[PATCH v3 12/15] lib: sbi: Implement SBI PMU extension

[Anup Patel]

On 26/06/21, 6:28 AM, "Atish Patra" <Atish.Patra at wdc.com> wrote:

    RISC-V SBI specfication 0.3 defines a PMU extension that allows supervisor
    mode to start/stop/configure pmu related events. This patch implements
    all of the functionality defined in the specification.

    Signed-off-by: Atish Patra <atish.patra at wdc.com>
    ---
     include/sbi/sbi_ecall.h |  1 +
     lib/sbi/objects.mk      |  1 +
     lib/sbi/sbi_ecall.c     |  5 +++
     lib/sbi/sbi_ecall_pmu.c | 93 +++++++++++++++++++++++++++++++++++++++++
     4 files changed, 100 insertions(+)
     create mode 100644 lib/sbi/sbi_ecall_pmu.c

    diff --git a/include/sbi/sbi_ecall.h b/include/sbi/sbi_ecall.h
    index 63ef866ba2d4..9500d0430429 100644
    --- a/include/sbi/sbi_ecall.h
    +++ b/include/sbi/sbi_ecall.h
    @@ -39,6 +39,7 @@ extern struct sbi_ecall_extension ecall_ipi;
     extern struct sbi_ecall_extension ecall_vendor;
     extern struct sbi_ecall_extension ecall_hsm;
     extern struct sbi_ecall_extension ecall_srst;
    +extern struct sbi_ecall_extension ecall_pmu;

     u16 sbi_ecall_version_major(void);

    diff --git a/lib/sbi/objects.mk b/lib/sbi/objects.mk
    index d9068b707854..7096f245ae0c 100644
    --- a/lib/sbi/objects.mk
    +++ b/lib/sbi/objects.mk
    @@ -20,6 +20,7 @@ libsbi-objs-y += sbi_ecall.o
     libsbi-objs-y += sbi_ecall_base.o
     libsbi-objs-y += sbi_ecall_hsm.o
     libsbi-objs-y += sbi_ecall_legacy.o
    +libsbi-objs-y += sbi_ecall_pmu.o
     libsbi-objs-y += sbi_ecall_replace.o
     libsbi-objs-y += sbi_ecall_vendor.o
     libsbi-objs-y += sbi_emulate_csr.o
    diff --git a/lib/sbi/sbi_ecall.c b/lib/sbi/sbi_ecall.c
    index e92a53930460..fad05bcc2c62 100644
    --- a/lib/sbi/sbi_ecall.c
    +++ b/lib/sbi/sbi_ecall.c
    @@ -11,6 +11,8 @@
     #include <sbi/sbi_ecall.h>
     #include <sbi/sbi_ecall_interface.h>
     #include <sbi/sbi_error.h>
    +#include <sbi/sbi_hart.h>
    +#include <sbi/sbi_scratch.h>

Drop these "#include" lines.

     #include <sbi/sbi_trap.h>

     u16 sbi_ecall_version_major(void)
    @@ -162,6 +164,9 @@ int sbi_ecall_init(void)
     	if (ret)
     		return ret;
     	ret = sbi_ecall_register_extension(&ecall_srst);
    +	if (ret)
    +		return ret;
    +	ret = sbi_ecall_register_extension(&ecall_pmu);
     	if (ret)
     		return ret;
     	ret = sbi_ecall_register_extension(&ecall_legacy);
    diff --git a/lib/sbi/sbi_ecall_pmu.c b/lib/sbi/sbi_ecall_pmu.c
    new file mode 100644
    index 000000000000..39d3857680c1
    --- /dev/null
    +++ b/lib/sbi/sbi_ecall_pmu.c
    @@ -0,0 +1,93 @@
    +/*
    + * SPDX-License-Identifier: BSD-2-Clause
    + *
    + * Copyright (c) 2021 Western Digital Corporation or its affiliates.
    + *
    + * Authors:
    + *   Atish Patra <atish.patra at wdc.com>
    + */
    +
    +#include <sbi/sbi_ecall.h>
    +#include <sbi/sbi_ecall_interface.h>
    +#include <sbi/sbi_error.h>
    +#include <sbi/sbi_hart.h>
    +#include <sbi/sbi_trap.h>
    +#include <sbi/sbi_version.h>
    +#include <sbi/sbi_pmu.h>
    +#include <sbi/sbi_scratch.h>
    +#include <sbi/riscv_asm.h>
    +
    +static int sbi_ecall_pmu_handler(unsigned long extid, unsigned long funcid,
    +				 const struct sbi_trap_regs *regs,
    +				 unsigned long *out_val,
    +				 struct sbi_trap_info *out_trap)
    +{
    +	int ret = 0;
    +	uint64_t temp;
    +
    +	switch (funcid) {
    +	case SBI_EXT_PMU_NUM_COUNTERS:
    +		ret = sbi_pmu_num_ctr();
    +		if (ret >= 0) {
    +			*out_val = ret;
    +			ret = 0;
    +		}
    +		break;
    +	case SBI_EXT_PMU_COUNTER_GET_INFO:
    +		ret = sbi_pmu_ctr_get_info(regs->a0, out_val);
    +		break;
    +	case SBI_EXT_PMU_COUNTER_CFG_MATCH:
    +#if __riscv_xlen == 32
    +		temp = ((uint64_t)regs->a5 << 32) | regs->a4;
    +#else
    +		temp = regs->a4;
    +#endif
    +		ret = sbi_pmu_ctr_cfg_match(regs->a0, regs->a1, regs->a2,
    +					    regs->a3, temp);
    +		if (ret >= 0) {
    +			*out_val = ret;
    +			ret = 0;
    +		}
    +
    +		break;
    +	case SBI_EXT_PMU_COUNTER_FW_READ:
    +		ret = sbi_pmu_ctr_read(regs->a0, out_val);
    +		break;
    +	case SBI_EXT_PMU_COUNTER_START:
    +
    +#if __riscv_xlen == 32
    +		temp = ((uint64_t)regs->a4 << 32) | regs->a3;
    +#else
    +		temp = regs->a3;
    +#endif
    +		ret = sbi_pmu_ctr_start(regs->a0, regs->a1, regs->a2, temp);
    +		break;
    +	case SBI_EXT_PMU_COUNTER_STOP:
    +		ret = sbi_pmu_ctr_stop(regs->a0, regs->a1, regs->a2);
    +		break;
    +	default:
    +		ret = SBI_ENOTSUPP;
    +	};
    +
    +	return ret;
    +}
    +
    +static int sbi_ecall_pmu_probe(unsigned long extid, unsigned long *out_val)
    +{
    +	struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
    +
    +	/* SBI PMU extension is useless without mcount inhibit features */
    +	if (sbi_hart_has_feature(scratch, SBI_HART_HAS_MCOUNTINHIBIT))
    +		*out_val = 1;
    +	else
    +		*out_val = 0;
    +
    +	return 0;
    +}
    +
    +struct sbi_ecall_extension ecall_pmu = {
    +	.extid_start = SBI_EXT_PMU,
    +	.extid_end = SBI_EXT_PMU,
    +	.handle = sbi_ecall_pmu_handler,
    +	.probe = sbi_ecall_pmu_probe,
    +};
    -- 
    2.25.1

Otherwise, looks good to me.

Reviewed-by: Anup Patel <anup.patel at wdc.com>

Regards,
Anup