[PATCH RFC] platform: generic: How to add custom extensions for sbi_call?
Anup Patel
Anup.Patel at wdc.com
Thu Apr 29 04:43:24 BST 2021
> -----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.
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/
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