[RFC 13/14] lib: sbi: Implement firmware counters

Anup Patel Anup.Patel at wdc.com
Tue May 11 09:08:37 BST 2021



> -----Original Message-----
> From: Atish Patra <atishp at atishpatra.org>
> Sent: 11 May 2021 00:29
> To: Anup Patel <Anup.Patel at wdc.com>
> Cc: Atish Patra <Atish.Patra at wdc.com>; opensbi at lists.infradead.org
> Subject: Re: [RFC 13/14] lib: sbi: Implement firmware counters
> 
> On Mon, Apr 19, 2021 at 5:37 AM Anup Patel <Anup.Patel at wdc.com> wrote:
> >
> >
> >
> > > -----Original Message-----
> > > From: Atish Patra <atish.patra at wdc.com>
> > > Sent: 20 March 2021 03:43
> > > To: opensbi at lists.infradead.org
> > > Cc: Atish Patra <Atish.Patra at wdc.com>; Anup Patel
> > > <Anup.Patel at wdc.com>
> > > Subject: [RFC 13/14] lib: sbi: Implement firmware counters
> > >
> > > RISC-V SBI v0.3 specification defines a set of firmware events that
> > > can provide additional information about the current firmware
> > > context. All of the firmware event monitoring are enabled now. The
> > > firmware events must be defined as raw perf event with MSB set as
> specified in the specification.
> > >
> > > Signed-off-by: Atish Patra <atish.patra at wdc.com>
> > > ---
> > >  include/sbi/sbi_tlb.h       |  1 +
> > >  lib/sbi/sbi_ecall_replace.c |  2 ++
> > >  lib/sbi/sbi_ipi.c           |  7 +++++++
> > >  lib/sbi/sbi_tlb.c           | 36 ++++++++++++++++++++++++++++++++++++
> > >  lib/sbi/sbi_trap.c          |  9 +++++++++
> > >  5 files changed, 55 insertions(+)
> > >
> > > diff --git a/include/sbi/sbi_tlb.h b/include/sbi/sbi_tlb.h index
> > > 48f1962d7dcf..680fcc758072 100644
> > > --- a/include/sbi/sbi_tlb.h
> > > +++ b/include/sbi/sbi_tlb.h
> > > @@ -33,6 +33,7 @@ struct sbi_tlb_info {
> > >       struct sbi_hartmask smask;
> > >  };
> > >
> > > +void sbi_tlb_pmu_incr_fw_ctr(struct sbi_tlb_info *data);
> > >  void sbi_tlb_local_hfence_vvma(struct sbi_tlb_info *tinfo);  void
> > > sbi_tlb_local_hfence_gvma(struct sbi_tlb_info *tinfo);  void
> > > sbi_tlb_local_sfence_vma(struct sbi_tlb_info *tinfo); diff --git
> > > a/lib/sbi/sbi_ecall_replace.c b/lib/sbi/sbi_ecall_replace.c index
> > > a7935d97300d..83544bb6e05f 100644
> > > --- a/lib/sbi/sbi_ecall_replace.c
> > > +++ b/lib/sbi/sbi_ecall_replace.c
> > > @@ -14,6 +14,7 @@
> > >  #include <sbi/sbi_error.h>
> > >  #include <sbi/sbi_hart.h>
> > >  #include <sbi/sbi_ipi.h>
> > > +#include <sbi/sbi_pmu.h>
> > >  #include <sbi/sbi_system.h>
> > >  #include <sbi/sbi_timer.h>
> > >  #include <sbi/sbi_tlb.h>
> > > @@ -27,6 +28,7 @@ static int sbi_ecall_time_handler(unsigned long
> > > extid, unsigned long funcid,
> > >       int ret = 0;
> > >
> > >       if (funcid == SBI_EXT_TIME_SET_TIMER) {
> > > +             sbi_pmu_incr_fw_ctr(SBI_PMU_FW_SET_TIMER);
> >
> > This one I am not sure.
> >
> > May be we should call sbi_pmu_incr_fw_ctr() from
