[Skiboot] [PATCH v8 3/7] Create Device-Tree(DT) nodes to pass "nest-counter" information

[Madhavan Srinivasan]

Add code to create a top level "nest-counter" node under "/" root
folder in device-tree to contain all the nest unit information.
Code creates a sub node for each chip to pass on the PORE SLW microcode
offset (part of HOMER) and the memory region to map using the "range" property.

Subsequent patches will create device tree nodes for each nest units under
the chip nodes. Each nest unit node will have a node for each event supported
by that unit.

Signed-off-by: Madhavan Srinivasan <maddy at linux.vnet.ibm.com>
---
 hw/nest.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)

diff --git a/hw/nest.c b/hw/nest.c
index 50b4942adba5..46d930384649 100644
--- a/hw/nest.c
+++ b/hw/nest.c
@@ -114,10 +114,74 @@ int load_catalog_lid(int loaded)
 
 void nest_pmu_init(int loaded)
 {
+	struct proc_chip *chip;
+	struct dt_node *dev, *chip_dev;
+	u64 addr = 0;
 
 	if (load_catalog_lid(loaded) != OPAL_SUCCESS) {
 		prerror("nest-counters: Catalog failed to load\n");
 		return;
 	}
 
+	/*
+	 * Now that we have catalog loaded and verified for nest counter
+	 * support, lets create device tree entries.
+	 *
+	 * Top level device node called "nest-counters" created under
+	 * "/" root folder to contain all the nest unit information
+	 */
+	dev = dt_new(dt_root, "nest-counters");
+	if (!dev) {
+		prerror("nest-counters: device node creation failed\n");
+		return;
+	}
+
+	/*
+	 * "ibm,opal-in-memory-counters" is the compatible string.
+	 * This will aid the autoload feature in powernv/ platform to load
+	 * nest pmu drivers in kernel.
+	 */
+	dt_add_property_strings(dev, "compatible", "ibm,opal-in-memory-counters");
+	dt_add_property_cells(dev, "#address-cells", 2);
+	dt_add_property_cells(dev, "#size-cells", 2);
+	dt_add_property(dev, "ranges", NULL, 0);
+
+	/*
+	 * Top level device node "nest-counters" will have per-chip nodes.
+	 * Each chip node will have slw ima offset and the nest pmu
+	 * units details.
+	 *
+	 * pore_slw_ima firmware will program nest counters with
+	 * pre-defined set of events (provided in catalog) and accumulate
+	 * counter data in a fixed homer offset called
+	 * "SLW 24x7 Counters Data Area (per chip)". This offset detail
+	 * provide in the range field.
+	 *
+	 * For homer memory layout refer "p8_homer_map.h" in hostboot git tree
+	 * of open-power github
+	 */
+	for_each_chip(chip) {
+		addr = chip->homer_base + SLW_IMA_OFFSET;
+		chip_dev = dt_new_addr(dev, "chip", addr);
+		if (!chip_dev) {
+			prerror("nest-counters:chip node creation failed\n");
+			goto fail;
+		}
+
+		/*
+		 *TODO: Need to fix phandle property to point to "reserved-
+		 * memory" node for HOMER.
+		 */
+		dt_add_property_cells(chip_dev, "ibm,chip-id", chip->id);
+		dt_add_property_cells(chip_dev, "#address-cells", 1);
+		dt_add_property_cells(chip_dev, "#size-cells", 1);
+		dt_add_property_cells(chip_dev, "ranges", 0, hi32(addr),
+						lo32(addr), SLW_IMA_SIZE);
+	}
+
+	return;
+
+fail:
+	dt_free(dev);
+	return;
 }
-- 
1.9.1