[Skiboot] [PATCH] occ: Set up OCC messaging even if we fail to setup pstates

[Shilpasri G Bhat]

Hi,

On 03/23/2018 06:54 AM, Stewart Smith wrote:
> This means that we no longer hit this bug if we fail to get valid pstates
> from the OCC.
> 
> [console-pexpect]#echo 1 > //sys/firmware/opal/sensor_groups//occ-csm0/clear
> echo 1 > //sys/firmware/opal/sensor_groups//occ-csm0/clear
> [   94.019971181,5] CPU ATTEMPT TO RE-ENTER FIRMWARE! PIR=083d cpu @0x33cf4000 -> pir=083d token=8
> [   94.020098392,5] CPU ATTEMPT TO RE-ENTER FIRMWARE! PIR=083d cpu @0x33cf4000 -> pir=083d token=8
> [   10.318805] Disabling lock debugging due to kernel taint
> [   10.318808] Severe Machine check interrupt [Not recovered]
> [   10.318812]   NIP [000000003003e434]: 0x3003e434
> [   10.318813]   Initiator: CPU
> [   10.318815]   Error type: Real address [Load/Store (foreign)]
> [   10.318817] opal: Hardware platform error: Unrecoverable Machine Check exception
> [   10.318821] CPU: 117 PID: 2745 Comm: sh Tainted: G   M             4.15.9-openpower1 #3
> [   10.318823] NIP:  000000003003e434 LR: 000000003003025c CTR: 0000000030030240
> [   10.318825] REGS: c00000003fa7bd80 TRAP: 0200   Tainted: G   M              (4.15.9-openpower1)
> [   10.318826] MSR:  9000000000201002 <SF,HV,ME,RI>  CR: 48002888  XER: 20040000
> [   10.318831] CFAR: 0000000030030258 DAR: 394a00147d5a03a6 DSISR: 00000008 SOFTE: 1
> 
> Signed-off-by: Stewart Smith <stewart at linux.vnet.ibm.com>
> ---

Thanks for the patch. We will need the below diff along with this patch.
diff --git a/hw/occ.c b/hw/occ.c
index d2b4a84..53e10f2 100644
--- a/hw/occ.c
+++ b/hw/occ.c
@@ -1242,6 +1242,13 @@ static void occ_cmd_interface_init(void)
        struct proc_chip *chip;
        int i = 0;

+       /* Check if the OCC data is valid */
+       for_each_chip(chip) {
+               pdata = get_occ_pstate_table(chip);
+               if (!pdata->valid)
+                       return;
+       }
+
        chip = next_chip(NULL);
        pdata = get_occ_pstate_table(chip);
        if (pdata->version != 0x90)
@@ -1610,6 +1614,12 @@ void occ_add_sensor_groups(struct dt_node *sg, u32
*phandles, u32 *ptype,
        };
        int i, j;

+       /*
+        * Dont add sensor groups if cmd-interface is not intialized
+        */
+       if (!chips)
+               return;
+
        for (i = 0; i < nr_occs; i++)
                if (chips[i].chip_id == chipid)
                        break;

>  hw/occ.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/hw/occ.c b/hw/occ.c
> index 37cf73c30bbd..90d3105eb1a8 100644
> --- a/hw/occ.c
> +++ b/hw/occ.c
> @@ -1365,6 +1365,9 @@ int occ_set_powercap(u32 handle, int token, u32 pcap)
>  	if (powercap_get_attr(handle) != POWERCAP_OCC_CUR)
>  		return OPAL_PERMISSION;
>  
> +	if (!chips)
> +		return OPAL_HARDWARE;
> +

This check is not required as powercap is initialized after cmd-interface
initialization. So occ_set_powercap() will not be invoked by host if
cmd-interface is not initialized.

>  	for (i = 0; i < nr_occs; i++)
>  		if (chips[i].occ_role == OCC_ROLE_MASTER)
>  			break;
> @@ -1721,14 +1724,11 @@ void occ_pstates_init(void)
>  	if (!add_cpu_pstate_properties(&pstate_nom)) {
>  		log_simple_error(&e_info(OPAL_RC_OCC_PSTATE_INIT),
>  			"Skiping core cpufreq init due to OCC error\n");
> -		return;
> -	}
> -
> -	/*
> -	 * Setup host based pstates and set nominal frequency only in
> -	 * P8.
> -	 */
> -	if (proc_gen == proc_gen_p8) {
> +	} else if (proc_gen == proc_gen_p8) {
> +		/*
> +		 * Setup host based pstates and set nominal frequency only in
> +		 * P8.
> +		 */
>  		for_each_chip(chip)
>  			for_each_available_core_in_chip(c, chip->id)
>  				cpu_pstates_prepare_core(chip, c, pstate_nom);
> 

Reviewed-and-tested-by: Shilpasri G Bhat <shilpa.bhat at linux.vnet.ibm.com>