> > sbi_timer_event_start() ?? No ??
> >
> 
> Sure.
> 
> > >  #if __riscv_xlen == 32
> > >               sbi_timer_event_start((((u64)regs->a1 << 32) |
> > > (u64)regs-
> > > >a0));  #else diff --git a/lib/sbi/sbi_ipi.c b/lib/sbi/sbi_ipi.c
> > > >index
> > > b50735e4099a..cd998ac7acfa 100644
> > > --- a/lib/sbi/sbi_ipi.c
> > > +++ b/lib/sbi/sbi_ipi.c
> > > @@ -19,6 +19,9 @@
> > >  #include <sbi/sbi_init.h>
> > >  #include <sbi/sbi_ipi.h>
> > >  #include <sbi/sbi_platform.h>
> > > +#include <sbi/sbi_pmu.h>
> > > +#include <sbi/sbi_string.h>
> > > +#include <sbi/sbi_tlb.h>
> > >
> > >  struct sbi_ipi_data {
> > >       unsigned long ipi_type;
> > > @@ -61,6 +64,10 @@ static int sbi_ipi_send(struct sbi_scratch
> > > *scratch, u32 remote_hartid,
> > >        */
> > >       atomic_raw_set_bit(event, &ipi_data->ipi_type);
> > >       smp_wmb();
> > > +     sbi_pmu_incr_fw_ctr(SBI_PMU_FW_IPI_SENT);
> > > +     if (sbi_strncmp(ipi_ops->name, "IPI_TLB", 7))
> > > +             sbi_tlb_pmu_incr_fw_ctr(data);
> > > +
> > >       sbi_platform_ipi_send(plat, remote_hartid);
> > >
> > >       if (ipi_ops->sync)
> > > diff --git a/lib/sbi/sbi_tlb.c b/lib/sbi/sbi_tlb.c index
> > > 73f59e8681e2..36b21a74a713 100644
> > > --- a/lib/sbi/sbi_tlb.c
> > > +++ b/lib/sbi/sbi_tlb.c
> > > @@ -21,6 +21,7 @@
> > >  #include <sbi/sbi_string.h>
> > >  #include <sbi/sbi_console.h>
> > >  #include <sbi/sbi_platform.h>
> > > +#include <sbi/sbi_pmu.h>
> > >
> > >  static unsigned long tlb_sync_off;
> > >  static unsigned long tlb_fifo_off;
> > > @@ -39,6 +40,8 @@ void sbi_tlb_local_hfence_vvma(struct sbi_tlb_info
> > > *tinfo)
> > >       unsigned long vmid  = tinfo->vmid;
> > >       unsigned long i, hgatp;
> > >
> > > +     sbi_pmu_incr_fw_ctr(SBI_PMU_FW_HFENCE_VVMA_RCVD);
> > > +
> > >       hgatp = csr_swap(CSR_HGATP,
> > >                        (vmid << HGATP_VMID_SHIFT) &
> > > HGATP_VMID_MASK);
> > >
> > > @@ -61,6 +64,8 @@ void sbi_tlb_local_hfence_gvma(struct sbi_tlb_info
> > > *tinfo)
> > >       unsigned long size  = tinfo->size;
> > >       unsigned long i;
> > >
> > > +     sbi_pmu_incr_fw_ctr(SBI_PMU_FW_HFENCE_GVMA_RCVD);
> > > +
> > >       if ((start == 0 && size == 0) || (size == SBI_TLB_FLUSH_ALL)) {
> > >               __sbi_hfence_gvma_all();
> > >               return;
> > > @@ -77,6 +82,8 @@ void sbi_tlb_local_sfence_vma(struct sbi_tlb_info
> > > *tinfo)
> > >       unsigned long size  = tinfo->size;
> > >       unsigned long i;
> > >
> > > +     sbi_pmu_incr_fw_ctr(SBI_PMU_FW_SFENCE_VMA_RCVD);
> > > +
> > >       if ((start == 0 && size == 0) || (size == SBI_TLB_FLUSH_ALL)) {
> > >               sbi_tlb_flush_all();
> > >               return;
> > > @@ -98,6 +105,8 @@ void sbi_tlb_local_hfence_vvma_asid(struct
> > > sbi_tlb_info *tinfo)
> > >       unsigned long vmid  = tinfo->vmid;
