4 files changed, 67 insertions, 33 deletions

diff --git a/hw/ast-bmc/ast-io.c b/hw/ast-bmc/ast-io.c
index 38ca86c4..11cc084c 100644
--- a/hw/ast-bmc/ast-io.c
+++ b/hw/ast-bmc/ast-io.c
@@ -360,7 +360,12 @@ bool ast_io_init(void)
 	return ast_io_is_rw();
 }
 
-bool ast_lpc_fw_needs_hiomap(void)
+bool ast_lpc_fw_ipmi_hiomap(void)
+{
+	return platform.bmc->sw->ipmi_oem_hiomap_cmd != 0;
+}
+
+bool ast_lpc_fw_mbox_hiomap(void)
 {
 	struct dt_node *n;
 
diff --git a/include/ast.h b/include/ast.h
index c6684fc8..5c46cf26 100644
--- a/include/ast.h
+++ b/include/ast.h
@@ -86,7 +86,8 @@ bool ast_sio_init(void);
 bool ast_io_init(void);
 bool ast_io_is_rw(void);
 bool ast_lpc_fw_maps_flash(void);
-bool ast_lpc_fw_needs_hiomap(void);
+bool ast_lpc_fw_ipmi_hiomap(void);
+bool ast_lpc_fw_mbox_hiomap(void);
 bool ast_scratch_reg_is_mbox(void);
 
 /* UART configuration */
diff --git a/platforms/astbmc/common.c b/platforms/astbmc/common.c
index 210b3ec2..bc0e58f8 100644
--- a/platforms/astbmc/common.c
+++ b/platforms/astbmc/common.c
@@ -208,8 +208,15 @@ static void astbmc_fixup_dt_mbox(struct dt_node *lpc)
 	struct dt_node *mbox;
 	char namebuf[32];
 
-	/* All P9 machines use mbox. P8 machines can indicate they support
-	 * it using the scratch register */
+	if (!lpc)
+		return;
+
+	/*
+	 * P9 machines always use hiomap, either by ipmi or mbox. P8 machines
+	 * can indicate they support mbox using the scratch register, or ipmi
+	 * by configuring the hiomap ipmi command. If neither are configured
+	 * for P8 then skiboot will drive the flash controller directly.
+	 */
 	if (proc_gen != proc_gen_p9 && !ast_scratch_reg_is_mbox())
 		return;
 
@@ -310,7 +317,7 @@ static void astbmc_fixup_bmc_sensors(void)
 	}
 }
 
-static void astbmc_fixup_dt(void)
+static struct dt_node *dt_find_primary_lpc(void)
 {
 	struct dt_node *n, *primary_lpc = NULL;
 
@@ -328,6 +335,15 @@ static void astbmc_fixup_dt(void)
 			break;
 	}
 
+	return primary_lpc;
+}
+
+static void astbmc_fixup_dt(void)
+{
+	struct dt_node *primary_lpc;
+
+	primary_lpc = dt_find_primary_lpc();
+
 	if (!primary_lpc)
 		return;
 
@@ -337,9 +353,6 @@ static void astbmc_fixup_dt(void)
 	/* BT is not in HB either */
 	astbmc_fixup_dt_bt(primary_lpc);
 
-	/* MBOX is not in HB */
-	astbmc_fixup_dt_mbox(primary_lpc);
-
 	/* The pel logging code needs a system-id property to work so
 	   make sure we have one. */
 	astbmc_fixup_dt_system_id();
@@ -412,7 +425,16 @@ void astbmc_early_init(void)
 		} else
 			prerror("PLAT: AST IO initialisation failed!\n");
 
-		ast_setup_sio_mbox(MBOX_IO_BASE, MBOX_LPC_IRQ);
+		/*
+		 * P9 prefers IPMI for HIOMAP but will use MBOX if IPMI is not
+		 * supported. P8 either uses IPMI HIOMAP or direct IO, and
+		 * never MBOX. Thus only populate the MBOX node on P9 to allow
+		 * fallback.
+		 */
+		if (proc_gen == proc_gen_p9) {
+			astbmc_fixup_dt_mbox(dt_find_primary_lpc());
+			ast_setup_sio_mbox(MBOX_IO_BASE, MBOX_LPC_IRQ);
+		}
 	} else {
 		/*
 		 * This may or may not be an error depending on if we set up
diff --git a/platforms/astbmc/pnor.c b/platforms/astbmc/pnor.c
index d2694768..1c364351 100644
--- a/platforms/astbmc/pnor.c
+++ b/platforms/astbmc/pnor.c
@@ -34,48 +34,54 @@ enum ast_flash_style {
     mbox_hiomap,
 };
 
+static enum ast_flash_style ast_flash_get_fallback_style(void)
+{
+    if (ast_lpc_fw_mbox_hiomap())
+	return mbox_hiomap;
+
+    if (ast_lpc_fw_maps_flash())
+	return raw_flash;
+
+    return raw_mem;
+}
+
 int pnor_init(void)
 {
 	struct spi_flash_ctrl *pnor_ctrl = NULL;
 	struct blocklevel_device *bl = NULL;
 	enum ast_flash_style style;
-	int rc;
+	int rc = 0;
 
-	if (ast_lpc_fw_needs_hiomap()) {
+	if (ast_lpc_fw_ipmi_hiomap()) {
 		style = ipmi_hiomap;
 		rc = ipmi_hiomap_init(&bl);
-		if (rc) {
-			style = mbox_hiomap;
-			rc = mbox_flash_init(&bl);
-		}
-	} else {
-		/* Open controller and flash. If the LPC->AHB doesn't point to
-		 * the PNOR flash base we assume we're booting from BMC system
-		 * memory (or some other place setup by the BMC to support LPC
-		 * FW reads & writes).
-		 */
+	}
+
+	if (!ast_lpc_fw_ipmi_hiomap() || rc) {
+		if (!ast_sio_is_enabled())
+			return -ENODEV;
 
-		if (ast_lpc_fw_maps_flash()) {
-			style = raw_flash;
+		style = ast_flash_get_fallback_style();
+		if (style == mbox_hiomap)
+			rc = mbox_flash_init(&bl);
+		else if (style == raw_flash)
 			rc = ast_sf_open(AST_SF_TYPE_PNOR, &pnor_ctrl);
-		} else {
-			printf("PLAT: Memboot detected\n");
-			style = raw_mem;
+		else if (style == raw_mem)
 			rc = ast_sf_open(AST_SF_TYPE_MEM, &pnor_ctrl);
+		else {
+			prerror("Unhandled flash mode: %d\n", style);
+			return -ENODEV;
 		}
-		if (rc) {
-			prerror("PLAT: Failed to open PNOR flash controller\n");
-			goto fail;
-		}
-
-		rc = flash_init(pnor_ctrl, &bl, NULL);
 	}
 
 	if (rc) {
-		prerror("PLAT: Failed to open init PNOR driver\n");
+		prerror("PLAT: Failed to init PNOR driver\n");
 		goto fail;
 	}
 
+	if (style == raw_flash || style == raw_mem)
+	    rc = flash_init(pnor_ctrl, &bl, NULL);
+
 	rc = flash_register(bl);
 	if (!rc)
 		return 0;