[Skiboot] [RFC 03/12] astbmc/slots: Add NVLink targeting information

[Oliver O'Halloran]

Add per-slot information about which NVLink groups are paired to this
slot. Note that we don't support NVLinks from multiple chips targeting
a single devices to binding a device to a single NVLink group is
reasonable. This patch is to prepare for removing the NPUs.

Signed-off-by: Oliver O'Halloran <oohall at gmail.com>
---
 platforms/astbmc/astbmc.h      | 10 ++++++++++
 platforms/astbmc/garrison.c    |  4 ++++
 platforms/astbmc/p8dnu.c       |  4 ++++
 platforms/astbmc/witherspoon.c |  6 ++++++
 4 files changed, 24 insertions(+)

diff --git a/platforms/astbmc/astbmc.h b/platforms/astbmc/astbmc.h
index d538f97538dc..2d0e35e4a325 100644
--- a/platforms/astbmc/astbmc.h
+++ b/platforms/astbmc/astbmc.h
@@ -28,6 +28,15 @@
  */
 #define ST_LOC_NPU_GROUP(group_id)	(group_id << 3)
 
+/*
+ * For the .nvlink property we set the high bit to indicate that this slot
+ * has a paired NVLink. This is mainly so we can test for an nvlink by doing
+ *	 if (entry->nvlink)
+ */
+#define ST_LOC_NVLINK_VALID (1 << 31)
+#define ST_LOC_NPU_TARGET(chip_id, group_id) \
+	(ST_LOC_NVLINK_VALID | ((chip_id) << 16) | (group_id))
+
 struct slot_table_entry {
 	enum slot_table_etype {
 		st_end,		/* End of list */
@@ -39,6 +48,7 @@ struct slot_table_entry {
 	uint32_t location;
 	const char *name;
 	const struct slot_table_entry *children;
+	uint32_t nvlink; /* set by ST_LOC_NPU_GROUP */
 };
 
 extern const struct bmc_platform astbmc_ami;
diff --git a/platforms/astbmc/garrison.c b/platforms/astbmc/garrison.c
index db886cbbfd63..1697b66f56c6 100644
--- a/platforms/astbmc/garrison.c
+++ b/platforms/astbmc/garrison.c
@@ -48,6 +48,7 @@ static const struct slot_table_entry garrison_phb0_2_slot[] = {
 		.etype = st_pluggable_slot,
 		.location = ST_LOC_DEVFN(0,0),
 		.name = "GPU1",
+		.nvlink = ST_LOC_NPU_TARGET(0, 1),
 	},
 	{ .etype = st_end },
 };
@@ -57,6 +58,7 @@ static const struct slot_table_entry garrison_phb0_3_slot[] = {
 		.etype = st_pluggable_slot,
 		.location = ST_LOC_DEVFN(0,0),
 		.name = "GPU2",
+		.nvlink = ST_LOC_NPU_TARGET(0, 0),
 	},
 	{ .etype = st_end },
 };
@@ -127,6 +129,7 @@ static const struct slot_table_entry garrison_phb1_2_slot[] = {
 		.etype = st_pluggable_slot,
 		.location = ST_LOC_DEVFN(0,0),
 		.name = "GPU3",
+		.nvlink = ST_LOC_NPU_TARGET(1, 1),
 	},
 	{ .etype = st_end },
 };
@@ -136,6 +139,7 @@ static const struct slot_table_entry garrison_phb1_3_slot[] = {
 		.etype = st_pluggable_slot,
 		.location = ST_LOC_DEVFN(0,0),
 		.name = "GPU4",
+		.nvlink = ST_LOC_NPU_TARGET(1, 0),
 	},
 	{ .etype = st_end },
 };
diff --git a/platforms/astbmc/p8dnu.c b/platforms/astbmc/p8dnu.c
index e4aeed4712eb..8cf532e26b8e 100644
--- a/platforms/astbmc/p8dnu.c
+++ b/platforms/astbmc/p8dnu.c
@@ -90,6 +90,7 @@ static const struct slot_table_entry p8dnu_phb0_2_slot[] = {
 		.etype = st_pluggable_slot,
 		.location = ST_LOC_DEVFN(0,0),
 		.name = "GPU1",
+		.nvlink = ST_LOC_NPU_TARGET(0, 1),
 	},
 	{ .etype = st_end },
 };
@@ -99,6 +100,7 @@ static const struct slot_table_entry p8dnu_phb0_3_slot[] = {
 		.etype = st_pluggable_slot,
 		.location = ST_LOC_DEVFN(0,0),
 		.name = "GPU2",
+		.nvlink = ST_LOC_NPU_TARGET(0, 0),
 	},
 	{ .etype = st_end },
 };
@@ -169,6 +171,7 @@ static const struct slot_table_entry p8dnu_phb1_2_slot[] = {
 		.etype = st_pluggable_slot,
 		.location = ST_LOC_DEVFN(0,0),
 		.name = "GPU3",
+		.nvlink = ST_LOC_NPU_TARGET(1, 1),
 	},
 	{ .etype = st_end },
 };
@@ -178,6 +181,7 @@ static const struct slot_table_entry p8dnu_phb1_3_slot[] = {
 		.etype = st_pluggable_slot,
 		.location = ST_LOC_DEVFN(0,0),
 		.name = "GPU4",
+		.nvlink = ST_LOC_NPU_TARGET(1, 0),
 	},
 	{ .etype = st_end },
 };
diff --git a/platforms/astbmc/witherspoon.c b/platforms/astbmc/witherspoon.c
index 3c64cb17095b..aa260f94af1a 100644
--- a/platforms/astbmc/witherspoon.c
+++ b/platforms/astbmc/witherspoon.c
@@ -35,16 +35,19 @@ static const struct slot_table_entry witherspoon_plx0_down[] = {
 		.etype = st_builtin_dev,
 		.location = ST_LOC_DEVFN(0xa,0),
 		.name = "GPU0",
+		.nvlink = ST_LOC_NPU_TARGET(0, 0),
 	},
 	{
 		.etype = st_builtin_dev,
 		.location = ST_LOC_DEVFN(0xb,0),
 		.name = "GPU1",
+		.nvlink = ST_LOC_NPU_TARGET(0, 1),
 	},
 	{
 		.etype = st_builtin_dev,
 		.location = ST_LOC_DEVFN(0xc,0),
 		.name = "GPU2",
+		.nvlink = ST_LOC_NPU_TARGET(0, 2),
 	},
 	{ .etype = st_end },
 };
@@ -54,16 +57,19 @@ static const struct slot_table_entry witherspoon_plx1_down[] = {
 		.etype = st_builtin_dev,
 		.location = ST_LOC_DEVFN(0x4,0),
 		.name = "GPU3",
+		.nvlink = ST_LOC_NPU_TARGET(8, 0),
 	},
 	{
 		.etype = st_builtin_dev,
 		.location = ST_LOC_DEVFN(0x8,0),
 		.name = "GPU4",
+		.nvlink = ST_LOC_NPU_TARGET(8, 1),
 	},
 	{
 		.etype = st_builtin_dev,
 		.location = ST_LOC_DEVFN(0xd,0),
 		.name = "GPU5",
+		.nvlink = ST_LOC_NPU_TARGET(8, 2),
 	},
 	{ .etype = st_end },
 };
-- 
2.9.4