> > >       unsigned long i, hgatp;
> > >
> > > +     sbi_pmu_incr_fw_ctr(SBI_PMU_FW_HFENCE_VVMA_ASID_RCVD);
> > > +
> > >       hgatp = csr_swap(CSR_HGATP,
> > >                        (vmid << HGATP_VMID_SHIFT) &
> > > HGATP_VMID_MASK);
> > >
> > > @@ -126,6 +135,8 @@ void sbi_tlb_local_hfence_gvma_vmid(struct
> > > sbi_tlb_info *tinfo)
> > >       unsigned long vmid  = tinfo->vmid;
> > >       unsigned long i;
> > >
> > > +     sbi_pmu_incr_fw_ctr(SBI_PMU_FW_HFENCE_GVMA_VMID_RCVD);
> > > +
> > >       if (start == 0 && size == 0) {
> > >               __sbi_hfence_gvma_all();
> > >               return;
> > > @@ -148,6 +159,8 @@ void sbi_tlb_local_sfence_vma_asid(struct
> > > sbi_tlb_info *tinfo)
> > >       unsigned long asid  = tinfo->asid;
> > >       unsigned long i;
> > >
> > > +     sbi_pmu_incr_fw_ctr(SBI_PMU_FW_SFENCE_VMA_ASID_RCVD);
> > > +
> > >       if (start == 0 && size == 0) {
> > >               sbi_tlb_flush_all();
> > >               return;
> > > @@ -172,9 +185,32 @@ void sbi_tlb_local_sfence_vma_asid(struct
> > > sbi_tlb_info *tinfo)
> > >
> > >  void sbi_tlb_local_fence_i(struct sbi_tlb_info *tinfo)  {
> > > +     sbi_pmu_incr_fw_ctr(SBI_PMU_FW_FENCE_I_RECVD);
> > > +
> > >       __asm__ __volatile("fence.i");  }
> > >
> > > +void sbi_tlb_pmu_incr_fw_ctr(struct sbi_tlb_info *data) {
> > > +     if (unlikely(!data))
> > > +             return;
> > > +
> > > +     if (data->local_fn == sbi_tlb_local_fence_i)
> > > +             sbi_pmu_incr_fw_ctr(SBI_PMU_FW_FENCE_I_SENT);
> > > +     else if (data->local_fn == sbi_tlb_local_sfence_vma)
> > > +             sbi_pmu_incr_fw_ctr(SBI_PMU_FW_SFENCE_VMA_SENT);
> > > +     else if (data->local_fn == sbi_tlb_local_sfence_vma_asid)
> > > +
> > >       sbi_pmu_incr_fw_ctr(SBI_PMU_FW_SFENCE_VMA_ASID_SENT);
> > > +     else if (data->local_fn == sbi_tlb_local_hfence_gvma)
> > > +
> > >       sbi_pmu_incr_fw_ctr(SBI_PMU_FW_HFENCE_GVMA_SENT);
> > > +     else if (data->local_fn == sbi_tlb_local_hfence_gvma_vmid)
> > > +
> > >       sbi_pmu_incr_fw_ctr(SBI_PMU_FW_HFENCE_GVMA_VMID_SENT);
> > > +     else if (data->local_fn == sbi_tlb_local_hfence_vvma)
> > > +             sbi_pmu_incr_fw_ctr(SBI_PMU_FW_HFENCE_VVMA_SENT);
> > > +     else if (data->local_fn == sbi_tlb_local_hfence_vvma_asid)
> > > +
> > >       sbi_pmu_incr_fw_ctr(SBI_PMU_FW_HFENCE_VVMA_ASID_SENT);
> > > +}
> > > +
> >
> > Drop the sbi_tlb_pmu_incr_fw_ctr() function and call
> > sbi_pmu_incr_fw_ctr() from sbi_tlb_request() function.
> >
> 
> sbi_tlb_pmu_incr_fw_ctr is called from sbi_ipi_send so that every request to
> other hart are counted.
> If we invoke sbi_pmu_incr_fw_ctr from sbi_tlb_request, we will be counting
> only 1 for every request from the supervisor.
> 
> Did I misunderstand the purpose of the tlb specific firmware counters ?

