HIOMAP: Reset bmc mbox in MPIPL path

During boot SBE and early hostboot does not use HIOMAP protocol to get image
from PNOR. Instead it expects PNOR TOC and Hostboot Boot Loader to be
available at particular address in LPC bus. mbox daemon in BMC side takes
care of this during normal boot. Once boot is complete mbox daemon switches
to normal mode.

During normal reboot, BMC side mbox daemon gets notification and takes care of
loading PNOR TOC and HBBL to LPC bus again.

In MPIPL path, OPAL calls SBE S0 interrupt to initiate MPIPL. BMC will not be
aware of this. But SBE expects PNOR TOC and HBBL to be available in LPC bus at
predefined address. Hence call HIOMAP Reset from OPAL in assert path.

This needs working LPC and IPMI driver in OPAL. If we have issue in these
drivers then we may not be able to reset BMC MBOX properly. Hence MPIPL may
fail. We have to live with this until we find a way to intiate BMC on MPIPL.

CC: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
[oliver: rebased]
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>

core/flash.c

@@ -15,6 +15,7 @@
 #include <device.h>
 #include <libflash/libflash.h>
 #include <libflash/libffs.h>
+#include <libflash/ipmi-hiomap.h>
 #include <libflash/blocklevel.h>
 #include <libflash/ecc.h>
 #include <libstb/secureboot.h>
@@ -79,6 +80,17 @@ void flash_release(void)
 	unlock(&flash_lock);
 }
 
+bool flash_unregister(void)
+{
+	struct blocklevel_device *bl = system_flash->bl;
+
+	if (bl->exit)
+		return bl->exit(bl);
+
+	prlog(PR_NOTICE, "FLASH: Unregister flash device is not supported\n");
+	return true;
+}
+
 static int flash_nvram_info(uint32_t *total_size)
 {
 	int rc;

hw/sbe-p9.c

@@ -952,6 +952,12 @@ void p9_sbe_terminate(void)
 	if (!dt_find_by_path(opal_node, "dump"))
 		return;
 
+	/* Unregister flash. It will request BMC MBOX reset */
+	if (!flash_unregister()) {
+		prlog(PR_DEBUG, "Failed to reset BMC MBOX\n");
+		return;
+	}
+
 	/* Save crashing CPU details */
 	opal_mpipl_save_crashing_pir();
 

include/skiboot.h

@@ -212,6 +212,7 @@ extern int flash_start_preload_resource(enum resource_id id, uint32_t subid,
 extern int flash_resource_loaded(enum resource_id id, uint32_t idx);
 extern bool flash_reserve(void);
 extern void flash_release(void);
+extern bool flash_unregister(void);
 #define FLASH_SUBPART_ALIGNMENT 0x1000
 #define FLASH_SUBPART_HEADER_SIZE FLASH_SUBPART_ALIGNMENT
 extern int flash_subpart_info(void *part_header, uint32_t header_len,

libflash/blocklevel.h

@@ -35,6 +35,7 @@ struct blocklevel_device {
 	int (*erase)(struct blocklevel_device *bl, uint64_t pos, uint64_t len);
 	int (*get_info)(struct blocklevel_device *bl, const char **name, uint64_t *total_size,
 			uint32_t *erase_granule);
+	bool (*exit)(struct blocklevel_device *bl);
 
 	/*
 	 * Keep the erase mask so that blocklevel_erase() can do sanity checking

libflash/ipmi-hiomap.c

@@ -210,6 +210,7 @@ static void ipmi_hiomap_cmd_cb(struct ipmi_msg *msg)
 	case HIOMAP_C_FLUSH:
 	case HIOMAP_C_ACK:
 	case HIOMAP_C_ERASE:
+	case HIOMAP_C_RESET:
 		if (msg->resp_size != 2) {
 			prerror("%u: Unexpected response size: %u\n", msg->data[0],
 				msg->resp_size);
@@ -516,6 +517,29 @@ static int hiomap_erase(struct ipmi_hiomap *ctx, uint64_t offset,
 	return 0;
 }
 
+static bool hiomap_reset(struct ipmi_hiomap *ctx)
+{
+	RESULT_INIT(res, ctx);
+	unsigned char req[2];
+	struct ipmi_msg *msg;
+
+	prlog(PR_NOTICE, "Reset\n");
+
+	req[0] = HIOMAP_C_RESET;
+	req[1] = ++ctx->seq;
+	msg = ipmi_mkmsg(IPMI_DEFAULT_INTERFACE,
+		         bmc_platform->sw->ipmi_oem_hiomap_cmd,
+			 ipmi_hiomap_cmd_cb, &res, req, sizeof(req), 2);
+	ipmi_queue_msg_sync(msg);
+
+	if (res.cc != IPMI_CC_NO_ERROR) {
+		prlog(PR_ERR, "%s failed: %d\n", __func__, res.cc);
+		return false;
+	}
+
+	return true;
+}
+
 static void hiomap_event(uint8_t events, void *context)
 {
 	struct ipmi_hiomap *ctx = context;
@@ -906,6 +930,7 @@ int ipmi_hiomap_init(struct blocklevel_device **bl)
 	ctx->bl.write = &ipmi_hiomap_write;
 	ctx->bl.erase = &ipmi_hiomap_erase;
 	ctx->bl.get_info = &ipmi_hiomap_get_flash_info;
+	ctx->bl.exit = &ipmi_hiomap_exit;
 
 	hiomap_init(ctx);
 
