[PATCH RFC] platform: generic: How to add custom extensions for sbi_call?
Guo Ren
guoren at kernel.org
Fri Apr 30 04:48:15 BST 2021
On Thu, Apr 29, 2021 at 11:43 AM Anup Patel <Anup.Patel at wdc.com> wrote:
>
>
>
> > -----Original Message-----
> > From: Guo Ren <guoren at kernel.org>
> > Sent: 29 April 2021 07:24
> > To: Guo Ren <guoren at kernel.org>; Anup Patel <anup at brainfault.org>;
> > Alistair Francis <alistair23 at gmail.com>; Atish Patra <atishp at atishpatra.org>
> > Cc: OpenSBI <opensbi at lists.infradead.org>; Guo Ren
> > <guoren at linux.alibaba.com>; Anup Patel <Anup.Patel at wdc.com>
> > Subject: Re: [PATCH RFC] platform: generic: How to add custom extensions
> > for sbi_call?
> >
> > @Anup Patel @Atish Patra @Alistair Francis
> >
> > Could we add a fdt_vendor_ext_provider for generic? How do you think?
> >
> > On Wed, Apr 28, 2021 at 9:55 PM <guoren at kernel.org> wrote:
> > >
> > > From: Guo Ren <guoren at linux.alibaba.com>
> > >
> > > Here is the sample of thead PMU sbi implementation, it could work with
> > > linux perf record:
> > >
> > > https://github.com/c-sky/csky-linux/blob/linux-5.10.4/drivers/perf/the
> > > ad_c900_pmu.c
> > >
> > > It support perf record with hardware event.
> > >
> > > How to support this in platform/generic?
>
> We will certainly extend platform/generic for allow vendor specific SBI
> calls but using vendor specific SBI calls should be last resort.
>
> In case of PMU, we already have a work-in-progress SBI PMU extension.
>
> The latest SBI PMU proposal is here:
> https://github.com/avpatel/riscv-sbi-doc/blob/pmu_v5/riscv-sbi.adoc
>
> The OpenSBI PMU implementation is here:
> https://github.com/atishp04/opensbi/tree/sbi_pmu_v1
>
> The Linux PMU driver is here:
> https://github.com/atishp04/linux/tree/sbi_pmu_v1
>
> I would suggest you to use SBI PMU extension for your platform. In fact,
> T-HEAD C9xx could be the first platform to actively use SBI PMU.
Good idea, I'll try SBI PMU.
Another issue is C9xx all support "PMU overflow interrupt", which
means it could work with "perf record".
So, I need to add an overflow irq handler in riscv_pmu.c to update the
perf period for the next event.
Here are our custom CSRs (For performance reason, updating perf period
should be done in s-mode, not sbi_call.):
/*
* Counter Enable register
*/
#define SCOUNTEREN 0x106
/*
* Counter inhibit register
*/
#define SCOUNTINHIBIT 0x5c8
/*
* 11: PMDS - rw, Performance monitor disable S-mode counting
* 10: PMDU - rw, Performance monitor disable U-mode counting
*/
#define SXSTATUS 0x5c0
/*
* Overflow interrupt enable & status register
*/
#define SCOUNTERINTEN 0x5c4
#define SCOUNTEROF 0x5c5
/*
* 63: TS - rw, status of trigger
* 13: PMDM - ro, Performance monitor disable machine mode counting
* 11: PMDS - rw, Performance monitor disable supervisor mode counting
* 10: PMDU - rw, Performance monitor disable user mode counting
* 0-1: TME - Trigger Mode, 2'b00 trigger disabled, 2'b01 triger enable
*/
#define SHPMCR 0x5c9
/*
* Start/End trigger register. It's used to focus on a region of the code.
