[PATCH v5 11/15] utils: fdt: Add fdt helper functions to parse PMU DT nodes

Anup Patel anup at brainfault.org
Sat Jul 10 22:28:18 PDT 2021


On Sat, Jul 10, 2021 at 9:48 PM Atish Patra <atish.patra at wdc.com> wrote:
>
> The PMU DT node bindings are defined in docs/pmu_support.md
> Add few fdt helper functions to parse the DT node and update the
> event-counter mapping tables.
>
> Reviewed-by: Anup Patel <anup.patel at wdc.com>
> Signed-off-by: Atish Patra <atish.patra at wdc.com>

Applied this patch to the riscv/opensbi repo.

Thanks,
Anup

> ---
>  include/sbi_utils/fdt/fdt_pmu.h |  46 +++++++++++++
>  lib/utils/fdt/fdt_fixup.c       |   2 +
>  lib/utils/fdt/fdt_pmu.c         | 111 ++++++++++++++++++++++++++++++++
>  lib/utils/fdt/objects.mk        |   1 +
>  4 files changed, 160 insertions(+)
>  create mode 100644 include/sbi_utils/fdt/fdt_pmu.h
>  create mode 100644 lib/utils/fdt/fdt_pmu.c
>
> diff --git a/include/sbi_utils/fdt/fdt_pmu.h b/include/sbi_utils/fdt/fdt_pmu.h
> new file mode 100644
> index 000000000000..2fa01edc0743
> --- /dev/null
> +++ b/include/sbi_utils/fdt/fdt_pmu.h
> @@ -0,0 +1,46 @@
> +// SPDX-License-Identifier: BSD-2-Clause
> +/*
> + * fdt_pmu.c - Flat Device Tree PMU helper routines
> + *
> + * Copyright (c) 2021 Western Digital Corporation or its affiliates.
> + *
> + * Authors:
> + *   Atish Patra <atish.patra at wdc.com>
> + */
> +
> +#ifndef __FDT_PMU_H__
> +#define __FDT_PMU_H__
> +
> +#include <sbi/sbi_types.h>
> +
> +/**
> + * Fix up the PMU node in the device tree
> + *
> + * This routine:
> + * 1. Disables opensbi specific properties from the DT
> + *
> + * It is recommended that platform support call this function in
> + * their final_init() platform operation.
> + *
> + * @param fdt device tree blob
> + */
> +void fdt_pmu_fixup(void *fdt);
> +
> +/**
> + * Setup PMU data from device tree
> + *
> + * @param fdt device tree blob
> + *
> + * @return 0 on success and negative error code on failure
> + */
> +int fdt_pmu_setup(void *fdt);
> +
> +/**
> + * Get the mhpmevent select value read from DT for a given event
> + * @param event_idx Event ID of the given event
> + *
> + * @return The select value read from DT or 0 if given index was not found
> + */
> +uint64_t fdt_pmu_get_select_value(uint32_t event_idx);
> +
> +#endif
> diff --git a/lib/utils/fdt/fdt_fixup.c b/lib/utils/fdt/fdt_fixup.c
> index 14655000b815..ac01ba3dfac1 100644
> --- a/lib/utils/fdt/fdt_fixup.c
> +++ b/lib/utils/fdt/fdt_fixup.c
> @@ -15,6 +15,7 @@
>  #include <sbi/sbi_scratch.h>
>  #include <sbi/sbi_string.h>
>  #include <sbi_utils/fdt/fdt_fixup.h>
> +#include <sbi_utils/fdt/fdt_pmu.h>
>  #include <sbi_utils/fdt/fdt_helper.h>
>
>  void fdt_cpu_fixup(void *fdt)
> @@ -263,6 +264,7 @@ void fdt_fixups(void *fdt)
>         fdt_plic_fixup(fdt);
>
>         fdt_reserved_memory_fixup(fdt);
> +       fdt_pmu_fixup(fdt);
>  }
>
>
> diff --git a/lib/utils/fdt/fdt_pmu.c b/lib/utils/fdt/fdt_pmu.c
> new file mode 100644
> index 000000000000..9ebf1c225017
> --- /dev/null
> +++ b/lib/utils/fdt/fdt_pmu.c
> @@ -0,0 +1,111 @@
> +// SPDX-License-Identifier: BSD-2-Clause
> +/*
> + * fdt_pmu.c - Flat Device Tree PMU helper routines
> + *
> + * Copyright (c) 2021 Western Digital Corporation or its affiliates.
> + *
> + * Authors:
> + *     Atish Patra <atish.patra at wdc.com>
> + */
> +
> +#include <libfdt.h>
> +#include <sbi/sbi_error.h>
> +#include <sbi/sbi_pmu.h>
> +#include <sbi_utils/fdt/fdt_helper.h>
> +
> +#define FDT_PMU_HW_EVENT_MAX (SBI_PMU_HW_EVENT_MAX * 2)
> +
> +struct fdt_pmu_hw_event_select {
> +       uint32_t eidx;
> +       uint64_t select;
> +};
> +
> +static struct fdt_pmu_hw_event_select fdt_pmu_evt_select[FDT_PMU_HW_EVENT_MAX] = {0};
