2023-09-12 07:18:25

by Jinhui Guo

Subject: [PATCH] perf/arm-cmn: Fix CMN_DTM_UNIT_INFO offset in CMN700

The por_dtm_unit_info's offest is 0x0960 in CMN700 according to
the CMN700 spec.

CMN700 spec link:
https://developer.arm.com/documentation/102308/0302/?lang=en
por_dtm_unit_info can be found in section [4.3.13.10 por_dtm_unit_info].

Signed-off-by: guojinhui.liam <[email protected]>
---
drivers/perf/arm-cmn.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
index 913dc04b3a40..6f3fafee0ac9 100644
--- a/drivers/perf/arm-cmn.c
+++ b/drivers/perf/arm-cmn.c
@@ -113,6 +113,7 @@
#define CMN_DTM_PMEVCNTSR 0x240

#define CMN_DTM_UNIT_INFO 0x0910
+#define CMN700_DTM_UNIT_INFO 0x0960

#define CMN_DTM_NUM_COUNTERS 4
/* Want more local counters? Why not replicate the whole DTM! Ugh... */
@@ -2247,6 +2248,8 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset)

if (cmn->part == PART_CMN600)
xp->dtc = 0xf;
+ else if (cmn->part == PART_CMN700)
+ xp->dtc = 1 << readl_relaxed(xp_region + CMN700_DTM_UNIT_INFO);
else
xp->dtc = 1 << readl_relaxed(xp_region + CMN_DTM_UNIT_INFO);

--
2.20.1

2023-09-12 08:21:27

by Robin Murphy

Subject: Re: [PATCH] perf/arm-cmn: Fix CMN_DTM_UNIT_INFO offset in CMN700

On 2023-09-12 05:03, guojinhui.liam wrote:
> The por_dtm_unit_info's offest is 0x0960 in CMN700 according to
> the CMN700 spec.
>
> CMN700 spec link:
> https://developer.arm.com/documentation/102308/0302/?lang=en
> por_dtm_unit_info can be found in section [4.3.13.10 por_dtm_unit_info].
>
> Signed-off-by: guojinhui.liam <[email protected]>
> ---
> drivers/perf/arm-cmn.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
> index 913dc04b3a40..6f3fafee0ac9 100644
> --- a/drivers/perf/arm-cmn.c
> +++ b/drivers/perf/arm-cmn.c
> @@ -113,6 +113,7 @@
> #define CMN_DTM_PMEVCNTSR 0x240
>
> #define CMN_DTM_UNIT_INFO 0x0910
> +#define CMN700_DTM_UNIT_INFO 0x0960
>
> #define CMN_DTM_NUM_COUNTERS 4
> /* Want more local counters? Why not replicate the whole DTM! Ugh... */
> @@ -2247,6 +2248,8 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset)
>
> if (cmn->part == PART_CMN600)
> xp->dtc = 0xf;
> + else if (cmn->part == PART_CMN700)
> + xp->dtc = 1 << readl_relaxed(xp_region + CMN700_DTM_UNIT_INFO);

I'd prefer to fix this more thoroughly, since there are still potential
issues with this code as-is. I already have that patch written[1],
however it ended up spawning a couple more patches to revisit actually
making meaningful use of the DTC domain information[2], which I've still
been debugging, but I hope to post the whole series soon.

Thanks,
Robin.

[1]
https://gitlab.arm.com/linux-arm/linux-rm/-/commit/e4216d99eed2cd951fc515f06ccf31672fb3f58d
[2]
https://gitlab.arm.com/linux-arm/linux-rm/-/commits/cmn-dev?ref_type=heads

> else
> xp->dtc = 1 << readl_relaxed(xp_region + CMN_DTM_UNIT_INFO);
>