[Skiboot] [PATCH 2/2] occ: Inform OCC of BMC PNOR ownership requests

[Jeremy Kerr]

We need to pass the PNOR access status to the OCCs, as they may write to
the PNOR in the event of a checkstop.

Signed-off-by: Jeremy Kerr <jk at ozlabs.org>

---
 hw/ipmi/ipmi-sel.c |    3 +++
 hw/occ.c           |   28 ++++++++++++++++++++++++++++
 include/skiboot.h  |    7 +++++++
 3 files changed, 38 insertions(+)

diff --git a/hw/ipmi/ipmi-sel.c b/hw/ipmi/ipmi-sel.c
index c86c2c9..8851dc3 100644
--- a/hw/ipmi/ipmi-sel.c
+++ b/hw/ipmi/ipmi-sel.c
@@ -195,6 +195,8 @@ static void sel_pnor(uint8_t access)
 	case REQUEST_PNOR:
 		prlog(PR_NOTICE, "IPMI: PNOR access requested\n");
 		granted = flash_reserve();
+		if (granted)
+			occ_pnor_set_owner(PNOR_OWNER_EXTERNAL);
 
 		/* Ack the request */
 		msg = ipmi_mkmsg_simple(IPMI_PNOR_ACCESS_STATUS, &granted, 1);
@@ -203,6 +205,7 @@ static void sel_pnor(uint8_t access)
 	case RELEASE_PNOR:
 		prlog(PR_NOTICE, "IPMI: PNOR access released\n");
 		flash_release();
+		occ_pnor_set_owner(PNOR_OWNER_HOST);
 		break;
 	default:
 		prlog(PR_ERR, "IPMI: invalid PNOR access requested: %02x\n",
diff --git a/hw/occ.c b/hw/occ.c
index 8eb6469..657f2ad 100644
--- a/hw/occ.c
+++ b/hw/occ.c
@@ -537,6 +537,34 @@ static void occ_do_reset(u8 scope, u32 dbob_id, u32 seq_id)
 	}
 }
 
+#define PV_OCC_GP0		0x01000000
+#define PV_OCC_GP0_AND		0x01000004
+#define PV_OCC_GP0_OR		0x01000005
+#define PV_OCC_GP0_PNOR_OWNER	PPC_BIT(18) /* 1 = OCC / Host, 0 = BMC */
+
+static void occ_pnor_set_one_owner(uint32_t chip_id, enum pnor_owner owner)
+{
+	uint64_t reg, mask;
+
+	if (owner == PNOR_OWNER_HOST) {
+		reg = PV_OCC_GP0_OR;
+		mask = PV_OCC_GP0_PNOR_OWNER;
+	} else {
+		reg = PV_OCC_GP0_AND;
+		mask = ~PV_OCC_GP0_PNOR_OWNER;
+	}
+
+	xscom_write(chip_id, reg, mask);
+}
+
+void occ_pnor_set_owner(enum pnor_owner owner)
+{
+	struct proc_chip *chip;
+
+	for_each_chip(chip)
+		occ_pnor_set_one_owner(chip->id, owner);
+}
+
 static bool fsp_occ_msg(u32 cmd_sub_mod, struct fsp_msg *msg)
 {
 	u32 dbob_id, seq_id;
diff --git a/include/skiboot.h b/include/skiboot.h
index beaa7db..0fe50e9 100644
--- a/include/skiboot.h
+++ b/include/skiboot.h
@@ -221,6 +221,13 @@ extern void occ_send_dummy_interrupt(void);
 /* OCC load support */
 extern void occ_poke_load_queue(void);
 
+/* OCC/Host PNOR ownership */
+enum pnor_owner {
+	PNOR_OWNER_HOST,
+	PNOR_OWNER_EXTERNAL,
+};
+extern void occ_pnor_set_owner(enum pnor_owner owner);
+
 /* PRD */
 extern void prd_psi_interrupt(uint32_t proc);
 extern void prd_tmgt_interrupt(uint32_t proc);