> +static uint32_t hw_event_count;
> +
> +uint64_t fdt_pmu_get_select_value(uint32_t event_idx)
> +{
> +       int i;
> +       struct fdt_pmu_hw_event_select *event;
> +
> +       for (i = 0; i < SBI_PMU_HW_EVENT_MAX; i++) {
> +               event = &fdt_pmu_evt_select[i];
> +               if (event->eidx == event_idx)
> +                       return event->select;
> +       }
> +
> +       return 0;
> +}
> +
> +int fdt_pmu_fixup(void *fdt)
> +{
> +       int pmu_offset;
> +
> +       if (!fdt)
> +               return SBI_EINVAL;
> +
> +       pmu_offset = fdt_node_offset_by_compatible(fdt, -1, "riscv,pmu");
> +       if (pmu_offset < 0)
> +               return SBI_EFAIL;
> +
> +       fdt_delprop(fdt, pmu_offset, "pmu,event-to-mhpmcounters");
> +       fdt_delprop(fdt, pmu_offset, "pmu,event-to-mhpmevent");
> +       fdt_delprop(fdt, pmu_offset, "pmu,raw-event-to-mhpmcounters");
> +
> +       return 0;
> +}
> +
> +int fdt_pmu_setup(void *fdt)
> +{
> +       int i, pmu_offset, len, result;
> +       const u32 *event_val;
> +       const u32 *event_ctr_map;
> +       struct fdt_pmu_hw_event_select *event;
> +       uint64_t raw_selector;
> +       u32 event_idx_start, event_idx_end, ctr_map;
> +
> +       if (!fdt)
> +               return SBI_EINVAL;
> +
> +       pmu_offset = fdt_node_offset_by_compatible(fdt, -1, "riscv,pmu");
> +       if (pmu_offset < 0)
> +               return SBI_EFAIL;
> +
> +       event_ctr_map = fdt_getprop(fdt, pmu_offset, "pmu,event-to-mhpmcounters", &len);
> +       if (!event_ctr_map || len < 8)
> +               return SBI_EFAIL;
> +       len = len / (sizeof(u32) * 3);
> +       for (i = 0; i < len; i++) {
> +               event_idx_start = fdt32_to_cpu(event_ctr_map[3 * i]);
> +               event_idx_end = fdt32_to_cpu(event_ctr_map[3 * i + 1]);
> +               ctr_map = fdt32_to_cpu(event_ctr_map[3 * i + 2]);
> +               sbi_pmu_add_hw_event_counter_map(event_idx_start, event_idx_end, ctr_map);
> +       }
> +
> +       event_val = fdt_getprop(fdt, pmu_offset, "pmu,event-to-mhpmevent", &len);
> +       if (!event_val || len < 8)
> +               return SBI_EFAIL;
> +       len = len / (sizeof(u32) * 3);
> +       for (i = 0; i < len; i++) {
> +               event = &fdt_pmu_evt_select[hw_event_count];
> +               event->eidx = fdt32_to_cpu(event_val[3 * i]);
> +               event->select = fdt32_to_cpu(event_val[3 * i + 1]);
> +               event->select = (event->select << 32) | fdt32_to_cpu(event_val[3 * i + 2]);
> +               hw_event_count++;
> +       }
> +
> +       event_val = fdt_getprop(fdt, pmu_offset, "pmu,raw-event-to-mhpmcounters", &len);
> +       if (!event_val || len < 8)
> +               return SBI_EFAIL;
> +       len = len / (sizeof(u32) * 3);
> +       for (i = 0; i < len; i++) {
> +               raw_selector = fdt32_to_cpu(event_val[3 * i]);
> +               raw_selector = (raw_selector << 32) | fdt32_to_cpu(event_val[3 * i + 1]);
> +               ctr_map = fdt32_to_cpu(event_val[3 * i + 2]);
> +               result = sbi_pmu_add_raw_event_counter_map(raw_selector, ctr_map);
> +               if (!result)
> +                       hw_event_count++;
> +       }
> +
> +       return 0;
> +}
> diff --git a/lib/utils/fdt/objects.mk b/lib/utils/fdt/objects.mk
> index d9f1eae19292..03800f96d74d 100644
> --- a/lib/utils/fdt/objects.mk
> +++ b/lib/utils/fdt/objects.mk
> @@ -5,5 +5,6 @@
>  #
>
>  libsbiutils-objs-y += fdt/fdt_domain.o
> +libsbiutils-objs-y += fdt/fdt_pmu.o
>  libsbiutils-objs-y += fdt/fdt_helper.o
>  libsbiutils-objs-y += fdt/fdt_fixup.o
> --
> 2.31.1
>
>
> --
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