*/
#define SHPMSP 0x5ca
#define SHPMEP 0x5cb
>
> Regards,
> Anup
>
> > >
> > > Thx
> > >
> > > Signed-off-by: Guo Ren <guoren at linux.alibaba.com>
> > > Cc: Anup Patel <anup.patel at wdc.com>
> > > ---
> > > platform/generic/platform.c | 159
> > > ++++++++++++++++++++++++++++++++++++++++++++
> > > 1 file changed, 159 insertions(+)
> > >
> > > diff --git a/platform/generic/platform.c b/platform/generic/platform.c
> > > index 7581556..52084dd 100644
> > > --- a/platform/generic/platform.c
> > > +++ b/platform/generic/platform.c
> > > @@ -206,7 +206,166 @@ static void generic_system_reset(u32 reset_type,
> > u32 reset_reason)
> > > writew(0x5555, (void *)0x100000); // qemu poweroff }
> > >
> > > +#include <sbi/sbi_trap.h>
> > > +#define CSR_MCOUNTERWEN 0x7c9
> > > +static void sbi_thead_pmu_init(void)
> > > +{
> > > + unsigned long interrupts;
> > > +
> > > + interrupts = csr_read(CSR_MIDELEG) | (1 << 17);
> > > + csr_write(CSR_MIDELEG, interrupts);
> > > +
> > > + /* CSR_MCOUNTEREN has already been set in mstatus_init() */
> > > + csr_write(CSR_MCOUNTERWEN, 0xffffffff);
> > > + csr_write(CSR_MHPMEVENT3, 1);
> > > + csr_write(CSR_MHPMEVENT4, 2);
> > > + csr_write(CSR_MHPMEVENT5, 3);
> > > + csr_write(CSR_MHPMEVENT6, 4);
> > > + csr_write(CSR_MHPMEVENT7, 5);
> > > + csr_write(CSR_MHPMEVENT8, 6);
> > > + csr_write(CSR_MHPMEVENT9, 7);
> > > + csr_write(CSR_MHPMEVENT10, 8);
> > > + csr_write(CSR_MHPMEVENT11, 9);
> > > + csr_write(CSR_MHPMEVENT12, 10);
> > > + csr_write(CSR_MHPMEVENT13, 11);
> > > + csr_write(CSR_MHPMEVENT14, 12);
> > > + csr_write(CSR_MHPMEVENT15, 13);
> > > + csr_write(CSR_MHPMEVENT16, 14);
> > > + csr_write(CSR_MHPMEVENT17, 15);
> > > + csr_write(CSR_MHPMEVENT18, 16);
> > > + csr_write(CSR_MHPMEVENT19, 17);
> > > + csr_write(CSR_MHPMEVENT20, 18);
> > > + csr_write(CSR_MHPMEVENT21, 19);
> > > + csr_write(CSR_MHPMEVENT22, 20);
> > > + csr_write(CSR_MHPMEVENT23, 21);
> > > + csr_write(CSR_MHPMEVENT24, 22);
> > > + csr_write(CSR_MHPMEVENT25, 23);
> > > + csr_write(CSR_MHPMEVENT26, 24);
> > > + csr_write(CSR_MHPMEVENT27, 25);
> > > + csr_write(CSR_MHPMEVENT28, 26); }
> > > +
> > > +static void sbi_thead_pmu_map(unsigned long idx, unsigned long
> > > +event_id) {
> > > + switch (idx) {
> > > + case 3:
> > > + csr_write(CSR_MHPMEVENT3, event_id);
> > > + break;
> > > + case 4:
> > > + csr_write(CSR_MHPMEVENT4, event_id);
> > > + break;
> > > + case 5:
> > > + csr_write(CSR_MHPMEVENT5, event_id);
> > > + break;
> > > + case 6:
> > > + csr_write(CSR_MHPMEVENT6, event_id);
> > > + break;
> > > + case 7:
> > > + csr_write(CSR_MHPMEVENT7, event_id);
> > > + break;
> > > + case 8:
> > > + csr_write(CSR_MHPMEVENT8, event_id);
> > > + break;
> > > + case 9:
> > > + csr_write(CSR_MHPMEVENT9, event_id);
> > > + break;
> > > + case 10:
> > > + csr_write(CSR_MHPMEVENT10, event_id);
