[Skiboot] [PATCH] Skip OCCs for chip that has occ_functional set to false

Stewart Smith stewart at linux.vnet.ibm.com
Thu Sep 3 13:37:29 AEST 2015

In some simulation environments, we simulate a system close to an
ibm-fsp system but with a crucial difference: we don't simulate OCCs.
This means that for a P8 (well, a simulated one) that looks like it's
part of a ibm-fsp system, we'd wait around for about a minute to be
asked to start OCCs and for the OCCs to start. Obviously, this would
never happen and we'd hit the OCC initialization timeout (correctly)
logging an error.

However, in this simulation environment, it isn't an error as the
required information to work out it isn't an error is (at least now)
provided in hdat under 'OCC Functional State'.

Previously, the ibm,occ-functional-state property was just passed
through the device tree to the host through the XSCOM node and
skiboot ignored it.

This patch takes note of occ-functional-state and skips waiting for
OCCs on any chips that have been marked as having non functional

In such simulation environments this means we:
a) don't log an error that isn't really an error
b) boot 1 minute quicker as we don't hit the timeout.

Signed-off-by: Stewart Smith <stewart at linux.vnet.ibm.com>
 core/chip.c    | 5 +++++
 hw/occ.c       | 7 +++++++
 include/chip.h | 6 ++++++
 3 files changed, 18 insertions(+)

diff --git a/core/chip.c b/core/chip.c
index f2f1a96..729bccb 100644
--- a/core/chip.c
+++ b/core/chip.c
@@ -96,6 +96,11 @@ void init_chips(void)
 		chip->pcid = dt_prop_get_u32_def(xn, "ibm,proc-chip-id",
+		if (dt_prop_get_u32_def(xn, "ibm,occ-functional-state", 1))
+			chip->occ_functional = true;
+		else
+			chip->occ_functional = false;
diff --git a/hw/occ.c b/hw/occ.c
index 8732133..7a72c27 100644
--- a/hw/occ.c
+++ b/hw/occ.c
@@ -98,6 +98,13 @@ static bool wait_for_all_occ_init(void)
 			return false;
+		if (!chip->occ_functional) {
+			prlog(PR_WARNING, "OCC: Chip: %x occ not functional\n",
+			      chip->id);
+			continue;
+		}
 		/* Get PState table address */
 		occ_data_area = chip->homer_base + P8_HOMER_SAPPHIRE_DATA_OFFSET;
 		occ_data = (struct occ_pstate_table *)occ_data_area;
diff --git a/include/chip.h b/include/chip.h
index 5951ef0..5109e25 100644
--- a/include/chip.h
+++ b/include/chip.h
@@ -129,6 +129,12 @@ struct proc_chip {
 	uint32_t		dbob_id;
 	uint32_t		pcid;
+	/* If we expect to have an OCC (i.e. P8) and it is functional,
+	 * set TRUE. If something has told us it is not, set FALSE and
+	 * we can not wait for OCCs to init. This is only going to be
+	 * FALSE in a simulator that doesn't simulate OCCs. */
+	bool			occ_functional;
 	/* Used by hw/xscom.c */
 	uint64_t		xscom_base;

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