skiboot/hw/imc: Add nest_memory region to "exports" node

Exports the In-Memory Collection counter nest memory to
the OS. This allows the OS to view the nest counter
region directly. This helps in nest microcode debug
and to check counter raw value.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/hw/imc.c b/hw/imc.c
index 60fc39d..99293ee 100644
--- a/hw/imc.c
+++ b/hw/imc.c
@@ -402,6 +402,9 @@ static void imc_dt_update_nest_node(struct dt_node *dev)
 	int i=0, nr_chip = nr_chips();
 	struct dt_node *node;
 	const struct dt_property *type;
+	uint32_t offset = 0, size = 0;
+	uint64_t baddr;
+	char namebuf[32];
 
 	/* Add the base_addr and chip-id properties for the nest node */
 	base_addr = malloc(sizeof(uint64_t) * nr_chip);
@@ -417,8 +420,27 @@ static void imc_dt_update_nest_node(struct dt_node *dev)
 		if (type && is_nest_node(node)) {
 			dt_add_property(node, "base-addr", base_addr, (i * sizeof(u64)));
 			dt_add_property(node, "chip-id", chipids, (i * sizeof(u32)));
+			offset = dt_prop_get_u32(node, "offset");
+			size = dt_prop_get_u32(node, "size");
 		}
 	}
+
+	/*
+	 * Enable only if we have active nest pmus.
+	 */
+	if (!size)
+		return;
+
+	node = dt_find_by_name(opal_node, "exports");
+	if (!node)
+		return;
+
+	for_each_chip(chip) {
+		snprintf(namebuf, sizeof(namebuf), "imc_nest_chip_%x", chip->id);
+		baddr = chip->homer_base;
+		baddr += offset;
+		dt_add_property_u64s(node, namebuf, baddr, size);
+	}
 }
 
 /*