[PATCH] perf/arm-cmn: Fix port detection for CMN-700

[Ilkka Koskinen]

Hi Robin,

On Mon, 3 Apr 2023, Robin Murphy wrote:
> On 2023-04-03 12:50, Robin Murphy wrote:
>> When the "extra device ports" configuration was first added, the
>> additional mxp_device_port_connect_info registers were added around the
>> existing mxp_mesh_port_connect_info registers. What I missed about
>> CMN-700 is that it shuffled them around to remove this discontinuity.
>> As such, tweak the definitions and factor out a helper for reading these
>> registers so we can deal with this discrepancy easily, which does at
>> least allow nicely tidying up the callsites. With this we can then also
>> do the nice thing and skip accesses completely rather than relying on
>> RES0 behaviour where we know the extra registers aren't defined.
>> 
>> Fixes: 23760a014417 ("perf/arm-cmn: Add CMN-700 support")
>> Reported-by: Jing Zhang <renyu.zj at linux.alibaba.com>
>> Signed-off-by: Robin Murphy <robin.murphy at arm.com>
>> ---
>>   drivers/perf/arm-cmn.c | 55 ++++++++++++++++++++++--------------------
>>   1 file changed, 29 insertions(+), 26 deletions(-)
>> 
>> diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
>> index c9689861be3f..367d41c5d983 100644
>> --- a/drivers/perf/arm-cmn.c
>> +++ b/drivers/perf/arm-cmn.c
>> @@ -57,14 +57,12 @@
>>   #define CMN_INFO_REQ_VC_NUM		GENMASK_ULL(1, 0)
>>     /* XPs also have some local topology info which has uses too */
>> -#define CMN_MXP__CONNECT_INFO_P0	0x0008
>> -#define CMN_MXP__CONNECT_INFO_P1	0x0010
>> -#define CMN_MXP__CONNECT_INFO_P2	0x0028
>> -#define CMN_MXP__CONNECT_INFO_P3	0x0030
>> -#define CMN_MXP__CONNECT_INFO_P4	0x0038
>> -#define CMN_MXP__CONNECT_INFO_P5	0x0040
>> +#define CMN_MXP__CONNECT_INFO(p)	(0x0008 + 8 * (p))
>>   #define CMN__CONNECT_INFO_DEVICE_TYPE	GENMASK_ULL(4, 0)
>>   +#define CMN_MAX_PORTS			6
>> +#define CI700_CONNECT_INFO_P2_5_OFFSET	0x20
>
> ...which of course should be 0x10 for the way the code below ended up, sigh. 
> I'll wait for any further review before resending.
>
> Cheers,
> Robin.

I quickly checked cmn650, cmn700, ci700 TRMs and the change looks good to 
me. I also tested the patch briefly on cmn650 and it was working fine just 
like I expected.

Cheers, Ilkka

>> +
>>   /* PMU registers occupy the 3rd 4KB page of each node's region */
>>   #define CMN_PMU_OFFSET			0x2000
>>   @@ -396,6 +394,25 @@ static struct arm_cmn_node *arm_cmn_node(const 
>> struct arm_cmn *cmn,
>>   	return NULL;
>>   }
>>   +static u32 arm_cmn_device_connect_info(const struct arm_cmn *cmn,
>> +				       const struct arm_cmn_node *xp, int 
>> port)
>> +{
>> +	int offset = CMN_MXP__CONNECT_INFO(port);
>> +
>> +	if (port >= 2) {
>> +		if (cmn->model & (CMN600 | CMN650))
>> +			return 0;
>> +		/*
>> +		 * CI-700 may have extra ports, but still has the
>> +		 * mesh_port_connect_info registers in the way.
>> +		 */
>> +		if (cmn->model == CI700)
>> +			offset += CI700_CONNECT_INFO_P2_5_OFFSET;
>> +	}
>> +
>> +	return readl_relaxed(xp->pmu_base - CMN_PMU_OFFSET + offset);
>> +}
>> +
>>   static struct dentry *arm_cmn_debugfs;
>>     #ifdef CONFIG_DEBUG_FS
>> @@ -469,7 +486,7 @@ static int arm_cmn_map_show(struct seq_file *s, void 
>> *data)
>>   	y = cmn->mesh_y;
>>   	while (y--) {
>>   		int xp_base = cmn->mesh_x * y;
>> -		u8 port[6][CMN_MAX_DIMENSION];
>> +		u8 port[CMN_MAX_PORTS][CMN_MAX_DIMENSION];
>>     		for (x = 0; x < cmn->mesh_x; x++)
>>   			seq_puts(s, "--------+");
>> @@ -477,14 +494,9 @@ static int arm_cmn_map_show(struct seq_file *s, void 
>> *data)
>>   		seq_printf(s, "\n%d    |", y);
>>   		for (x = 0; x < cmn->mesh_x; x++) {
>>   			struct arm_cmn_node *xp = cmn->xps + xp_base + x;
>> -			void __iomem *base = xp->pmu_base - CMN_PMU_OFFSET;
>>   -			port[0][x] = readl_relaxed(base + 
>> CMN_MXP__CONNECT_INFO_P0);
>> -			port[1][x] = readl_relaxed(base + 
>> CMN_MXP__CONNECT_INFO_P1);
>> -			port[2][x] = readl_relaxed(base + 
>> CMN_MXP__CONNECT_INFO_P2);
>> -			port[3][x] = readl_relaxed(base + 
>> CMN_MXP__CONNECT_INFO_P3);
>> -			port[4][x] = readl_relaxed(base + 
>> CMN_MXP__CONNECT_INFO_P4);
>> -			port[5][x] = readl_relaxed(base + 
>> CMN_MXP__CONNECT_INFO_P5);
>> +			for (p = 0; p < CMN_MAX_PORTS; p++)
>> +				port[p][x] = arm_cmn_device_connect_info(cmn, 
>> xp, p);
>>   			seq_printf(s, " XP #%-2d |", xp_base + x);
>>   		}
>>   @@ -2083,18 +2095,9 @@ static int arm_cmn_discover(struct arm_cmn *cmn, 
>> unsigned int rgn_offset)
>>   		 * from this, since in that case we will see at least one XP
>>   		 * with port 2 connected, for the HN-D.
>>   		 */
>> -		if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P0))
>> -			xp_ports |= BIT(0);
>> -		if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P1))
>> -			xp_ports |= BIT(1);
>> -		if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P2))
>> -			xp_ports |= BIT(2);
>> -		if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P3))
>> -			xp_ports |= BIT(3);
>> -		if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P4))
>> -			xp_ports |= BIT(4);
>> -		if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P5))
>> -			xp_ports |= BIT(5);
>> +		for (int p = 0; p < CMN_MAX_PORTS; p++)
>> +			if (arm_cmn_device_connect_info(cmn, xp, p))
>> +				xp_ports |= BIT(p);
>>     		if (cmn->multi_dtm && (xp_ports & 0xc))
>>   			arm_cmn_init_dtm(dtm++, xp, 1);
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>