[Skiboot] [PATCH] hw/imc: Check ucode state in all the chip

[Stewart Smith]

Madhavan Srinivasan <maddy at linux.vnet.ibm.com> writes:
> disable_unavailable_units() checks whether the ucode
> is in the running state before enabling the nest units
> in the device tree. From a recent debug, it is found
> that on some system boot, ucode is not loaded and
> running in all the chips in the system. And this
> caused a fail in OPAL_IMC_COUNTERS_STOP call where
> we check for ucode state on each chip. Bug here is
> that disable_unavailable_units() checks the state
> of the ucode only in boot cpu chip. Patch adds a
> condition in disable_unavailable_units() to check
> for the ucode state in all the chip before enabling
> the nest units in the device tree node.
>
> Fixes: f98d59958db19 ('skiboot: Find the IMC DTB')
> Signed-off-by: Madhavan Srinivasan <maddy at linux.vnet.ibm.com>
> ---
>  hw/imc.c | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/hw/imc.c b/hw/imc.c
> index 88d0302d9da6..1db94ec6ac1b 100644
> --- a/hw/imc.c
> +++ b/hw/imc.c
> @@ -320,10 +320,23 @@ static void disable_unavailable_units(struct dt_node *dev)
>  	struct imc_chip_cb *cb;
>  	struct dt_node *target;
>  	int i;
> +	bool flag = true;
> +	struct proc_chip *chip;
> +
> +	/*
> +	 * Check the state of ucode in all the chip.
> +	 * Disable the nest unit if ucode is not initialized
> +	 * in any of the chip.
> +	 */
> +	for_each_chip(chip) {
> +		cb = get_imc_cb(chip->id);
> +		if (!cb)
> +			flag = false;
> +	}
>
>  	/* Fetch the IMC control block structure */
>  	cb = get_imc_cb(this_cpu()->chip_id);
> -	if (cb)
> +	if (cb && flag)
>  		avl_vec = be64_to_cpu(cb->imc_chip_avl_vector);
>  	else {
>  		avl_vec = 0; /* Remove only nest imc device nodes */

(just confirming what we chatted about on slack), there's a bug here
where it's not properly handling things unless it's the last chip that
the ucode isn't running on.

Awaiting v2 :)

-- 
Stewart Smith
OPAL Architect, IBM.