp_ipmi {
+	struct list_head	msg_queue;
+	void			*ipmi_req_buf;
+	void			*ipmi_resp_buf;
+	/* There can only be one outstanding request whose reference is stored
+	 * in 'cur_msg' and the 'lock' protects against the concurrent updates
+	 * of it through request and response. The same 'lock' also protects
+	 * the list manipulation.
+	 */
+	struct fsp_ipmi_msg	*cur_msg;
+	struct lock		lock;
+} fsp_ipmi;
+
+static int fsp_ipmi_send_request(void);
+
+static void fsp_ipmi_cmd_done(uint8_t cmd, uint8_t netfn, uint8_t cc)
+{
+	struct fsp_ipmi_msg *fsp_ipmi_msg = fsp_ipmi.cur_msg;
+
+	lock(&fsp_ipmi.lock);
+	list_del(&fsp_ipmi_msg->link);
+	fsp_ipmi.cur_msg = NULL;
+	unlock(&fsp_ipmi.lock);
+
+	ipmi_cmd_done(cmd, netfn, cc, &fsp_ipmi_msg->ipmi_msg);
+}
+
+
+static void fsp_ipmi_req_complete(struct fsp_msg *msg)
+{
+	uint8_t status = (msg->resp->word1 >> 8) & 0xff;
+	uint32_t length = msg->resp->data.words[0];
+	struct fsp_ipmi_msg *fsp_ipmi_msg;
+	struct ipmi_msg *ipmi_msg;
+
+	fsp_freemsg(msg);
+
+	if (status != FSP_STATUS_SUCCESS) {
+		fsp_ipmi_msg = msg->user_data;
+		assert(fsp_ipmi_msg == fsp_ipmi.cur_msg);
+
+		ipmi_msg = &fsp_ipmi_msg->ipmi_msg;
+
+		if (length != (ipmi_msg->req_size + FSP_IPMI_REQ_MIN_LEN))
+			prlog(PR_DEBUG, "IPMI: Length mismatch in req completion "
+			      "(%d, %d)\n", ipmi_msg->req_size, length);
+
+		log_simple_error(&e_info(OPAL_RC_IPMI_REQ), "IPMI: Request "
+				 "failed with status:0x%02x\n", status);
+		/* FSP will not send the response now, so clear the current
+		 * outstanding request
+		 */
+		fsp_ipmi_cmd_done(ipmi_msg->cmd,
+				  IPMI_NETFN_RETURN_CODE(ipmi_msg->netfn),
+				  IPMI_ERR_UNSPECIFIED);
+
+		/* Send the next request in the queue */
+		fsp_ipmi_send_request();
+	}
+}
+
+static int fsp_ipmi_send_request(void)
+{
+	uint8_t *req_buf = fsp_ipmi.ipmi_req_buf;
+	struct ipmi_msg *ipmi_msg;
+	struct fsp_msg *msg;
+	int rc;
+
+	lock(&fsp_ipmi.lock);
+	/* An outstanding request is still pending */
+	if (fsp_ipmi.cur_msg) {
+		unlock(&fsp_ipmi.lock);
+		return OPAL_SUCCESS;
+	}
+
+	fsp_ipmi.cur_msg = list_top(&fsp_ipmi.msg_queue, struct fsp_ipmi_msg,
+				    link);
+	unlock(&fsp_ipmi.lock);
+
+	if (!fsp_ipmi.cur_msg)
+		return OPAL_SUCCESS;
+
+	ipmi_msg = &fsp_ipmi.cur_msg->ipmi_msg;
+	prlog(PR_TRACE, "IPMI: Send request, netfn:0x%02x, cmd:0x%02x, "
+	      "req_len:%d\n", ipmi_msg->netfn, ipmi_msg->cmd, ipmi_msg->req_size);
+
+	/* KCS request message format */
+	*req_buf++ = ipmi_msg->netfn;	/* BYTE 1 */
+	*req_buf++ = ipmi_msg->cmd;	/* BYTE 2 */
+	if (ipmi_msg->req_size)
+		memcpy(req_buf, ipmi_msg->data, ipmi_msg->req_size);
+
+	msg = fsp_mkmsg(FSP_CMD_FETCH_PLAT_DATA, 5, 0, PSI_DMA_PLAT_REQ_BUF,
