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

[Jing Zhang]

在 2023/4/3 下午8:47, Robin Murphy 写道:
> 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@xxxxxxxxxxxxxxxxx>
>> Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
>> ---
>>   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.
> 
>> +
>>   /* 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++)


Hi Robin,

I tested the patch on CMN700, it works fine as I expected.
And maybe the variable 'p' should be defined to the front?

Thanks,
Jing


>> +            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);