[Skiboot] [PATCH 2/2] hw/imc: don't access homer memory if it was not initialised

[Madhavan Srinivasan]

On Sunday 25 March 2018 06:18 AM, Nicholas Piggin wrote:
> This can happen under mambo, at least.

looks good. In mambo, we could access homer via disable_unavailable_units()
which is out of mambo_quirk check.

Reviewed-by: Madhavan Srinivasan <maddy at linux.vnet.ibm.com>

> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
> ---
>   hw/imc.c | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/hw/imc.c b/hw/imc.c
> index 5bc59b59..c7999e1e 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;