+			0, PSI_DMA_PLAT_RESP_BUF,
+			ipmi_msg->req_size + FSP_IPMI_REQ_MIN_LEN);
+	if (!msg) {
+		log_simple_error(&e_info(OPAL_RC_IPMI_REQ), "IPMI: Failed to "
+				 "allocate request message\n");
+		fsp_ipmi_cmd_done(ipmi_msg->cmd,
+				  IPMI_NETFN_RETURN_CODE(ipmi_msg->netfn),
+				  IPMI_ERR_UNSPECIFIED);
+		return OPAL_NO_MEM;
+	}
+
+	msg->user_data = fsp_ipmi.cur_msg;
+	rc = fsp_queue_msg(msg, fsp_ipmi_req_complete);
+	if (rc) {
+		log_simple_error(&e_info(OPAL_RC_IPMI_REQ), "IPMI: Failed to "
+				 "queue request message (%d)\n", rc);
+		fsp_freemsg(msg);
+		fsp_ipmi_cmd_done(ipmi_msg->cmd,
+				  IPMI_NETFN_RETURN_CODE(ipmi_msg->netfn),
+				  IPMI_ERR_UNSPECIFIED);
+		return OPAL_INTERNAL_ERROR;
+	}
+
+	return OPAL_SUCCESS;
+}
+
+static struct ipmi_msg *fsp_ipmi_alloc_msg(size_t req_size, size_t resp_size)
+{
+	struct fsp_ipmi_msg *fsp_ipmi_msg;
+	struct ipmi_msg *ipmi_msg;
+
+	fsp_ipmi_msg = zalloc(sizeof(*fsp_ipmi_msg) + MAX(req_size, resp_size));
+	if (!fsp_ipmi_msg)
+		return NULL;
+
+	ipmi_msg = &fsp_ipmi_msg->ipmi_msg;
+
+	ipmi_msg->req_size = req_size;
+	ipmi_msg->resp_size = resp_size;
+	ipmi_msg->data = (uint8_t *)(fsp_ipmi_msg + 1);
+
+	return ipmi_msg;
+}
+
+static void fsp_ipmi_free_msg(struct ipmi_msg *ipmi_msg)
+{
+	struct fsp_ipmi_msg *fsp_ipmi_msg = container_of(ipmi_msg,
+			struct fsp_ipmi_msg, ipmi_msg);
+
+	free(fsp_ipmi_msg);
+}
+
+static int fsp_ipmi_queue_msg(struct ipmi_msg *ipmi_msg)
+{
+	struct fsp_ipmi_msg *fsp_ipmi_msg = container_of(ipmi_msg,
+			struct fsp_ipmi_msg, ipmi_msg);
+
+	lock(&fsp_ipmi.lock);
+	list_add_tail(&fsp_ipmi.msg_queue, &fsp_ipmi_msg->link);
+	unlock(&fsp_ipmi.lock);
+
+	return fsp_ipmi_send_request();
+}
+
+static int fsp_ipmi_queue_msg_head(struct ipmi_msg *ipmi_msg)
+{
+	struct fsp_ipmi_msg *fsp_ipmi_msg = container_of(ipmi_msg,
+			struct fsp_ipmi_msg, ipmi_msg);
+
+	lock(&fsp_ipmi.lock);
+	list_add(&fsp_ipmi.msg_queue, &fsp_ipmi_msg->link);
+	unlock(&fsp_ipmi.lock);
+
+	return fsp_ipmi_send_request();
+}
+
+static int fsp_ipmi_dequeue_msg(struct ipmi_msg *ipmi_msg)
+{
+	struct fsp_ipmi_msg *fsp_ipmi_msg = container_of(ipmi_msg,
+			struct fsp_ipmi_msg, ipmi_msg);
+
+	lock(&fsp_ipmi.lock);
+	list_del_from(&fsp_ipmi.msg_queue, &fsp_ipmi_msg->link);
+	unlock(&fsp_ipmi.lock);
+
+	return 0;
+}
+
+static struct ipmi_backend fsp_ipmi_backend = {
+	.alloc_msg	= fsp_ipmi_alloc_msg,
+	.free_msg	= fsp_ipmi_free_msg,
+	.queue_msg	= fsp_ipmi_queue_msg,
+	.queue_msg_head	= fsp_ipmi_queue_msg_head,
+	.dequeue_msg	= fsp_ipmi_dequeue_msg,
+};
+
+static bool fsp_ipmi_send_response(uint32_t cmd)
+{
+	struct fsp_msg *resp;
+	int rc;
+
+	resp = fsp_mkmsg(cmd, 0);
+	if (!resp) {
