[Skiboot] [PATCH 2/3] skiboot: Enable opal calls to init/start/stop IMC Trace mode

[Madhavan Srinivasan]

On 04/10/18 11:39 AM, Anju T Sudhakar wrote:
> Patch to enhance the imc opal call to support and handle trace_imc mode.
>
> To initialize the trace-mode, TRACE_IMC_SCOM value is written to
> TRACE_IMC_ADDR of the respective core.
>
> TRACE_IMC_SCOM is a 64bit value, and each bit represent the following:
> 0:1       : SAMPSEL
> 2:33      : CPMC_LOAD
> 34:40     : CPMC1SEL
> 41:47     : CPMC2SEL
> 48:50     : BUFFERSIZE
> 51:63      : RESERVED
> For the nonce the value for TRACE_IMC_SCOM is hard coded.
> During initialization htm_mode is disabled, and enabled only at start.
>
> The opal calls to start/stop the counters, will write CORE_IMC_HTM_MODE_ENABLE/
> CORE_IMC_HTM_MODE_DISABLE respectively to the htm_scom_index of the desired
> cores.
>
> Additional switch cases are added to the current opal calls to start/stop
> the counters for trace-mode.


May not be a critical thing, but as a follow up patch later point
can you also update the imc documentation and imc devicetree tree file
about the trace mode.Apart from that patch looks fine to me

