Messages in this thread | | | Subject | Re: [PATCH] firmware: arm_sdei: pass sdei_api_event_register right parameters | From | 乱石 <> | Date | Tue, 19 Oct 2021 11:35:43 +0800 |
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Hi James,
在 2021/10/19 1:32, James Morse 写道: > Hi Liguang, > > On 11/10/2021 06:40, 乱石 wrote: >> 在 2021/10/9 1:39, James Morse 写道: >>> On 10/09/2021 05:01, Liguang Zhang wrote: >>>> Function _local_event_enable is used for private sdei event >>>> registeration called by sdei_event_register. We should pass >>> (registration) >>>> sdei_api_event_register right flag and mpidr parameters, otherwise atf >>>> may trigger assert errors. >>>> diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c >>>> index a7e762c352f9..0736752dadde 100644 >>>> --- a/drivers/firmware/arm_sdei.c >>>> +++ b/drivers/firmware/arm_sdei.c >>>> @@ -558,14 +558,16 @@ static int sdei_api_event_register(u32 event_num, unsigned long >>>> entry_point, >>>> static void _local_event_register(void *data) >>>> { >>>> int err; >>>> + u64 mpidr; >>>> struct sdei_registered_event *reg; >>>> struct sdei_crosscall_args *arg = data; >>>> WARN_ON(preemptible()); >>>> + mpidr = read_cpuid_mpidr(); >>>> reg = per_cpu_ptr(arg->event->private_registered, smp_processor_id()); >>>> err = sdei_api_event_register(arg->event->event_num, sdei_entry_point, >>>> - reg, 0, 0); >>>> + reg, SDEI_EVENT_REGISTER_RM_PE, mpidr); >>> Hmmm, this looks like a bug in TFA. >>> >>> 5.1.2.2 "Parameters" of DEN 0054B has: >>> | Routing mode is valid only for a shared event. For a private event, the routing mode is >>> | ignored. >>> >>> Worse, the mpidr field has: >>> | Currently the format is defined only when the selected routing mode is RM_PE. > >> For a private event, we route SDEI_EVENT_REGISTER_RM_PE and mpidr parameters may be more >> rationable. > You are making this call from Linux? > > This isn't valid for private events. Private events are private to the CPU - they can only > be reset, register and taken on that CPU. The specification for SDEI_EVENT_ROUTING_SET has > this: > | This call is used to change the routing information of a shared event. > > To borrow the GIC's terms: Private events are like PPI, Shared events are like SPI. > > >>> Over in trusted firmware land: >>> >>> https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/services/std_svc/sdei/sdei_main.c?h=v2.5#n361 >>> >>> >>> | static int64_t sdei_event_register(int ev_num, >>> | uint64_t ep, >>> | uint64_t arg, >>> | uint64_t flags, >>> | uint64_t mpidr) >>> | { >>> >>> | /* Private events always target the PE */ >>> | if (is_event_private(map)) >>> | flags = SDEI_REGF_RM_PE; >>> >>> It looks like this re-uses the 'caller specified the routing' code, but didn't update the >>> mpidr. >>> >>> >>> You mention TFA takes an assert failure, I assume that brings the machine down. >>> (Presumably you don't have a CPU with an affinity of zero.) >> Yes, that brings the machine down. In opensource ATF, CPU with an affinity of zero. >> >> The problem backaround: >> >> we use local secure arch timer as sdei watchdog timer > Is that an SPI? If so, you should really be generating a shared event.
It's an PPI, secured arch timer used for hardlockup detection.
> > >> for hardlockup detection, in os >> panic ,we mask sdei event, then trigger the assert >> if (se->reg_flags == SDEI_REGF_RM_PE) >> >> assert(se->affinity == my_mpidr); > > I'm not sure where this code in TFA is, but RM_PE for a private event is going to hit this > on all but one CPU. You shouldn't be able to set RM_PE for a private event. > > > I assume this is the TFA side of the problem from your colleague: > https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/11393 > > > Does the problem occur with this TFA patch applied, and without any attempt to mess with > the routing of per-cpu/private events?
Thanks for your reply. With the patch applied, the problem resolved.
Thanks,
Liguang
> > > Thanks, > > James
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