[Skiboot] [RFC PATCH 5/7] skiboot: Add opal call for nest IMA configuration

[Madhavan Srinivasan]

On Tuesday 25 October 2016 06:15 PM, Hemant Kumar wrote:
> Add a new opal call to control the nest IMA counters.
> opal_nest_ima_counters_control() is to start and stop OCC
> microcode for nest PMU counter collection based on the "operation"
> parameter.

Would prefer the title of the patch to be

"skiboot: Add opal call to enable/disable Nest IMA microcode"

OPAL Call is to start/stop the Nest microcode running in the OCC
complex.

Nest counters are configured by the microcode and not by OPAL
or kernel.

>
> Signed-off-by: Hemant Kumar <hemant at linux.vnet.ibm.com>
> ---
>   hw/ima.c           | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>   include/opal-api.h |  3 ++-
>   2 files changed, 71 insertions(+), 1 deletion(-)
>
> diff --git a/hw/ima.c b/hw/ima.c
> index 7dd8d8c..cce5473 100644
> --- a/hw/ima.c
> +++ b/hw/ima.c
> @@ -139,3 +139,72 @@ void ima_init(void)
>   err:
>   	free(buf);
>   }
> +
> +/*
> + * opal_nest_ima_counters_control : This call controls the nest IMA counters.
nest IMA "microcode" and not "counters".

> + *
> + * mode      : For now, this call supports only NEST_IMA_PRODUCTION_MODE.
> + *             This mode can start/stop the PORE SLW IMA engine for nest
Instead of "PORE SLW IMA", can it be "Nest IMA Microcode"?
> + *             instrumentation from Host OS.
> + * operation : Start(0x0) or Stop(0x1) the engine.
> + *
> + * This call can be extended to include more operations, if needed and the
> + * other two parameters value_1 and value_2 are for the very same purpose.
> + * Right now, they are unused and should be zero.
> + */
> +static int64_t opal_nest_ima_counters_control(uint64_t mode,
> +					      uint64_t operation,
> +					      uint64_t value_1,
> +					      uint64_t value_2)
> +{
> +	struct proc_chip *chip;
> +	u64 op;
> +	int ret;
> +	uint64_t cb_loc;
> +	struct ima_chip_cb *cb;
> +
> +	if ((mode != NEST_IMA_PRODUCTION_MODE) || value_1 || value_2) {
> +		ret = OPAL_PARAMETER;
> +		goto nest_ret;
> +	}
> +
> +	chip = get_chip(this_cpu()->chip_id);
> +
> +	/* Fetch the IMA control block structure */
> +	cb_loc = chip->homer_base + CB_STRUCT_OFFSET;
> +	cb = (struct ima_chip_cb *)cb_loc;
> +
> +	switch (operation) {
> +	case 0:
> +		/* Check whether the engine is already stopped */
> +		if (cb->ima_chip_run_status == SLW_IMA_PAUSE) {

Can it be "NEST_IMA_PAUSE" instead of  "SLW_IMA_PAUSE"?


> +			ret = OPAL_SUCCESS;
> +			goto nest_ret;
> +		}
> +
> +		op = NEST_IMA_DISABLE;
> +		break;
> +	case 1:
> +		/* Check whether the engine is already running */
> +		if (cb->ima_chip_run_status == SLW_IMA_RESUME) {

Same here. Can it be NEST_IMA_RESUME instead of SLW_IMA_RESUME
> +			ret = OPAL_SUCCESS;
> +			goto nest_ret;
> +		}
> +
> +		op = NEST_IMA_ENABLE;
> +		break;
> +	default:
> +		prerror("IMA: unknown operation for nest ima\n");
> +		ret = OPAL_PARAMETER;
> +		goto nest_ret;
> +	}
> +
> +	/* Write the command now to the control block */
> +	cb->ima_chip_command = op;
> +
> +	ret = OPAL_SUCCESS;
> +nest_ret:
> +	return ret;
> +}
> +
> +opal_call(OPAL_NEST_IMA_COUNTERS_CONTROL, opal_nest_ima_counters_control, 4);
> diff --git a/include/opal-api.h b/include/opal-api.h
> index 05ff51d..cbb5dcf 100644
> --- a/include/opal-api.h
> +++ b/include/opal-api.h
> @@ -181,7 +181,8 @@
>   #define OPAL_INT_SET_MFRR			125
>   #define OPAL_PCI_TCE_KILL			126
>   #define OPAL_NMMU_SET_PTCR			127
> -#define OPAL_LAST				127
> +#define OPAL_NEST_IMA_COUNTERS_CONTROL		128
> +#define OPAL_LAST				128
>
>   /* Device tree flags */
>