@@ -955,11 +980,16 @@ int ipmi_hiomap_init(struct blocklevel_device **bl)
 	return rc;
 }
 
-void ipmi_hiomap_exit(struct blocklevel_device *bl)
+bool ipmi_hiomap_exit(struct blocklevel_device *bl)
 {
+	bool status = true;
+
 	struct ipmi_hiomap *ctx;
 	if (bl) {
 		ctx = container_of(bl, struct ipmi_hiomap, bl);
+		status = hiomap_reset(ctx);
 		free(ctx);
 	}
+
+	return status;
 }

libflash/ipmi-hiomap.h

@@ -40,6 +40,6 @@ struct ipmi_hiomap {
 };
 
 int ipmi_hiomap_init(struct blocklevel_device **bl);
-void ipmi_hiomap_exit(struct blocklevel_device *bl);
+bool ipmi_hiomap_exit(struct blocklevel_device *bl);
 
 #endif /* __LIBFLASH_IPMI_HIOMAP_H */

libflash/mbox-flash.c

@@ -803,6 +803,28 @@ static int mbox_flash_read(struct blocklevel_device *bl, uint64_t pos,
 	return rc;
 }
 
+static bool mbox_flash_reset(struct blocklevel_device *bl)
+{
+	int rc;
+	struct mbox_flash_data *mbox_flash;
+	struct bmc_mbox_msg msg = MSG_CREATE(MBOX_C_RESET_STATE);
+
+	prlog(PR_NOTICE, "MBOX reset\n");
+	mbox_flash = container_of(bl, struct mbox_flash_data, bl);
+
+	rc = msg_send(mbox_flash, &msg, mbox_flash->timeout);
+	if (rc) {
+		prlog(PR_ERR, "Failed to enqueue/send BMC MBOX RESET msg\n");
+		return false;
+	}
+	if (wait_for_bmc(mbox_flash, mbox_flash->timeout)) {
+		prlog(PR_ERR, "Error waiting for BMC\n");
+		return false;
+	}
+
+	return true;
+}
+
 static int mbox_flash_get_info(struct blocklevel_device *bl, const char **name,
 		uint64_t *total_size, uint32_t *erase_granule)
 {
@@ -1138,6 +1160,7 @@ int mbox_flash_init(struct blocklevel_device **bl)
 	mbox_flash->bl.write = &mbox_flash_write;
 	mbox_flash->bl.erase = &mbox_flash_erase_v2;
 	mbox_flash->bl.get_info = &mbox_flash_get_info;
+	mbox_flash->bl.exit = &mbox_flash_exit;
 
 	if (bmc_mbox_get_attn_reg() & MBOX_ATTN_BMC_REBOOT)
 		rc = handle_reboot(mbox_flash);
@@ -1154,11 +1177,15 @@ int mbox_flash_init(struct blocklevel_device **bl)
 	return 0;
 }
 
-void mbox_flash_exit(struct blocklevel_device *bl)
+bool mbox_flash_exit(struct blocklevel_device *bl)
 {
+	bool status = true;
 	struct mbox_flash_data *mbox_flash;
 	if (bl) {
+		status = mbox_flash_reset(bl);
 		mbox_flash = container_of(bl, struct mbox_flash_data, bl);
 		free(mbox_flash);
 	}
+
+	return status;
 }

libflash/mbox-flash.h

@@ -6,7 +6,7 @@
 
 int mbox_flash_lock(struct blocklevel_device *bl, uint64_t pos, uint64_t len);
 int mbox_flash_init(struct blocklevel_device **bl);
-void mbox_flash_exit(struct blocklevel_device *bl);
+bool mbox_flash_exit(struct blocklevel_device *bl);
 #endif /* __LIBFLASH_MBOX_FLASH_H */
 
 

libflash/test/mbox-server.c

@@ -273,6 +273,7 @@ int bmc_mbox_enqueue(struct bmc_mbox_msg *msg,
 	switch (msg->command) {
 		case MBOX_C_RESET_STATE:
 			prlog(PR_INFO, "RESET_STATE\n");
+			server_state.win_type = WIN_CLOSED;
 			rc = open_window(msg, false, 0, LPC_BLOCKS);
 			memset(msg->args, 0, sizeof(msg->args));
 			break;