The sbi_ipi_send() is for sending any kind of IPIs and remote TLB request is
just one type of IPI request.

For example, we will be having inter-domain messaging using the
sbi_ipi_send() as well so if sbi_tlb_pmu_incr_fw_ctr() Is called from
sbi_ipi_send() then it will unnecessary increment TLB events.

> 
> 
> > >  static void sbi_tlb_entry_process(struct sbi_tlb_info *tinfo)  {
> > >       u32 rhartid;
> > > diff --git a/lib/sbi/sbi_trap.c b/lib/sbi/sbi_trap.c index
> > > b7349d2c914e..3b540ea7f76c 100644
> > > --- a/lib/sbi/sbi_trap.c
> > > +++ b/lib/sbi/sbi_trap.c
> > > @@ -16,6 +16,7 @@
> > >  #include <sbi/sbi_illegal_insn.h>
> > >  #include <sbi/sbi_ipi.h>
> > >  #include <sbi/sbi_misaligned_ldst.h>
> > > +#include <sbi/sbi_pmu.h>
> > >  #include <sbi/sbi_scratch.h>
> > >  #include <sbi/sbi_timer.h>
> > >  #include <sbi/sbi_trap.h>
> > > @@ -230,6 +231,7 @@ void sbi_trap_handler(struct sbi_trap_regs *regs)
> > >                       sbi_timer_process();
> > >                       break;
> > >               case IRQ_M_SOFT:
> > > +                     sbi_pmu_incr_fw_ctr(SBI_PMU_FW_IPI_RECVD);
> > >                       sbi_ipi_process();
> >
> > Move sbi_pmu_incr_fw_ctr() call to sbi_ipi_process()
> >
> > >                       break;
> > >               default:
> > > @@ -241,14 +243,17 @@ void sbi_trap_handler(struct sbi_trap_regs
> > > *regs)
> > >
> > >       switch (mcause) {
> > >       case CAUSE_ILLEGAL_INSTRUCTION:
> > > +             sbi_pmu_incr_fw_ctr(SBI_PMU_FW_ILLEGAL_INSN);
> >
> > Move sbi_pmu_incr_fw_ctr() call to sbi_illegal_insn_handler()
> >
> Done.
> 
> > >               rc  = sbi_illegal_insn_handler(mtval, regs);
> > >               msg = "illegal instruction handler failed";
> > >               break;
> > >       case CAUSE_MISALIGNED_LOAD:
> > > +             sbi_pmu_incr_fw_ctr(SBI_PMU_FW_MISALIGNED_LOAD);
> > >               rc = sbi_misaligned_load_handler(mtval, mtval2,
> > > mtinst, regs);
> >
> > Same as above.
> >
> Done.
> 
> > >               msg = "misaligned load handler failed";
> > >               break;
> > >       case CAUSE_MISALIGNED_STORE:
> > > +             sbi_pmu_incr_fw_ctr(SBI_PMU_FW_MISALIGNED_STORE);
> > >               rc  = sbi_misaligned_store_handler(mtval, mtval2,
> > > mtinst, regs);
> >
> > Same as above.
> >
> Done.
> 
> > >               msg = "misaligned store handler failed";
> > >               break;
> > > @@ -257,6 +262,10 @@ void sbi_trap_handler(struct sbi_trap_regs
> *regs)
> > >               rc  = sbi_ecall_handler(regs);
> > >               msg = "ecall handler failed";
> > >               break;
> > > +     case CAUSE_LOAD_ACCESS:
> > > +             sbi_pmu_incr_fw_ctr(SBI_PMU_FW_ACCESS_LOAD);
> > > +     case CAUSE_STORE_ACCESS:
> > > +             sbi_pmu_incr_fw_ctr(SBI_PMU_FW_ACCESS_STORE);
> >
> > These ones are fine over here at the moment but eventually we might
> > have separate access fault handling file.
> >
> 
> ok.
> 
> > >       default:
> > >               /* If the trap came from S or U mode, redirect it there */
> > >               trap.epc = regs->mepc;
> > > --
> > > 2.25.1
> >
> > Regards,
> > Anup
> >
> >
> > --
> > opensbi mailing list
> > opensbi at lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/opensbi
> 
> 
> 
> --
> Regards,
> Atish

Regards,
Anup


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