On 01/07/2019 16:17, maddy wrote:
>
> On 01/07/19 11:24 AM, Alexey Kardashevskiy wrote:
>>
>> On 29/06/2019 06:08, Claudio Carvalho wrote:
>>> When the ultravisor firmware is available, it takes control over the
>>> LDBAR register. In this case, thread-imc updates and save/restore
>>> operations on the LDBAR register are handled by ultravisor.
>> What does LDBAR do? "Power ISA™ Version 3.0 B" or "User’s Manual POWER9
>> Processor" do not tell.
> LDBAR is a per-thread SPR used by thread-imc pmu to dump the counter
> data into memory.
> LDBAR contains memory address along with few other configuration bits
> (it is populated
> by the thread-imc pmu driver). It is populated and enabled only when any
> of the thread
> imc pmu events are monitored.
I was actually looking for a spec for this register, what is the
document name?
>
> Maddy
>>
>>
>>> Signed-off-by: Claudio Carvalho <cclaudio@xxxxxxxxxxxxx>
>>> Reviewed-by: Ram Pai <linuxram@xxxxxxxxxx>
>>> Reviewed-by: Ryan Grimm <grimm@xxxxxxxxxxxxx>
>>> Acked-by: Madhavan Srinivasan <maddy@xxxxxxxxxxxxxxxxxx>
>>> Acked-by: Paul Mackerras <paulus@xxxxxxxxxx>
>>> ---
>>> arch/powerpc/kvm/book3s_hv_rmhandlers.S | 2 ++
>>> arch/powerpc/platforms/powernv/idle.c | 6 ++++--
>>> arch/powerpc/platforms/powernv/opal-imc.c | 4 ++++
>>> 3 files changed, 10 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
>>> b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
>>> index f9b2620fbecd..cffb365d9d02 100644
>>> --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
>>> +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
>>> @@ -375,8 +375,10 @@ BEGIN_FTR_SECTION
>>> mtspr SPRN_RPR, r0
>>> ld r0, KVM_SPLIT_PMMAR(r6)
>>> mtspr SPRN_PMMAR, r0
>>> +BEGIN_FW_FTR_SECTION_NESTED(70)
>>> ld r0, KVM_SPLIT_LDBAR(r6)
>>> mtspr SPRN_LDBAR, r0
>>> +END_FW_FTR_SECTION_NESTED(FW_FEATURE_ULTRAVISOR, 0, 70)
>>> isync
>>> FTR_SECTION_ELSE
>>> /* On P9 we use the split_info for coordinating LPCR changes */
>>> diff --git a/arch/powerpc/platforms/powernv/idle.c
>>> b/arch/powerpc/platforms/powernv/idle.c
>>> index 77f2e0a4ee37..5593a2d55959 100644
>>> --- a/arch/powerpc/platforms/powernv/idle.c
>>> +++ b/arch/powerpc/platforms/powernv/idle.c
>>> @@ -679,7 +679,8 @@ static unsigned long power9_idle_stop(unsigned
>>> long psscr, bool mmu_on)
>>> sprs.ptcr = mfspr(SPRN_PTCR);
>>> sprs.rpr = mfspr(SPRN_RPR);
>>> sprs.tscr = mfspr(SPRN_TSCR);
>>> - sprs.ldbar = mfspr(SPRN_LDBAR);
>>> + if (!firmware_has_feature(FW_FEATURE_ULTRAVISOR))
>>> + sprs.ldbar = mfspr(SPRN_LDBAR);
>>> sprs_saved = true;
>>> @@ -762,7 +763,8 @@ static unsigned long power9_idle_stop(unsigned
>>> long psscr, bool mmu_on)
>>> mtspr(SPRN_PTCR, sprs.ptcr);
>>> mtspr(SPRN_RPR, sprs.rpr);
>>> mtspr(SPRN_TSCR, sprs.tscr);
>>> - mtspr(SPRN_LDBAR, sprs.ldbar);
>>> + if (!firmware_has_feature(FW_FEATURE_ULTRAVISOR))
>>> + mtspr(SPRN_LDBAR, sprs.ldbar);
>>> if (pls >= pnv_first_tb_loss_level) {
>>> /* TB loss */
>>> diff --git a/arch/powerpc/platforms/powernv/opal-imc.c
>>> b/arch/powerpc/platforms/powernv/opal-imc.c
>>> index 1b6932890a73..5fe2d4526cbc 100644
>>> --- a/arch/powerpc/platforms/powernv/opal-imc.c
>>> +++ b/arch/powerpc/platforms/powernv/opal-imc.c
>>> @@ -254,6 +254,10 @@ static int opal_imc_counters_probe(struct
>>> platform_device *pdev)
>>> bool core_imc_reg = false, thread_imc_reg = false;
>>> u32 type;
>>> + /* Disable IMC devices, when Ultravisor is enabled. */
>>> + if (firmware_has_feature(FW_FEATURE_ULTRAVISOR))
>>> + return -EACCES;
>>> +
>>> /*
>>> * Check whether this is kdump kernel. If yes, force the
>>> engines to
>>> * stop and return.
>>>
>
--
Alexey