> > > + break;
> > > + case 11:
> > > + csr_write(CSR_MHPMEVENT11, event_id);
> > > + break;
> > > + case 12:
> > > + csr_write(CSR_MHPMEVENT12, event_id);
> > > + break;
> > > + case 13:
> > > + csr_write(CSR_MHPMEVENT13, event_id);
> > > + break;
> > > + case 14:
> > > + csr_write(CSR_MHPMEVENT14, event_id);
> > > + break;
> > > + case 15:
> > > + csr_write(CSR_MHPMEVENT15, event_id);
> > > + break;
> > > + case 16:
> > > + csr_write(CSR_MHPMEVENT16, event_id);
> > > + break;
> > > + case 17:
> > > + csr_write(CSR_MHPMEVENT17, event_id);
> > > + break;
> > > + case 18:
> > > + csr_write(CSR_MHPMEVENT18, event_id);
> > > + break;
> > > + case 19:
> > > + csr_write(CSR_MHPMEVENT19, event_id);
> > > + break;
> > > + case 20:
> > > + csr_write(CSR_MHPMEVENT20, event_id);
> > > + break;
> > > + case 21:
> > > + csr_write(CSR_MHPMEVENT21, event_id);
> > > + break;
> > > + case 22:
> > > + csr_write(CSR_MHPMEVENT22, event_id);
> > > + break;
> > > + case 23:
> > > + csr_write(CSR_MHPMEVENT23, event_id);
> > > + break;
> > > + case 24:
> > > + csr_write(CSR_MHPMEVENT24, event_id);
> > > + break;
> > > + case 25:
> > > + csr_write(CSR_MHPMEVENT25, event_id);
> > > + break;
> > > + case 26:
> > > + csr_write(CSR_MHPMEVENT26, event_id);
> > > + break;
> > > + case 27:
> > > + csr_write(CSR_MHPMEVENT27, event_id);
> > > + break;
> > > + case 28:
> > > + csr_write(CSR_MHPMEVENT28, event_id);
> > > + break;
> > > + case 29:
> > > + csr_write(CSR_MHPMEVENT29, event_id);
> > > + break;
> > > + case 30:
> > > + csr_write(CSR_MHPMEVENT30, event_id);
> > > + break;
> > > + case 31:
> > > + csr_write(CSR_MHPMEVENT31, event_id);
> > > + break;
> > > + }
> > > +}
> > > +
> > > +static void sbi_thead_pmu_set(unsigned long type, unsigned long idx,
> > > +unsigned long event_id) {
> > > + switch (type) {
> > > + case 2:
> > > + sbi_thead_pmu_map(idx, event_id);
> > > + break;
> > > + default:
> > > + sbi_thead_pmu_init();
> > > + break;
> > > + }
> > > +}
> > > +
> > > +static int thead_vendor_ext_provider(long extid, long funcid,
> > > + const struct sbi_trap_regs *regs, unsigned long *out_value,
> > > + struct sbi_trap_info *out_trap) {
> > > + switch (extid) {
> > > + case 0x09000001:
> > > + sbi_thead_pmu_set(regs->a0, regs->a1, regs->a2);
> > > + break;
> > > + default:
> > > + sbi_hart_hang();
> > > + }
> > > + return 0;
> > > +}
> > > +
> > > const struct sbi_platform_operations platform_ops = {
> > > + .vendor_ext_provider = thead_vendor_ext_provider,
> > > .early_init = generic_early_init,
> > > .final_init = generic_final_init,
> > > .early_exit = generic_early_exit,
> > > --
> > > 2.7.4
> > >
> >
> >
> > --
> > Best Regards
> > Guo Ren
> >
> > ML: https://lore.kernel.org/linux-csky/
--
Best Regards
Guo Ren
ML: https://lore.kernel.org/linux-csky/
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