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

>
> Signed-off-by: Anju T Sudhakar <anju at linux.vnet.ibm.com>
> Cc: Akshay Adiga <akshay.adiga at linux.vnet.ibm.com>
> ---
>   hw/imc.c | 103 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 103 insertions(+)
>
> diff --git a/hw/imc.c b/hw/imc.c
> index 3392eaf1..55098433 100644
> --- a/hw/imc.c
> +++ b/hw/imc.c
> @@ -22,6 +22,15 @@
>   #include <device.h>
>   #include <p9_stop_api.H>
>
> +/*
> + * IMC trace scom values
> + */
> +#define samplesel	1	/* select cpmc2 */
> +#define cpmcload	0xfa	/* Value to be loaded into cpmc2 at sampling start */
> +#define cpmc1sel	2	/* Event: CPM_CCYC */
> +#define cpmc2sel	2	/* Event: CPM_32MHZ_CYC */
> +#define buffersize	0	/* b’000’- 4K entries * 64 per entry = 256K buffersize */
> +
>   /*
>    * Nest IMC PMU names along with their bit values as represented in the
>    * imc_chip_avl_vector(in struct imc_chip_cb, look at include/imc.h).
> @@ -264,6 +273,8 @@ static int get_imc_device_type(struct dt_node *node)
>   		return IMC_COUNTER_CORE;
>   	case IMC_COUNTER_THREAD:
>   		return IMC_COUNTER_THREAD;
> +	case IMC_COUNTER_TRACE:
> +		return IMC_COUNTER_TRACE;
>   	default:
>   		break;
>   	}
> @@ -283,11 +294,23 @@ static bool is_nest_node(struct dt_node *node)
>   static bool is_imc_device_type_supported(struct dt_node *node)
>   {
>   	u32 val = get_imc_device_type(node);
> +	struct proc_chip *chip = get_chip(this_cpu()->chip_id);
> +	uint64_t pvr;
>
>   	if ((val == IMC_COUNTER_CHIP) || (val == IMC_COUNTER_CORE) ||
>   						(val == IMC_COUNTER_THREAD))
>   		return true;
>
> +	if (val == IMC_COUNTER_TRACE) {
> +		pvr = mfspr(SPR_PVR);
> +		/*
> +		 * Trace mode is supported in Nimbus DD2.2
> +		 * and later versions.
> +		 */
> +		if ((chip->type == PROC_CHIP_P9_NIMBUS) &&
> +			(PVR_VERS_MAJ(pvr) == 2) && (PVR_VERS_MIN(pvr) >= 2))
> +			return true;
> +	}
>   	return false;
>   }
>
> @@ -644,6 +667,8 @@ static int64_t opal_imc_counters_init(uint32_t type, uint64_t addr, uint64_t cpu
>   	int port_id, phys_core_id;
>   	int ret;
>   	uint32_t scoms;
> +	uint64_t trace_scom_val = TRACE_IMC_SCOM(samplesel, cpmcload,
> +					    cpmc1sel, cpmc2sel, buffersize);
>
>   	switch (type) {
>   	case OPAL_IMC_COUNTERS_NEST:
> @@ -738,6 +763,53 @@ static int64_t opal_imc_counters_init(uint32_t type, uint64_t addr, uint64_t cpu
>   			return OPAL_HARDWARE;
>   		}
>   		return OPAL_SUCCESS;
> +	case OPAL_IMC_COUNTERS_TRACE:
> +		if (!c)
> +			return OPAL_PARAMETER;
> +
> +		phys_core_id = cpu_get_core_index(c);
> +		port_id = phys_core_id % 4;
> +
> +		if (proc_chip_quirks & QUIRK_MAMBO_CALLOUTS)
> +			return OPAL_SUCCESS;
> +
> +		if (has_deep_states) {
> +			if (wakeup_engine_state == WAKEUP_ENGINE_PRESENT) {
> +				struct proc_chip *chip = get_chip(c->chip_id);
> +
> +				prlog(PR_INFO, "Configuring stopapi for IMC trace-mode\n");
> +				scoms = XSCOM_ADDR_P9_EC(phys_core_id, TRACE_IMC_ADDR);
> +				ret = p9_stop_save_scom((void *)chip->homer_base, scoms,
> +					trace_scom_val,
> +					P9_STOP_SCOM_REPLACE,
> +					P9_STOP_SECTION_CORE_SCOM);
> +				if (ret) {
> +					prerror("IMC trace_mode stopapi ret = %d, scoms = %x (core id = %x)\n", ret, scoms, phys_core_id);
> +					if (ret != STOP_SAVE_SCOM_ENTRY_UPDATE_FAILED)
> +						wakeup_engine_state = WAKEUP_ENGINE_FAILED;
> +					else
> +						prerror("SCOM entries are full\n");
> +					return OPAL_HARDWARE;
> +				}
> +			} else {
> +				prerror("IMC: TRACE:  Wakeup engine in error state!");
> +				return OPAL_HARDWARE;
> +			}
> +		}
> +		if (xscom_write(c->chip_id,
> +			XSCOM_ADDR_P9_EP(phys_core_id, htm_scom_index[port_id]),
> +					(u64)CORE_IMC_HTM_MODE_DISABLE)) {
> +				prerror("IMC: error in xscom_write for htm mode\n");
> +				return OPAL_HARDWARE;
> +		}
> +		if (xscom_write(c->chip_id,
> +			XSCOM_ADDR_P9_EC(phys_core_id,
> +					TRACE_IMC_ADDR), trace_scom_val)) {
> +			prerror("IMC: error in xscom_write for trace mode\n");
> +			return OPAL_HARDWARE;
> +		}
> +		return OPAL_SUCCESS;
> +
>   	}
>
>   	return OPAL_SUCCESS;
> @@ -797,6 +869,21 @@ static int64_t opal_imc_counters_start(uint32_t type, uint64_t cpu_pir)
>   			return OPAL_HARDWARE;
>   		}
>
> +		return OPAL_SUCCESS;
> +	case OPAL_IMC_COUNTERS_TRACE:
> +		phys_core_id = cpu_get_core_index(c);
> +		port_id = phys_core_id % 4;
> +
> +		if (proc_chip_quirks & QUIRK_MAMBO_CALLOUTS)
> +			return OPAL_SUCCESS;
> +
> +		if (xscom_write(c->chip_id,
> +				XSCOM_ADDR_P9_EP(phys_core_id,
> +						 htm_scom_index[port_id]),
> +				(u64)CORE_IMC_HTM_MODE_ENABLE)) {
> +			prerror("IMC OPAL_start: error in xscom_write for htm_mode\n");
> +			return OPAL_HARDWARE;
> +		}
>   		return OPAL_SUCCESS;
>   	}
>
> @@ -857,6 +944,22 @@ static int64_t opal_imc_counters_stop(uint32_t type, uint64_t cpu_pir)
>   		}
>
>   		return OPAL_SUCCESS;
> +	case OPAL_IMC_COUNTERS_TRACE:
> +		phys_core_id = cpu_get_core_index(c);
> +		port_id = phys_core_id % 4;
> +
> +		if (proc_chip_quirks & QUIRK_MAMBO_CALLOUTS)
> +			return OPAL_SUCCESS;
> +
> +		if (xscom_write(c->chip_id,
> +				XSCOM_ADDR_P9_EP(phys_core_id,
> +						htm_scom_index[port_id]),
> +				(u64)CORE_IMC_HTM_MODE_DISABLE)) {
> +			prerror("IMC: error in xscom_write for htm_mode\n");
> +			return OPAL_HARDWARE;
> +		}
> +		return OPAL_SUCCESS;
> +
>   	}
>
>   	return OPAL_SUCCESS;