+		log_simple_error(&e_info(OPAL_RC_IPMI_RESP), "IPMI: Failed to "
+				 "allocate response message\n");
+		return false;
+	}
+
+	rc = fsp_queue_msg(resp, fsp_freemsg);
+	if (rc) {
+		fsp_freemsg(resp);
+		log_simple_error(&e_info(OPAL_RC_IPMI_RESP), "IPMI: Failed to "
+				 "queue response message\n");
+		return false;
+	}
+
+	return true;
+}
+
+static bool fsp_ipmi_read_response(struct fsp_msg *msg)
+{
+	uint8_t *resp_buf = fsp_ipmi.ipmi_resp_buf;
+	uint32_t status = msg->data.words[3];
+	uint32_t length = msg->data.words[2];
+	struct ipmi_msg *ipmi_msg;
+	uint8_t netfn, cmd, cc;
+
+	assert(fsp_ipmi.cur_msg);
+	ipmi_msg = &fsp_ipmi.cur_msg->ipmi_msg;
+
+	/* Response TCE token */
+	assert(msg->data.words[1] == PSI_DMA_PLAT_RESP_BUF);
+
+	if (status != FSP_STATUS_SUCCESS) {
+		log_simple_error(&e_info(OPAL_RC_IPMI_RESP), "IPMI: Response "
+				 "with bad status:0x%02x\n", status);
+		fsp_ipmi_cmd_done(ipmi_msg->cmd,
+				  IPMI_NETFN_RETURN_CODE(ipmi_msg->netfn),
+				  IPMI_ERR_UNSPECIFIED);
+		return fsp_ipmi_send_response(FSP_RSP_PLAT_DATA |
+					      FSP_STATUS_GENERIC_ERROR);
+	}
+
+	/* KCS response message format */
+	netfn = *resp_buf++;
+	cmd = *resp_buf++;
+	cc = *resp_buf++;
+	length -= FSP_IPMI_RESP_MIN_LEN;
+
+	prlog(PR_TRACE, "IPMI: fsp response received, netfn:0x%02x, cmd:0x%02x,"
+	      " cc:0x%02x, length:%d\n", netfn, cmd, cc, length);
+
+	if (length > ipmi_msg->resp_size) {
+		prlog(PR_DEBUG, "IPMI: Length mismatch in response (%d, %d)\n",
+		      length, ipmi_msg->resp_size);
+		length = ipmi_msg->resp_size; /* Truncate */
+		cc = IPMI_ERR_MSG_TRUNCATED;
+	}
+
+	ipmi_msg->resp_size = length;
+	if (length)
+		memcpy(ipmi_msg->data, resp_buf, length);
+
+	fsp_ipmi_cmd_done(cmd, netfn, cc);
+
+	return fsp_ipmi_send_response(FSP_RSP_PLAT_DATA);
+}
+
+static bool fsp_ipmi_response(uint32_t cmd_sub_mod, struct fsp_msg *msg)
+{
+	bool rc;
+
+	switch (cmd_sub_mod) {
+	case FSP_CMD_SEND_PLAT_DATA:
+		prlog(PR_TRACE, "FSP_CMD_SEND_PLAT_DATA command received\n");
+		rc = fsp_ipmi_read_response(msg);
+		break;
+	default:
+		return false;
+	};
+
+	/* If response sent successfully, pick the next request */
+	if (rc == true)
+		fsp_ipmi_send_request();
+
+	return rc;
+}
+
+static struct fsp_client fsp_ipmi_client = {
+	.message = fsp_ipmi_response,
+};
+
+void fsp_ipmi_init(void)
+{
+	fsp_tce_map(PSI_DMA_PLAT_REQ_BUF, fsp_ipmi.ipmi_req_buf,
+		    PSI_DMA_PLAT_REQ_BUF_SIZE);
+	fsp_tce_map(PSI_DMA_PLAT_RESP_BUF, fsp_ipmi.ipmi_resp_buf,
+		    PSI_DMA_PLAT_RESP_BUF_SIZE);
+
+	list_head_init(&fsp_ipmi.msg_queue);
+	init_lock(&fsp_ipmi.lock);
+
+	fsp_register_client(&fsp_ipmi_client, FSP_MCLASS_FETCH_SPDATA);
+	ipmi_register_backend(&fsp_ipmi_backend);
+}