[PATCH V2 0/3] fix cpu softlock when using T-HEAD c9xx pmu

[Samuel Holland]

On 8/15/23 04:39, Inochi Amaoto wrote:
> These patches fix the system hang issue caused by using perf tool on
> T-HEAD c9xx related platforms.
> 
> These patch solves two issues for T-HEAD c9xx pmu:
> When detecting features of PMU, MHPMCOUNTER3 is written to all 1s. This
> will cause an unexpected overflow interrupt before starting the PMU in
> T-HEAD cores.
> 
> Another thing is the T-HEAD c9xx pmu is not a standart pmu, especially
> in interrupt process and access delegation. For interrupt process, the
> T-HEAD pmu uses MCOUNTERINTEN and MCOUNTEROF to control and identify the
> interrupt. For access delegation. It needs to set MCOUNTERWEN to allow
> S-mode to access related CSRs.
> 
> Changed from V1:
> 1. fix the hang issue when using perf with high profile frequency.
> 2. optimze the performance of irq process of T-HEAD c9xx pmu.
> 
> Inochi Amaoto (3):
>   lib: sbi_pmu: ensure update hpm counter before starting counting
>   platform: generic: allwinner: fix OF process for T-HEAD c9xx pmu
>   lib: sbi_pmu: keep overflow interrupt of stopped hpm counter disabled
> 
>  lib/sbi/sbi_pmu.c                      | 17 +++++++++++------
>  platform/generic/allwinner/sun20i-d1.c | 25 +++++++++++++++----------
>  2 files changed, 26 insertions(+), 16 deletions(-)

For the series:
Tested-by: Samuel Holland <samuel at sholland.org>