hw/imc: don't access homer memory if it was not initialised

This can happen under mambo, at least.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/hw/imc.c b/hw/imc.c
index 53e84c2..a56f336 100644
--- a/hw/imc.c
+++ b/hw/imc.c
@@ -154,6 +154,9 @@ static struct imc_chip_cb *get_imc_cb(uint32_t chip_id)
 	struct proc_chip *chip = get_chip(chip_id);
 	struct imc_chip_cb *cb;
 
+	if (!chip->homer_base)
+		return NULL; /* The No Homers Club */
+
 	cb = (struct imc_chip_cb *)(chip->homer_base + P9_CB_STRUCT_OFFSET);
 	if (!is_nest_mem_initialized(cb))
 		return NULL;